diff options
Diffstat (limited to 'tools/go_marshal/gomarshal')
| -rw-r--r-- | tools/go_marshal/gomarshal/BUILD | 21 | ||||
| -rw-r--r-- | tools/go_marshal/gomarshal/generator.go | 433 | ||||
| -rw-r--r-- | tools/go_marshal/gomarshal/generator_interfaces.go | 165 | ||||
| -rw-r--r-- | tools/go_marshal/gomarshal/generator_interfaces_array_newtype.go | 183 | ||||
| -rw-r--r-- | tools/go_marshal/gomarshal/generator_interfaces_primitive_newtype.go | 229 | ||||
| -rw-r--r-- | tools/go_marshal/gomarshal/generator_interfaces_struct.go | 450 | ||||
| -rw-r--r-- | tools/go_marshal/gomarshal/generator_tests.go | 183 | ||||
| -rw-r--r-- | tools/go_marshal/gomarshal/util.go | 418 |
8 files changed, 0 insertions, 2082 deletions
diff --git a/tools/go_marshal/gomarshal/BUILD b/tools/go_marshal/gomarshal/BUILD deleted file mode 100644 index 44cb33ae4..000000000 --- a/tools/go_marshal/gomarshal/BUILD +++ /dev/null @@ -1,21 +0,0 @@ -load("//tools:defs.bzl", "go_library") - -licenses(["notice"]) - -go_library( - name = "gomarshal", - srcs = [ - "generator.go", - "generator_interfaces.go", - "generator_interfaces_array_newtype.go", - "generator_interfaces_primitive_newtype.go", - "generator_interfaces_struct.go", - "generator_tests.go", - "util.go", - ], - stateify = False, - visibility = [ - "//:sandbox", - ], - deps = ["//tools/tags"], -) diff --git a/tools/go_marshal/gomarshal/generator.go b/tools/go_marshal/gomarshal/generator.go deleted file mode 100644 index 729489de5..000000000 --- a/tools/go_marshal/gomarshal/generator.go +++ /dev/null @@ -1,433 +0,0 @@ -// Copyright 2019 The gVisor Authors. -// -// Licensed under the Apache License, Version 2.0 (the "License"); -// you may not use this file except in compliance with the License. -// 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 gomarshal implements the go_marshal code generator. See README.md. -package gomarshal - -import ( - "bytes" - "fmt" - "go/ast" - "go/parser" - "go/token" - "os" - "sort" - "strings" - - "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. -// -// This only applies to import aliases at the moment. All other identifiers -// are qualified by a receiver argument, since they're struct fields. -// -// 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", - // All single-letter identifiers. -} - -// Constructed fromt badIdents in init(). -var badIdentsMap map[string]struct{} - -func init() { - badIdentsMap = make(map[string]struct{}) - for _, ident := range badIdents { - badIdentsMap[ident] = struct{}{} - } -} - -// Generator drives code generation for a single invocation of the go_marshal -// utility. -// -// The Generator holds arguments passed to the tool, and drives parsing, -// processing and code Generator for all types marked with +marshal declared in -// the input files. -// -// See Generator.run() as the entry point. -type Generator struct { - // Paths to input go source files. - inputs []string - // Output file to write generated go source. - output *os.File - // Output file to write generated tests. - outputTest *os.File - // Package name for the generated file. - pkg string - // Set of extra packages to import in the generated file. - imports *importTable -} - -// NewGenerator creates a new code Generator. -func NewGenerator(srcs []string, out, outTest, pkg string, imports []string) (*Generator, error) { - f, err := os.OpenFile(out, os.O_CREATE|os.O_WRONLY|os.O_TRUNC, 0644) - if err != nil { - return nil, fmt.Errorf("Couldn't open output file %q: %v", out, err) - } - fTest, err := os.OpenFile(outTest, os.O_CREATE|os.O_WRONLY|os.O_TRUNC, 0644) - if err != nil { - return nil, fmt.Errorf("Couldn't open test output file %q: %v", out, err) - } - g := Generator{ - inputs: srcs, - output: f, - outputTest: fTest, - pkg: pkg, - imports: newImportTable(), - } - for _, i := range imports { - // All imports on the extra imports list are unconditionally marked as - // used, so that they're always added to the generated code. - g.imports.add(i).markUsed() - } - - // The following imports may or may not be used by the generated code, - // depending on what's required for the target types. Don't mark these as - // used by default. - g.imports.add("io") - g.imports.add("reflect") - g.imports.add("runtime") - g.imports.add("unsafe") - g.imports.add(marshalImport) - g.imports.add(safecopyImport) - g.imports.add(usermemImport) - - return &g, nil -} - -// writeHeader writes the header for the generated source file. The header -// includes the package name, package level comments and import statements. -func (g *Generator) writeHeader() error { - var b sourceBuffer - b.emit("// Automatically generated marshal implementation. See tools/go_marshal.