diff options
Diffstat (limited to 'tools/go_marshal')
| -rw-r--r-- | tools/go_marshal/analysis/analysis_unsafe.go | 4 | ||||
| -rw-r--r-- | tools/go_marshal/defs.bzl | 3 | ||||
| -rw-r--r-- | tools/go_marshal/gomarshal/BUILD | 3 | ||||
| -rw-r--r-- | tools/go_marshal/gomarshal/generator.go | 143 | ||||
| -rw-r--r-- | tools/go_marshal/gomarshal/generator_interfaces.go | 748 | ||||
| -rw-r--r-- | tools/go_marshal/gomarshal/generator_interfaces_array_newtype.go | 141 | ||||
| -rw-r--r-- | tools/go_marshal/gomarshal/generator_interfaces_primitive_newtype.go | 282 | ||||
| -rw-r--r-- | tools/go_marshal/gomarshal/generator_interfaces_struct.go | 614 | ||||
| -rw-r--r-- | tools/go_marshal/gomarshal/generator_tests.go | 54 | ||||
| -rw-r--r-- | tools/go_marshal/gomarshal/util.go | 176 | ||||
| -rw-r--r-- | tools/go_marshal/marshal/marshal.go | 103 | ||||
| -rw-r--r-- | tools/go_marshal/primitive/BUILD | 18 | ||||
| -rw-r--r-- | tools/go_marshal/primitive/primitive.go | 175 | ||||
| -rw-r--r-- | tools/go_marshal/test/BUILD | 14 | ||||
| -rw-r--r-- | tools/go_marshal/test/benchmark_test.go | 42 | ||||
| -rw-r--r-- | tools/go_marshal/test/external/external.go | 8 | ||||
| -rw-r--r-- | tools/go_marshal/test/marshal_test.go | 515 | ||||
| -rw-r--r-- | tools/go_marshal/test/test.go | 69 |
18 files changed, 2370 insertions, 742 deletions
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 d79786a68..323e33882 100644 --- a/tools/go_marshal/defs.bzl +++ b/tools/go_marshal/defs.bzl @@ -53,9 +53,10 @@ go_marshal = rule( # marshal_deps are the dependencies requied by generated code. marshal_deps = [ - "//tools/go_marshal/marshal", + "//pkg/gohacks", "//pkg/safecopy", "//pkg/usermem", + "//tools/go_marshal/marshal", ] # marshal_test_deps are required by test targets. diff --git a/tools/go_marshal/gomarshal/BUILD b/tools/go_marshal/gomarshal/BUILD index b5d5a4487..44cb33ae4 100644 --- a/tools/go_marshal/gomarshal/BUILD +++ b/tools/go_marshal/gomarshal/BUILD @@ -7,6 +7,9 @@ go_library( 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", ], diff --git a/tools/go_marshal/gomarshal/generator.go b/tools/go_marshal/gomarshal/generator.go index d365a1f3c..177013dbb 100644 --- a/tools/go_marshal/gomarshal/generator.go +++ b/tools/go_marshal/gomarshal/generator.go @@ -28,12 +28,6 @@ import ( "gvisor.dev/gvisor/tools/tags" ) -const ( - marshalImport = "gvisor.dev/gvisor/tools/go_marshal/marshal" - safecopyImport = "gvisor.dev/gvisor/pkg/safecopy" - usermemImport = "gvisor.dev/gvisor/pkg/usermem" -) - // 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. @@ -44,8 +38,8 @@ const ( // All recievers are single letters, so we don't allow import aliases to be a // single letter. var badIdents = []string{ - "addr", "blk", "buf", "dst", "dsts", "err", "hdr", "idx", "inner", "len", - "ptr", "src", "srcs", "task", "val", + "addr", "blk", "buf", "dst", "dsts", "count", "err", "hdr", "idx", "inner", + "length", "limit", "ptr", "size", "src", "srcs", "task", "val", // All single-letter identifiers. } @@ -110,9 +104,10 @@ func NewGenerator(srcs []string, out, outTest, pkg string, imports []string) (*G g.imports.add("reflect") g.imports.add("runtime") g.imports.add("unsafe") - g.imports.add(marshalImport) - g.imports.add(safecopyImport) - g.imports.add(usermemImport) + 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 } @@ -194,10 +189,73 @@ func (g *Generator) parse() ([]*ast.File, []*token.FileSet, error) { return files, fsets, nil } +// 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) collectMarshallableTypes(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? @@ -212,9 +270,11 @@ func (g *Generator) collectMarshallableTypes(a *ast.File, f *token.FileSet) []*a } // 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 } } @@ -229,16 +289,17 @@ func (g *Generator) collectMarshallableTypes(a *ast.File, f *token.FileSet) []*a switch t.Type.(type) { case *ast.StructType: debugfAt(f.Position(t.Pos()), "Collected marshallable struct %s.\n", t.Name.Name) - types = append(types, t) - continue case *ast.Ident: // Newtype on primitive. debugfAt(f.Position(t.Pos()), "Collected marshallable newtype on primitive %s.