diff options
Diffstat (limited to 'tools/go_marshal')
27 files changed, 2903 insertions, 670 deletions
diff --git a/tools/go_marshal/BUILD b/tools/go_marshal/BUILD index c862b277c..f79defea7 100644 --- a/tools/go_marshal/BUILD +++ b/tools/go_marshal/BUILD @@ -1,6 +1,6 @@ -load("@io_bazel_rules_go//go:def.bzl", "go_binary") +load("//tools:defs.bzl", "bzl_library", "go_binary") -package(licenses = ["notice"]) +licenses(["notice"]) go_binary( name = "go_marshal", @@ -12,3 +12,14 @@ go_binary( "//tools/go_marshal/gomarshal", ], ) + +config_setting( + name = "marshal_config_verbose", + values = {"define": "gomarshal=verbose"}, +) + +bzl_library( + name = "defs_bzl", + srcs = ["defs.bzl"], + visibility = ["//visibility:private"], +) diff --git a/tools/go_marshal/README.md b/tools/go_marshal/README.md index 481575bd3..68d759083 100644 --- a/tools/go_marshal/README.md +++ b/tools/go_marshal/README.md @@ -9,30 +9,16 @@ automatically generating code to marshal go data structures to memory. `binary.Marshal` by moving the go runtime reflection necessary to marshal a struct to compile-time. -`go_marshal` automatically generates implementations for `abi.Marshallable` and -`safemem.{Reader,Writer}`. Call-sites for serialization (typically syscall -implementations) can directly invoke `safemem.Reader.ReadToBlocks` and -`safemem.Writer.WriteFromBlocks`. Data structures that require custom -serialization will have manual implementations for these interfaces. +`go_marshal` automatically generates implementations for `marshal.Marshallable` +and `safemem.{Reader,Writer}`. Data structures that require custom serialization +will have manual implementations for these interfaces. Data structures can be flagged for code generation by adding a struct-level comment `// +marshal`. # Usage -See `defs.bzl`: two new rules are provided, `go_marshal` and `go_library`. - -The recommended way to generate a go library with marshalling is to use the -`go_library` with mostly identical configuration as the native go_library rule. - -``` -load("<PKGPATH>/gvisor/tools/go_marshal:defs.bzl", "go_library") - -go_library( - name = "foo", - srcs = ["foo.go"], -) -``` +See `defs.bzl`: a new rule is provided, `go_marshal`. Under the hood, the `go_marshal` rule is used to generate a file that will appear in a Go target; the output file should appear explicitly in a srcs list. @@ -54,11 +40,7 @@ go_library( "foo.go", "foo_abi.go", ], - deps = [ - "<PKGPATH>/gvisor/pkg/abi", - "<PKGPATH>/gvisor/pkg/sentry/safemem/safemem", - "<PKGPATH>/gvisor/pkg/sentry/usermem/usermem", - ], + ... ) ``` @@ -69,22 +51,6 @@ These tests use reflection to verify properties of the ABI struct, and should be considered part of the generated interfaces (but are too expensive to execute at runtime). Ensure these tests run at some point. -``` -$ cat BUILD -load("<PKGPATH>/gvisor/tools/go_marshal:defs.bzl", "go_library") - -go_library( - name = "foo", - srcs = ["foo.go"], -) -$ blaze build :foo -$ blaze query ... -<path-to-dir>:foo_abi_autogen -<path-to-dir>:foo_abi_autogen_test -$ blaze test :foo_abi_autogen_test -<test-output> -``` - # Restrictions Not all valid go type definitions can be used with `go_marshal`. `go_marshal` is @@ -131,22 +97,6 @@ for embedded structs that are not aligned. Because of this, it's generally best to avoid using `marshal:"unaligned"` and insert explicit padding fields instead. -## Debugging go_marshal - -To enable debugging output from the go marshal tool, pass the `-debug` flag to -the tool. When using the build rules from above, add a `debug = True` field to -the build rule like this: - -``` -load("<PKGPATH>/gvisor/tools/go_marshal:defs.bzl", "go_library") - -go_library( - name = "foo", - srcs = ["foo.go"], - debug = True, -) -``` - ## Modifying the `go_marshal` Tool The following are some guidelines for modifying the `go_marshal` tool: diff --git a/tools/go_marshal/analysis/BUILD b/tools/go_marshal/analysis/BUILD index c859ced77..c2a4d45c4 100644 --- a/tools/go_marshal/analysis/BUILD +++ b/tools/go_marshal/analysis/BUILD @@ -1,12 +1,11 @@ -load("@io_bazel_rules_go//go:def.bzl", "go_library") +load("//tools:defs.bzl", "go_library") -package(licenses = ["notice"]) +licenses(["notice"]) go_library( name = "analysis", testonly = 1, srcs = ["analysis_unsafe.go"], - importpath = "gvisor.dev/gvisor/tools/go_marshal/analysis", visibility = [ "//:sandbox", ], diff --git a/tools/go_marshal/analysis/analysis_unsafe.go b/tools/go_marshal/analysis/analysis_unsafe.go index 9a9a4f298..cd55cf5cb 100644 --- a/tools/go_marshal/analysis/analysis_unsafe.go +++ b/tools/go_marshal/analysis/analysis_unsafe.go @@ -161,6 +161,10 @@ func AlignmentCheck(t *testing.T, typ reflect.Type) (ok bool, delta uint64) { if typ.NumField() > 0 && nextXOff != int(typ.Size()) { implicitPad := int(typ.Size()) - nextXOff f := typ.Field(typ.NumField() - 1) // Final field + if tag, ok := f.Tag.Lookup("marshal"); ok && tag == "unaligned" { + // Final field explicitly marked unaligned. + break + } t.Fatalf("Suspect offset for field %s.%s at the end of %s, detected an implicit %d byte padding from offset %d to %d at the end of the struct; either add %d bytes of explict padding at end of the struct or tag the final field %s as `marshal:\"unaligned\"`.", typ.Name(), f.Name, typ.Name(), implicitPad, nextXOff, typ.Size(), implicitPad, f.Name) } diff --git a/tools/go_marshal/defs.bzl b/tools/go_marshal/defs.bzl index c32eb559f..323e33882 100644 --- a/tools/go_marshal/defs.bzl +++ b/tools/go_marshal/defs.bzl @@ -1,57 +1,14 @@ -"""Marshal is a tool for generating marshalling interfaces for Go types. - -The recommended way is to use the go_library rule defined below with mostly -identical configuration as the native go_library rule. - -load("//tools/go_marshal:defs.bzl", "go_library") - -go_library( - name = "foo", - srcs = ["foo.go"], -) - -Under the hood, the go_marshal rule is used to generate a file that will -appear in a Go target; the output file should appear explicitly in a srcs list. -For example (the above is still the preferred way): - -load("//tools/go_marshal:defs.bzl", "go_marshal") - -go_marshal( - name = "foo_abi", - srcs = ["foo.go"], - out = "foo_abi.go", - package = "foo", -) - -go_library( - name = "foo", - srcs = [ - "foo.go", - "foo_abi.go", - ], - deps = [ - "//tools/go_marshal:marshal", - "//pkg/sentry/platform/safecopy", - "//pkg/sentry/usermem", - ], -) -""" - -load("@io_bazel_rules_go//go:def.bzl", _go_library = "go_library", _go_test = "go_test") +"""Marshal is a tool for generating marshalling interfaces for Go types.""" def _go_marshal_impl(ctx): """Execute the go_marshal tool.""" output = ctx.outputs.lib output_test = ctx.outputs.test - (build_dir, _, _) = ctx.build_file_path.rpartition("/BUILD") - - decl = "/".join(["gvisor.dev/gvisor", build_dir]) # Run the marshal command. args = ["-output=%s" % output.path] args += ["-pkg=%s" % ctx.attr.package] args += ["-output_test=%s" % output_test.path] - args += ["-declarationPkg=%s" % decl] if ctx.attr.debug: args += ["-debug"] @@ -83,7 +40,6 @@ go_marshal = rule( implementation = _go_marshal_impl, attrs = { "srcs": attr.label_list(mandatory = True, allow_files = True), - "libname": attr.string(mandatory = True), "imports": attr.string_list(mandatory = False), "package": attr.string(mandatory = True), "debug": attr.bool(doc = "enable debugging output from the go_marshal tool"), @@ -95,58 +51,15 @@ go_marshal = rule( }, ) -def go_library(name, srcs, deps = [], imports = [], debug = False, **kwargs): - """wraps the standard go_library and does mashalling interface generation. - - Args: - name: Same as native go_library. - srcs: Same as native go_library. - deps: Same as native go_library. - imports: Extra import paths to pass to the go_marshal tool. - debug: Enables debugging output from the go_marshal tool. - **kwargs: Remaining args to pass to the native go_library rule unmodified. - """ - go_marshal( - name = name + "_abi_autogen", - libname = name, - srcs = [src for src in srcs if src.endswith(".go")], - debug = debug, - imports = imports, - package = name, - ) - - extra_deps = [ - "//tools/go_marshal/marshal", - "//pkg/sentry/platform/safecopy", - "//pkg/sentry/usermem", - ] - - all_srcs = srcs + [name + "_abi_autogen_unsafe.go"] - all_deps = deps + [] # + extra_deps - - for extra in extra_deps: - if extra not in deps: - all_deps.append(extra) - - _go_library( - name = name, - srcs = all_srcs, - deps = all_deps, - **kwargs - ) - - # Don't pass importpath arg to go_test. - kwargs.pop("importpath", "") - - _go_test( - name = name + "_abi_autogen_test", - srcs = [name + "_abi_autogen_test.go"], - # Generated test has a fixed set of dependencies since we generate these - # tests. They should only depend on the library generated above, and the - # Marshallable interface. - deps = [ - ":" + name, - "//tools/go_marshal/analysis", - ], - **kwargs - ) +# marshal_deps are the dependencies requied by generated code. +marshal_deps = [ + "//pkg/gohacks", + "//pkg/safecopy", + "//pkg/usermem", + "//tools/go_marshal/marshal", +] + +# marshal_test_deps are required by test targets. +marshal_test_deps = [ + "//tools/go_marshal/analysis", +] diff --git a/tools/go_marshal/gomarshal/BUILD b/tools/go_marshal/gomarshal/BUILD index a0eae6492..44cb33ae4 100644 --- a/tools/go_marshal/gomarshal/BUILD +++ b/tools/go_marshal/gomarshal/BUILD @@ -1,17 +1,21 @@ -load("@io_bazel_rules_go//go:def.bzl", "go_library") +load("//tools:defs.bzl", "go_library") -package(licenses = ["notice"]) +licenses(["notice"]) go_library( name = "gomarshal", srcs = [ "generator.go", "generator_interfaces.go", + "generator_interfaces_array_newtype.go", + "generator_interfaces_primitive_newtype.go", + "generator_interfaces_struct.go", "generator_tests.go", "util.go", ], - importpath = "gvisor.dev/gvisor/tools/go_marshal/gomarshal", + stateify = False, visibility = [ "//:sandbox", ], + deps = ["//tools/tags"], ) diff --git a/tools/go_marshal/gomarshal/generator.go b/tools/go_marshal/gomarshal/generator.go index 641ccd938..19bcd4e6a 100644 --- a/tools/go_marshal/gomarshal/generator.go +++ b/tools/go_marshal/gomarshal/generator.go @@ -23,17 +23,14 @@ import ( "go/token" "os" "sort" -) + "strings" -const ( - marshalImport = "gvisor.dev/gvisor/tools/go_marshal/marshal" - usermemImport = "gvisor.dev/gvisor/pkg/sentry/usermem" - safecopyImport = "gvisor.dev/gvisor/pkg/sentry/platform/safecopy" + "gvisor.dev/gvisor/tools/tags" ) -// List of identifiers we use in generated code, that may conflict a -// similarly-named source identifier. Avoid problems by refusing the generate -// code when we see these. +// List of identifiers we use in generated code that may conflict with a +// similarly-named source identifier. Abort gracefully when we see these to +// avoid potentially confusing compilation failures in generated code. // // This only applies to import aliases at the moment. All other identifiers // are qualified by a receiver argument, since they're struct fields. @@ -41,10 +38,21 @@ const ( // All recievers are single letters, so we don't allow import aliases to be a // single letter. var badIdents = []string{ - "src", "srcs", "dst", "dsts", "blk", "buf", "err", + "addr", "blk", "buf", "dst", "dsts", "count", "err", "hdr", "idx", "inner", + "length", "limit", "ptr", "size", "src", "srcs", "task", "val", // All single-letter identifiers. } +// Constructed fromt badIdents in init(). +var badIdentsMap map[string]struct{} + +func init() { + badIdentsMap = make(map[string]struct{}) + for _, ident := range badIdents { + badIdentsMap[ident] = struct{}{} + } +} + // Generator drives code generation for a single invocation of the go_marshal // utility. // @@ -62,15 +70,12 @@ type Generator struct { outputTest *os.File // Package name for the generated file. pkg string - // Go import path for package we're processing. This package should directly - // declare the type we're generating code for. - declaration string // Set of extra packages to import in the generated file. imports *importTable } // NewGenerator creates a new code Generator. -func NewGenerator(srcs []string, out, outTest, pkg, declaration string, imports []string) (*Generator, error) { +func NewGenerator(srcs []string, out, outTest, pkg string, imports []string) (*Generator, error) { f, err := os.OpenFile(out, os.O_CREATE|os.O_WRONLY|os.O_TRUNC, 0644) if err != nil { return nil, fmt.Errorf("Couldn't open output file %q: %v", out, err) @@ -80,25 +85,29 @@ func NewGenerator(srcs []string, out, outTest, pkg, declaration string, imports return nil, fmt.Errorf("Couldn't open test output file %q: %v", out, err) } g := Generator{ - inputs: srcs, - output: f, - outputTest: fTest, - pkg: pkg, - declaration: declaration, - imports: newImportTable(), + inputs: srcs, + output: f, + outputTest: fTest, + pkg: pkg, + imports: newImportTable(), } for _, i := range imports { // All imports on the extra imports list are unconditionally marked as - // used, so they're always added to the generated code. + // used, so that they're always added to the generated code. g.imports.add(i).markUsed() } - g.imports.add(marshalImport).markUsed() - // The follow imports may or may not be used by the generated - // code, depending what's required for the target types. Don't - // mark these imports as used by default. - g.imports.add(usermemImport) - g.imports.add(safecopyImport) + + // The following imports may or may not be used by the generated code, + // depending on what's required for the target types. Don't mark these as + // used by default. + g.imports.add("io") + g.imports.add("reflect") + g.imports.add("runtime") g.imports.add("unsafe") + g.imports.add("gvisor.dev/gvisor/pkg/gohacks") + g.imports.add("gvisor.dev/gvisor/pkg/safecopy") + g.imports.add("gvisor.dev/gvisor/pkg/usermem") + g.imports.add("gvisor.dev/gvisor/tools/go_marshal/marshal") return &g, nil } @@ -108,6 +117,14 @@ func NewGenerator(srcs []string, out, outTest, pkg, declaration string, imports func (g *Generator) writeHeader() error { var b sourceBuffer b.emit("// Automatically generated marshal implementation. See tools/go_marshal.\n\n") + + // Emit build tags. + if t := tags.Aggregate(g.inputs); len(t) > 0 { + b.emit(strings.Join(t.Lines(), "\n")) + b.emit("\n\n") + } + + // Package header. b.emit("package %s\n\n", g.pkg) if err := b.write(g.output); err != nil { return err @@ -172,10 +189,73 @@ func (g *Generator) parse() ([]*ast.File, []*token.FileSet, error) { return files, fsets, nil } -// collectMarshallabeTypes walks the parsed AST and collects a list of type +// sliceAPI carries information about the '+marshal slice' directive. +type sliceAPI struct { + // Comment node in the AST containing the +marshal tag. + comment *ast.Comment + // Identifier fragment to use when naming generated functions for the slice + // API. + ident string + // Whether the generated functions should reference the newtype name, or the + // inner type name. Only meaningful on newtype declarations on primitives. + inner bool +} + +// marshallableType carries information about a type marked with the '+marshal' +// directive. +type marshallableType struct { + spec *ast.TypeSpec + slice *sliceAPI +} + +func newMarshallableType(fset *token.FileSet, tagLine *ast.Comment, spec *ast.TypeSpec) marshallableType { + mt := marshallableType{ + spec: spec, + slice: nil, + } + + var unhandledTags []string + + for _, tag := range strings.Fields(strings.TrimPrefix(tagLine.Text, "// +marshal")) { + if strings.HasPrefix(tag, "slice:") { + tokens := strings.Split(tag, ":") + if len(tokens) < 2 || len(tokens) > 3 { + abortAt(fset.Position(tagLine.Slash), fmt.Sprintf("+marshal directive has invalid 'slice' clause. Expecting format 'slice:<IDENTIFIER>[:inner]', got '%v'", tag)) + } + if len(tokens[1]) == 0 { + abortAt(fset.Position(tagLine.Slash), "+marshal slice directive has empty identifier argument. Expecting '+marshal slice:identifier'") + } + + sa := &sliceAPI{ + comment: tagLine, + ident: tokens[1], + } + mt.slice = sa + + if len(tokens) == 3 { + if tokens[2] != "inner" { + abortAt(fset.Position(tagLine.Slash), "+marshal slice directive has an invalid argument. Expecting '+marshal slice:<IDENTIFIER>[:inner]'") + } + sa.inner = true + } + + continue + } + + unhandledTags = append(unhandledTags, tag) + } + + if len(unhandledTags) > 0 { + abortAt(fset.Position(tagLine.Slash), fmt.Sprintf("+marshal directive contained the following unknown clauses: %v", strings.Join(unhandledTags, " "))) + } + + return mt +} + +// collectMarshallableTypes walks the parsed AST and collects a list of type // declarations for which we need to generate the Marshallable interface. -func (g *Generator) collectMarshallabeTypes(a *ast.File, f *token.FileSet) []*ast.TypeSpec { - var types []*ast.TypeSpec +func (g *Generator) collectMarshallableTypes(a *ast.File, f *token.FileSet) []marshallableType { + var types []marshallableType for _, decl := range a.Decls { gdecl, ok := decl.(*ast.GenDecl) // Type declaration? @@ -190,9 +270,11 @@ func (g *Generator) collectMarshallabeTypes(a *ast.File, f *token.FileSet) []*as } // Does the comment contain a "+marshal" line? marked := false + var tagLine *ast.Comment for _, c := range gdecl.Doc.List { - if c.Text == "// +marshal" { + if strings.HasPrefix(c.Text, "// +marshal") { marked = true + tagLine = c break } } @@ -201,14 +283,23 @@ func (g *Generator) collectMarshallabeTypes(a *ast.File, f *token.FileSet) []*as continue } for _, spec := range gdecl.Specs { - // We already confirmed we're in a type declaration earlier. + // We already confirmed we're in a type declaration earlier, so this + // cast will succeed. t := spec.(*ast.TypeSpec) - if _, ok := t.Type.