\n\n") - - // Emit build tags. - if t := tags.Aggregate(g.inputs); len(t) > 0 { - b.emit(strings.Join(t.Lines(), "\n")) - b.emit("\n\n") - } - - // Package header. - b.emit("package %s\n\n", g.pkg) - if err := b.write(g.output); err != nil { - return err - } - - return g.imports.write(g.output) -} - -// writeTypeChecks writes a statement to force the compiler to perform a type -// check for all Marshallable types referenced by the generated code. -func (g *Generator) writeTypeChecks(ms map[string]struct{}) error { - if len(ms) == 0 { - return nil - } - - msl := make([]string, 0, len(ms)) - for m, _ := range ms { - msl = append(msl, m) - } - sort.Strings(msl) - - var buf bytes.Buffer - fmt.Fprint(&buf, "// Marshallable types used by this file.\n") - - for _, m := range msl { - fmt.Fprintf(&buf, "var _ marshal.Marshallable = (*%s)(nil)\n", m) - } - fmt.Fprint(&buf, "\n") - - _, err := fmt.Fprint(g.output, buf.String()) - return err -} - -// parse processes all input files passed this generator and produces a set of -// parsed go ASTs. -func (g *Generator) parse() ([]*ast.File, []*token.FileSet, error) { - debugf("go_marshal invoked with %d input files:\n", len(g.inputs)) - for _, path := range g.inputs { - debugf(" %s\n", path) - } - - files := make([]*ast.File, 0, len(g.inputs)) - fsets := make([]*token.FileSet, 0, len(g.inputs)) - - for _, path := range g.inputs { - fset := token.NewFileSet() - f, err := parser.ParseFile(fset, path, nil, parser.ParseComments) - if err != nil { - // Not a valid input file? - return nil, nil, fmt.Errorf("Input %q can't be parsed: %v", path, err) - } - - if debugEnabled() { - debugf("AST for %q:\n", path) - ast.Print(fset, f) - } - - files = append(files, f) - fsets = append(fsets, fset) - } - - return files, fsets, nil -} - -// 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 - for _, decl := range a.Decls { - gdecl, ok := decl.(*ast.GenDecl) - // Type declaration? - if !ok || gdecl.Tok != token.TYPE { - debugfAt(f.Position(decl.Pos()), "Skipping declaration since it's not a type declaration.\n") - continue - } - // Does it have a comment? - if gdecl.Doc == nil { - debugfAt(f.Position(gdecl.Pos()), "Skipping declaration since it doesn't have a comment.\n") - continue - } - // Does the comment contain a "+marshal" line? - marked := false - for _, c := range gdecl.Doc.List { - if c.Text == "// +marshal" { - marked = true - break - } - } - if !marked { - debugfAt(f.Position(gdecl.Pos()), "Skipping declaration since it doesn't have a comment containing +marshal line.\n") - continue - } - for _, spec := range gdecl.Specs { - // We already confirmed we're in a type declaration earlier, so this - // cast will succeed. - t := spec.(*ast.TypeSpec) - 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) - types = append(types, t) - continue - } - // 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)) - } - } - return types -} - -// collectImports collects all imports from all input source files. Some of -// these imports are copied to the generated output, if they're referenced by -// the generated code. -// -// collectImports de-duplicates imports while building the list, and ensures -// identifiers in the generated code don't conflict with any imported package -// names. -func (g *Generator) collectImports(a *ast.File, f *token.FileSet) map[string]importStmt { - is := make(map[string]importStmt) - for _, decl := range a.Decls { - gdecl, ok := decl.(*ast.GenDecl) - // Import statement? - if !ok || gdecl.Tok != token.IMPORT { - continue - } - for _, spec := range gdecl.Specs { - i := g.imports.addFromSpec(spec.(*ast.ImportSpec), f) - debugf("Collected import '%s' as '%s'\n", i.path, i.name) - - // 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 { - 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 { - abortAt(f.Position(spec.Pos()), fmt.Sprintf("Import name '%s' is likely to conflict with code generated by go_marshal, use a different import alias", i.name)) - } - } - } - return is - -} - -func (g *Generator) generateOne(t *ast.TypeSpec, fset *token.FileSet) *interfaceGenerator { - i := newInterfaceGenerator(t, fset) - switch ty := t.Type.