\n", t.Name.Name) - types = append(types, t) - continue + 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)) } - // 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)) + types = append(types, newMarshallableType(f, tagLine, t)) + } } return types @@ -265,7 +326,7 @@ 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 _, ok := badIdentsMap[i.name]; ok { @@ -277,28 +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 { - i := newInterfaceGenerator(t, fset) - switch ty := t.Type.(type) { +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() - i.emitMarshallableForStruct() - return i + 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() - return i + 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) - i.emitTests() +func (g *Generator) generateOneTestSuite(t marshallableType) *testGenerator { + i := newTestGenerator(t.spec) + i.emitTests(t.slice) return i } @@ -348,7 +421,7 @@ func (g *Generator) Run() error { // the list of imports we need to copy to the generated code. 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)) @@ -406,7 +479,7 @@ func (g *Generator) writeTests(ts []*testGenerator) error { // empty example instead. if len(ts) == 0 { b.reset() - b.emit("func ExampleEmptyTestSuite() {\n") + 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") diff --git a/tools/go_marshal/gomarshal/generator_interfaces.go b/tools/go_marshal/gomarshal/generator_interfaces.go index ea1af998e..e3c3dac63 100644 --- a/tools/go_marshal/gomarshal/generator_interfaces.go +++ b/tools/go_marshal/gomarshal/generator_interfaces.go @@ -74,25 +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. @@ -100,71 +87,6 @@ func (g *interfaceGenerator) abortAt(p token.Pos, msg string) { abortAt(g.f.Position(p), msg) } -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)) - } -} - -// 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() { - 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) { - 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, 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. @@ -191,8 +113,8 @@ func (g *interfaceGenerator) shiftDynamic(bufVar, name string) { g.emit("%s = %s[%s.SizeBytes():]\n", bufVar, bufVar, name) } -// marshalStructFieldScalar writes a single scalar field from a struct to a byte slice. -func (g *interfaceGenerator) marshalStructFieldScalar(accessor, typ, 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) @@ -215,9 +137,8 @@ func (g *interfaceGenerator) marshalStructFieldScalar(accessor, typ, bufVar stri } } -// unmarshalStructFieldScalar reads a single scalar field from a struct, from a -// byte slice. -func (g *interfaceGenerator) unmarshalStructFieldScalar(accessor, typ, bufVar string) { +// unmarshalScalar reads a single scalar from a byte slice. +func (g *interfaceGenerator) unmarshalScalar(accessor, typ, bufVar string) { switch typ { case "byte": g.emit("%s = %s[0]\n", accessor, bufVar) @@ -244,579 +165,112 @@ func (g *interfaceGenerator) unmarshalStructFieldScalar(accessor, typ, bufVar st } } -// 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("inner := (*%s)(%s)\n", typ, accessor) - g.emit("inner.MarshalBytes(%s[:%s.SizeBytes()])\n", bufVar, accessor) - } +// 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) } -// 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("inner := (*%s)(%s)\n", typ, accessor) - g.emit("inner.UnmarshalBytes(%s[:%s.SizeBytes()])\n", bufVar, accessor) - } +// 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) } -// 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 +// 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) } -func (g *interfaceGenerator) emitMarshallableForStruct() { - // 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)(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, 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.marshalStructFieldScalar(g.fieldAccessor(n), t.Name, "dst") - }, - selector: func(n, tX, tSel *ast.Ident) { - g.marshalStructFieldScalar(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 idx := 0; idx < %d; idx++ {\n", size) - g.inIndent(func() { - g.marshalStructFieldScalar(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() { - 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.unmarshalStructFieldScalar(g.fieldAccessor(n), t.Name, "src") - }, - selector: func(n, tX, tSel *ast.Ident) { - g.unmarshalStructFieldScalar(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 - } - - g.emit("for idx := 0; idx < %d; idx++ {\n", size) - g.inIndent(func() { - g.unmarshalStructFieldScalar(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("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() { - 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") - - 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") - - g.emit("// CopyOut implements marshal.Marshallable.CopyOut.