(*ast.StructType); ok { - debugfAt(f.Position(t.Pos()), "Collected marshallable type %s.\n", t.Name.Name) - types = append(types, t) - continue + switch t.Type.(type) { + case *ast.StructType: + debugfAt(f.Position(t.Pos()), "Collected marshallable struct %s.\n", t.Name.Name) + case *ast.Ident: // Newtype on primitive. + debugfAt(f.Position(t.Pos()), "Collected marshallable newtype on primitive %s.\n", t.Name.Name) + case *ast.ArrayType: // Newtype on array. + debugfAt(f.Position(t.Pos()), "Collected marshallable newtype on array %s.\n", t.Name.Name) + default: + // A user specifically requested marshalling on this type, but we + // don't support it. + abortAt(f.Position(t.Pos()), fmt.Sprintf("Marshalling codegen was requested on type '%s', but go-marshal doesn't support this kind of declaration.\n", t.Name)) } - debugf("Skipping declaration %v since it's not a struct declaration.\n", gdecl) + types = append(types, newMarshallableType(f, tagLine, t)) + } } return types @@ -222,11 +313,6 @@ func (g *Generator) collectMarshallabeTypes(a *ast.File, f *token.FileSet) []*as // identifiers in the generated code don't conflict with any imported package // names. func (g *Generator) collectImports(a *ast.File, f *token.FileSet) map[string]importStmt { - badImportNames := make(map[string]bool) - for _, i := range badIdents { - badImportNames[i] = true - } - is := make(map[string]importStmt) for _, decl := range a.Decls { gdecl, ok := decl.(*ast.GenDecl) @@ -240,10 +326,10 @@ func (g *Generator) collectImports(a *ast.File, f *token.FileSet) map[string]imp // Make sure we have an import that doesn't use any local names that // would conflict with identifiers in the generated code. - if len(i.name) == 1 { + if len(i.name) == 1 && i.name != "_" { abortAt(f.Position(spec.Pos()), fmt.Sprintf("Import has a single character local name '%s'; this may conflict with code generated by go_marshal, use a multi-character import alias", i.name)) } - if badImportNames[i.name] { + if _, ok := badIdentsMap[i.name]; ok { abortAt(f.Position(spec.Pos()), fmt.Sprintf("Import name '%s' is likely to conflict with code generated by go_marshal, use a different import alias", i.name)) } } @@ -252,20 +338,40 @@ func (g *Generator) collectImports(a *ast.File, f *token.FileSet) map[string]imp } -func (g *Generator) generateOne(t *ast.TypeSpec, fset *token.FileSet) *interfaceGenerator { - // We're guaranteed to have only struct type specs by now. See - // Generator.collectMarshallabeTypes. - i := newInterfaceGenerator(t, fset) - i.validate() - i.emitMarshallable() +func (g *Generator) generateOne(t marshallableType, fset *token.FileSet) *interfaceGenerator { + i := newInterfaceGenerator(t.spec, fset) + switch ty := t.spec.Type.(type) { + case *ast.StructType: + i.validateStruct(t.spec, ty) + i.emitMarshallableForStruct(ty) + if t.slice != nil { + i.emitMarshallableSliceForStruct(ty, t.slice) + } + case *ast.Ident: + i.validatePrimitiveNewtype(ty) + i.emitMarshallableForPrimitiveNewtype(ty) + if t.slice != nil { + i.emitMarshallableSliceForPrimitiveNewtype(ty, t.slice) + } + case *ast.ArrayType: + i.validateArrayNewtype(t.spec.Name, ty) + // After validate, we can safely call arrayLen. + i.emitMarshallableForArrayNewtype(t.spec.Name, ty, ty.Elt.(*ast.Ident)) + if t.slice != nil { + abortAt(fset.Position(t.slice.comment.Slash), fmt.Sprintf("Array type marked as '+marshal slice:...', but this is not supported. Perhaps fold one of the dimensions?")) + } + default: + // This should've been filtered out by collectMarshallabeTypes. + panic(fmt.Sprintf("Unexpected type %+v", ty)) + } return i } // generateOneTestSuite generates a test suite for the automatically generated // implementations type t. -func (g *Generator) generateOneTestSuite(t *ast.TypeSpec) *testGenerator { - i := newTestGenerator(t, g.declaration) - i.emitTests() +func (g *Generator) generateOneTestSuite(t marshallableType) *testGenerator { + i := newTestGenerator(t.spec) + i.emitTests(t.slice) return i } @@ -304,35 +410,24 @@ func (g *Generator) Run() error { for i, a := range asts { // Collect type declarations marked for code generation and generate // Marshallable interfaces. - for _, t := range g.collectMarshallabeTypes(a, fsets[i]) { + for _, t := range g.collectMarshallableTypes(a, fsets[i]) { impl := g.generateOne(t, fsets[i]) // Collect Marshallable types referenced by the generated code. - for ref, _ := range impl.ms { + for ref := range impl.ms { ms[ref] = struct{}{} } impls = append(impls, impl) // Collect imports referenced by the generated code and add them to // the list of imports we need to copy to the generated code. - for name, _ := range impl.is { + for name := range impl.is { if !g.imports.markUsed(name) { - panic(fmt.Sprintf("Generated code for '%s' referenced a non-existent import with local name '%s'", impl.typeName(), name)) + panic(fmt.Sprintf("Generated code for '%s' referenced a non-existent import with local name '%s'. Either go-marshal needs to add an import to the generated file, or a package in an input source file has a package name differ from the final component of its path, which go-marshal doesn't know how to detect; use an import alias to work around this limitation.", impl.typeName(), name)) } } ts = append(ts, g.generateOneTestSuite(t)) } } - // Tool was invoked with input files with no data structures marked for code - // generation. This is probably not what the user intended. - if len(impls) == 0 { - var buf bytes.Buffer - fmt.Fprintf(&buf, "go_marshal invoked on these files, but they don't contain any types requiring code generation. Perhaps mark some with \"// +marshal\"?:\n") - for _, i := range g.inputs { - fmt.Fprintf(&buf, " %s\n", i) - } - abort(buf.String()) - } - // Write output file header. These include things like package name and // import statements. if err := g.writeHeader(); err != nil { @@ -359,11 +454,12 @@ func (g *Generator) Run() error { // source file. func (g *Generator) writeTests(ts []*testGenerator) error { var b sourceBuffer - b.emit("package %s_test\n\n", g.pkg) + b.emit("package %s\n\n", g.pkg) if err := b.write(g.outputTest); err != nil { return err } + // Collect and write test import statements. imports := newImportTable() for _, t := range ts { imports.merge(t.imports) @@ -373,6 +469,27 @@ func (g *Generator) writeTests(ts []*testGenerator) error { return err } + // Write test functions. + + // If we didn't generate any Marshallable implementations, we can't just + // emit an empty test file, since that causes the build to fail with "no + // tests/benchmarks/examples found". Unfortunately we can't signal bazel to + // omit the entire package since the outputs are already defined before + // go-marshal is called. If we'd otherwise emit an empty test suite, emit an + // empty example instead. + if len(ts) == 0 { + b.reset() + b.emit("func Example() {\n") + b.inIndent(func() { + b.emit("// This example is intentionally empty to ensure this file contains at least\n") + b.emit("// one testable entity. go-marshal is forced to emit a test file if a package\n") + b.emit("// is marked marshallable, but emitting a test file with no entities results\n") + b.emit("// in a build failure.\n") + }) + b.emit("}\n") + return b.write(g.outputTest) + } + for _, t := range ts { if err := t.write(g.outputTest); err != nil { return err diff --git a/tools/go_marshal/gomarshal/generator_interfaces.go b/tools/go_marshal/gomarshal/generator_interfaces.go index a712c14dc..e3c3dac63 100644 --- a/tools/go_marshal/gomarshal/generator_interfaces.go +++ b/tools/go_marshal/gomarshal/generator_interfaces.go @@ -55,9 +55,6 @@ func (g *interfaceGenerator) typeName() string { // newinterfaceGenerator creates a new interface generator. func newInterfaceGenerator(t *ast.TypeSpec, fset *token.FileSet) *interfaceGenerator { - if _, ok := t.Type.(*ast.StructType); !ok { - panic(fmt.Sprintf("Attempting to generate code for a not struct type %v", t)) - } g := &interfaceGenerator{ t: t, r: receiverName(t), @@ -77,25 +74,12 @@ func (g *interfaceGenerator) recordUsedMarshallable(m string) { func (g *interfaceGenerator) recordUsedImport(i string) { g.is[i] = struct{}{} - } func (g *interfaceGenerator) recordPotentiallyNonPackedField(fieldName string) { g.as[fieldName] = struct{}{} } -func (g *interfaceGenerator) forEachField(fn func(f *ast.Field)) { - // This is guaranteed to succeed because g.t is always a struct. - st := g.t.Type.(*ast.StructType) - for _, field := range st.Fields.List { - fn(field) - } -} - -func (g *interfaceGenerator) fieldAccessor(n *ast.Ident) string { - return fmt.Sprintf("%s.%s", g.r, n.Name) -} - // abortAt aborts the go_marshal tool with the given error message, with a // reference position to the input source. Same as abortAt, but uses g to // resolve p to position. @@ -103,67 +87,6 @@ func (g *interfaceGenerator) abortAt(p token.Pos, msg string) { abortAt(g.f.Position(p), msg) } -// validate ensures the type we're working with can be marshalled. These checks -// are done ahead of time and in one place so we can make assumptions later. -func (g *interfaceGenerator) validate() { - g.forEachField(func(f *ast.Field) { - if len(f.Names) == 0 { - g.abortAt(f.Pos(), "Cannot marshal structs with embedded fields, give the field a name; use '_' for anonymous fields such as padding fields") - } - }) - - g.forEachField(func(f *ast.Field) { - fieldDispatcher{ - primitive: func(_, t *ast.Ident) { - switch t.Name { - case "int8", "uint8", "byte", "int16", "uint16", "int32", "uint32", "int64", "uint64": - // These are the only primitive types we're allow. Below, we - // provide suggestions for some disallowed types and reject - // them, then attempt to marshal any remaining types by - // invoking the marshal.Marshallable interface on them. If - // these types don't actually implement - // marshal.Marshallable, compilation of the generated code - // will fail with an appropriate error message. - return - case "int": - g.abortAt(f.Pos(), "Type 'int' has ambiguous width, use int32 or int64") - case "uint": - g.abortAt(f.Pos(), "Type 'uint' has ambiguous width, use uint32 or uint64") - case "string": - g.abortAt(f.Pos(), "Type 'string' is dynamically-sized and cannot be marshalled, use a fixed size byte array '[...]byte' instead") - default: - debugfAt(g.f.Position(f.Pos()), fmt.Sprintf("Found derived type '%s', will attempt dispatch via marshal.Marshallable.\n", t.Name)) - } - }, - selector: func(_, _, _ *ast.Ident) { - // No validation to perform on selector fields. However this - // callback must still be provided. - }, - array: func(n, _ *ast.Ident, len int) { - a := f.Type.(*ast.ArrayType) - if a.Len == nil { - g.abortAt(f.Pos(), fmt.Sprintf("Dynamically sized slice '%s' cannot be marshalled, arrays must be statically sized", n.Name)) - } - - if _, ok := a.Len.(*ast.BasicLit); !ok { - g.abortAt(a.Len.Pos(), fmt.Sprintf("Array size must be a literal, don's use consts or expressions")) - } - - if _, ok := a.Elt.(*ast.Ident); !ok { - g.abortAt(a.Elt.Pos(), fmt.Sprintf("Marshalling not supported for arrays with %s elements, array elements must be primitive types", kindString(a.Elt))) - } - - if len <= 0 { - g.abortAt(a.Len.Pos(), fmt.Sprintf("Marshalling not supported for zero length arrays, why does an ABI struct have one?")) - } - }, - unhandled: func(_ *ast.Ident) { - g.abortAt(f.Pos(), fmt.Sprintf("Marshalling not supported for %s fields", kindString(f.Type))) - }, - }.dispatch(f) - }) -} - // scalarSize returns the size of type identified by t. If t isn't a primitive // type, the size isn't known at code generation time, and must be resolved via // the marshal.Marshallable interface. @@ -190,7 +113,8 @@ func (g *interfaceGenerator) shiftDynamic(bufVar, name string) { g.emit("%s = %s[%s.SizeBytes():]\n", bufVar, bufVar, name) } -func (g *interfaceGenerator) marshalScalar(accessor, typ string, bufVar string) { +// marshalScalar writes a single scalar to a byte slice. +func (g *interfaceGenerator) marshalScalar(accessor, typ, bufVar string) { switch typ { case "int8", "uint8", "byte": g.emit("%s[0] = byte(%s)\n", bufVar, accessor) @@ -213,43 +137,26 @@ func (g *interfaceGenerator) marshalScalar(accessor, typ string, bufVar string) } } -func (g *interfaceGenerator) unmarshalScalar(accessor, typ string, bufVar string) { +// unmarshalScalar reads a single scalar from a byte slice. +func (g *interfaceGenerator) unmarshalScalar(accessor, typ, bufVar string) { switch typ { - case "int8": - g.emit("%s = int8(%s[0])\n", accessor, bufVar) - g.shift(bufVar, 1) - case "uint8": - g.emit("%s = uint8(%s[0])\n", accessor, bufVar) - g.shift(bufVar, 1) case "byte": g.emit("%s = %s[0]\n", accessor, bufVar) g.shift(bufVar, 1) - - case "int16": - g.recordUsedImport("usermem") - g.emit("%s = int16(usermem.ByteOrder.Uint16(%s[:2]))\n", accessor, bufVar) - g.shift(bufVar, 2) - case "uint16": + case "int8", "uint8": + g.emit("%s = %s(%s[0])\n", accessor, typ, bufVar) + g.shift(bufVar, 1) + case "int16", "uint16": g.recordUsedImport("usermem") - g.emit("%s = usermem.ByteOrder.Uint16(%s[:2])\n", accessor, bufVar) + g.emit("%s = %s(usermem.ByteOrder.Uint16(%s[:2]))\n", accessor, typ, bufVar) g.shift(bufVar, 2) - - case "int32": - g.recordUsedImport("usermem") - g.emit("%s = int32(usermem.ByteOrder.Uint32(%s[:4]))\n", accessor, bufVar) - g.shift(bufVar, 4) - case "uint32": + case "int32", "uint32": g.recordUsedImport("usermem") - g.emit("%s = usermem.ByteOrder.Uint32(%s[:4])\n", accessor, bufVar) + g.emit("%s = %s(usermem.ByteOrder.Uint32(%s[:4]))\n", accessor, typ, bufVar) g.shift(bufVar, 4) - - case "int64": - g.recordUsedImport("usermem") - g.emit("%s = int64(usermem.ByteOrder.Uint64(%s[:8]))\n", accessor, bufVar) - g.shift(bufVar, 8) - case "uint64": + case "int64", "uint64": g.recordUsedImport("usermem") - g.emit("%s = usermem.ByteOrder.Uint64(%s[:8])\n", accessor, bufVar) + g.emit("%s = %s(usermem.ByteOrder.Uint64(%s[:8]))\n", accessor, typ, bufVar) g.shift(bufVar, 8) default: g.emit("%s.UnmarshalBytes(%s[:%s.SizeBytes()])\n", accessor, bufVar, accessor) @@ -258,250 +165,112 @@ func (g *interfaceGenerator) unmarshalScalar(accessor, typ string, bufVar string } } -// areFieldsPackedExpression returns a go expression checking whether g.t's fields are -// packed. Returns "", false if g.t has no fields that may be potentially -// packed, otherwise returns <clause>, true, where <clause> is an expression -// like "t.a.Packed() && t.b.Packed() && t.c.Packed()". -func (g *interfaceGenerator) areFieldsPackedExpression() (string, bool) { - if len(g.as) == 0 { - return "", false - } - - cs := make([]string, 0, len(g.as)) - for accessor, _ := range g.as { - cs = append(cs, fmt.Sprintf("%s.Packed()", accessor)) - } - return strings.Join(cs, " && "), true +// emitCastToByteSlice unsafely casts an arbitrary type's underlying memory to a +// byte slice, bypassing escape analysis. The caller is responsible for ensuring +// srcPtr lives until they're done with dstVar, the runtime does not consider +// dstVar dependent on srcPtr due to the escape analysis bypass. +// +// srcPtr must be a pointer. +// +// This function uses internally uses the identifier "hdr", and cannot be used +// in a context where it is already bound. +func (g *interfaceGenerator) emitCastToByteSlice(srcPtr, dstVar, lenExpr string) { + g.recordUsedImport("gohacks") + g.emit("// Construct a slice backed by dst's underlying memory.\n") + g.emit("var %s []byte\n", dstVar) + g.emit("hdr := (*reflect.SliceHeader)(unsafe.Pointer(&%s))\n", dstVar) + g.emit("hdr.Data = uintptr(gohacks.Noescape(unsafe.Pointer(%s)))\n", srcPtr) + g.emit("hdr.Len = %s\n", lenExpr) + g.emit("hdr.Cap = %s\n\n", lenExpr) } -func (g *interfaceGenerator) emitMarshallable() { - // Is g.t a packed struct without consideing field types? - thisPacked := true - g.forEachField(func(f *ast.Field) { - if f.Tag != nil { - if f.Tag.Value == "`marshal:\"unaligned\"`" { - if thisPacked { - debugfAt(g.f.Position(g.t.Pos()), - fmt.Sprintf("Marking type '%s' as not packed due to tag `marshal:\"unaligned\"`.\n", g.t.Name)) - thisPacked = false - } - } - } - }) - - g.emit("// SizeBytes implements marshal.Marshallable.SizeBytes.\n") - g.emit("func (%s *%s) SizeBytes() int {\n", g.r, g.typeName()) - g.inIndent(func() { - primitiveSize := 0 - var dynamicSizeTerms []string - - g.forEachField(fieldDispatcher{ - primitive: func(n, t *ast.Ident) { - if size, dynamic := g.scalarSize(t); !dynamic { - primitiveSize += size - } else { - g.recordUsedMarshallable(t.Name) - dynamicSizeTerms = append(dynamicSizeTerms, fmt.Sprintf("%s.SizeBytes()", g.fieldAccessor(n))) - } - }, - selector: func(n, tX, tSel *ast.Ident) { - tName := fmt.Sprintf("%s.%s", tX.Name, tSel.Name) - g.recordUsedImport(tX.Name) - g.recordUsedMarshallable(tName) - dynamicSizeTerms = append(dynamicSizeTerms, fmt.Sprintf("(*%s)(nil).SizeBytes()", tName)) - }, - array: func(n, t *ast.Ident, len int) { - if len < 1 { - // Zero-length arrays should've been rejected by validate(). - panic("unreachable") - } - if size, dynamic := g.scalarSize(t); !dynamic { - primitiveSize += size * len - } else { - g.recordUsedMarshallable(t.Name) - dynamicSizeTerms = append(dynamicSizeTerms, fmt.Sprintf("(*%s)(nil).SizeBytes()*%d", t.Name, len)) - } - }, - }.dispatch) - g.emit("return %d", primitiveSize) - if len(dynamicSizeTerms) > 0 { - g.incIndent() - } - { - for _, d := range dynamicSizeTerms { - g.emitNoIndent(" +\n") - g.emit(d) - } - } - if len(dynamicSizeTerms) > 0 { - g.decIndent() - } - }) - g.emit("\n}\n\n") - - g.emit("// MarshalBytes implements marshal.Marshallable.MarshalBytes.