(type) { - case *ast.StructType: - i.validateStruct(t, ty) - i.emitMarshallableForStruct(ty) - case *ast.Ident: - i.validatePrimitiveNewtype(ty) - i.emitMarshallableForPrimitiveNewtype(ty) - case *ast.ArrayType: - i.validateArrayNewtype(t.Name, ty) - // After validate, we can safely call arrayLen. - i.emitMarshallableForArrayNewtype(t.Name, ty.Elt.(*ast.Ident), arrayLen(ty)) - 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() - return i -} - -// Run is the entry point to code generation using g. -// -// Run parses all input source files specified in g and emits generated code. -func (g *Generator) Run() error { - // Parse our input source files into ASTs and token sets. - asts, fsets, err := g.parse() - if err != nil { - return err - } - - if len(asts) != len(fsets) { - panic("ASTs and FileSets don't match") - } - - // Map of imports in source files; key = local package name, value = import - // path. - is := make(map[string]importStmt) - for i, a := range asts { - // Collect all imports from the source files. We may need to copy some - // of these to the generated code if they're referenced. This has to be - // done before the loop below because we need to process all ASTs before - // we start requesting imports to be copied one by one as we encounter - // them in each generated source. - for name, i := range g.collectImports(a, fsets[i]) { - is[name] = i - } - } - - var impls []*interfaceGenerator - var ts []*testGenerator - // Set of Marshallable types referenced by generated code. - ms := make(map[string]struct{}) - for i, a := range asts { - // Collect type declarations marked for code generation and generate - // Marshallable interfaces. - for _, t := range g.collectMarshallableTypes(a, fsets[i]) { - impl := g.generateOne(t, fsets[i]) - // Collect Marshallable types referenced by the generated code. - for ref, _ := range impl.ms { - ms[ref] = struct{}{} - } - impls = append(impls, impl) - // Collect imports referenced by the generated code and add them to - // the list of imports we need to copy to the generated code. - for name, _ := range impl.is { - if !g.imports.markUsed(name) { - panic(fmt.Sprintf("Generated code for '%s' referenced a non-existent import with local name '%s'", impl.typeName(), name)) - } - } - ts = append(ts, g.generateOneTestSuite(t)) - } - } - - // Write output file header. These include things like package name and - // import statements. - if err := g.writeHeader(); err != nil { - return err - } - - // Write type checks for referenced marshallable types to output file. - if err := g.writeTypeChecks(ms); err != nil { - return err - } - - // Write generated interfaces to output file. - for _, i := range impls { - if err := i.write(g.output); err != nil { - return err - } - } - - // Write generated tests to test file. - return g.writeTests(ts) -} - -// writeTests outputs tests for the generated interface implementations to a go -// source file. -func (g *Generator) writeTests(ts []*testGenerator) error { - var b sourceBuffer - b.emit("package %s\n\n", g.pkg) - if err := b.write(g.outputTest); err != nil { - return err - } - - // Collect and write test import statements. - imports := newImportTable() - for _, t := range ts { - imports.merge(t.imports) - } - - if err := imports.write(g.outputTest); err != nil { - return err - } - - // Write test functions. - - // If we didn't generate any Marshallable implementations, we can't just - // emit an empty test file, since that causes the build to fail with "no - // tests/benchmarks/examples found". Unfortunately we can't signal bazel to - // omit the entire package since the outputs are already defined before - // go-marshal is called. If we'd otherwise emit an empty test suite, emit an - // empty example instead. - if len(ts) == 0 { - b.reset() - b.emit("func ExampleEmptyTestSuite() {\n") - b.inIndent(func() { - b.emit("// This example is intentionally empty to ensure this file contains at least\n") - b.emit("// one testable entity. go-marshal is forced to emit a test file if a package\n") - b.emit("// is marked marshallable, but emitting a test file with no entities results\n") - b.emit("// in a build failure.