\n") - g.recordUsedImport("marshal") - g.recordUsedImport("usermem") - g.emit("func (%s *%s) CopyOut(task marshal.Task, addr usermem.Addr) 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())\n", g.r) - g.emit("%s.MarshalBytes(buf)\n", g.r) - g.emit("_, err := task.CopyOutBytes(addr, buf)\n") - g.emit("return 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.emit("// Bypass escape analysis on %s. The no-op arithmetic operation on the\n", g.r) - g.emit("// pointer makes the compiler think val doesn't depend on %s.\n", g.r) - g.emit("// See src/runtime/stubs.go:noescape() in the golang toolchain.\n") - g.emit("ptr := unsafe.Pointer(%s)\n", g.r) - g.emit("val := uintptr(ptr)\n") - g.emit("val = val^0\n\n") - - g.emit("// Construct a slice backed by %s's underlying memory.\n", g.r) - g.emit("var buf []byte\n") - g.emit("hdr := (*reflect.SliceHeader)(unsafe.Pointer(&buf))\n") - g.emit("hdr.Data = val\n") - g.emit("hdr.Len = %s.SizeBytes()\n", g.r) - g.emit("hdr.Cap = %s.SizeBytes()\n\n", g.r) - - g.emit("_, err := task.CopyOutBytes(addr, buf)\n") - g.emit("// Since we bypassed the compiler's escape analysis, indicate that %s\n", g.r) - g.emit("// must live until after the CopyOutBytes.\n") - g.emit("runtime.KeepAlive(%s)\n", g.r) - g.emit("return err\n") - } else { - fallback() - } - }) - g.emit("}\n\n") - - g.emit("// CopyIn implements marshal.Marshallable.CopyIn.\n") - g.recordUsedImport("marshal") - g.recordUsedImport("usermem") - g.emit("func (%s *%s) CopyIn(task marshal.Task, addr usermem.Addr) 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())\n", g.r) - g.emit("_, err := task.CopyInBytes(addr, buf)\n") - g.emit("if err != nil {\n") - g.inIndent(func() { - g.emit("return err\n") - }) - g.emit("}\n") - - g.emit("%s.UnmarshalBytes(buf)\n", g.r) - g.emit("return nil\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.emit("// Bypass escape analysis on %s. The no-op arithmetic operation on the\n", g.r) - g.emit("// pointer makes the compiler think val doesn't depend on %s.\n", g.r) - g.emit("// See src/runtime/stubs.go:noescape() in the golang toolchain.\n") - g.emit("ptr := unsafe.Pointer(%s)\n", g.r) - g.emit("val := uintptr(ptr)\n") - g.emit("val = val^0\n\n") - - g.emit("// Construct a slice backed by %s's underlying memory.\n", g.r) - g.emit("var buf []byte\n") - g.emit("hdr := (*reflect.SliceHeader)(unsafe.Pointer(&buf))\n") - g.emit("hdr.Data = val\n") - g.emit("hdr.Len = %s.SizeBytes()\n", g.r) - g.emit("hdr.Cap = %s.SizeBytes()\n\n", g.r) - - g.emit("_, err := task.CopyInBytes(addr, buf)\n") - g.emit("// Since we bypassed the compiler's escape analysis, indicate that %s\n", g.r) - g.emit("// must live until after the CopyInBytes.\n") - g.emit("runtime.KeepAlive(%s)\n", g.r) - g.emit("return 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("n, err := w.Write(buf)\n") - g.emit("return int64(n), 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.emit("// Bypass escape analysis on %s. The no-op arithmetic operation on the\n", g.r) - g.emit("// pointer makes the compiler think val doesn't depend on %s.\n", g.r) - g.emit("// See src/runtime/stubs.go:noescape() in the golang toolchain.\n") - g.emit("ptr := unsafe.Pointer(%s)\n", g.r) - g.emit("val := uintptr(ptr)\n") - g.emit("val = val^0\n\n") - - g.emit("// Construct a slice backed by %s's underlying memory.\n", g.r) - g.emit("var buf []byte\n") - g.emit("hdr := (*reflect.SliceHeader)(unsafe.Pointer(&buf))\n") - g.emit("hdr.Data = val\n") - g.emit("hdr.Len = %s.SizeBytes()\n", g.r) - g.emit("hdr.Cap = %s.SizeBytes()\n\n", g.r) - - g.emit("len, err := w.Write(buf)\n") - g.emit("// Since we bypassed the compiler's escape analysis, indicate that %s\n", g.r) - g.emit("// must live until after the Write.