\n") - g.emit("func (%s *%s) MarshalBytes(dst []byte) {\n", g.r, g.typeName()) - g.inIndent(func() { - g.forEachField(fieldDispatcher{ - primitive: func(n, t *ast.Ident) { - if n.Name == "_" { - g.emit("// Padding: dst[:sizeof(%s)] ~= %s(0)\n", t.Name, t.Name) - if len, dynamic := g.scalarSize(t); !dynamic { - g.shift("dst", len) - } else { - // We can't use shiftDynamic here because we don't have - // an instance of the dynamic type we can referece here - // (since the version in this struct is anonymous). Use - // a typed nil pointer to call SizeBytes() instead. - g.emit("dst = dst[(*%s)(nil).SizeBytes():]\n", t.Name) - } - return - } - g.marshalScalar(g.fieldAccessor(n), t.Name, "dst") - }, - selector: func(n, tX, tSel *ast.Ident) { - g.marshalScalar(g.fieldAccessor(n), fmt.Sprintf("%s.%s", tX.Name, tSel.Name), "dst") - }, - array: func(n, t *ast.Ident, size int) { - if n.Name == "_" { - g.emit("// Padding: dst[:sizeof(%s)*%d] ~= [%d]%s{0}\n", t.Name, size, size, t.Name) - if len, dynamic := g.scalarSize(t); !dynamic { - g.shift("dst", len*size) - } else { - // We can't use shiftDynamic here because we don't have - // an instance of the dynamic type we can reference here - // (since the version in this struct is anonymous). Use - // a typed nil pointer to call SizeBytes() instead. - g.emit("dst = dst[(*%s)(nil).SizeBytes()*%d:]\n", t.Name, size) - } - return - } - - g.emit("for i := 0; i < %d; i++ {\n", size) - g.inIndent(func() { - g.marshalScalar(fmt.Sprintf("%s[i]", g.fieldAccessor(n)), t.Name, "dst") - }) - g.emit("}\n") - }, - }.dispatch) - }) - g.emit("}\n\n") - - g.emit("// UnmarshalBytes implements marshal.Marshallable.UnmarshalBytes.\n") - g.emit("func (%s *%s) UnmarshalBytes(src []byte) {\n", g.r, g.typeName()) - g.inIndent(func() { - g.forEachField(fieldDispatcher{ - primitive: func(n, t *ast.Ident) { - if n.Name == "_" { - g.emit("// Padding: var _ %s ~= src[:sizeof(%s)]\n", t.Name, t.Name) - if len, dynamic := g.scalarSize(t); !dynamic { - g.shift("src", len) - } else { - // We can't use shiftDynamic here because we don't have - // an instance of the dynamic type we can reference here - // (since the version in this struct is anonymous). Use - // a typed nil pointer to call SizeBytes() instead. - g.emit("src = src[(*%s)(nil).SizeBytes():]\n", t.Name) - g.recordPotentiallyNonPackedField(fmt.Sprintf("(*%s)(nil)", t.Name)) - } - return - } - g.unmarshalScalar(g.fieldAccessor(n), t.Name, "src") - }, - selector: func(n, tX, tSel *ast.Ident) { - g.unmarshalScalar(g.fieldAccessor(n), fmt.Sprintf("%s.%s", tX.Name, tSel.Name), "src") - }, - array: func(n, t *ast.Ident, size int) { - if n.Name == "_" { - g.emit("// Padding: ~ copy([%d]%s(%s), src[:sizeof(%s)*%d])\n", size, t.Name, g.fieldAccessor(n), t.Name, size) - if len, dynamic := g.scalarSize(t); !dynamic { - g.shift("src", len*size) - } else { - // We can't use shiftDynamic here because we don't have - // an instance of the dynamic type we can referece here - // (since the version in this struct is anonymous). Use - // a typed nil pointer to call SizeBytes() instead. - g.emit("src = src[(*%s)(nil).SizeBytes()*%d:]\n", t.Name, size) - } - return - } +// emitCastToByteSlice unsafely casts a slice with elements of an abitrary type +// to a byte slice. As part of the cast, the byte slice is made to look +// independent of the src slice by bypassing escape analysis. This means the +// byte slice can be used without causing the source to escape. The caller is +// responsible for ensuring srcPtr lives until they're done with dstVar, as the +// runtime no longer considers dstVar dependent on srcPtr and is free to GC it. +// +// srcPtr must be a pointer. +// +// This function uses internally uses the identifiers "ptr", "val" and "hdr", +// and cannot be used in a context where these identifiers are already bound. +func (g *interfaceGenerator) emitCastSliceToByteSlice(srcPtr, dstVar, lenExpr string) { + g.emitNoEscapeSliceDataPointer(srcPtr, "val") + + g.emit("// Construct a slice backed by dst's underlying memory.\n") + g.emit("var %s []byte\n", dstVar) + g.emit("hdr := (*reflect.SliceHeader)(unsafe.Pointer(&%s))\n", dstVar) + g.emit("hdr.Data = uintptr(val)\n") + g.emit("hdr.Len = %s\n", lenExpr) + g.emit("hdr.Cap = %s\n\n", lenExpr) +} - g.emit("for i := 0; i < %d; i++ {\n", size) - g.inIndent(func() { - g.unmarshalScalar(fmt.Sprintf("%s[i]", g.fieldAccessor(n)), t.Name, "src") - }) - g.emit("}\n") - }, - }.dispatch) - }) - g.emit("}\n\n") +// emitNoEscapeSliceDataPointer unsafely casts a slice's data pointer to an +// unsafe.Pointer, bypassing escape analysis. The caller is responsible for +// ensuring srcPtr lives until they're done with dstVar, as the runtime no +// longer considers dstVar dependent on srcPtr and is free to GC it. +// +// srcPtr must be a pointer. +// +// This function uses internally uses the identifier "ptr" cannot be used in a +// context where this identifier is already bound. +func (g *interfaceGenerator) emitNoEscapeSliceDataPointer(srcPtr, dstVar string) { + g.recordUsedImport("gohacks") + g.emit("ptr := unsafe.Pointer(%s)\n", srcPtr) + g.emit("%s := gohacks.Noescape(unsafe.Pointer((*reflect.SliceHeader)(ptr).Data))\n\n", dstVar) +} - g.emit("// Packed implements marshal.Marshallable.Packed.\n") - g.emit("func (%s *%s) Packed() bool {\n", g.r, g.typeName()) - g.inIndent(func() { - expr, fieldsMaybePacked := g.areFieldsPackedExpression() - switch { - case !thisPacked: - g.emit("return false\n") - case fieldsMaybePacked: - g.emit("return %s\n", expr) - default: - g.emit("return true\n") +func (g *interfaceGenerator) emitKeepAlive(ptrVar string) { + g.emit("// Since we bypassed the compiler's escape analysis, indicate that %s\n", ptrVar) + g.emit("// must live until the use above.\n") + g.emit("runtime.KeepAlive(%s)\n", ptrVar) +} - } - }) - g.emit("}\n\n") +func (g *interfaceGenerator) expandBinaryExpr(b *strings.Builder, e *ast.BinaryExpr) { + switch x := e.X.(type) { + case *ast.BinaryExpr: + // Recursively expand sub-expression. + g.expandBinaryExpr(b, x) + case *ast.Ident: + fmt.Fprintf(b, "%s", x.Name) + case *ast.BasicLit: + fmt.Fprintf(b, "%s", x.Value) + default: + g.abortAt(e.Pos(), "Cannot convert binary expression to output code. Go-marshal currently only handles simple expressions of literals, constants and basic identifiers") + } - g.emit("// MarshalUnsafe implements marshal.Marshallable.MarshalUnsafe.\n") - g.emit("func (%s *%s) MarshalUnsafe(dst []byte) {\n", g.r, g.typeName()) - g.inIndent(func() { - if thisPacked { - g.recordUsedImport("safecopy") - g.recordUsedImport("unsafe") - if cond, ok := g.areFieldsPackedExpression(); ok { - g.emit("if %s {\n", cond) - g.inIndent(func() { - g.emit("safecopy.CopyIn(dst, unsafe.Pointer(%s))\n", g.r) - }) - g.emit("} else {\n") - g.inIndent(func() { - g.emit("%s.MarshalBytes(dst)\n", g.r) - }) - g.emit("}\n") - } else { - g.emit("safecopy.CopyIn(dst, unsafe.Pointer(%s))\n", g.r) - } - } else { - g.emit("// Type %s doesn't have a packed layout in memory, fallback to MarshalBytes.\n", g.typeName()) - g.emit("%s.MarshalBytes(dst)\n", g.r) - } - }) - g.emit("}\n\n") + fmt.Fprintf(b, "%s", e.Op) - g.emit("// UnmarshalUnsafe implements marshal.Marshallable.UnmarshalUnsafe.\n") - g.emit("func (%s *%s) UnmarshalUnsafe(src []byte) {\n", g.r, g.typeName()) - g.inIndent(func() { - if thisPacked { - g.recordUsedImport("safecopy") - g.recordUsedImport("unsafe") - if cond, ok := g.areFieldsPackedExpression(); ok { - g.emit("if %s {\n", cond) - g.inIndent(func() { - g.emit("safecopy.CopyOut(unsafe.Pointer(%s), src)\n", g.r) - }) - g.emit("} else {\n") - g.inIndent(func() { - g.emit("%s.UnmarshalBytes(src)\n", g.r) - }) - g.emit("}\n") - } else { - g.emit("safecopy.CopyOut(unsafe.Pointer(%s), src)\n", g.r) - } - } else { - g.emit("// Type %s doesn't have a packed layout in memory, fall back to UnmarshalBytes.\n", g.typeName()) - g.emit("%s.UnmarshalBytes(src)\n", g.r) - } - }) - g.emit("}\n\n") + switch y := e.Y.(type) { + case *ast.BinaryExpr: + // Recursively expand sub-expression. + g.expandBinaryExpr(b, y) + case *ast.Ident: + fmt.Fprintf(b, "%s", y.Name) + case *ast.BasicLit: + fmt.Fprintf(b, "%s", y.Value) + default: + g.abortAt(e.Pos(), "Cannot convert binary expression to output code. Go-marshal currently only handles simple expressions of literals, constants and basic identifiers") + } +} +// arrayLenExpr returns a string containing a valid golang expression +// representing the length of array a. The returned expression should be treated +// as a single value, and will be already parenthesized as required. +func (g *interfaceGenerator) arrayLenExpr(a *ast.ArrayType) string { + var b strings.Builder + + switch l := a.Len.(type) { + case *ast.Ident: + fmt.Fprintf(&b, "%s", l.Name) + case *ast.BasicLit: + fmt.Fprintf(&b, "%s", l.Value) + case *ast.BinaryExpr: + g.expandBinaryExpr(&b, l) + return fmt.Sprintf("(%s)", b.String()) + default: + g.abortAt(l.Pos(), "Cannot convert this array len expression to output code. Go-marshal currently only handles simple expressions of literals, constants and basic identifiers") + } + return b.String() } diff --git a/tools/go_marshal/gomarshal/generator_interfaces_array_newtype.go b/tools/go_marshal/gomarshal/generator_interfaces_array_newtype.go new file mode 100644 index 000000000..72ef03a22 --- /dev/null +++ b/tools/go_marshal/gomarshal/generator_interfaces_array_newtype.go @@ -0,0 +1,146 @@ +// Copyright 2020 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +// This file contains the bits of the code generator specific to marshalling +// newtypes on arrays. + +package gomarshal + +import ( + "fmt" + "go/ast" +) + +func (g *interfaceGenerator) validateArrayNewtype(n *ast.Ident, a *ast.ArrayType) { + if a.Len == nil { + g.abortAt(a.Pos(), fmt.Sprintf("Dynamically sized slice '%s' cannot be marshalled, arrays must be statically sized", n.Name)) + } + + if _, ok := a.Elt.(*ast.Ident); !ok { + g.abortAt(a.Elt.Pos(), fmt.Sprintf("Marshalling not supported for arrays with %s elements, array elements must be primitive types", kindString(a.Elt))) + } +} + +func (g *interfaceGenerator) emitMarshallableForArrayNewtype(n *ast.Ident, a *ast.ArrayType, elt *ast.Ident) { + g.recordUsedImport("io") + g.recordUsedImport("marshal") + g.recordUsedImport("reflect") + g.recordUsedImport("runtime") + g.recordUsedImport("safecopy") + g.recordUsedImport("unsafe") + g.recordUsedImport("usermem") + + lenExpr := g.arrayLenExpr(a) + + g.emit("// SizeBytes implements marshal.Marshallable.SizeBytes.\n") + g.emit("//go:nosplit\n") + g.emit("func (%s *%s) SizeBytes() int {\n", g.r, g.typeName()) + g.inIndent(func() { + if size, dynamic := g.scalarSize(elt); !dynamic { + g.emit("return %d * %s\n", size, lenExpr) + } else { + g.emit("return (*%s)(nil).SizeBytes() * %s\n", n.Name, lenExpr) + } + }) + g.emit("}\n\n") + + g.emit("// MarshalBytes implements marshal.Marshallable.MarshalBytes.\n") + g.emit("func (%s *%s) MarshalBytes(dst []byte) {\n", g.r, g.typeName()) + g.inIndent(func() { + g.emit("for idx := 0; idx < %s; idx++ {\n", lenExpr) + g.inIndent(func() { + g.marshalScalar(fmt.Sprintf("%s[idx]", g.r), elt.Name, "dst") + }) + g.emit("}\n") + }) + g.emit("}\n\n") + + g.emit("// UnmarshalBytes implements marshal.Marshallable.UnmarshalBytes.\n") + g.emit("func (%s *%s) UnmarshalBytes(src []byte) {\n", g.r, g.typeName()) + g.inIndent(func() { + g.emit("for idx := 0; idx < %s; idx++ {\n", lenExpr) + g.inIndent(func() { + g.unmarshalScalar(fmt.Sprintf("%s[idx]", g.r), elt.Name, "src") + }) + g.emit("}\n") + }) + g.emit("}\n\n") + + g.emit("// Packed implements marshal.Marshallable.Packed.\n") + g.emit("//go:nosplit\n") + g.emit("func (%s *%s) Packed() bool {\n", g.r, g.typeName()) + g.inIndent(func() { + g.emit("// Array newtypes are always packed.\n") + g.emit("return true\n") + }) + g.emit("}\n\n") + + g.emit("// MarshalUnsafe implements marshal.Marshallable.MarshalUnsafe.\n") + g.emit("func (%s *%s) MarshalUnsafe(dst []byte) {\n", g.r, g.typeName()) + g.inIndent(func() { + g.emit("safecopy.CopyIn(dst, unsafe.Pointer(%s))\n", g.r) + }) + g.emit("}\n\n") + + g.emit("// UnmarshalUnsafe implements marshal.Marshallable.UnmarshalUnsafe.\n") + g.emit("func (%s *%s) UnmarshalUnsafe(src []byte) {\n", g.r, g.typeName()) + g.inIndent(func() { + g.emit("safecopy.CopyOut(unsafe.Pointer(%s), src)\n", g.r) + }) + g.emit("}\n\n") + + g.emit("// CopyOutN implements marshal.Marshallable.CopyOutN.\n") + g.emit("//go:nosplit\n") + g.emit("func (%s *%s) CopyOutN(task marshal.Task, addr usermem.Addr, limit int) (int, error) {\n", g.r, g.typeName()) + g.inIndent(func() { + g.emitCastToByteSlice(g.r, "buf", fmt.Sprintf("%s.SizeBytes()", g.r)) + + g.emit("length, err := task.CopyOutBytes(addr, buf[:limit]) // escapes: okay.\n") + g.emitKeepAlive(g.r) + g.emit("return length, err\n") + }) + g.emit("}\n\n") + + g.emit("// CopyOut implements marshal.Marshallable.CopyOut.\n") + g.emit("//go:nosplit\n") + g.emit("func (%s *%s) CopyOut(task marshal.Task, addr usermem.Addr) (int, error) {\n", g.r, g.typeName()) + g.inIndent(func() { + g.emit("return %s.CopyOutN(task, addr, %s.SizeBytes())\n", g.r, g.r) + }) + g.emit("}\n\n") + + g.emit("// CopyIn implements marshal.Marshallable.CopyIn.\n") + g.emit("//go:nosplit\n") + g.emit("func (%s *%s) CopyIn(task marshal.Task, addr usermem.Addr) (int, error) {\n", g.r, g.typeName()) + g.inIndent(func() { + g.emitCastToByteSlice(g.r, "buf", fmt.Sprintf("%s.SizeBytes()", g.r)) + + g.emit("length, err := task.CopyInBytes(addr, buf) // escapes: okay.\n") + g.emitKeepAlive(g.r) + g.emit("return length, err\n") + }) + g.emit("}\n\n") + + g.emit("// WriteTo implements io.WriterTo.WriteTo.\n") + g.emit("func (%s *%s) WriteTo(w io.Writer) (int64, error) {\n", g.r, g.typeName()) + g.inIndent(func() { + g.emitCastToByteSlice(g.r, "buf", fmt.Sprintf("%s.SizeBytes()", g.r)) + + g.emit("length, err := w.Write(buf)\n") + g.emitKeepAlive(g.r) + g.emit("return int64(length), err\n") + + }) + g.emit("}\n\n") +} diff --git a/tools/go_marshal/gomarshal/generator_interfaces_primitive_newtype.go b/tools/go_marshal/gomarshal/generator_interfaces_primitive_newtype.go new file mode 100644 index 000000000..39f654ea8 --- /dev/null +++ b/tools/go_marshal/gomarshal/generator_interfaces_primitive_newtype.go @@ -0,0 +1,289 @@ +// Copyright 2020 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +// This file contains the bits of the code generator specific to marshalling +// newtypes on primitives. + +package gomarshal + +import ( + "fmt" + "go/ast" +) + +// marshalPrimitiveScalar writes a single primitive variable to a byte +// slice. +func (g *interfaceGenerator) marshalPrimitiveScalar(accessor, typ, bufVar string) { + switch typ { + case "int8", "uint8", "byte": + g.emit("%s[0] = byte(*%s)\n", bufVar, accessor) + case "int16", "uint16": + g.recordUsedImport("usermem") + g.emit("usermem.ByteOrder.PutUint16(%s[:2], uint16(*%s))\n", bufVar, accessor) + case "int32", "uint32": + g.recordUsedImport("usermem") + g.emit("usermem.ByteOrder.PutUint32(%s[:4], uint32(*%s))\n", bufVar, accessor) + case "int64", "uint64": + g.recordUsedImport("usermem") + g.emit("usermem.ByteOrder.PutUint64(%s[:8], uint64(*%s))\n", bufVar, accessor) + default: + g.emit("// Explicilty cast to the underlying type before dispatching to\n") + g.emit("// MarshalBytes, so we don't recursively call %s.MarshalBytes\n", accessor) + g.emit("inner := (*%s)(%s)\n", typ, accessor) + g.emit("inner.MarshalBytes(%s[:%s.SizeBytes()])\n", bufVar, accessor) + } +} + +// unmarshalPrimitiveScalar read a single primitive variable from a byte slice. +func (g *interfaceGenerator) unmarshalPrimitiveScalar(accessor, typ, bufVar, typeCast string) { + switch typ { + case "byte": + g.emit("*%s = %s(%s[0])\n", accessor, typeCast, bufVar) + case "int8", "uint8": + g.emit("*%s = %s(%s(%s[0]))\n", accessor, typeCast, typ, bufVar) + case "int16", "uint16": + g.recordUsedImport("usermem") + g.emit("*%s = %s(%s(usermem.ByteOrder.Uint16(%s[:2])))\n", accessor, typeCast, typ, bufVar) + case "int32", "uint32": + g.recordUsedImport("usermem") + g.emit("*%s = %s(%s(usermem.ByteOrder.Uint32(%s[:4])))\n", accessor, typeCast, typ, bufVar) + case "int64", "uint64": + g.recordUsedImport("usermem") + g.emit("*%s = %s(%s(usermem.ByteOrder.Uint64(%s[:8])))\n", accessor, typeCast, typ, bufVar) + default: + g.emit("// Explicilty cast to the underlying type before dispatching to\n") + g.emit("// UnmarshalBytes, so we don't recursively call %s.UnmarshalBytes\n", accessor) + g.emit("inner := (*%s)(%s)\n", typ, accessor) + g.emit("inner.UnmarshalBytes(%s[:%s.SizeBytes()])\n", bufVar, accessor) + } +} + +func (g *interfaceGenerator) validatePrimitiveNewtype(t *ast.Ident) { + switch t.Name { + case "int8", "uint8", "byte", "int16", "uint16", "int32", "uint32", "int64", "uint64": + // These are the only primitive types we're allow. Below, we provide + // suggestions for some disallowed types and reject them, then attempt + // to marshal any remaining types by invoking the marshal.Marshallable + // interface on them. If these types don't actually implement + // marshal.Marshallable, compilation of the generated code will fail + // with an appropriate error message. + return + case "int": + g.abortAt(t.Pos(), "Type 'int' has ambiguous width, use int32 or int64") + case "uint": + g.abortAt(t.Pos(), "Type 'uint' has ambiguous width, use uint32 or uint64") + case "string": + g.abortAt(t.Pos(), "Type 'string' is dynamically-sized and cannot be marshalled, use a fixed size byte array '[...]byte' instead") + default: + debugfAt(g.f.Position(t.Pos()), fmt.Sprintf("Found derived type '%s', will attempt dispatch via marshal.Marshallable.