\n") - }) - b.emit("}\n") - return b.write(g.outputTest) - } - - for _, t := range ts { - if err := t.write(g.outputTest); err != nil { - return err - } - } - return nil -} diff --git a/tools/go_marshal/gomarshal/generator_interfaces.go b/tools/go_marshal/gomarshal/generator_interfaces.go deleted file mode 100644 index 8babf61d2..000000000 --- a/tools/go_marshal/gomarshal/generator_interfaces.go +++ /dev/null @@ -1,165 +0,0 @@ -// Copyright 2019 The gVisor Authors. -// -// Licensed under the Apache License, Version 2.0 (the "License"); -// you may not use this file except in compliance with the License. -// 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 gomarshal - -import ( - "go/ast" - "go/token" -) - -// interfaceGenerator generates marshalling interfaces for a single type. -// -// getState is not thread-safe. -type interfaceGenerator struct { - sourceBuffer - - // The type we're serializing. - t *ast.TypeSpec - - // Receiver argument for generated methods. - r string - - // FileSet containing the tokens for the type we're processing. - f *token.FileSet - - // is records external packages referenced by the generated implementation. - is map[string]struct{} - - // ms records Marshallable types referenced by the generated implementation - // of t's interfaces. - ms map[string]struct{} - - // as records embedded fields in t that are potentially not packed. The key - // is the accessor for the field. - as map[string]struct{} -} - -// typeName returns the name of the type this g represents. -func (g *interfaceGenerator) typeName() string { - return g.t.Name.Name -} - -// newinterfaceGenerator creates a new interface generator. -func newInterfaceGenerator(t *ast.TypeSpec, fset *token.FileSet) *interfaceGenerator { - g := &interfaceGenerator{ - t: t, - r: receiverName(t), - f: fset, - is: make(map[string]struct{}), - ms: make(map[string]struct{}), - as: make(map[string]struct{}), - } - g.recordUsedMarshallable(g.typeName()) - return g -} - -func (g *interfaceGenerator) recordUsedMarshallable(m string) { - g.ms[m] = struct{}{} - -} - -func (g *interfaceGenerator) recordUsedImport(i string) { - g.is[i] = struct{}{} - -} - -func (g *interfaceGenerator) recordPotentiallyNonPackedField(fieldName string) { - g.as[fieldName] = struct{}{} -} - -// 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. -func (g *interfaceGenerator) abortAt(p token.Pos, msg string) { - abortAt(g.f.Position(p), msg) -} - -// 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. -func (g *interfaceGenerator) scalarSize(t *ast.Ident) (size int, unknownSize bool) { - switch t.Name { - case "int8", "uint8", "byte": - return 1, false - case "int16", "uint16": - return 2, false - case "int32", "uint32": - return 4, false - case "int64", "uint64": - return 8, false - default: - return 0, true - } -} - -func (g *interfaceGenerator) shift(bufVar string, n int) { - g.emit("%s = %s[%d:]\n", bufVar, bufVar, n) -} - -func (g *interfaceGenerator) shiftDynamic(bufVar, name string) { - g.emit("%s = %s[%s.SizeBytes():]\n", bufVar, bufVar, name) -} - -// 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) - g.shift(bufVar, 1) - case "int16", "uint16": - g.recordUsedImport("usermem") - g.emit("usermem.ByteOrder.PutUint16(%s[:2], uint16(%s))\n", bufVar, accessor) - g.shift(bufVar, 2) - case "int32", "uint32": - g.recordUsedImport("usermem") - g.emit("usermem.ByteOrder.PutUint32(%s[:4], uint32(%s))\n", bufVar, accessor) - g.shift(bufVar, 4) - case "int64", "uint64": - g.recordUsedImport("usermem") - g.emit("usermem.ByteOrder.PutUint64(%s[:8], uint64(%s))\n", bufVar, accessor) - g.shift(bufVar, 8) - default: - g.emit("%s.MarshalBytes(%s[:%s.SizeBytes()])\n", accessor, bufVar, accessor) - g.shiftDynamic(bufVar, accessor) - } -} - -// 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) - g.shift(bufVar, 1) - case "int8", "uint8": - g.emit("%s = %s(%s[0])\n", accessor, typ, bufVar) - g.shift(bufVar, 1) - case "int16", "uint16": - g.recordUsedImport("usermem") - g.emit("%s = %s(usermem.ByteOrder.Uint16(%s[:2]))\n", accessor, typ, bufVar) - g.shift(bufVar, 2) - case "int32", "uint32": - g.recordUsedImport("usermem") - g.emit("%s = %s(usermem.ByteOrder.Uint32(%s[:4]))\n", accessor, typ, bufVar) - g.shift(bufVar, 4) - case "int64", "uint64": - g.recordUsedImport("usermem") - g.emit("%s = %s(usermem.ByteOrder.Uint64(%s[:8]))\n", accessor, typ, bufVar) - g.shift(bufVar, 8) - default: - g.emit("%s.UnmarshalBytes(%s[:%s.SizeBytes()])\n", accessor, bufVar, accessor) - g.shiftDynamic(bufVar, accessor) - g.recordPotentiallyNonPackedField(accessor) - } -} diff --git a/tools/go_marshal/gomarshal/generator_interfaces_array_newtype.go b/tools/go_marshal/gomarshal/generator_interfaces_array_newtype.go deleted file mode 100644 index da36d9305..000000000 --- a/tools/go_marshal/gomarshal/generator_interfaces_array_newtype.go +++ /dev/null @@ -1,183 +0,0 @@ -// 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.Len.