\n") - g.emit("runtime.KeepAlive(%s)\n", g.r) - g.emit("return int64(len), err\n") - } else { - fallback() - } - }) - g.emit("}\n\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) } -// 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() { - g.recordUsedImport("io") - g.recordUsedImport("marshal") - g.recordUsedImport("reflect") - g.recordUsedImport("runtime") - g.recordUsedImport("safecopy") - g.recordUsedImport("unsafe") - g.recordUsedImport("usermem") - - nt := g.t.Type.(*ast.Ident) - - g.emit("// SizeBytes implements marshal.Marshallable.SizeBytes.\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("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("// CopyOut implements marshal.Marshallable.CopyOut.\n") - g.emit("func (%s *%s) CopyOut(task marshal.Task, addr usermem.Addr) error {\n", g.r, g.typeName()) - g.inIndent(func() { - // Fast serialization. - g.emit("// Bypass escape analysis on %s. The no-op arithmetic operation on the\n", g.r) - g.emit("// pointer makes the compiler think val doesn't depend on %s.\n", g.r) - g.emit("// See src/runtime/stubs.go:noescape() in the golang toolchain.\n") - g.emit("ptr := unsafe.Pointer(%s)\n", g.r) - g.emit("val := uintptr(ptr)\n") - g.emit("val = val^0\n\n") - - g.emit("// Construct a slice backed by %s's underlying memory.\n", g.r) - g.emit("var buf []byte\n") - g.emit("hdr := (*reflect.SliceHeader)(unsafe.Pointer(&buf))\n") - g.emit("hdr.Data = val\n") - g.emit("hdr.Len = %s.SizeBytes()\n", g.r) - g.emit("hdr.Cap = %s.SizeBytes()\n\n", g.r) - - g.emit("_, err := task.CopyOutBytes(addr, buf)\n") - g.emit("// Since we bypassed the compiler's escape analysis, indicate that %s\n", g.r) - g.emit("// must live until after the CopyOutBytes.\n") - g.emit("runtime.KeepAlive(%s)\n", g.r) - g.emit("return err\n") - }) - g.emit("}\n\n") - - g.emit("// CopyIn implements marshal.Marshallable.CopyIn.\n") - g.emit("func (%s *%s) CopyIn(task marshal.Task, addr usermem.Addr) error {\n", g.r, g.typeName()) - g.inIndent(func() { - g.emit("// Bypass escape analysis on %s. The no-op arithmetic operation on the\n", g.r) - g.emit("// pointer makes the compiler think val doesn't depend on %s.\n", g.r) - g.emit("// See src/runtime/stubs.go:noescape() in the golang toolchain.\n") - g.emit("ptr := unsafe.Pointer(%s)\n", g.r) - g.emit("val := uintptr(ptr)\n") - g.emit("val = val^0\n\n") - - g.emit("// Construct a slice backed by %s's underlying memory.\n", g.r) - g.emit("var buf []byte\n") - g.emit("hdr := (*reflect.SliceHeader)(unsafe.Pointer(&buf))\n") - g.emit("hdr.Data = val\n") - g.emit("hdr.Len = %s.SizeBytes()\n", g.r) - g.emit("hdr.Cap = %s.SizeBytes()\n\n", g.r) - - g.emit("_, err := task.CopyInBytes(addr, buf)\n") - g.emit("// Since we bypassed the compiler's escape analysis, indicate that %s\n", g.r) - g.emit("// must live until after the CopyInBytes.\n") - g.emit("runtime.KeepAlive(%s)\n", g.r) - g.emit("return 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.emit("// Bypass escape analysis on %s. The no-op arithmetic operation on the\n", g.r) - g.emit("// pointer makes the compiler think val doesn't depend on %s.\n", g.r) - g.emit("// See src/runtime/stubs.go:noescape() in the golang toolchain.\n") - g.emit("ptr := unsafe.Pointer(%s)\n", g.r) - g.emit("val := uintptr(ptr)\n") - g.emit("val = val^0\n\n") - - g.emit("// Construct a slice backed by %s's underlying memory.\n", g.r) - g.emit("var buf []byte\n") - g.emit("hdr := (*reflect.SliceHeader)(unsafe.Pointer(&buf))\n") - g.emit("hdr.Data = val\n") - g.emit("hdr.Len = %s.SizeBytes()\n", g.r) - g.emit("hdr.Cap = %s.SizeBytes()\n\n", g.r) +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("len, err := w.Write(buf)\n") - g.emit("// Since we bypassed the compiler's escape analysis, indicate that %s\n", g.r) - g.emit("// must live until after the Write.