\n", t.Name)) + } +} + +// emitMarshallableForPrimitiveNewtype outputs code to implement the +// marshal.Marshallable interface for a newtype on a primitive. Primitive +// newtypes are always packed, so we can omit the various fallbacks required for +// non-packed structs. +func (g *interfaceGenerator) emitMarshallableForPrimitiveNewtype(nt *ast.Ident) { + g.recordUsedImport("io") + g.recordUsedImport("marshal") + g.recordUsedImport("reflect") + g.recordUsedImport("runtime") + g.recordUsedImport("safecopy") + g.recordUsedImport("unsafe") + g.recordUsedImport("usermem") + + g.emit("// SizeBytes implements marshal.Marshallable.SizeBytes.\n") + g.emit("//go:nosplit\n") + g.emit("func (%s *%s) SizeBytes() int {\n", g.r, g.typeName()) + g.inIndent(func() { + if size, dynamic := g.scalarSize(nt); !dynamic { + g.emit("return %d\n", size) + } else { + g.emit("return (*%s)(nil).SizeBytes()\n", nt.Name) + } + }) + g.emit("}\n\n") + + g.emit("// MarshalBytes implements marshal.Marshallable.MarshalBytes.\n") + g.emit("func (%s *%s) MarshalBytes(dst []byte) {\n", g.r, g.typeName()) + g.inIndent(func() { + g.marshalPrimitiveScalar(g.r, nt.Name, "dst") + }) + g.emit("}\n\n") + + g.emit("// UnmarshalBytes implements marshal.Marshallable.UnmarshalBytes.\n") + g.emit("func (%s *%s) UnmarshalBytes(src []byte) {\n", g.r, g.typeName()) + g.inIndent(func() { + g.unmarshalPrimitiveScalar(g.r, nt.Name, "src", g.typeName()) + }) + g.emit("}\n\n") + + g.emit("// Packed implements marshal.Marshallable.Packed.\n") + g.emit("//go:nosplit\n") + g.emit("func (%s *%s) Packed() bool {\n", g.r, g.typeName()) + g.inIndent(func() { + g.emit("// Scalar newtypes are always packed.\n") + g.emit("return true\n") + }) + g.emit("}\n\n") + + g.emit("// MarshalUnsafe implements marshal.Marshallable.MarshalUnsafe.\n") + g.emit("func (%s *%s) MarshalUnsafe(dst []byte) {\n", g.r, g.typeName()) + g.inIndent(func() { + g.emit("safecopy.CopyIn(dst, unsafe.Pointer(%s))\n", g.r) + }) + g.emit("}\n\n") + + g.emit("// UnmarshalUnsafe implements marshal.Marshallable.UnmarshalUnsafe.\n") + g.emit("func (%s *%s) UnmarshalUnsafe(src []byte) {\n", g.r, g.typeName()) + g.inIndent(func() { + g.emit("safecopy.CopyOut(unsafe.Pointer(%s), src)\n", g.r) + }) + g.emit("}\n\n") + + g.emit("// CopyOutN implements marshal.Marshallable.CopyOutN.\n") + g.emit("//go:nosplit\n") + g.emit("func (%s *%s) CopyOutN(task marshal.Task, addr usermem.Addr, limit int) (int, error) {\n", g.r, g.typeName()) + g.inIndent(func() { + g.emitCastToByteSlice(g.r, "buf", fmt.Sprintf("%s.SizeBytes()", g.r)) + + g.emit("length, err := task.CopyOutBytes(addr, buf[:limit]) // escapes: okay.\n") + g.emitKeepAlive(g.r) + g.emit("return length, err\n") + }) + g.emit("}\n\n") + + g.emit("// CopyOut implements marshal.Marshallable.CopyOut.\n") + g.emit("//go:nosplit\n") + g.emit("func (%s *%s) CopyOut(task marshal.Task, addr usermem.Addr) (int, error) {\n", g.r, g.typeName()) + g.inIndent(func() { + g.emit("return %s.CopyOutN(task, addr, %s.SizeBytes())\n", g.r, g.r) + }) + g.emit("}\n\n") + + g.emit("// CopyIn implements marshal.Marshallable.CopyIn.\n") + g.emit("//go:nosplit\n") + g.emit("func (%s *%s) CopyIn(task marshal.Task, addr usermem.Addr) (int, error) {\n", g.r, g.typeName()) + g.inIndent(func() { + g.emitCastToByteSlice(g.r, "buf", fmt.Sprintf("%s.SizeBytes()", g.r)) + + g.emit("length, err := task.CopyInBytes(addr, buf) // escapes: okay.\n") + g.emitKeepAlive(g.r) + g.emit("return length, err\n") + }) + g.emit("}\n\n") + + g.emit("// WriteTo implements io.WriterTo.WriteTo.\n") + g.emit("func (%s *%s) WriteTo(w io.Writer) (int64, error) {\n", g.r, g.typeName()) + g.inIndent(func() { + g.emitCastToByteSlice(g.r, "buf", fmt.Sprintf("%s.SizeBytes()", g.r)) + + g.emit("length, err := w.Write(buf)\n") + g.emitKeepAlive(g.r) + g.emit("return int64(length), err\n") + + }) + g.emit("}\n\n") +} + +func (g *interfaceGenerator) emitMarshallableSliceForPrimitiveNewtype(nt *ast.Ident, slice *sliceAPI) { + g.recordUsedImport("marshal") + g.recordUsedImport("usermem") + g.recordUsedImport("reflect") + g.recordUsedImport("runtime") + g.recordUsedImport("unsafe") + + eltType := g.typeName() + if slice.inner { + eltType = nt.Name + } + + g.emit("// Copy%sIn copies in a slice of %s objects from the task's memory.\n", slice.ident, eltType) + g.emit("//go:nosplit\n") + g.emit("func Copy%sIn(task marshal.Task, addr usermem.Addr, dst []%s) (int, error) {\n", slice.ident, eltType) + g.inIndent(func() { + g.emit("count := len(dst)\n") + g.emit("if count == 0 {\n") + g.inIndent(func() { + g.emit("return 0, nil\n") + }) + g.emit("}\n") + g.emit("size := (*%s)(nil).SizeBytes()\n\n", g.typeName()) + + g.emitCastSliceToByteSlice("&dst", "buf", "size * count") + + g.emit("length, err := task.CopyInBytes(addr, buf) // escapes: okay.\n") + g.emitKeepAlive("dst") + g.emit("return length, err\n") + }) + g.emit("}\n\n") + + g.emit("// Copy%sOut copies a slice of %s objects to the task's memory.\n", slice.ident, eltType) + g.emit("//go:nosplit\n") + g.emit("func Copy%sOut(task marshal.Task, addr usermem.Addr, src []%s) (int, error) {\n", slice.ident, eltType) + g.inIndent(func() { + g.emit("count := len(src)\n") + g.emit("if count == 0 {\n") + g.inIndent(func() { + g.emit("return 0, nil\n") + }) + g.emit("}\n") + g.emit("size := (*%s)(nil).SizeBytes()\n\n", g.typeName()) + + g.emitCastSliceToByteSlice("&src", "buf", "size * count") + + g.emit("length, err := task.CopyOutBytes(addr, buf) // escapes: okay.\n") + g.emitKeepAlive("src") + g.emit("return length, err\n") + }) + g.emit("}\n\n") + + g.emit("// MarshalUnsafe%s is like %s.MarshalUnsafe, but for a []%s.\n", slice.ident, g.typeName(), g.typeName()) + g.emit("func MarshalUnsafe%s(src []%s, dst []byte) (int, error) {\n", slice.ident, g.typeName()) + g.inIndent(func() { + g.emit("count := len(src)\n") + g.emit("if count == 0 {\n") + g.inIndent(func() { + g.emit("return 0, nil\n") + }) + g.emit("}\n") + g.emit("size := (*%s)(nil).SizeBytes()\n\n", g.typeName()) + + g.emitNoEscapeSliceDataPointer("&src", "val") + + g.emit("length, err := safecopy.CopyIn(dst[:(size*count)], val)\n") + g.emitKeepAlive("src") + g.emit("return length, err\n") + }) + g.emit("}\n\n") + + g.emit("// UnmarshalUnsafe%s is like %s.UnmarshalUnsafe, but for a []%s.\n", slice.ident, g.typeName(), g.typeName()) + g.emit("func UnmarshalUnsafe%s(dst []%s, src []byte) (int, error) {\n", slice.ident, g.typeName()) + g.inIndent(func() { + g.emit("count := len(dst)\n") + g.emit("if count == 0 {\n") + g.inIndent(func() { + g.emit("return 0, nil\n") + }) + g.emit("}\n") + g.emit("size := (*%s)(nil).SizeBytes()\n\n", g.typeName()) + + g.emitNoEscapeSliceDataPointer("&dst", "val") + + g.emit("length, err := safecopy.CopyOut(val, src[:(size*count)])\n") + g.emitKeepAlive("dst") + g.emit("return length, err\n") + }) + g.emit("}\n\n") +} diff --git a/tools/go_marshal/gomarshal/generator_interfaces_struct.go b/tools/go_marshal/gomarshal/generator_interfaces_struct.go new file mode 100644 index 000000000..4b9cea08a --- /dev/null +++ b/tools/go_marshal/gomarshal/generator_interfaces_struct.go @@ -0,0 +1,622 @@ +// Copyright 2020 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +// This file contains the bits of the code generator specific to marshalling +// structs. + +package gomarshal + +import ( + "fmt" + "go/ast" + "strings" +) + +func (g *interfaceGenerator) fieldAccessor(n *ast.Ident) string { + return fmt.Sprintf("%s.%s", g.r, n.Name) +} + +// areFieldsPackedExpression returns a go expression checking whether g.t's fields are +// packed. Returns "", false if g.t has no fields that may be potentially +// packed, otherwise returns <clause>, true, where <clause> is an expression +// like "t.a.Packed() && t.b.Packed() && t.c.Packed()". +func (g *interfaceGenerator) areFieldsPackedExpression() (string, bool) { + if len(g.as) == 0 { + return "", false + } + + cs := make([]string, 0, len(g.as)) + for accessor, _ := range g.as { + cs = append(cs, fmt.Sprintf("%s.Packed()", accessor)) + } + return strings.Join(cs, " && "), true +} + +// validateStruct ensures the type we're working with can be marshalled. These +// checks are done ahead of time and in one place so we can make assumptions +// later. +func (g *interfaceGenerator) validateStruct(ts *ast.TypeSpec, st *ast.StructType) { + forEachStructField(st, func(f *ast.Field) { + if len(f.Names) == 0 { + g.abortAt(f.Pos(), "Cannot marshal structs with embedded fields, give the field a name; use '_' for anonymous fields such as padding fields") + } + }) + + forEachStructField(st, func(f *ast.Field) { + fieldDispatcher{ + primitive: func(_, t *ast.Ident) { + g.validatePrimitiveNewtype(t) + }, + selector: func(_, _, _ *ast.Ident) { + // No validation to perform on selector fields. However this + // callback must still be provided. + }, + array: func(n *ast.Ident, a *ast.ArrayType, _ *ast.Ident) { + g.validateArrayNewtype(n, a) + }, + unhandled: func(_ *ast.Ident) { + g.abortAt(f.Pos(), fmt.Sprintf("Marshalling not supported for %s fields", kindString(f.Type))) + }, + }.dispatch(f) + }) +} + +func (g *interfaceGenerator) isStructPacked(st *ast.StructType) bool { + packed := true + forEachStructField(st, func(f *ast.Field) { + if f.Tag != nil { + if f.Tag.Value == "`marshal:\"unaligned\"`" { + if packed { + debugfAt(g.f.Position(g.t.Pos()), + fmt.Sprintf("Marking type '%s' as not packed due to tag `marshal:\"unaligned\"`.\n", g.t.Name)) + packed = false + } + } + } + }) + return packed +} + +func (g *interfaceGenerator) emitMarshallableForStruct(st *ast.StructType) { + thisPacked := g.isStructPacked(st) + + g.emit("// SizeBytes implements marshal.Marshallable.SizeBytes.\n") + g.emit("func (%s *%s) SizeBytes() int {\n", g.r, g.typeName()) + g.inIndent(func() { + primitiveSize := 0 + var dynamicSizeTerms []string + + forEachStructField(st, fieldDispatcher{ + primitive: func(n, t *ast.Ident) { + if size, dynamic := g.scalarSize(t); !dynamic { + primitiveSize += size + } else { + g.recordUsedMarshallable(t.Name) + dynamicSizeTerms = append(dynamicSizeTerms, fmt.Sprintf("(*%s)(nil).SizeBytes()", t.Name)) + } + }, + selector: func(n, tX, tSel *ast.Ident) { + tName := fmt.Sprintf("%s.%s", tX.Name, tSel.Name) + g.recordUsedImport(tX.Name) + g.recordUsedMarshallable(tName) + dynamicSizeTerms = append(dynamicSizeTerms, fmt.Sprintf("(*%s)(nil).SizeBytes()", tName)) + }, + array: func(n *ast.Ident, a *ast.ArrayType, t *ast.Ident) { + lenExpr := g.arrayLenExpr(a) + if size, dynamic := g.scalarSize(t); !dynamic { + dynamicSizeTerms = append(dynamicSizeTerms, fmt.Sprintf("%d*%s", size, lenExpr)) + } else { + g.recordUsedMarshallable(t.Name) + dynamicSizeTerms = append(dynamicSizeTerms, fmt.Sprintf("(*%s)(nil).SizeBytes()*%s", t.Name, lenExpr)) + } + }, + }.dispatch) + g.emit("return %d", primitiveSize) + if len(dynamicSizeTerms) > 0 { + g.incIndent() + } + { + for _, d := range dynamicSizeTerms { + g.emitNoIndent(" +\n") + g.emit(d) + } + } + if len(dynamicSizeTerms) > 0 { + g.decIndent() + } + }) + g.emit("\n}\n\n") + + g.emit("// MarshalBytes implements marshal.Marshallable.MarshalBytes.\n") + g.emit("func (%s *%s) MarshalBytes(dst []byte) {\n", g.r, g.typeName()) + g.inIndent(func() { + forEachStructField(st, fieldDispatcher{ + primitive: func(n, t *ast.Ident) { + if n.Name == "_" { + g.emit("// Padding: dst[:sizeof(%s)] ~= %s(0)\n", t.Name, t.Name) + if len, dynamic := g.scalarSize(t); !dynamic { + g.shift("dst", len) + } else { + // We can't use shiftDynamic here because we don't have + // an instance of the dynamic type we can reference here + // (since the version in this struct is anonymous). Use + // a typed nil pointer to call SizeBytes() instead. + g.emit("dst = dst[(*%s)(nil).SizeBytes():]\n", t.Name) + } + return + } + g.marshalScalar(g.fieldAccessor(n), t.Name, "dst") + }, + selector: func(n, tX, tSel *ast.Ident) { + if n.Name == "_" { + g.emit("// Padding: dst[:sizeof(%s)] ~= %s(0)\n", tX.Name, tSel.Name) + g.emit("dst = dst[(*%s.%s)(nil).SizeBytes():]\n", tX.Name, tSel.Name) + return + } + g.marshalScalar(g.fieldAccessor(n), fmt.Sprintf("%s.%s", tX.Name, tSel.Name), "dst") + }, + array: func(n *ast.Ident, a *ast.ArrayType, t *ast.Ident) { + lenExpr := g.arrayLenExpr(a) + if n.Name == "_" { + g.emit("// Padding: dst[:sizeof(%s)*%s] ~= [%s]%s{0}\n", t.Name, lenExpr, lenExpr, t.Name) + if size, dynamic := g.scalarSize(t); !dynamic { + g.emit("dst = dst[%d*(%s):]\n", size, lenExpr) + } else { + // We can't use shiftDynamic here because we don't have + // an instance of the dynamic type we can reference here + // (since the version in this struct is anonymous). Use + // a typed nil pointer to call SizeBytes() instead. + g.emit("dst = dst[(*%s)(nil).SizeBytes()*(%s):]\n", t.Name, lenExpr) + } + return + } + + g.emit("for idx := 0; idx < %s; idx++ {\n", lenExpr) + g.inIndent(func() { + g.marshalScalar(fmt.Sprintf("%s[idx]", g.fieldAccessor(n)), t.Name, "dst") + }) + g.emit("}\n") + }, + }.dispatch) + }) + g.emit("}\n\n") + + g.emit("// UnmarshalBytes implements marshal.Marshallable.UnmarshalBytes.\n") + g.emit("func (%s *%s) UnmarshalBytes(src []byte) {\n", g.r, g.typeName()) + g.inIndent(func() { + forEachStructField(st, fieldDispatcher{ + primitive: func(n, t *ast.Ident) { + if n.Name == "_" { + g.emit("// Padding: var _ %s ~= src[:sizeof(%s)]\n", t.Name, t.Name) + if len, dynamic := g.scalarSize(t); !dynamic { + g.shift("src", len) + } else { + // We don't have an instance of the dynamic type we can + // reference here (since the version in this struct is + // anonymous). Use a typed nil pointer to call + // SizeBytes() instead. + g.shiftDynamic("src", fmt.Sprintf("(*%s)(nil)", t.Name)) + g.recordPotentiallyNonPackedField(fmt.Sprintf("(*%s)(nil)", t.Name)) + } + return + } + g.unmarshalScalar(g.fieldAccessor(n), t.Name, "src") + }, + selector: func(n, tX, tSel *ast.Ident) { + if n.Name == "_" { + g.emit("// Padding: %s ~= src[:sizeof(%s.%s)]\n", g.fieldAccessor(n), tX.Name, tSel.Name) + g.emit("src = src[(*%s.%s)(nil).SizeBytes():]\n", tX.Name, tSel.Name) + g.recordPotentiallyNonPackedField(fmt.Sprintf("(*%s.%s)(nil)", tX.Name, tSel.Name)) + return + } + g.unmarshalScalar(g.fieldAccessor(n), fmt.Sprintf("%s.%s", tX.Name, tSel.Name), "src") + }, + array: func(n *ast.Ident, a *ast.ArrayType, t *ast.Ident) { + lenExpr := g.arrayLenExpr(a) + if n.Name == "_" { + g.emit("// Padding: ~ copy([%s]%s(%s), src[:sizeof(%s)*%s])\n", lenExpr, t.Name, g.fieldAccessor(n), t.Name, lenExpr) + if size, dynamic := g.scalarSize(t); !dynamic { + g.emit("src = src[%d*(%s):]\n", size, lenExpr) + } else { + // We can't use shiftDynamic here because we don't have + // an instance of the dynamic type we can referece here + // (since the version in this struct is anonymous). Use + // a typed nil pointer to call SizeBytes() instead. + g.emit("src = src[(*%s)(nil).SizeBytes()*(%s):]\n", t.Name, lenExpr) + } + return + } + + g.emit("for idx := 0; idx < %s; idx++ {\n", lenExpr) + g.inIndent(func() { + g.unmarshalScalar(fmt.Sprintf("%s[idx]", g.fieldAccessor(n)), t.Name, "src") + }) + g.emit("}\n") + }, + }.dispatch) + }) + g.emit("}\n\n") + + g.emit("// Packed implements marshal.Marshallable.Packed.\n") + g.emit("//go:nosplit\n") + g.emit("func (%s *%s) Packed() bool {\n", g.r, g.typeName()) + g.inIndent(func() { + expr, fieldsMaybePacked := g.areFieldsPackedExpression() + switch { + case !thisPacked: + g.emit("return false\n") + case fieldsMaybePacked: + g.emit("return %s\n", expr) + default: + g.emit("return true\n") + + } + }) + g.emit("}\n\n") + + g.emit("// MarshalUnsafe implements marshal.Marshallable.MarshalUnsafe.\n") + g.emit("func (%s *%s) MarshalUnsafe(dst []byte) {\n", g.r, g.typeName()) + g.inIndent(func() { + fallback := func() { + g.emit("// Type %s doesn't have a packed layout in memory, fallback to MarshalBytes.\n", g.typeName()) + g.emit("%s.MarshalBytes(dst)\n", g.r) + } + if thisPacked { + g.recordUsedImport("safecopy") + g.recordUsedImport("unsafe") + if cond, ok := g.areFieldsPackedExpression(); ok { + g.emit("if %s {\n", cond) + g.inIndent(func() { + g.emit("safecopy.CopyIn(dst, unsafe.Pointer(%s))\n", g.r) + }) + g.emit("} else {\n") + g.inIndent(fallback) + g.emit("}\n") + } else { + g.emit("safecopy.CopyIn(dst, unsafe.Pointer(%s))\n", g.r) + } + } else { + fallback() + } + }) + g.emit("}\n\n") + + g.emit("// UnmarshalUnsafe implements marshal.Marshallable.UnmarshalUnsafe.\n") + g.emit("func (%s *%s) UnmarshalUnsafe(src []byte) {\n", g.r, g.typeName()) + g.inIndent(func() { + fallback := func() { + g.emit("// Type %s doesn't have a packed layout in memory, fallback to UnmarshalBytes.\n", g.typeName()) + g.emit("%s.UnmarshalBytes(src)\n", g.r) + } + if thisPacked { + g.recordUsedImport("safecopy") + g.recordUsedImport("unsafe") + if cond, ok := g.areFieldsPackedExpression(); ok { + g.emit("if %s {\n", cond) + g.inIndent(func() { + g.emit("safecopy.CopyOut(unsafe.Pointer(%s), src)\n", g.r) + }) + g.emit("} else {\n") + g.inIndent(fallback) + g.emit("}\n") + } else { + g.emit("safecopy.CopyOut(unsafe.Pointer(%s), src)\n", g.r) + } + } else { + fallback() + } + }) + g.emit("}\n\n") + + g.emit("// CopyOutN implements marshal.Marshallable.CopyOutN.\n") + g.emit("//go:nosplit\n") + g.recordUsedImport("marshal") + g.recordUsedImport("usermem") + g.emit("func (%s *%s) CopyOutN(task marshal.Task, addr usermem.Addr, limit int) (int, error) {\n", g.r, g.typeName()) + g.inIndent(func() { + fallback := func() { + g.emit("// Type %s doesn't have a packed layout in memory, fall back to MarshalBytes.\n", g.typeName()) + g.emit("buf := task.CopyScratchBuffer(%s.SizeBytes()) // escapes: okay.\n", g.r) + g.emit("%s.MarshalBytes(buf) // escapes: fallback.\n", g.r) + g.emit("return task.CopyOutBytes(addr, buf[:limit]) // escapes: okay.\n") + } + if thisPacked { + g.recordUsedImport("reflect") + g.recordUsedImport("runtime") + g.recordUsedImport("unsafe") + if cond, ok := g.areFieldsPackedExpression(); ok { + g.emit("if !