(*ast.BasicLit); !ok { - g.abortAt(a.Len.Pos(), fmt.Sprintf("Array size must be a literal, don't 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 arrayLen(a) <= 0 { - g.abortAt(a.Len.Pos(), fmt.Sprintf("Marshalling not supported for zero length arrays, why does an ABI struct have one?")) - } -} - -func (g *interfaceGenerator) emitMarshallableForArrayNewtype(n, elt *ast.Ident, len int) { - 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(elt); !dynamic { - g.emit("return %d\n", size*len) - } else { - g.emit("return (*%s)(nil).SizeBytes() * %d\n", n.Name, len) - } - }) - 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 < %d; idx++ {\n", len) - 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 < %d; idx++ {\n", len) - 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("// 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) - - 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") - - }) - 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 deleted file mode 100644 index 159397825..000000000 --- a/tools/go_marshal/gomarshal/generator_interfaces_primitive_newtype.go +++ /dev/null @@ -1,229 +0,0 @@ -// 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("// 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) - - 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") - - }) - g.emit("}\n\n") -} diff --git a/tools/go_marshal/gomarshal/generator_interfaces_struct.go b/tools/go_marshal/gomarshal/generator_interfaces_struct.go deleted file mode 100644 index e66a38b2e..000000000 --- a/tools/go_marshal/gomarshal/generator_interfaces_struct.go +++ /dev/null @@ -1,450 +0,0 @@ -// 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, len int) { - g.validateArrayNewtype(n, f.Type.(*ast.ArrayType)) - }, - unhandled: func(_ *ast.Ident) { - g.abortAt(f.Pos(), fmt.Sprintf("Marshalling not supported for %s fields", kindString(f.Type))) - }, - }.dispatch(f) - }) -} - -func (g *interfaceGenerator) emitMarshallableForStruct(st *ast.StructType) { - // Is g.t a packed struct without consideing field types? - thisPacked := true - forEachStructField(st, 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 - - 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, 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() { - 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 referece here - // (since the version in this struct is anonymous). Use - // a typed nil pointer to call SizeBytes() instead. - g.emit("dst = dst[(*%s)(nil).SizeBytes():]\n", t.Name) - } - return - } - g.marshalScalar(g.fieldAccessor(n), t.Name, "dst") - }, - selector: func(n, tX, tSel *ast.Ident) { - g.marshalScalar(g.fieldAccessor(n), fmt.Sprintf("%s.%s", tX.Name, tSel.Name), "dst") - }, - array: func(n, t *ast.Ident, size int) { - if n.Name == "_" { - g.emit("// Padding: dst[:sizeof(%s)*%d] ~= [%d]%s{0}\n", t.Name, size, size, t.Name) - if len, dynamic := g.scalarSize(t); !dynamic { - g.shift("dst", len*size) - } else { - // We can't use shiftDynamic here because we don't have - // an instance of the dynamic type we can reference here - // (since the version in this struct is anonymous). Use - // a typed nil pointer to call SizeBytes() instead. - g.emit("dst = dst[(*%s)(nil).SizeBytes()*%d:]\n", t.Name, size) - } - return - } - - g.emit("for idx := 0; idx < %d; idx++ {\n", size) - 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 can't use shiftDynamic here because we don't have - // an instance of the dynamic type we can reference here - // (since the version in this struct is anonymous). Use - // a typed nil pointer to call SizeBytes() instead. - g.emit("src = src[(*%s)(nil).SizeBytes():]\n", t.Name) - g.recordPotentiallyNonPackedField(fmt.Sprintf("(*%s)(nil)", t.Name)) - } - return - } - g.unmarshalScalar(g.fieldAccessor(n), t.Name, "src") - }, - selector: func(n, tX, tSel *ast.Ident) { - g.unmarshalScalar(g.fieldAccessor(n), fmt.Sprintf("%s.