\n") - g.emit("runtime.KeepAlive(%s)\n", g.r) - g.emit("return int64(len), err\n") + fmt.Fprintf(b, "%s", e.Op) - }) - 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..8d6f102d5 --- /dev/null +++ b/tools/go_marshal/gomarshal/generator_interfaces_array_newtype.go @@ -0,0 +1,141 @@ +// 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("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("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("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])\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("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("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)\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..ef9bb903d --- /dev/null +++ b/tools/go_marshal/gomarshal/generator_interfaces_primitive_newtype.go @@ -0,0 +1,282 @@ +// 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("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("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("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])\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("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("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)\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("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)\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("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)\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..4236e978e --- /dev/null +++ b/tools/go_marshal/gomarshal/generator_interfaces_struct.go @@ -0,0 +1,614 @@ +// 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("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() { + 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") + + 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") + + g.emit("// CopyOutN implements marshal.Marshallable.CopyOutN.\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())\n", g.r) + g.emit("%s.MarshalBytes(buf)\n", g.r) + g.emit("return task.CopyOutBytes(addr, buf[:limit])\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])\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.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.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())\n", g.r) + g.emit("length, err := task.CopyInBytes(addr, buf)\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)\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)\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.\n") + g.emit("if length < size*count && 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 8ba47eb67..631295373 100644 --- a/tools/go_marshal/gomarshal/generator_tests.go +++ b/tools/go_marshal/gomarshal/generator_tests.go @@ -30,6 +30,11 @@ var standardImports = []string{ "gvisor.dev/gvisor/tools/go_marshal/analysis", } +var sliceAPIImports = []string{ + "encoding/binary", + "gvisor.dev/gvisor/pkg/usermem", +} + type testGenerator struct { sourceBuffer @@ -58,6 +63,11 @@ func newTestGenerator(t *ast.TypeSpec) *testGenerator { for _, i := range standardImports { g.imports.add(i).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 } @@ -132,6 +142,42 @@ func (g *testGenerator) emitTestMarshalUnmarshalPreservesData() { }) } +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()) @@ -164,18 +210,22 @@ func (g *testGenerator) emitTestSizeBytesOnTypedNilPtr() { 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)") + 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 e2bca4e7c..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) @@ -270,6 +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 { @@ -295,14 +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() { @@ -314,40 +327,78 @@ func (i *importStmt) equivalent(other *importStmt) bool { } // 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 { - if old, ok := i.is[s.name]; ok && !old.equivalent(s) { - // A collision should always be between an import inserted by the - // go-marshal tool and an import from the original source file (assuming - // the original source file was valid). We could theoretically handle - // the collision by assigning a local name to our import. However, this - // would need to be plumbed throughout the generator. Given that - // collisions should be rare, simply panic on collision. - panic(fmt.Sprintf("Import collision: old: %s as %v; new: %v as %v", old.path, old.name, s.path, s.name)) - } - i.is[s.name] = s + i.is[s.name] = append(i.is[s.name], s) return s } @@ -363,16 +414,20 @@ func (i *importTable) addFromSpec(spec *ast.ImportSpec, f *token.FileSet) *impor // 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 + } } } @@ -383,9 +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/marshal/marshal.go