%s {\n", cond) + g.inIndent(fallback) + g.emit("}\n\n") + } + // Fast serialization. + g.emitCastToByteSlice(g.r, "buf", fmt.Sprintf("%s.SizeBytes()", g.r)) + + g.emit("length, err := task.CopyOutBytes(addr, buf[:limit]) // escapes: okay.\n") + g.emitKeepAlive(g.r) + g.emit("return length, err\n") + } else { + fallback() + } + }) + g.emit("}\n\n") + + g.emit("// CopyOut implements marshal.Marshallable.CopyOut.\n") + g.emit("//go:nosplit\n") + g.recordUsedImport("marshal") + g.recordUsedImport("usermem") + g.emit("func (%s *%s) CopyOut(task marshal.Task, addr usermem.Addr) (int, error) {\n", g.r, g.typeName()) + g.inIndent(func() { + g.emit("return %s.CopyOutN(task, addr, %s.SizeBytes())\n", g.r, g.r) + }) + g.emit("}\n\n") + + g.emit("// CopyIn implements marshal.Marshallable.CopyIn.\n") + g.emit("//go:nosplit\n") + g.recordUsedImport("marshal") + g.recordUsedImport("usermem") + g.emit("func (%s *%s) CopyIn(task marshal.Task, addr usermem.Addr) (int, error) {\n", g.r, g.typeName()) + g.inIndent(func() { + fallback := func() { + g.emit("// Type %s doesn't have a packed layout in memory, fall back to UnmarshalBytes.\n", g.typeName()) + g.emit("buf := task.CopyScratchBuffer(%s.SizeBytes()) // escapes: okay.\n", g.r) + g.emit("length, err := task.CopyInBytes(addr, buf) // escapes: okay.\n") + g.emit("// Unmarshal unconditionally. If we had a short copy-in, this results in a\n") + g.emit("// partially unmarshalled struct.\n") + g.emit("%s.UnmarshalBytes(buf) // escapes: fallback.\n", g.r) + g.emit("return length, err\n") + } + if thisPacked { + g.recordUsedImport("reflect") + g.recordUsedImport("runtime") + g.recordUsedImport("unsafe") + if cond, ok := g.areFieldsPackedExpression(); ok { + g.emit("if !%s {\n", cond) + g.inIndent(fallback) + g.emit("}\n\n") + } + // Fast deserialization. + g.emitCastToByteSlice(g.r, "buf", fmt.Sprintf("%s.SizeBytes()", g.r)) + + g.emit("length, err := task.CopyInBytes(addr, buf) // escapes: okay.\n") + g.emitKeepAlive(g.r) + g.emit("return length, err\n") + } else { + fallback() + } + }) + g.emit("}\n\n") + + g.emit("// WriteTo implements io.WriterTo.WriteTo.\n") + g.recordUsedImport("io") + g.emit("func (%s *%s) WriteTo(w io.Writer) (int64, error) {\n", g.r, g.typeName()) + g.inIndent(func() { + fallback := func() { + g.emit("// Type %s doesn't have a packed layout in memory, fall back to MarshalBytes.\n", g.typeName()) + g.emit("buf := make([]byte, %s.SizeBytes())\n", g.r) + g.emit("%s.MarshalBytes(buf)\n", g.r) + g.emit("length, err := w.Write(buf)\n") + g.emit("return int64(length), err\n") + } + if thisPacked { + g.recordUsedImport("reflect") + g.recordUsedImport("runtime") + g.recordUsedImport("unsafe") + if cond, ok := g.areFieldsPackedExpression(); ok { + g.emit("if !%s {\n", cond) + g.inIndent(fallback) + g.emit("}\n\n") + } + // Fast serialization. + g.emitCastToByteSlice(g.r, "buf", fmt.Sprintf("%s.SizeBytes()", g.r)) + + g.emit("length, err := w.Write(buf)\n") + g.emitKeepAlive(g.r) + g.emit("return int64(length), err\n") + } else { + fallback() + } + }) + g.emit("}\n\n") +} + +func (g *interfaceGenerator) emitMarshallableSliceForStruct(st *ast.StructType, slice *sliceAPI) { + thisPacked := g.isStructPacked(st) + + if slice.inner { + abortAt(g.f.Position(slice.comment.Slash), fmt.Sprintf("The ':inner' argument to '+marshal slice:%s:inner' is only applicable to newtypes on primitives. Remove it from this struct declaration.", slice.ident)) + } + + g.recordUsedImport("marshal") + g.recordUsedImport("usermem") + + g.emit("// Copy%sIn copies in a slice of %s objects from the task's memory.\n", slice.ident, g.typeName()) + g.emit("func Copy%sIn(task marshal.Task, addr usermem.Addr, dst []%s) (int, error) {\n", slice.ident, g.typeName()) + g.inIndent(func() { + g.emit("count := len(dst)\n") + g.emit("if count == 0 {\n") + g.inIndent(func() { + g.emit("return 0, nil\n") + }) + g.emit("}\n") + g.emit("size := (*%s)(nil).SizeBytes()\n\n", g.typeName()) + + fallback := func() { + g.emit("// Type %s doesn't have a packed layout in memory, fall back to UnmarshalBytes.\n", g.typeName()) + g.emit("buf := task.CopyScratchBuffer(size * count)\n") + g.emit("length, err := task.CopyInBytes(addr, buf)\n\n") + + g.emit("// Unmarshal as much as possible, even on error. First handle full objects.\n") + g.emit("limit := length/size\n") + g.emit("for idx := 0; idx < limit; idx++ {\n") + g.inIndent(func() { + g.emit("dst[idx].UnmarshalBytes(buf[size*idx:size*(idx+1)])\n") + }) + g.emit("}\n\n") + + g.emit("// Handle any final partial object. buf is guaranteed to be long enough for the\n") + g.emit("// final element, but may not contain valid data for the entire range. This may\n") + g.emit("// result in unmarshalling zero values for some parts of the object.\n") + g.emit("if length%size != 0 {\n") + g.inIndent(func() { + g.emit("idx := limit\n") + g.emit("dst[idx].UnmarshalBytes(buf[size*idx:size*(idx+1)])\n") + }) + g.emit("}\n\n") + + g.emit("return length, err\n") + } + if thisPacked { + g.recordUsedImport("reflect") + g.recordUsedImport("runtime") + g.recordUsedImport("unsafe") + if _, ok := g.areFieldsPackedExpression(); ok { + g.emit("if !dst[0].Packed() {\n") + g.inIndent(fallback) + g.emit("}\n\n") + } + // Fast deserialization. + g.emitCastSliceToByteSlice("&dst", "buf", "size * count") + + g.emit("length, err := task.CopyInBytes(addr, buf)\n") + g.emitKeepAlive("dst") + g.emit("return length, err\n") + } else { + fallback() + } + }) + g.emit("}\n\n") + + g.emit("// Copy%sOut copies a slice of %s objects to the task's memory.\n", slice.ident, g.typeName()) + g.emit("func Copy%sOut(task marshal.Task, addr usermem.Addr, src []%s) (int, error) {\n", slice.ident, g.typeName()) + g.inIndent(func() { + g.emit("count := len(src)\n") + g.emit("if count == 0 {\n") + g.inIndent(func() { + g.emit("return 0, nil\n") + }) + g.emit("}\n") + g.emit("size := (*%s)(nil).SizeBytes()\n\n", g.typeName()) + + fallback := func() { + g.emit("// Type %s doesn't have a packed layout in memory, fall back to MarshalBytes.\n", g.typeName()) + g.emit("buf := task.CopyScratchBuffer(size * count)\n") + g.emit("for idx := 0; idx < count; idx++ {\n") + g.inIndent(func() { + g.emit("src[idx].MarshalBytes(buf[size*idx:size*(idx+1)])\n") + }) + g.emit("}\n") + g.emit("return task.CopyOutBytes(addr, buf)\n") + } + if thisPacked { + g.recordUsedImport("reflect") + g.recordUsedImport("runtime") + g.recordUsedImport("unsafe") + if _, ok := g.areFieldsPackedExpression(); ok { + g.emit("if !src[0].Packed() {\n") + g.inIndent(fallback) + g.emit("}\n\n") + } + // Fast serialization. + g.emitCastSliceToByteSlice("&src", "buf", "size * count") + + g.emit("length, err := task.CopyOutBytes(addr, buf)\n") + g.emitKeepAlive("src") + g.emit("return length, err\n") + } else { + fallback() + } + }) + g.emit("}\n\n") + + g.emit("// MarshalUnsafe%s is like %s.MarshalUnsafe, but for a []%s.\n", slice.ident, g.typeName(), g.typeName()) + g.emit("func MarshalUnsafe%s(src []%s, dst []byte) (int, error) {\n", slice.ident, g.typeName()) + g.inIndent(func() { + g.emit("count := len(src)\n") + g.emit("if count == 0 {\n") + g.inIndent(func() { + g.emit("return 0, nil\n") + }) + g.emit("}\n") + g.emit("size := (*%s)(nil).SizeBytes()\n\n", g.typeName()) + + fallback := func() { + g.emit("// Type %s doesn't have a packed layout in memory, fall back to MarshalBytes.\n", g.typeName()) + g.emit("for idx := 0; idx < count; idx++ {\n") + g.inIndent(func() { + g.emit("src[idx].MarshalBytes(dst[size*idx:(size)*(idx+1)])\n") + }) + g.emit("}\n") + g.emit("return size * count, nil\n") + } + if thisPacked { + g.recordUsedImport("reflect") + g.recordUsedImport("runtime") + g.recordUsedImport("unsafe") + if _, ok := g.areFieldsPackedExpression(); ok { + g.emit("if !src[0].Packed() {\n") + g.inIndent(fallback) + g.emit("}\n\n") + } + g.emitNoEscapeSliceDataPointer("&src", "val") + + g.emit("length, err := safecopy.CopyIn(dst[:(size*count)], val)\n") + g.emitKeepAlive("src") + g.emit("return length, err\n") + } else { + fallback() + } + }) + g.emit("}\n\n") + + g.emit("// UnmarshalUnsafe%s is like %s.UnmarshalUnsafe, but for a []%s.\n", slice.ident, g.typeName(), g.typeName()) + g.emit("func UnmarshalUnsafe%s(dst []%s, src []byte) (int, error) {\n", slice.ident, g.typeName()) + g.inIndent(func() { + g.emit("count := len(dst)\n") + g.emit("if count == 0 {\n") + g.inIndent(func() { + g.emit("return 0, nil\n") + }) + g.emit("}\n") + g.emit("size := (*%s)(nil).SizeBytes()\n\n", g.typeName()) + + fallback := func() { + g.emit("// Type %s doesn't have a packed layout in memory, fall back to UnmarshalBytes.\n", g.typeName()) + g.emit("for idx := 0; idx < count; idx++ {\n") + g.inIndent(func() { + g.emit("dst[idx].UnmarshalBytes(src[size*idx:size*(idx+1)])\n") + }) + g.emit("}\n") + g.emit("return size * count, nil\n") + } + if thisPacked { + g.recordUsedImport("reflect") + g.recordUsedImport("runtime") + g.recordUsedImport("unsafe") + if _, ok := g.areFieldsPackedExpression(); ok { + g.emit("if !dst[0].Packed() {\n") + g.inIndent(fallback) + g.emit("}\n\n") + } + g.emitNoEscapeSliceDataPointer("&dst", "val") + + g.emit("length, err := safecopy.CopyOut(val, src[:(size*count)])\n") + g.emitKeepAlive("dst") + g.emit("return length, err\n") + } else { + fallback() + } + }) + g.emit("}\n\n") +} diff --git a/tools/go_marshal/gomarshal/generator_tests.go b/tools/go_marshal/gomarshal/generator_tests.go index df25cb5b2..631295373 100644 --- a/tools/go_marshal/gomarshal/generator_tests.go +++ b/tools/go_marshal/gomarshal/generator_tests.go @@ -22,12 +22,19 @@ import ( ) var standardImports = []string{ + "bytes", "fmt", "reflect", "testing", + "gvisor.dev/gvisor/tools/go_marshal/analysis", } +var sliceAPIImports = []string{ + "encoding/binary", + "gvisor.dev/gvisor/pkg/usermem", +} + type testGenerator struct { sourceBuffer @@ -46,10 +53,7 @@ type testGenerator struct { decl *importStmt } -func newTestGenerator(t *ast.TypeSpec, declaration string) *testGenerator { - if _, ok := t.Type.(*ast.StructType); !ok { - panic(fmt.Sprintf("Attempting to generate code for a not struct type %v", t)) - } +func newTestGenerator(t *ast.TypeSpec) *testGenerator { g := &testGenerator{ t: t, r: receiverName(t), @@ -59,22 +63,17 @@ func newTestGenerator(t *ast.TypeSpec, declaration string) *testGenerator { for _, i := range standardImports { g.imports.add(i).markUsed() } - g.decl = g.imports.add(declaration) - g.decl.markUsed() + // These imports are used if a type requests the slice API. Don't + // mark them as used by default. + for _, i := range sliceAPIImports { + g.imports.add(i) + } return g } func (g *testGenerator) typeName() string { - return fmt.Sprintf("%s.%s", g.decl.name, g.t.Name.Name) -} - -func (g *testGenerator) forEachField(fn func(f *ast.Field)) { - // This is guaranteed to succeed because g.t is always a struct. - st := g.t.Type.(*ast.StructType) - for _, field := range st.Fields.List { - fn(field) - } + return g.t.Name.Name } func (g *testGenerator) testFuncName(base string) string { @@ -89,10 +88,10 @@ func (g *testGenerator) inTestFunction(name string, body func()) { func (g *testGenerator) emitTestNonZeroSize() { g.inTestFunction("TestSizeNonZero", func() { - g.emit("x := &%s{}\n", g.typeName()) + g.emit("var x %v\n", g.typeName()) g.emit("if x.SizeBytes() == 0 {\n") g.inIndent(func() { - g.emit("t.Fatal(\"Marshallable.Size() should not return zero\")\n") + g.emit("t.Fatal(\"Marshallable.SizeBytes() should not return zero\")\n") }) g.emit("}\n") }) @@ -100,7 +99,7 @@ func (g *testGenerator) emitTestNonZeroSize() { func (g *testGenerator) emitTestSuspectAlignment() { g.inTestFunction("TestSuspectAlignment", func() { - g.emit("x := %s{}\n", g.typeName()) + g.emit("var x %v\n", g.typeName()) g.emit("analysis.AlignmentCheck(t, reflect.TypeOf(x))\n") }) } @@ -118,35 +117,115 @@ func (g *testGenerator) emitTestMarshalUnmarshalPreservesData() { g.emit("y.UnmarshalBytes(buf)\n") g.emit("if !reflect.DeepEqual(x, y) {\n") g.inIndent(func() { - g.emit("t.Fatal(fmt.Sprintf(\"Data corrupted across Marshal/Unmarshal cycle:\\nBefore: %%+v\\nAfter: %%+v\\n\", x, y))\n") + g.emit("t.Fatal(fmt.Sprintf(\"Data corrupted across MarshalBytes/UnmarshalBytes cycle:\\nBefore: %+v\\nAfter: %+v\\n\", x, y))\n") }) g.emit("}\n") g.emit("yUnsafe.UnmarshalBytes(bufUnsafe)\n") g.emit("if !reflect.DeepEqual(x, yUnsafe) {\n") g.inIndent(func() { - g.emit("t.Fatal(fmt.Sprintf(\"Data corrupted across MarshalUnsafe/Unmarshal cycle:\\nBefore: %%+v\\nAfter: %%+v\\n\", x, yUnsafe))\n") + g.emit("t.Fatal(fmt.Sprintf(\"Data corrupted across MarshalUnsafe/UnmarshalBytes cycle:\\nBefore: %+v\\nAfter: %+v\\n\", x, yUnsafe))\n") }) g.emit("}\n\n") g.emit("z.UnmarshalUnsafe(buf)\n") g.emit("if !reflect.DeepEqual(x, z) {\n") g.inIndent(func() { - g.emit("t.Fatal(fmt.Sprintf(\"Data corrupted across Marshal/UnmarshalUnsafe cycle:\\nBefore: %%+v\\nAfter: %%+v\\n\", x, z))\n") + g.emit("t.Fatal(fmt.Sprintf(\"Data corrupted across MarshalBytes/UnmarshalUnsafe cycle:\\nBefore: %+v\\nAfter: %+v\\n\", x, z))\n") }) g.emit("}\n") g.emit("zUnsafe.UnmarshalUnsafe(bufUnsafe)\n") g.emit("if !reflect.DeepEqual(x, zUnsafe) {\n") g.inIndent(func() { - g.emit("t.Fatal(fmt.Sprintf(\"Data corrupted across MarshalUnsafe/UnmarshalUnsafe cycle:\\nBefore: %%+v\\nAfter: %%+v\\n\", x, zUnsafe))\n") + g.emit("t.Fatal(fmt.Sprintf(\"Data corrupted across MarshalUnsafe/UnmarshalUnsafe cycle:\\nBefore: %+v\\nAfter: %+v\\n\", x, zUnsafe))\n") + }) + g.emit("}\n") + }) +} + +func (g *testGenerator) emitTestMarshalUnmarshalSlicePreservesData(slice *sliceAPI) { + for _, name := range []string{"binary", "usermem"} { + if !g.imports.markUsed(name) { + panic(fmt.Sprintf("Generated test for '%s' referenced a non-existent import with local name '%s'", g.typeName(), name)) + } + } + + g.inTestFunction("TestSafeMarshalUnmarshalSlicePreservesData", func() { + g.emit("var x, y, yUnsafe [8]%s\n", g.typeName()) + g.emit("analysis.RandomizeValue(&x)\n\n") + g.emit("size := (*%s)(nil).SizeBytes() * len(x)\n", g.typeName()) + g.emit("buf := bytes.NewBuffer(make([]byte, size))\n") + g.emit("buf.Reset()\n") + g.emit("if err := binary.Write(buf, usermem.ByteOrder, x[:]); err != nil {\n") + g.inIndent(func() { + g.emit("t.Fatal(fmt.Sprintf(\"binary.Write failed: %v\", err))\n") + }) + g.emit("}\n") + g.emit("bufUnsafe := make([]byte, size)\n") + g.emit("MarshalUnsafe%s(x[:], bufUnsafe)\n\n", slice.ident) + + g.emit("UnmarshalUnsafe%s(y[:], buf.Bytes())\n", slice.ident) + g.emit("if !reflect.DeepEqual(x, y) {\n") + g.inIndent(func() { + g.emit("t.Fatal(fmt.Sprintf(\"Data corrupted across binary.Write/UnmarshalUnsafeSlice cycle:\\nBefore: %+v\\nAfter: %+v\\n\", x, y))\n") + }) + g.emit("}\n") + g.emit("UnmarshalUnsafe%s(yUnsafe[:], bufUnsafe)\n", slice.ident) + g.emit("if !reflect.DeepEqual(x, yUnsafe) {\n") + g.inIndent(func() { + g.emit("t.Fatal(fmt.Sprintf(\"Data corrupted across MarshalUnsafeSlice/UnmarshalUnsafeSlice cycle:\\nBefore: %+v\\nAfter: %+v\\n\", x, yUnsafe))\n") + }) + g.emit("}\n\n") + }) +} + +func (g *testGenerator) emitTestWriteToUnmarshalPreservesData() { + g.inTestFunction("TestWriteToUnmarshalPreservesData", func() { + g.emit("var x, y, yUnsafe %s\n", g.typeName()) + g.emit("analysis.RandomizeValue(&x)\n\n") + + g.emit("var buf bytes.Buffer\n\n") + + g.emit("x.WriteTo(&buf)\n") + g.emit("y.UnmarshalBytes(buf.Bytes())\n\n") + g.emit("yUnsafe.UnmarshalUnsafe(buf.Bytes())\n\n") + + g.emit("if !reflect.DeepEqual(x, y) {\n") + g.inIndent(func() { + g.emit("t.Fatal(fmt.Sprintf(\"Data corrupted across WriteTo/UnmarshalBytes cycle:\\nBefore: %+v\\nAfter: %+v\\n\", x, y))\n") + }) + g.emit("}\n") + g.emit("if !reflect.DeepEqual(x, yUnsafe) {\n") + g.inIndent(func() { + g.emit("t.Fatal(fmt.Sprintf(\"Data corrupted across WriteTo/UnmarshalUnsafe cycle:\\nBefore: %+v\\nAfter: %+v\\n\", x, yUnsafe))\n") + }) + g.emit("}\n") + }) +} + +func (g *testGenerator) emitTestSizeBytesOnTypedNilPtr() { + g.inTestFunction("TestSizeBytesOnTypedNilPtr", func() { + g.emit("var x %s\n", g.typeName()) + g.emit("sizeFromConcrete := x.SizeBytes()\n") + g.emit("sizeFromTypedNilPtr := (*%s)(nil).SizeBytes()\n\n", g.typeName()) + + g.emit("if sizeFromTypedNilPtr != sizeFromConcrete {\n") + g.inIndent(func() { + g.emit("t.Fatalf(\"SizeBytes() on typed nil pointer (%v) doesn't match size returned by a concrete object (%v).\\n\", sizeFromTypedNilPtr, sizeFromConcrete)\n") }) g.emit("}\n") }) } -func (g *testGenerator) emitTests() { +func (g *testGenerator) emitTests(slice *sliceAPI) { g.emitTestNonZeroSize() g.emitTestSuspectAlignment() g.emitTestMarshalUnmarshalPreservesData() + g.emitTestWriteToUnmarshalPreservesData() + g.emitTestSizeBytesOnTypedNilPtr() + + if slice != nil { + g.emitTestMarshalUnmarshalSlicePreservesData(slice) + } } func (g *testGenerator) write(out io.Writer) error { diff --git a/tools/go_marshal/gomarshal/util.go b/tools/go_marshal/gomarshal/util.go index 967537abf..d94314302 100644 --- a/tools/go_marshal/gomarshal/util.go +++ b/tools/go_marshal/gomarshal/util.go @@ -25,7 +25,6 @@ import ( "path" "reflect" "sort" - "strconv" "strings" ) @@ -64,12 +63,18 @@ func kindString(e ast.Expr) string { } } +func forEachStructField(st *ast.StructType, fn func(f *ast.Field)) { + for _, field := range st.Fields.List { + fn(field) + } +} + // fieldDispatcher is a collection of callbacks for handling different types of // fields in a struct declaration. type fieldDispatcher struct { primitive func(n, t *ast.Ident) selector func(n, tX, tSel *ast.Ident) - array func(n, t *ast.Ident, size int) + array func(n *ast.Ident, a *ast.ArrayType, t *ast.Ident) unhandled func(n *ast.Ident) } @@ -96,22 +101,12 @@ func (fd fieldDispatcher) dispatch(f *ast.Field) { case *ast.SelectorExpr: fd.selector(name, v.X.