%s", tX.Name, tSel.Name), "src") - }, - array: func(n, t *ast.Ident, size int) { - if n.Name == "_" { - g.emit("// Padding: ~ copy([%d]%s(%s), src[:sizeof(%s)*%d])\n", size, t.Name, g.fieldAccessor(n), t.Name, size) - if len, dynamic := g.scalarSize(t); !dynamic { - g.shift("src", len*size) - } else { - // We can't use shiftDynamic here because we don't have - // an instance of the dynamic type we can referece here - // (since the version in this struct is anonymous). Use - // a typed nil pointer to call SizeBytes() instead. - g.emit("src = src[(*%s)(nil).SizeBytes()*%d:]\n", t.Name, size) - } - return - } - - g.emit("for idx := 0; idx < %d; idx++ {\n", size) - 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("// 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") -} diff --git a/tools/go_marshal/gomarshal/generator_tests.go b/tools/go_marshal/gomarshal/generator_tests.go deleted file mode 100644 index fd992e44a..000000000 --- a/tools/go_marshal/gomarshal/generator_tests.go +++ /dev/null @@ -1,183 +0,0 @@ -// Copyright 2019 The gVisor Authors. -// -// Licensed under the Apache License, Version 2.0 (the "License"); -// you may not use this file except in compliance with the License. -// 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 gomarshal - -import ( - "fmt" - "go/ast" - "io" - "strings" -) - -var standardImports = []string{ - "bytes", - "fmt", - "reflect", - "testing", - - "gvisor.dev/gvisor/tools/go_marshal/analysis", -} - -type testGenerator struct { - sourceBuffer - - // The type we're serializing. - t *ast.TypeSpec - - // Receiver argument for generated methods. - r string - - // Imports used by generated code. - imports *importTable - - // Import statement for the package declaring the type we generated code - // for. We need this to construct test instances for the type, since the - // tests aren't written in the same package. - decl *importStmt -} - -func newTestGenerator(t *ast.TypeSpec) *testGenerator { - g := &testGenerator{ - t: t, - r: receiverName(t), - imports: newImportTable(), - } - - for _, i := range standardImports { - g.imports.add(i).markUsed() - } - - return g -} - -func (g *testGenerator) typeName() string { - return g.t.Name.Name -} - -func (g *testGenerator) testFuncName(base string) string { - return fmt.Sprintf("%s%s", base, strings.Title(g.t.Name.Name)) -} - -func (g *testGenerator) inTestFunction(name string, body func()) { - g.emit("func %s(t *testing.T) {\n", g.testFuncName(name)) - g.inIndent(body) - g.emit("}\n\n") -} - -func (g *testGenerator) emitTestNonZeroSize() { - g.inTestFunction("TestSizeNonZero", func() { - g.emit("var x %v\n", g.typeName()) - g.emit("if x.SizeBytes() == 0 {\n") - g.inIndent(func() { - g.emit("t.Fatal(\"Marshallable.SizeBytes() should not return zero\")\n") - }) - g.emit("}\n") - }) -} - -func (g *testGenerator) emitTestSuspectAlignment() { - g.inTestFunction("TestSuspectAlignment", func() { - g.emit("var x %v\n", g.typeName()) - g.emit("analysis.AlignmentCheck(t, reflect.TypeOf(x))\n") - }) -} - -func (g *testGenerator) emitTestMarshalUnmarshalPreservesData() { - g.inTestFunction("TestSafeMarshalUnmarshalPreservesData", func() { - g.emit("var x, y, z, yUnsafe, zUnsafe %s\n", g.typeName()) - g.emit("analysis.RandomizeValue(&x)\n\n") - - g.emit("buf := make([]byte, x.SizeBytes())\n") - g.emit("x.MarshalBytes(buf)\n") - g.emit("bufUnsafe := make([]byte, x.SizeBytes())\n") - g.emit("x.MarshalUnsafe(bufUnsafe)\n\n") - - g.emit("y.UnmarshalBytes(buf)\n") - g.emit("if !reflect.DeepEqual(x, y) {\n") - g.inIndent(func() { - g.emit("t.Fatal(fmt.Sprintf(\"Data corrupted across MarshalBytes/UnmarshalBytes cycle:\\nBefore: %+v\\nAfter: %+v\\n\", x, y))\n") - }) - g.emit("}\n") - g.emit("yUnsafe.UnmarshalBytes(bufUnsafe)\n") - g.emit("if !reflect.DeepEqual(x, yUnsafe) {\n") - g.inIndent(func() { - g.emit("t.Fatal(fmt.Sprintf(\"Data corrupted across MarshalUnsafe/UnmarshalBytes cycle:\\nBefore: %+v\\nAfter: %+v\\n\", x, yUnsafe))\n") - }) - g.emit("}\n\n") - - g.emit("z.UnmarshalUnsafe(buf)\n") - g.emit("if !reflect.DeepEqual(x, z) {\n") - g.inIndent(func() { - g.emit("t.Fatal(fmt.Sprintf(\"Data corrupted across MarshalBytes/UnmarshalUnsafe cycle:\\nBefore: %+v\\nAfter: %+v\\n\", x, z))\n") - }) - g.emit("}\n") - g.emit("zUnsafe.UnmarshalUnsafe(bufUnsafe)\n") - g.emit("if !reflect.DeepEqual(x, zUnsafe) {\n") - g.inIndent(func() { - g.emit("t.Fatal(fmt.Sprintf(\"Data corrupted across MarshalUnsafe/UnmarshalUnsafe cycle:\\nBefore: %+v\\nAfter: %+v\\n\", x, zUnsafe))\n") - }) - g.emit("}\n") - }) -} - -func (g *testGenerator) emitTestWriteToUnmarshalPreservesData() { - g.inTestFunction("TestWriteToUnmarshalPreservesData", func() { - g.emit("var x, y, yUnsafe %s\n", g.typeName()) - g.emit("analysis.RandomizeValue(&x)\n\n") - - g.emit("var buf bytes.Buffer\n\n") - - g.emit("x.WriteTo(&buf)\n") - g.emit("y.UnmarshalBytes(buf.Bytes())\n\n") - g.emit("yUnsafe.UnmarshalUnsafe(buf.Bytes())\n\n") - - g.emit("if !reflect.DeepEqual(x, y) {\n") - g.inIndent(func() { - g.emit("t.Fatal(fmt.Sprintf(\"Data corrupted across WriteTo/UnmarshalBytes cycle:\\nBefore: %+v\\nAfter: %+v\\n\", x, y))\n") - }) - g.emit("}\n") - g.emit("if !reflect.DeepEqual(x, yUnsafe) {\n") - g.inIndent(func() { - g.emit("t.Fatal(fmt.Sprintf(\"Data corrupted across WriteTo/UnmarshalUnsafe cycle:\\nBefore: %+v\\nAfter: %+v\\n\", x, yUnsafe))\n") - }) - g.emit("}\n") - }) -} - -func (g *testGenerator) emitTestSizeBytesOnTypedNilPtr() { - g.inTestFunction("TestSizeBytesOnTypedNilPtr", func() { - g.emit("var x %s\n", g.typeName()) - g.emit("sizeFromConcrete := x.SizeBytes()\n") - g.emit("sizeFromTypedNilPtr := (*%s)(nil).SizeBytes()\n\n", g.typeName()) - - g.emit("if sizeFromTypedNilPtr != sizeFromConcrete {\n") - g.inIndent(func() { - g.emit("t.Fatalf(\"SizeBytes() on typed nil pointer (%v) doesn't match size returned by a concrete object (%v).\\n\", sizeFromTypedNilPtr, sizeFromConcrete)\n") - }) - g.emit("}\n") - }) -} - -func (g *testGenerator) emitTests() { - g.emitTestNonZeroSize() - g.emitTestSuspectAlignment() - g.emitTestMarshalUnmarshalPreservesData() - g.emitTestWriteToUnmarshalPreservesData() - g.emitTestSizeBytesOnTypedNilPtr() -} - -func (g *testGenerator) write(out io.Writer) error { - return g.sourceBuffer.write(out) -} diff --git a/tools/go_marshal/gomarshal/util.go b/tools/go_marshal/gomarshal/util.go deleted file mode 100644 index a0936e013..000000000 --- a/tools/go_marshal/gomarshal/util.go +++ /dev/null @@ -1,418 +0,0 @@ -// Copyright 2019 The gVisor Authors. -// -// Licensed under the Apache License, Version 2.0 (the "License"); -// you may not use this file except in compliance with the License. -// 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 gomarshal - -import ( - "bytes" - "flag" - "fmt" - "go/ast" - "go/token" - "io" - "os" - "path" - "reflect" - "sort" - "strconv" - "strings" -) - -var debug = flag.Bool("debug", false, "enables debugging output") - -// receiverName returns an appropriate receiver name given a type spec. -func receiverName(t *ast.TypeSpec) string { - if len(t.Name.Name) < 1 { - // Zero length type name? - panic("unreachable") - } - return strings.ToLower(t.Name.Name[:1]) -} - -// kindString returns a user-friendly representation of an AST expr type. -func kindString(e ast.Expr) string { - switch e.(type) { - case *ast.Ident: - return "scalar" - case *ast.ArrayType: - return "array" - case *ast.StructType: - return "struct" - case *ast.StarExpr: - return "pointer" - case *ast.FuncType: - return "function" - case *ast.InterfaceType: - return "interface" - case *ast.MapType: - return "map" - case *ast.ChanType: - return "channel" - default: - return reflect.TypeOf(e).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) - unhandled func(n *ast.Ident) -} - -// Precondition: a must have a literal for the array length. Consts and -// expressions are not allowed as array lengths, and should be rejected by the -// caller. -func arrayLen(a *ast.ArrayType) int { - if a.Len == nil { - // Probably a slice? Must be handled by caller. - panic("Nil array length in array type") - } - lenLit, ok := a.Len.(*ast.BasicLit) - if !ok { - panic("Array has non-literal for length") - } - len, err := strconv.Atoi(lenLit.Value) - if err != nil { - panic(fmt.Sprintf("Failed to parse array length '%s' as number: %v", lenLit.Value, err)) - } - return len -} - -// Precondition: All dispatch callbacks that will be invoked must be -// provided. Embedded fields are not allowed, len(f.Names) >= 1. -func (fd fieldDispatcher) dispatch(f *ast.Field) { - // Each field declaration may actually be multiple declarations of the same - // type. For example, consider: - // - // type Point struct { - // x, y, z int - // } - // - // We invoke the call-backs once per such instance. Embedded fields are not - // allowed, and results in a panic. - if len(f.Names) < 1 { - panic("Precondition not met: attempted to dispatch on embedded field") - } - - for _, name := range f.Names { - switch v := f.Type.(type) { - case *ast.Ident: - fd.primitive(name, v) - case *ast.SelectorExpr: - fd.selector(name, v.X.(*ast.Ident), v.Sel) - case *ast.ArrayType: - switch t := v.Elt.