b/tools/go_marshal/marshal/marshal.go index f129788e0..cb2166252 100644 --- a/tools/go_marshal/marshal/marshal.go +++ b/tools/go_marshal/marshal/marshal.go @@ -42,7 +42,11 @@ type Task interface { CopyInBytes(addr usermem.Addr, b []byte) (int, error) } -// Marshallable represents a type that can be marshalled to and from memory. +// 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 @@ -54,12 +58,18 @@ type Marshallable interface { // 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. dst may be smaller than + // SizeBytes(), which results in a part of the struct being marshalled. Note + // that this may have unexpected results for non-packed types, as implicit + // padding needs to be taken into account when reasoning about how much of + // the type is serialized. MarshalBytes(dst []byte) - // UnmarshalBytes deserializes a type from src. src must be at least - // SizeBytes() long. + // UnmarshalBytes deserializes a type from src. src may be smaller than + // SizeBytes(), which results in a partially deserialized struct. Note that + // this may have unexpected results for non-packed types, as implicit + // padding needs to be taken into account when reasoning about how much of + // the type is deserialized. UnmarshalBytes(src []byte) // Packed returns true if the marshalled size of the type is the same as the @@ -67,13 +77,20 @@ 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 // representation to the dst buffer. This is only safe to do when the type // has no implicit padding, see Marshallable.Packed. When Packed would // return false, MarshalUnsafe should fall back to the safer but slower - // MarshalBytes. + // MarshalBytes. dst may be smaller than SizeBytes(), see comment for + // MarshalBytes for implications. MarshalUnsafe(dst []byte) // UnmarshalUnsafe deserializes a type by directly copying to the underlying @@ -82,7 +99,8 @@ type Marshallable interface { // 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. + // mechanism implemented in UnmarshalBytes. src may be smaller than + // SizeBytes(), see comment for UnmarshalBytes for implications. UnmarshalUnsafe(src []byte) // CopyIn deserializes a Marshallable type from a task's memory. This may @@ -91,12 +109,79 @@ type Marshallable interface { // marshalled does not escape. The implementation should avoid creating // extra copies in memory by directly deserializing to the object's // underlying memory. - CopyIn(task Task, addr usermem.Addr) error + // + // 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. - CopyOut(task Task, addr usermem.Addr) error + // + // 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's +// // more efficient that repeatedly calling calling Foo.MarshalUnsafe over a +// // []Foo in a loop. +// func MarshalUnsafeFooSlice(src []Foo, dst []byte) (int, error) { ... } +// +// // UnmarshalUnsafeFooSlice is like Foo.UnmarshalUnsafe, buf for a []Foo. It's +// // more efficient that repeatedly calling calling Foo.UnmarshalUnsafe over a +// // []Foo in a loop. +// 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/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..ebcf130ae --- /dev/null +++ b/tools/go_marshal/primitive/primitive.go @@ -0,0 +1,175 @@ +// 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 ( + "gvisor.dev/gvisor/pkg/usermem" + "gvisor.dev/gvisor/tools/go_marshal/marshal" +) + +// 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 + +// 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 f27c5ce52..3b839799d 100644 --- a/tools/go_marshal/test/BUILD +++ b/tools/go_marshal/test/BUILD @@ -39,3 +39,17 @@ go_binary( "//tools/go_marshal/marshal", ], ) + +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 c79defe9e..224d308c7 100644 --- a/tools/go_marshal/test/benchmark_test.go +++ b/tools/go_marshal/test/benchmark_test.go @@ -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/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 93229dedb..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 @@ -104,12 +132,45 @@ type Stat struct { _ [3]int64 } -// SignalSet is an example marshallable newtype on a primitive. +// 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 +// +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 +} |