(*ast.Ident), v.Sel) case *ast.ArrayType: - len := 0 - if v.Len != nil { - // Non-literal array length is handled by generatorInterfaces.validate(). - if lenLit, ok := v.Len.(*ast.BasicLit); ok { - var err error - len, err = strconv.Atoi(lenLit.Value) - if err != nil { - panic(err) - } - } - } switch t := v.Elt.(type) { case *ast.Ident: - fd.array(name, t, len) + fd.array(name, v, t) default: - fd.array(name, nil, len) + // Should be handled with a better error message during validate. + panic(fmt.Sprintf("Array element type is of unsupported kind. Expected *ast.Ident, got %v", t)) } default: fd.unhandled(name) @@ -219,6 +214,11 @@ type sourceBuffer struct { b bytes.Buffer } +func (b *sourceBuffer) reset() { + b.indent = 0 + b.b.Reset() +} + func (b *sourceBuffer) incIndent() { b.indent++ } @@ -265,6 +265,11 @@ type importStmt struct { aliased bool // Indicates whether this import was referenced by generated code. used bool + // AST node and file set representing the import statement, if any. These + // are only non-nil if the import statement originates from an input source + // file. + spec *ast.ImportSpec + fset *token.FileSet } func newImport(p string) *importStmt { @@ -290,14 +295,27 @@ func newImportFromSpec(spec *ast.ImportSpec, f *token.FileSet) *importStmt { name: name, path: p, aliased: spec.Name != nil, + spec: spec, + fset: f, } } +// String implements fmt.Stringer.String. This generates a string for the import +// statement appropriate for writing directly to generated code. func (i *importStmt) String() string { if i.aliased { - return fmt.Sprintf("%s \"%s\"", i.name, i.path) + return fmt.Sprintf("%s %q", i.name, i.path) } - return fmt.Sprintf("\"%s\"", i.path) + return fmt.Sprintf("%q", i.path) +} + +// debugString returns a debug string representing an import statement. This +// representation is not valid golang code and is used for debugging output. +func (i *importStmt) debugString() string { + if i.spec != nil && i.fset != nil { + return fmt.Sprintf("%s: %s", i.fset.Position(i.spec.Path.Pos()), i) + } + return fmt.Sprintf("(go-marshal import): %s", i) } func (i *importStmt) markUsed() { @@ -305,58 +323,111 @@ func (i *importStmt) markUsed() { } func (i *importStmt) equivalent(other *importStmt) bool { - return i == other + return i.name == other.name && i.path == other.path && i.aliased == other.aliased } // importTable represents a collection of importStmts. +// +// An importTable may contain multiple import statements referencing the same +// local name. All import statements aliasing to the same local name are +// technically ambiguous, as if such an import name is used in the generated +// code, it's not clear which import statement it refers to. We ignore any +// potential collisions until actually writing the import table to the generated +// source file. See importTable.write. +// +// Given the following import statements across all the files comprising a +// package marshalled: +// +// "sync" +// "pkg/sync" +// "pkg/sentry/kernel" +// ktime "pkg/sentry/kernel/time" +// +// An importTable representing them would look like this: +// +// importTable { +// is: map[string][]*importStmt { +// "sync": []*importStmt{ +// importStmt{name:"sync", path:"sync", aliased:false} +// importStmt{name:"sync", path:"pkg/sync", aliased:false} +// }, +// "kernel": []*importStmt{importStmt{ +// name: "kernel", +// path: "pkg/sentry/kernel", +// aliased: false +// }}, +// "ktime": []*importStmt{importStmt{ +// name: "ktime", +// path: "pkg/sentry/kernel/time", +// aliased: true, +// }}, +// } +// } +// +// Note that the local name "sync" is assigned to two different import +// statements. This is possible if the import statements are from different +// source files in the same package. +// +// Since go-marshal generates a single output file per package regardless of the +// number of input files, if "sync" is referenced by any generated code, it's +// unclear which import statement "sync" refers to. While it's theoretically +// possible to resolve this by assigning a unique local alias to each instance +// of the sync package, go-marshal currently aborts when it encounters such an +// ambiguity. +// +// TODO(b/151478251): importTable considers the final component of an import +// path to be the package name, but this is only a convention. The actual +// package name is determined by the package statement in the source files for +// the package. type importTable struct { // Map of imports and whether they should be copied to the output. - is map[string]*importStmt + is map[string][]*importStmt } func newImportTable() *importTable { return &importTable{ - is: make(map[string]*importStmt), + is: make(map[string][]*importStmt), } } -// Merges import statements from other into i. Collisions in import statements -// result in a panic. +// Merges import statements from other into i. func (i *importTable) merge(other *importTable) { - for name, im := range other.is { - if dup, ok := i.is[name]; ok && dup.equivalent(im) { - panic(fmt.Sprintf("Found colliding import statements: ours: %+v, other's: %+v", dup, im)) - } - - i.is[name] = im + for name, ims := range other.is { + i.is[name] = append(i.is[name], ims...) } } +func (i *importTable) addStmt(s *importStmt) *importStmt { + i.is[s.name] = append(i.is[s.name], s) + return s +} + func (i *importTable) add(s string) *importStmt { n := newImport(s) - i.is[n.name] = n - return n + return i.addStmt(n) } func (i *importTable) addFromSpec(spec *ast.ImportSpec, f *token.FileSet) *importStmt { - n := newImportFromSpec(spec, f) - i.is[n.name] = n - return n + return i.addStmt(newImportFromSpec(spec, f)) } // Marks the import named n as used. If no such import is in the table, returns // false. func (i *importTable) markUsed(n string) bool { - if n, ok := i.is[n]; ok { - n.markUsed() + if ns, ok := i.is[n]; ok { + for _, n := range ns { + n.markUsed() + } return true } return false } func (i *importTable) clear() { - for _, i := range i.is { - i.used = false + for _, is := range i.is { + for _, i := range is { + i.used = false + } } } @@ -367,9 +438,42 @@ func (i *importTable) write(out io.Writer) error { } imports := make([]string, 0, len(i.is)) - for _, i := range i.is { - if i.used { - imports = append(imports, i.String()) + for name, is := range i.is { + var lastUsed *importStmt + var ambiguous bool + + for _, i := range is { + if i.used { + if lastUsed != nil { + if !i.equivalent(lastUsed) { + ambiguous = true + } + } + lastUsed = i + } + } + + if ambiguous { + // We have two or more import statements across the different source + // files that share a local name, and at least one of these imports + // are used by the generated code. This ambiguity can't be resolved + // by go-marshal and requires the user intervention. Dump a list of + // the colliding import statements and let the user modify the input + // files as appropriate. + var b strings.Builder + fmt.Fprintf(&b, "The imported name %q is used by one of the types marked for marshalling, and which import statement the code refers to is ambiguous. Perhaps give the imports unique local names?\n\n", name) + fmt.Fprintf(&b, "The following %d import statements are ambiguous for the local name %q:\n", len(is), name) + // Note: len(is) is guaranteed to be 1 or greater or ambiguous can't + // be true. Therefore the slicing below is safe. + for _, i := range is[:len(is)-1] { + fmt.Fprintf(&b, " %v\n", i.debugString()) + } + fmt.Fprintf(&b, " %v", is[len(is)-1].debugString()) + panic(b.String()) + } + + if lastUsed != nil { + imports = append(imports, lastUsed.String()) } } sort.Strings(imports) diff --git a/tools/go_marshal/main.go b/tools/go_marshal/main.go index 3d12eb93c..f74be5c29 100644 --- a/tools/go_marshal/main.go +++ b/tools/go_marshal/main.go @@ -1,4 +1,4 @@ -// Copyright 2019 Google LLC +// Copyright 2019 The gVisor Authors. // // Licensed under the Apache License, Version 2.0 (the "License"); // you may not use this file except in compliance with the License. @@ -31,11 +31,10 @@ import ( ) var ( - pkg = flag.String("pkg", "", "output package") - output = flag.String("output", "", "output file") - outputTest = flag.String("output_test", "", "output file for tests") - imports = flag.String("imports", "", "comma-separated list of extra packages to import in generated code") - declarationPkg = flag.String("declarationPkg", "", "import path of target declaring the types we're generating on") + pkg = flag.String("pkg", "", "output package") + output = flag.String("output", "", "output file") + outputTest = flag.String("output_test", "", "output file for tests") + imports = flag.String("imports", "", "comma-separated list of extra packages to import in generated code") ) func main() { @@ -62,7 +61,7 @@ func main() { // as an import. extraImports = strings.Split(*imports, ",") } - g, err := gomarshal.NewGenerator(flag.Args(), *output, *outputTest, *pkg, *declarationPkg, extraImports) + g, err := gomarshal.NewGenerator(flag.Args(), *output, *outputTest, *pkg, extraImports) if err != nil { panic(err) } diff --git a/tools/go_marshal/marshal/BUILD b/tools/go_marshal/marshal/BUILD index 47dda97a1..4aec98218 100644 --- a/tools/go_marshal/marshal/BUILD +++ b/tools/go_marshal/marshal/BUILD @@ -1,14 +1,17 @@ -load("@io_bazel_rules_go//go:def.bzl", "go_library") +load("//tools:defs.bzl", "go_library") -package(licenses = ["notice"]) +licenses(["notice"]) go_library( name = "marshal", srcs = [ "marshal.go", + "marshal_impl_util.go", ], - importpath = "gvisor.dev/gvisor/tools/go_marshal/marshal", visibility = [ "//:sandbox", ], + deps = [ + "//pkg/usermem", + ], ) diff --git a/tools/go_marshal/marshal/marshal.go b/tools/go_marshal/marshal/marshal.go index a313a27ed..85b196f08 100644 --- a/tools/go_marshal/marshal/marshal.go +++ b/tools/go_marshal/marshal/marshal.go @@ -20,18 +20,50 @@ // tools/go_marshal. See the go_marshal README for details. package marshal -// Marshallable represents a type that can be marshalled to and from memory. +import ( + "io" + + "gvisor.dev/gvisor/pkg/usermem" +) + +// Task provides a subset of kernel.Task, used in marshalling. We don't import +// the kernel package directly to avoid circular dependency. +type Task interface { + // CopyScratchBuffer provides a task goroutine-local scratch buffer. See + // kernel.CopyScratchBuffer. + CopyScratchBuffer(size int) []byte + + // CopyOutBytes writes the contents of b to the task's memory. See + // kernel.CopyOutBytes. + CopyOutBytes(addr usermem.Addr, b []byte) (int, error) + + // CopyInBytes reads the contents of the task's memory to b. See + // kernel.CopyInBytes. + CopyInBytes(addr usermem.Addr, b []byte) (int, error) +} + +// Marshallable represents operations on a type that can be marshalled to and +// from memory. +// +// go-marshal automatically generates implementations for this interface for +// types marked as '+marshal'. type Marshallable interface { + io.WriterTo + // SizeBytes is the size of the memory representation of a type in // marshalled form. + // + // SizeBytes must handle a nil receiver. Practically, this means SizeBytes + // cannot deference any fields on the object implementing it (but will + // likely make use of the type of these fields). SizeBytes() int - // MarshalBytes serializes a copy of a type to dst. dst must be at least - // SizeBytes() long. + // MarshalBytes serializes a copy of a type to dst. + // Precondition: dst must be at least SizeBytes() in length. MarshalBytes(dst []byte) - // UnmarshalBytes deserializes a type from src. src must be at least - // SizeBytes() long. + // UnmarshalBytes deserializes a type from src. + // Precondition: src must be at least SizeBytes() in length. UnmarshalBytes(src []byte) // Packed returns true if the marshalled size of the type is the same as the @@ -39,6 +71,12 @@ type Marshallable interface { // starting at unaligned addresses (should always be true by default for ABI // structs, verified by automatically generated tests when using // go_marshal), and has no fields marked `marshal:"unaligned"`. + // + // Packed must return the same result for all possible values of the type + // implementing it. Violating this constraint implies the type doesn't have + // a static memory layout, and will lead to memory corruption. + // Go-marshal-generated code reuses the result of Packed for multiple values + // of the same type. Packed() bool // MarshalUnsafe serializes a type by bulk copying its in-memory @@ -46,15 +84,100 @@ type Marshallable interface { // has no implicit padding, see Marshallable.Packed. When Packed would // return false, MarshalUnsafe should fall back to the safer but slower // MarshalBytes. + // Precondition: dst must be at least SizeBytes() in length. MarshalUnsafe(dst []byte) - // UnmarshalUnsafe deserializes a type directly to the underlying memory - // allocated for the object by the runtime. + // UnmarshalUnsafe deserializes a type by directly copying to the underlying + // memory allocated for the object by the runtime. // // This allows much faster unmarshalling of types which have no implicit // padding, see Marshallable.Packed. When Packed would return false, // UnmarshalUnsafe should fall back to the safer but slower unmarshal - // mechanism implemented in UnmarshalBytes (usually by calling - // UnmarshalBytes directly). + // mechanism implemented in UnmarshalBytes. + // Precondition: src must be at least SizeBytes() in length. UnmarshalUnsafe(src []byte) + + // CopyIn deserializes a Marshallable type from a task's memory. This may + // only be called from a task goroutine. This is more efficient than calling + // UnmarshalUnsafe on Marshallable.Packed types, as the type being + // marshalled does not escape. The implementation should avoid creating + // extra copies in memory by directly deserializing to the object's + // underlying memory. + // + // If the copy-in from the task memory is only partially successful, CopyIn + // should still attempt to deserialize as much data as possible. See comment + // for UnmarshalBytes. + CopyIn(task Task, addr usermem.Addr) (int, error) + + // CopyOut serializes a Marshallable type to a task's memory. This may only + // be called from a task goroutine. This is more efficient than calling + // MarshalUnsafe on Marshallable.Packed types, as the type being serialized + // does not escape. The implementation should avoid creating extra copies in + // memory by directly serializing from the object's underlying memory. + // + // The copy-out to the task memory may be partially successful, in which + // case CopyOut returns how much data was serialized. See comment for + // MarshalBytes for implications. + CopyOut(task Task, addr usermem.Addr) (int, error) + + // CopyOutN is like CopyOut, but explicitly requests a partial + // copy-out. Note that this may yield unexpected results for non-packed + // types and the caller may only want to allow this for packed types. See + // comment on MarshalBytes. + // + // The limit must be less than or equal to SizeBytes(). + CopyOutN(task Task, addr usermem.Addr, limit int) (int, error) } + +// go-marshal generates additional functions for a type based on additional +// clauses to the +marshal directive. They are documented below. +// +// Slice API +// ========= +// +// Adding a "slice" clause to the +marshal directive for structs or newtypes on +// primitives like this: +// +// // +marshal slice:FooSlice +// type Foo struct { ... } +// +// Generates four additional functions for marshalling slices of Foos like this: +// +// // MarshalUnsafeFooSlice is like Foo.MarshalUnsafe, buf for a []Foo. It +// // might be more efficient that repeatedly calling Foo.MarshalUnsafe +// // over a []Foo in a loop if the type is Packed. +// // Preconditions: dst must be at least len(src)*Foo.SizeBytes() in length. +// func MarshalUnsafeFooSlice(src []Foo, dst []byte) (int, error) { ... } +// +// // UnmarshalUnsafeFooSlice is like Foo.UnmarshalUnsafe, buf for a []Foo. It +// // might be more efficient that repeatedly calling Foo.UnmarshalUnsafe +// // over a []Foo in a loop if the type is Packed. +// // Preconditions: src must be at least len(dst)*Foo.SizeBytes() in length. +// func UnmarshalUnsafeFooSlice(dst []Foo, src []byte) (int, error) { ... } +// +// // CopyFooSliceIn copies in a slice of Foo objects from the task's memory. +// func CopyFooSliceIn(task marshal.Task, addr usermem.Addr, dst []Foo) (int, error) { ... } +// +// // CopyFooSliceIn copies out a slice of Foo objects to the task's memory. +// func CopyFooSliceOut(task marshal.Task, addr usermem.Addr, src []Foo) (int, error) { ... } +// +// The name of the functions are of the format "Copy%sIn" and "Copy%sOut", where +// %s is the first argument to the slice clause. This directive is not supported +// for newtypes on arrays. +// +// The slice clause also takes an optional second argument, which must be the +// value "inner": +// +// // +marshal slice:Int32Slice:inner +// type Int32 int32 +// +// This is only valid on newtypes on primitives, and causes the generated +// functions to accept slices of the inner type instead: +// +// func CopyInt32SliceIn(task marshal.Task, addr usermem.Addr, dst []int32) (int, error) { ... } +// +// Without "inner", they would instead be: +// +// func CopyInt32SliceIn(task marshal.Task, addr usermem.Addr, dst []Int32) (int, error) { ... } +// +// This may help avoid a cast depending on how the generated functions are used. diff --git a/tools/go_marshal/marshal/marshal_impl_util.go b/tools/go_marshal/marshal/marshal_impl_util.go new file mode 100644 index 000000000..89c7d3575 --- /dev/null +++ b/tools/go_marshal/marshal/marshal_impl_util.go @@ -0,0 +1,78 @@ +// Copyright 2020 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package marshal + +import ( + "io" + + "gvisor.dev/gvisor/pkg/usermem" +) + +// StubMarshallable implements the Marshallable interface. +// StubMarshallable is a convenient embeddable type for satisfying the +// marshallable interface, but provides no actual implementation. It is +// useful when the marshallable interface needs to be implemented manually, +// but the caller doesn't require the full marshallable interface. +type StubMarshallable struct{} + +// WriteTo implements Marshallable.WriteTo. +func (StubMarshallable) WriteTo(w io.Writer) (n int64, err error) { + panic("Please implement your own WriteTo function") +} + +// SizeBytes implements Marshallable.SizeBytes. +func (StubMarshallable) SizeBytes() int { + panic("Please implement your own SizeBytes function") +} + +// MarshalBytes implements Marshallable.MarshalBytes. +func (StubMarshallable) MarshalBytes(dst []byte) { + panic("Please implement your own MarshalBytes function") +} + +// UnmarshalBytes implements Marshallable.UnmarshalBytes. +func (StubMarshallable) UnmarshalBytes(src []byte) { + panic("Please implement your own UnMarshalBytes function") +} + +// Packed implements Marshallable.Packed. +func (StubMarshallable) Packed() bool { + panic("Please implement your own Packed function") +} + +// MarshalUnsafe implements Marshallable.MarshalUnsafe. +func (StubMarshallable) MarshalUnsafe(dst []byte) { + panic("Please implement your own MarshalUnsafe function") +} + +// UnmarshalUnsafe implements Marshallable.UnmarshalUnsafe. +func (StubMarshallable) UnmarshalUnsafe(src []byte) { + panic("Please implement your own UnmarshalUnsafe function") +} + +// CopyIn implements Marshallable.CopyIn. +func (StubMarshallable) CopyIn(task Task, addr usermem.Addr) (int, error) { + panic("Please implement your own CopyIn function") +} + +// CopyOut implements Marshallable.CopyOut. +func (StubMarshallable) CopyOut(task Task, addr usermem.Addr) (int, error) { + panic("Please implement your own CopyOut function") +} + +// CopyOutN implements Marshallable.CopyOutN. +func (StubMarshallable) CopyOutN(task Task, addr usermem.Addr, limit int) (int, error) { + panic("Please implement your own CopyOutN function") +} diff --git a/tools/go_marshal/primitive/BUILD b/tools/go_marshal/primitive/BUILD new file mode 100644 index 000000000..cc08ba63a --- /dev/null +++ b/tools/go_marshal/primitive/BUILD @@ -0,0 +1,18 @@ +load("//tools:defs.bzl", "go_library") + +licenses(["notice"]) + +go_library( + name = "primitive", + srcs = [ + "primitive.go", + ], + marshal = True, + visibility = [ + "//:sandbox", + ], + deps = [ + "//pkg/usermem", + "//tools/go_marshal/marshal", + ], +) diff --git a/tools/go_marshal/primitive/primitive.go b/tools/go_marshal/primitive/primitive.go new file mode 100644 index 000000000..d93edda8b --- /dev/null +++ b/tools/go_marshal/primitive/primitive.go @@ -0,0 +1,247 @@ +// Copyright 2020 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +// Package primitive defines marshal.Marshallable implementations for primitive +// types. +package primitive + +import ( + "io" + + "gvisor.dev/gvisor/pkg/usermem" + "gvisor.dev/gvisor/tools/go_marshal/marshal" +) + +// Int8 is a marshal.Marshallable implementation for int8. +// +// +marshal slice:Int8Slice:inner +type Int8 int8 + +// Uint8 is a marshal.Marshallable implementation for uint8. +// +// +marshal slice:Uint8Slice:inner +type Uint8 uint8 + +// Int16 is a marshal.Marshallable implementation for int16. +// +// +marshal slice:Int16Slice:inner +type Int16 int16 + +// Uint16 is a marshal.Marshallable implementation for uint16. +// +// +marshal slice:Uint16Slice:inner +type Uint16 uint16 + +// Int32 is a marshal.Marshallable implementation for int32. +// +// +marshal slice:Int32Slice:inner +type Int32 int32 + +// Uint32 is a marshal.Marshallable implementation for uint32. +// +// +marshal slice:Uint32Slice:inner +type Uint32 uint32 + +// Int64 is a marshal.Marshallable implementation for int64. +// +// +marshal slice:Int64Slice:inner +type Int64 int64 + +// Uint64 is a marshal.Marshallable implementation for uint64. +// +// +marshal slice:Uint64Slice:inner +type Uint64 uint64 + +// ByteSlice is a marshal.Marshallable implementation for []byte. +// This is a convenience wrapper around a dynamically sized type, and can't be +// embedded in other marshallable types because it breaks assumptions made by +// go-marshal internals. It violates the "no dynamically-sized types" +// constraint of the go-marshal library. +type ByteSlice []byte + +// SizeBytes implements marshal.Marshallable.SizeBytes. +func (b *ByteSlice) SizeBytes() int { + return len(*b) +} + +// MarshalBytes implements marshal.Marshallable.MarshalBytes. +func (b *ByteSlice) MarshalBytes(dst []byte) { + copy(dst, *b) +} + +// UnmarshalBytes implements marshal.Marshallable.UnmarshalBytes. +func (b *ByteSlice) UnmarshalBytes(src []byte) { + copy(*b, src) +} + +// Packed implements marshal.Marshallable.Packed. +func (b *ByteSlice) Packed() bool { + return false +} + +// MarshalUnsafe implements marshal.Marshallable.MarshalUnsafe. +func (b *ByteSlice) MarshalUnsafe(dst []byte) { + b.MarshalBytes(dst) +} + +// UnmarshalUnsafe implements marshal.Marshallable.UnmarshalUnsafe. +func (b *ByteSlice) UnmarshalUnsafe(src []byte) { + b.UnmarshalBytes(src) +} + +// CopyIn implements marshal.Marshallable.CopyIn. +func (b *ByteSlice) CopyIn(task marshal.Task, addr usermem.Addr) (int, error) { + return task.CopyInBytes(addr, *b) +} + +// CopyOut implements marshal.Marshallable.CopyOut. +func (b *ByteSlice) CopyOut(task marshal.Task, addr usermem.Addr) (int, error) { + return task.CopyOutBytes(addr, *b) +} + +// CopyOutN implements marshal.Marshallable.CopyOutN. +func (b *ByteSlice) CopyOutN(task marshal.Task, addr usermem.Addr, limit int) (int, error) { + return task.CopyOutBytes(addr, (*b)[:limit]) +} + +// WriteTo implements io.WriterTo.WriteTo. +func (b *ByteSlice) WriteTo(w io.Writer) (int64, error) { + n, err := w.Write(*b) + return int64(n), err +} + +var _ marshal.Marshallable = (*ByteSlice)(nil) + +// Below, we define some convenience functions for marshalling primitive types +// using the newtypes above, without requiring superfluous casts. + +// 16-bit integers + +// CopyInt16In is a convenient wrapper for copying in an int16 from the task's +// memory. +func CopyInt16In(task marshal.Task, addr usermem.Addr, dst *int16) (int, error) { + var buf Int16 + n, err := buf.CopyIn(task, addr) + if err != nil { + return n, err + } + *dst = int16(buf) + return n, nil +} + +// CopyInt16Out is a convenient wrapper for copying out an int16 to the task's +// memory. +func CopyInt16Out(task marshal.Task, addr usermem.Addr, src int16) (int, error) { + srcP := Int16(src) + return srcP.CopyOut(task, addr) +} + +// CopyUint16In is a convenient wrapper for copying in a uint16 from the task's +// memory. +func CopyUint16In(task marshal.Task, addr usermem.Addr, dst *uint16) (int, error) { + var buf Uint16 + n, err := buf.CopyIn(task, addr) + if err != nil { + return n, err + } + *dst = uint16(buf) + return n, nil +} + +// CopyUint16Out is a convenient wrapper for copying out a uint16 to the task's +// memory. +func CopyUint16Out(task marshal.Task, addr usermem.Addr, src uint16) (int, error) { + srcP := Uint16(src) + return srcP.CopyOut(task, addr) +} + +// 32-bit integers + +// CopyInt32In is a convenient wrapper for copying in an int32 from the task's +// memory. +func CopyInt32In(task marshal.Task, addr usermem.Addr, dst *int32) (int, error) { + var buf Int32 + n, err := buf.CopyIn(task, addr) + if err != nil { + return n, err + } + *dst = int32(buf) + return n, nil +} + +// CopyInt32Out is a convenient wrapper for copying out an int32 to the task's +// memory. +func CopyInt32Out(task marshal.Task, addr usermem.Addr, src int32) (int, error) { + srcP := Int32(src) + return srcP.CopyOut(task, addr) +} + +// CopyUint32In is a convenient wrapper for copying in a uint32 from the task's +// memory. +func CopyUint32In(task marshal.Task, addr usermem.Addr, dst *uint32) (int, error) { + var buf Uint32 + n, err := buf.CopyIn(task, addr) + if err != nil { + return n, err + } + *dst = uint32(buf) + return n, nil +} + +// CopyUint32Out is a convenient wrapper for copying out a uint32 to the task's +// memory. +func CopyUint32Out(task marshal.Task, addr usermem.Addr, src uint32) (int, error) { + srcP := Uint32(src) + return srcP.CopyOut(task, addr) +} + +// 64-bit integers + +// CopyInt64In is a convenient wrapper for copying in an int64 from the task's +// memory. +func CopyInt64In(task marshal.Task, addr usermem.Addr, dst *int64) (int, error) { + var buf Int64 + n, err := buf.CopyIn(task, addr) + if err != nil { + return n, err + } + *dst = int64(buf) + return n, nil +} + +// CopyInt64Out is a convenient wrapper for copying out an int64 to the task's +// memory. +func CopyInt64Out(task marshal.Task, addr usermem.Addr, src int64) (int, error) { + srcP := Int64(src) + return srcP.CopyOut(task, addr) +} + +// CopyUint64In is a convenient wrapper for copying in a uint64 from the task's +// memory. +func CopyUint64In(task marshal.Task, addr usermem.Addr, dst *uint64) (int, error) { + var buf Uint64 + n, err := buf.CopyIn(task, addr) + if err != nil { + return n, err + } + *dst = uint64(buf) + return n, nil +} + +// CopyUint64Out is a convenient wrapper for copying out a uint64 to the task's +// memory. +func CopyUint64Out(task marshal.Task, addr usermem.Addr, src uint64) (int, error) { + srcP := Uint64(src) + return srcP.CopyOut(task, addr) +} diff --git a/tools/go_marshal/test/BUILD b/tools/go_marshal/test/BUILD index fa82f8e9b..3d989823a 100644 --- a/tools/go_marshal/test/BUILD +++ b/tools/go_marshal/test/BUILD @@ -1,8 +1,6 @@ -load("@io_bazel_rules_go//go:def.bzl", "go_test") +load("//tools:defs.bzl", "go_library", "go_test") -package(licenses = ["notice"]) - -load("//tools/go_marshal:defs.bzl", "go_library") +licenses(["notice"]) package_group( name = "gomarshal_test", @@ -17,7 +15,7 @@ go_test( deps = [ ":test", "//pkg/binary", - "//pkg/sentry/usermem", + "//pkg/usermem", "//tools/go_marshal/analysis", ], ) @@ -26,6 +24,21 @@ go_library( name = "test", testonly = 1, srcs = ["test.go"], - importpath = "gvisor.dev/gvisor/tools/go_marshal/test", + marshal = True, + visibility = ["//tools/go_marshal/test:__subpackages__"], deps = ["//tools/go_marshal/test/external"], ) + +go_test( + name = "marshal_test", + size = "small", + srcs = ["marshal_test.go"], + deps = [ + ":test", + "//pkg/syserror", + "//pkg/usermem", + "//tools/go_marshal/analysis", + "//tools/go_marshal/marshal", + "@com_github_google_go_cmp//cmp:go_default_library", + ], +) diff --git a/tools/go_marshal/test/benchmark_test.go b/tools/go_marshal/test/benchmark_test.go index e70db06d8..224d308c7 100644 --- a/tools/go_marshal/test/benchmark_test.go +++ b/tools/go_marshal/test/benchmark_test.go @@ -22,9 +22,9 @@ import ( "testing" "gvisor.dev/gvisor/pkg/binary" - "gvisor.dev/gvisor/pkg/sentry/usermem" + "gvisor.dev/gvisor/pkg/usermem" "gvisor.dev/gvisor/tools/go_marshal/analysis" - test "gvisor.dev/gvisor/tools/go_marshal/test" + "gvisor.dev/gvisor/tools/go_marshal/test" ) // Marshalling using the standard encoding/binary package. @@ -176,3 +176,45 @@ func BenchmarkGoMarshalUnsafe(b *testing.B) { panic(fmt.Sprintf("Data corruption across marshal/unmarshal cycle:\nBefore: %+v\nAfter: %+v\n", s1, s2)) } } + +func BenchmarkBinarySlice(b *testing.B) { + var s1, s2 [64]test.Stat + analysis.RandomizeValue(&s1) + + size := binary.Size(s1) + + b.ResetTimer() + + for n := 0; n < b.N; n++ { + buf := make([]byte, 0, size) + buf = binary.Marshal(buf, usermem.ByteOrder, &s1) + binary.Unmarshal(buf, usermem.ByteOrder, &s2) + } + + b.StopTimer() + + // Sanity check, make sure the values were preserved. + if !reflect.DeepEqual(s1, s2) { + panic(fmt.Sprintf("Data corruption across marshal/unmarshal cycle:\nBefore: %+v\nAfter: %+v\n", s1, s2)) + } +} + +func BenchmarkGoMarshalUnsafeSlice(b *testing.B) { + var s1, s2 [64]test.Stat + analysis.RandomizeValue(&s1) + + b.ResetTimer() + + for n := 0; n < b.N; n++ { + buf := make([]byte, (*test.Stat)(nil).SizeBytes()*len(s1)) + test.MarshalUnsafeStatSlice(s1[:], buf) + test.UnmarshalUnsafeStatSlice(s2[:], buf) + } + + b.StopTimer() + + // Sanity check, make sure the values were preserved. + if !reflect.DeepEqual(s1, s2) { + panic(fmt.Sprintf("Data corruption across marshal/unmarshal cycle:\nBefore: %+v\nAfter: %+v\n", s1, s2)) + } +} diff --git a/tools/go_marshal/test/escape/BUILD b/tools/go_marshal/test/escape/BUILD new file mode 100644 index 000000000..f74e6ffae --- /dev/null +++ b/tools/go_marshal/test/escape/BUILD @@ -0,0 +1,14 @@ +load("//tools:defs.bzl", "go_library") + +licenses(["notice"]) + +go_library( + name = "escape", + testonly = 1, + srcs = ["escape.go"], + deps = [ + "//pkg/usermem", + "//tools/go_marshal/marshal", + "//tools/go_marshal/test", + ], +) diff --git a/tools/go_marshal/test/escape/escape.go b/tools/go_marshal/test/escape/escape.go new file mode 100644 index 000000000..6a46ddbf8 --- /dev/null +++ b/tools/go_marshal/test/escape/escape.go @@ -0,0 +1,95 @@ +// Copyright 2020 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package escape + +import ( + "gvisor.dev/gvisor/pkg/usermem" + "gvisor.dev/gvisor/tools/go_marshal/marshal" + "gvisor.dev/gvisor/tools/go_marshal/test" +) + +// dummyTask implements marshal.Task. +type dummyTask struct { +} + +func (*dummyTask) CopyScratchBuffer(size int) []byte { + return make([]byte, size) +} + +func (*dummyTask) CopyOutBytes(addr usermem.Addr, b []byte) (int, error) { + return len(b), nil +} + +func (*dummyTask) CopyInBytes(addr usermem.Addr, b []byte) (int, error) { + return len(b), nil +} + +func (t *dummyTask) MarshalBytes(addr usermem.Addr, marshallable marshal.Marshallable) { + buf := t.CopyScratchBuffer(marshallable.SizeBytes()) + marshallable.MarshalBytes(buf) + t.CopyOutBytes(addr, buf) +} + +func (t *dummyTask) MarshalUnsafe(addr usermem.Addr, marshallable marshal.Marshallable) { + buf := t.CopyScratchBuffer(marshallable.SizeBytes()) + marshallable.MarshalUnsafe(buf) + t.CopyOutBytes(addr, buf) +} + +// +checkescape:all +//go:nosplit +func doCopyIn(t *dummyTask) { + var stat test.Stat + stat.CopyIn(t, usermem.Addr(0xf000ba12)) +} + +// +checkescape:all +//go:nosplit +func doCopyOut(t *dummyTask) { + var stat test.Stat + stat.CopyOut(t, usermem.Addr(0xf000ba12)) +} + +// +mustescape:builtin +// +mustescape:stack +func doMarshalBytesDirect(t *dummyTask) { + var stat test.Stat + buf := t.CopyScratchBuffer(stat.SizeBytes()) + stat.MarshalBytes(buf) + t.CopyOutBytes(usermem.Addr(0xf000ba12), buf) +} + +// +mustescape:builtin +// +mustescape:stack +func doMarshalUnsafeDirect(t *dummyTask) { + var stat test.Stat + buf := t.CopyScratchBuffer(stat.SizeBytes()) + stat.MarshalUnsafe(buf) + t.CopyOutBytes(usermem.Addr(0xf000ba12), buf) +} + +// +mustescape:local,heap +// +mustescape:stack +func doMarshalBytesViaMarshallable(t *dummyTask) { + var stat test.Stat + t.MarshalBytes(usermem.Addr(0xf000ba12), &stat) +} + +// +mustescape:local,heap +// +mustescape:stack +func doMarshalUnsafeViaMarshallable(t *dummyTask) { + var stat test.Stat + t.MarshalUnsafe(usermem.Addr(0xf000ba12), &stat) +} diff --git a/tools/go_marshal/test/external/BUILD b/tools/go_marshal/test/external/BUILD index 8fb43179b..0cf6da603 100644 --- a/tools/go_marshal/test/external/BUILD +++ b/tools/go_marshal/test/external/BUILD @@ -1,11 +1,11 @@ -package(licenses = ["notice"]) +load("//tools:defs.bzl", "go_library") -load("//tools/go_marshal:defs.bzl", "go_library") +licenses(["notice"]) go_library( name = "external", testonly = 1, srcs = ["external.go"], - importpath = "gvisor.dev/gvisor/tools/go_marshal/test/external", + marshal = True, visibility = ["//tools/go_marshal/test:gomarshal_test"], ) diff --git a/tools/go_marshal/test/external/external.go b/tools/go_marshal/test/external/external.go index 4be3722f3..26fe8e0c8 100644 --- a/tools/go_marshal/test/external/external.go +++ b/tools/go_marshal/test/external/external.go @@ -21,3 +21,11 @@ package external type External struct { j int64 } + +// NotPacked is an unaligned Marshallable type for use in testing. +// +// +marshal +type NotPacked struct { + a int32 + b byte `marshal:"unaligned"` +} diff --git a/tools/go_marshal/test/marshal_test.go b/tools/go_marshal/test/marshal_test.go new file mode 100644 index 000000000..16829ee45 --- /dev/null +++ b/tools/go_marshal/test/marshal_test.go @@ -0,0 +1,515 @@ +// Copyright 2020 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +// Package marshal_test contains manual tests for the marshal interface. These +// are intended to test behaviour not covered by the automatically generated +// tests. +package marshal_test + +import ( + "bytes" + "encoding/binary" + "fmt" + "reflect" + "runtime" + "testing" + "unsafe" + + "github.com/google/go-cmp/cmp" + "gvisor.dev/gvisor/pkg/syserror" + "gvisor.dev/gvisor/pkg/usermem" + "gvisor.dev/gvisor/tools/go_marshal/analysis" + "gvisor.dev/gvisor/tools/go_marshal/marshal" + "gvisor.dev/gvisor/tools/go_marshal/test" +) + +var simulatedErr error = syserror.EFAULT + +// mockTask implements marshal.Task. +type mockTask struct { + taskMem usermem.BytesIO +} + +// populate fills the task memory with the contents of val. +func (t *mockTask) populate(val interface{}) { + var buf bytes.Buffer + // Use binary.Write so we aren't testing go-marshal against its own + // potentially buggy implementation. + if err := binary.Write(&buf, usermem.ByteOrder, val); err != nil { + panic(err) + } + t.taskMem.Bytes = buf.Bytes() +} + +func (t *mockTask) setLimit(n int) { + if len(t.taskMem.Bytes) < n { + grown := make([]byte, n) + copy(grown, t.taskMem.Bytes) + t.taskMem.Bytes = grown + return + } + t.taskMem.Bytes = t.taskMem.Bytes[:n] +} + +// CopyScratchBuffer implements marshal.Task.CopyScratchBuffer. +func (t *mockTask) CopyScratchBuffer(size int) []byte { + return make([]byte, size) +} + +// CopyOutBytes implements marshal.Task.CopyOutBytes. The implementation +// completely ignores the target address and stores a copy of b in its +// internally buffer, overriding any previous contents. +func (t *mockTask) CopyOutBytes(_ usermem.Addr, b []byte) (int, error) { + return t.taskMem.CopyOut(nil, 0, b, usermem.IOOpts{}) +} + +// CopyInBytes implements marshal.Task.CopyInBytes. The implementation +// completely ignores the source address and always fills b from the begining of +// its internal buffer. +func (t *mockTask) CopyInBytes(_ usermem.Addr, b []byte) (int, error) { + return t.taskMem.CopyIn(nil, 0, b, usermem.IOOpts{}) +} + +// unsafeMemory returns the underlying memory for m. The returned slice is only +// valid for the lifetime for m. The garbage collector isn't aware that the +// returned slice is related to m, the caller must ensure m lives long enough. +func unsafeMemory(m marshal.Marshallable) []byte { + if !m.Packed() { + // We can't return a slice pointing to the underlying memory + // since the layout isn't packed. Allocate a temporary buffer + // and marshal instead. + var buf bytes.Buffer + if err := binary.Write(&buf, usermem.ByteOrder, m); err != nil { + panic(err) + } + return buf.Bytes() + } + + // reflect.ValueOf(m) + // .Elem() // Unwrap interface to inner concrete object + // .Addr() // Pointer value to object + // .Pointer() // Actual address from the pointer value + ptr := reflect.ValueOf(m).Elem().Addr().Pointer() + + size := m.SizeBytes() + + var mem []byte + hdr := (*reflect.SliceHeader)(unsafe.Pointer(&mem)) + hdr.Data = ptr + hdr.Len = size + hdr.Cap = size + + return mem +} + +// unsafeMemorySlice returns the underlying memory for m. The returned slice is +// only valid for the lifetime for m. The garbage collector isn't aware that the +// returned slice is related to m, the caller must ensure m lives long enough. +// +// Precondition: m must be a slice. +func unsafeMemorySlice(m interface{}, elt marshal.Marshallable) []byte { + kind := reflect.TypeOf(m).Kind() + if kind != reflect.Slice { + panic("unsafeMemorySlice called on non-slice") + } + + if !elt.Packed() { + // We can't return a slice pointing to the underlying memory + // since the layout isn't packed. Allocate a temporary buffer + // and marshal instead. + var buf bytes.Buffer + if err := binary.Write(&buf, usermem.ByteOrder, m); err != nil { + panic(err) + } + return buf.Bytes() + } + + v := reflect.ValueOf(m) + length := v.Len() * elt.SizeBytes() + + var mem []byte + hdr := (*reflect.SliceHeader)(unsafe.Pointer(&mem)) + hdr.Data = v.Pointer() // This is a pointer to the first elem for slices. + hdr.Len = length + hdr.Cap = length + + return mem +} + +func isZeroes(buf []byte) bool { + for _, b := range buf { + if b != 0 { + return false + } + } + return true +} + +// compareMemory compares the first n bytes of two chuncks of memory represented +// by expected and actual. +func compareMemory(t *testing.T, expected, actual []byte, n int) { + t.Logf("Expected (%d): %v (%d) + (%d) %v\n", len(expected), expected[:n], n, len(expected)-n, expected[n:]) + t.Logf("Actual (%d): %v (%d) + (%d) %v\n", len(actual), actual[:n], n, len(actual)-n, actual[n:]) + + if diff := cmp.Diff(expected[:n], actual[:n]); diff != "" { + t.Errorf("Memory buffers don't match:\n--- expected only\n+++ actual only\n%v", diff) + } +} + +// limitedCopyIn populates task memory with src, then unmarshals task memory to +// dst. The task signals an error at limit bytes during copy-in, which should +// result in a truncated unmarshalling. +func limitedCopyIn(t *testing.T, src, dst marshal.Marshallable, limit int) { + var task mockTask + task.populate(src) + task.setLimit(limit) + + n, err := dst.CopyIn(&task, usermem.Addr(0)) + if n != limit { + t.Errorf("CopyIn copied unexpected number of bytes, expected %d, got %d", limit, n) + } + if err != simulatedErr { + t.Errorf("CopyIn returned unexpected error, expected %v, got %v", simulatedErr, err) + } + + expectedMem := unsafeMemory(src) + defer runtime.KeepAlive(src) + actualMem := unsafeMemory(dst) + defer runtime.KeepAlive(dst) + + compareMemory(t, expectedMem, actualMem, n) + + // The last n bytes should be zero for actual, since actual was + // zero-initialized, and CopyIn shouldn't have touched those bytes. However + // we can only guarantee we didn't touch anything in the last n bytes if the + // layout is packed. + if dst.Packed() && !isZeroes(actualMem[n:]) { + t.Errorf("Expected the last %d bytes of copied in object to be zeroes, got %v\n", dst.SizeBytes()-n, actualMem) + } +} + +// limitedCopyOut marshals src to task memory. The task signals an error at +// limit bytes during copy-out, which should result in a truncated marshalling. +func limitedCopyOut(t *testing.T, src marshal.Marshallable, limit int) { + var task mockTask + task.setLimit(limit) + + n, err := src.CopyOut(&task, usermem.Addr(0)) + if n != limit { + t.Errorf("CopyOut copied unexpected number of bytes, expected %d, got %d", limit, n) + } + if err != simulatedErr { + t.Errorf("CopyOut returned unexpected error, expected %v, got %v", simulatedErr, err) + } + + expectedMem := unsafeMemory(src) + defer runtime.KeepAlive(src) + actualMem := task.taskMem.Bytes + + compareMemory(t, expectedMem, actualMem, n) +} + +// copyOutN marshals src to task memory, requesting the marshalling to be +// limited to limit bytes. +func copyOutN(t *testing.T, src marshal.Marshallable, limit int) { + var task mockTask + task.setLimit(limit) + + n, err := src.CopyOutN(&task, usermem.Addr(0), limit) + if err != nil { + t.Errorf("CopyOut returned unexpected error: %v", err) + } + if n != limit { + t.Errorf("CopyOut copied unexpected number of bytes, expected %d, got %d", limit, n) + } + + expectedMem := unsafeMemory(src) + defer runtime.KeepAlive(src) + actualMem := task.taskMem.Bytes + + t.Logf("Expected: %v + %v\n", expectedMem[:n], expectedMem[n:]) + t.Logf("Actual : %v + %v\n", actualMem[:n], actualMem[n:]) + + compareMemory(t, expectedMem, actualMem, n) +} + +// TestLimitedMarshalling verifies marshalling/unmarshalling succeeds when the +// underyling copy in/out operations partially succeed. +func TestLimitedMarshalling(t *testing.T) { + types := []reflect.Type{ + // Packed types. + reflect.TypeOf((*test.Type2)(nil)), + reflect.TypeOf((*test.Type3)(nil)), + reflect.TypeOf((*test.Timespec)(nil)), + reflect.TypeOf((*test.Stat)(nil)), + reflect.TypeOf((*test.InetAddr)(nil)), + reflect.TypeOf((*test.SignalSet)(nil)), + reflect.TypeOf((*test.SignalSetAlias)(nil)), + // Non-packed types. + reflect.TypeOf((*test.Type1)(nil)), + reflect.TypeOf((*test.Type4)(nil)), + reflect.TypeOf((*test.Type5)(nil)), + reflect.TypeOf((*test.Type6)(nil)), + reflect.TypeOf((*test.Type7)(nil)), + reflect.TypeOf((*test.Type8)(nil)), + } + + for _, tyPtr := range types { + // Remove one level of pointer-indirection from the type. We get this + // back when we pass the type to reflect.New. + ty := tyPtr.Elem() + + // Partial copy-in. + t.Run(fmt.Sprintf("PartialCopyIn_%v", ty), func(t *testing.T) { + expected := reflect.New(ty).Interface().(marshal.Marshallable) + actual := reflect.New(ty).Interface().(marshal.Marshallable) + analysis.RandomizeValue(expected) + + limitedCopyIn(t, expected, actual, expected.SizeBytes()/2) + }) + + // Partial copy-out. + t.Run(fmt.Sprintf("PartialCopyOut_%v", ty), func(t *testing.T) { + expected := reflect.New(ty).Interface().(marshal.Marshallable) + analysis.RandomizeValue(expected) + + limitedCopyOut(t, expected, expected.SizeBytes()/2) + }) + + // Explicitly request partial copy-out. + t.Run(fmt.Sprintf("PartialCopyOutN_%v", ty), func(t *testing.T) { + expected := reflect.New(ty).Interface().(marshal.Marshallable) + analysis.RandomizeValue(expected) + + copyOutN(t, expected, expected.SizeBytes()/2) + }) + } +} + +// TestLimitedMarshalling verifies marshalling/unmarshalling of slices of +// marshallable types succeed when the underyling copy in/out operations +// partially succeed. +func TestLimitedSliceMarshalling(t *testing.T) { + types := []struct { + arrayPtrType reflect.Type + copySliceIn func(task marshal.Task, addr usermem.Addr, dstSlice interface{}) (int, error) + copySliceOut func(task marshal.Task, addr usermem.Addr, srcSlice interface{}) (int, error) + unsafeMemory func(arrPtr interface{}) []byte + }{ + // Packed types. + { + reflect.TypeOf((*[20]test.Stat)(nil)), + func(task marshal.Task, addr usermem.Addr, dst interface{}) (int, error) { + slice := dst.(*[20]test.Stat)[:] + return test.CopyStatSliceIn(task, addr, slice) + }, + func(task marshal.Task, addr usermem.Addr, src interface{}) (int, error) { + slice := src.(*[20]test.Stat)[:] + return test.CopyStatSliceOut(task, addr, slice) + }, + func(a interface{}) []byte { + slice := a.(*[20]test.Stat)[:] + return unsafeMemorySlice(slice, &slice[0]) + }, + }, + { + reflect.TypeOf((*[1]test.Stat)(nil)), + func(task marshal.Task, addr usermem.Addr, dst interface{}) (int, error) { + slice := dst.(*[1]test.Stat)[:] + return test.CopyStatSliceIn(task, addr, slice) + }, + func(task marshal.Task, addr usermem.Addr, src interface{}) (int, error) { + slice := src.(*[1]test.Stat)[:] + return test.CopyStatSliceOut(task, addr, slice) + }, + func(a interface{}) []byte { + slice := a.(*[1]test.Stat)[:] + return unsafeMemorySlice(slice, &slice[0]) + }, + }, + { + reflect.TypeOf((*[5]test.SignalSetAlias)(nil)), + func(task marshal.Task, addr usermem.Addr, dst interface{}) (int, error) { + slice := dst.(*[5]test.SignalSetAlias)[:] + return test.CopySignalSetAliasSliceIn(task, addr, slice) + }, + func(task marshal.Task, addr usermem.Addr, src interface{}) (int, error) { + slice := src.(*[5]test.SignalSetAlias)[:] + return test.CopySignalSetAliasSliceOut(task, addr, slice) + }, + func(a interface{}) []byte { + slice := a.(*[5]test.SignalSetAlias)[:] + return unsafeMemorySlice(slice, &slice[0]) + }, + }, + // Non-packed types. + { + reflect.TypeOf((*[20]test.Type1)(nil)), + func(task marshal.Task, addr usermem.Addr, dst interface{}) (int, error) { + slice := dst.(*[20]test.Type1)[:] + return test.CopyType1SliceIn(task, addr, slice) + }, + func(task marshal.Task, addr usermem.Addr, src interface{}) (int, error) { + slice := src.(*[20]test.Type1)[:] + return test.CopyType1SliceOut(task, addr, slice) + }, + func(a interface{}) []byte { + slice := a.(*[20]test.Type1)[:] + return unsafeMemorySlice(slice, &slice[0]) + }, + }, + { + reflect.TypeOf((*[1]test.Type1)(nil)), + func(task marshal.Task, addr usermem.Addr, dst interface{}) (int, error) { + slice := dst.(*[1]test.Type1)[:] + return test.CopyType1SliceIn(task, addr, slice) + }, + func(task marshal.Task, addr usermem.Addr, src interface{}) (int, error) { + slice := src.(*[1]test.Type1)[:] + return test.CopyType1SliceOut(task, addr, slice) + }, + func(a interface{}) []byte { + slice := a.(*[1]test.Type1)[:] + return unsafeMemorySlice(slice, &slice[0]) + }, + }, + { + reflect.TypeOf((*[7]test.Type8)(nil)), + func(task marshal.Task, addr usermem.Addr, dst interface{}) (int, error) { + slice := dst.(*[7]test.Type8)[:] + return test.CopyType8SliceIn(task, addr, slice) + }, + func(task marshal.Task, addr usermem.Addr, src interface{}) (int, error) { + slice := src.(*[7]test.Type8)[:] + return test.CopyType8SliceOut(task, addr, slice) + }, + func(a interface{}) []byte { + slice := a.(*[7]test.Type8)[:] + return unsafeMemorySlice(slice, &slice[0]) + }, + }, + } + + for _, tt := range types { + // The body of this loop is generic over the type tt.arrayPtrType, with + // the help of reflection. To aid in readability, comments below show + // the equivalent go code assuming + // tt.arrayPtrType = typeof(*[20]test.Stat). + + // Equivalent: + // var x *[20]test.Stat + // arrayTy := reflect.TypeOf(*x) + arrayTy := tt.arrayPtrType.Elem() + + // Partial copy-in of slices. + t.Run(fmt.Sprintf("PartialCopySliceIn_%v", arrayTy), func(t *testing.T) { + // Equivalent: + // var x [20]test.Stat + // length := len(x) + length := arrayTy.Len() + if length < 1 { + panic("Test type can't be zero-length array") + } + // Equivalent: + // elem := new(test.Stat).(marshal.Marshallable) + elem := reflect.New(arrayTy.Elem()).Interface().(marshal.Marshallable) + + // Equivalent: + // var expected, actual interface{} + // expected = new([20]test.Stat) + // actual = new([20]test.Stat) + expected := reflect.New(arrayTy).Interface() + actual := reflect.New(arrayTy).Interface() + + analysis.RandomizeValue(expected) + + limit := (length * elem.SizeBytes()) / 2 + // Also make sure the limit is partially inside one of the elements. + limit += elem.SizeBytes() / 2 + analysis.RandomizeValue(expected) + + var task mockTask + task.populate(expected) + task.setLimit(limit) + + n, err := tt.copySliceIn(&task, usermem.Addr(0), actual) + if n != limit { + t.Errorf("CopyIn copied unexpected number of bytes, expected %d, got %d", limit, n) + } + if n < length*elem.SizeBytes() && err != simulatedErr { + t.Errorf("CopyIn returned unexpected error, expected %v, got %v", simulatedErr, err) + } + + expectedMem := tt.unsafeMemory(expected) + defer runtime.KeepAlive(expected) + actualMem := tt.unsafeMemory(actual) + defer runtime.KeepAlive(actual) + + compareMemory(t, expectedMem, actualMem, n) + + // The last n bytes should be zero for actual, since actual was + // zero-initialized, and CopyIn shouldn't have touched those bytes. However + // we can only guarantee we didn't touch anything in the last n bytes if the + // layout is packed. + if elem.Packed() && !isZeroes(actualMem[n:]) { + t.Errorf("Expected the last %d bytes of copied in object to be zeroes, got %v\n", (elem.SizeBytes()*length)-n, actualMem) + } + }) + + // Partial copy-out of slices. + t.Run(fmt.Sprintf("PartialCopySliceOut_%v", arrayTy), func(t *testing.T) { + // Equivalent: + // var x [20]test.Stat + // length := len(x) + length := arrayTy.Len() + if length < 1 { + panic("Test type can't be zero-length array") + } + // Equivalent: + // elem := new(test.Stat).(marshal.Marshallable) + elem := reflect.New(arrayTy.Elem()).Interface().(marshal.Marshallable) + + // Equivalent: + // var expected, actual interface{} + // expected = new([20]test.Stat) + // actual = new([20]test.Stat) + expected := reflect.New(arrayTy).Interface() + + analysis.RandomizeValue(expected) + + limit := (length * elem.SizeBytes()) / 2 + // Also make sure the limit is partially inside one of the elements. + limit += elem.SizeBytes() / 2 + analysis.RandomizeValue(expected) + + var task mockTask + task.populate(expected) + task.setLimit(limit) + + n, err := tt.copySliceOut(&task, usermem.Addr(0), expected) + if n != limit { + t.Errorf("CopyIn copied unexpected number of bytes, expected %d, got %d", limit, n) + } + if n < length*elem.SizeBytes() && err != simulatedErr { + t.Errorf("CopyIn returned unexpected error, expected %v, got %v", simulatedErr, err) + } + + expectedMem := tt.unsafeMemory(expected) + defer runtime.KeepAlive(expected) + actualMem := task.taskMem.Bytes + + compareMemory(t, expectedMem, actualMem, n) + }) + } +} diff --git a/tools/go_marshal/test/test.go b/tools/go_marshal/test/test.go index 8de02d707..f75ca1b7f 100644 --- a/tools/go_marshal/test/test.go +++ b/tools/go_marshal/test/test.go @@ -23,7 +23,7 @@ import ( // Type1 is a test data type. // -// +marshal +// +marshal slice:Type1Slice type Type1 struct { a Type2 x, y int64 // Multiple field names. @@ -75,6 +75,34 @@ type Type5 struct { m int64 } +// Type6 is a test data type ends mid-word. +// +// +marshal +type Type6 struct { + a int64 + b int64 + // If c isn't marked unaligned, analysis fails (as it should, since + // the unsafe API corrupts Type7). + c byte `marshal:"unaligned"` +} + +// Type7 is a test data type that contains a child struct that ends +// mid-word. +// +marshal +type Type7 struct { + x Type6 + y int64 +} + +// Type8 is a test data type which contains an external non-packed field. +// +// +marshal slice:Type8Slice +type Type8 struct { + a int64 + np ex.NotPacked + b int64 +} + // Timespec represents struct timespec in <time.h>. // // +marshal @@ -85,7 +113,7 @@ type Timespec struct { // Stat represents struct stat. // -// +marshal +// +marshal slice:StatSlice type Stat struct { Dev uint64 Ino uint64 @@ -103,3 +131,46 @@ type Stat struct { CTime Timespec _ [3]int64 } + +// InetAddr is an example marshallable newtype on an array. +// +// +marshal +type InetAddr [4]byte + +// SignalSet is an example marshallable newtype on a primitive. +// +// +marshal slice:SignalSetSlice:inner +type SignalSet uint64 + +// SignalSetAlias is an example newtype on another marshallable type. +// +// +marshal slice:SignalSetAliasSlice +type SignalSetAlias SignalSet + +const sizeA = 64 +const sizeB = 8 + +// TestArray is a test data structure on an array with a constant length. +// +// +marshal +type TestArray [sizeA]int32 + +// TestArray2 is a newtype on an array with a simple arithmetic expression of +// constants for the array length. +// +// +marshal +type TestArray2 [sizeA * sizeB]int32 + +// TestArray2 is a newtype on an array with a simple arithmetic expression of +// mixed constants and literals for the array length. +// +// +marshal +type TestArray3 [sizeA*sizeB + 12]int32 + +// Type9 is a test data type containing an array with a non-literal length. +// +// +marshal +type Type9 struct { + x int64 + y [sizeA]int32 +} |