(type) { - case *ast.Ident: - fd.array(name, t, arrayLen(v)) - default: - // 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) - } - } -} - -// debugEnabled indicates whether debugging is enabled for gomarshal. -func debugEnabled() bool { - return *debug -} - -// abort aborts the go_marshal tool with the given error message. -func abort(msg string) { - if !strings.HasSuffix(msg, "\n") { - msg += "\n" - } - fmt.Print(msg) - os.Exit(1) -} - -// abortAt aborts the go_marshal tool with the given error message, with -// a reference position to the input source. -func abortAt(p token.Position, msg string) { - abort(fmt.Sprintf("%v:\n %s\n", p, msg)) -} - -// debugf conditionally prints a debug message. -func debugf(f string, a ...interface{}) { - if debugEnabled() { - fmt.Printf(f, a...) - } -} - -// debugfAt conditionally prints a debug message with a reference to a position -// in the input source. -func debugfAt(p token.Position, f string, a ...interface{}) { - if debugEnabled() { - fmt.Printf("%s:\n %s", p, fmt.Sprintf(f, a...)) - } -} - -// emit generates a line of code in the output file. -// -// emit is a wrapper around writing a formatted string to the output -// buffer. emit can be invoked in one of two ways: -// -// (1) emit("some string") -// When emit is called with a single string argument, it is simply copied to -// the output buffer without any further formatting. -// (2) emit(fmtString, args...) -// emit can also be invoked in a similar fashion to *Printf() functions, -// where the first argument is a format string. -// -// Calling emit with a single argument that is not a string will result in a -// panic, as the caller's intent is ambiguous. -func emit(out io.Writer, indent int, a ...interface{}) { - const spacesPerIndentLevel = 4 - - if len(a) < 1 { - panic("emit() called with no arguments") - } - - if indent > 0 { - if _, err := fmt.Fprint(out, strings.Repeat(" ", indent*spacesPerIndentLevel)); err != nil { - // Writing to the emit output should not fail. Typically the output - // is a byte.Buffer; writes to these never fail. - panic(err) - } - } - - first, ok := a[0].(string) - if !ok { - // First argument must be either the string to emit (case 1 from - // function-level comment), or a format string (case 2). - panic(fmt.Sprintf("First argument to emit() is not a string: %+v", a[0])) - } - - if len(a) == 1 { - // Single string argument. Assume no formatting requested. - if _, err := fmt.Fprint(out, first); err != nil { - // Writing to out should not fail. - panic(err) - } - return - - } - - // Formatting requested. - if _, err := fmt.Fprintf(out, first, a[1:]...); err != nil { - // Writing to out should not fail. - panic(err) - } -} - -// sourceBuffer represents fragments of generated go source code. -// -// sourceBuffer provides a convenient way to build up go souce fragments in -// memory. May be safely zero-value initialized. Not thread-safe. -type sourceBuffer struct { - // Current indentation level. - indent int - - // Memory buffer containing contents while they're being generated. - b bytes.Buffer -} - -func (b *sourceBuffer) reset() { - b.indent = 0 - b.b.Reset() -} - -func (b *sourceBuffer) incIndent() { - b.indent++ -} - -func (b *sourceBuffer) decIndent() { - if b.indent <= 0 { - panic("decIndent() without matching incIndent()") - } - b.indent-- -} - -func (b *sourceBuffer) emit(a ...interface{}) { - emit(&b.b, b.indent, a...) -} - -func (b *sourceBuffer) emitNoIndent(a ...interface{}) { - emit(&b.b, 0 /*indent*/, a...) -} - -func (b *sourceBuffer) inIndent(body func()) { - b.incIndent() - body() - b.decIndent() -} - -func (b *sourceBuffer) write(out io.Writer) error { - _, err := fmt.Fprint(out, b.b.String()) - return err -} - -// Write implements io.Writer.Write. -func (b *sourceBuffer) Write(buf []byte) (int, error) { - return (b.b.Write(buf)) -} - -// importStmt represents a single import statement. -type importStmt struct { - // Local name of the imported package. - name string - // Import path. - path string - // Indicates whether the local name is an alias, or simply the final - // component of the path. - aliased bool - // Indicates whether this import was referenced by generated code. - used bool -} - -func newImport(p string) *importStmt { - name := path.Base(p) - return &importStmt{ - name: name, - path: p, - aliased: false, - } -} - -func newImportFromSpec(spec *ast.ImportSpec, f *token.FileSet) *importStmt { - p := spec.Path.Value[1 : len(spec.Path.Value)-1] // Strip the " quotes around path. - name := path.Base(p) - if name == "" || name == "/" || name == "." { - panic(fmt.Sprintf("Couldn't process local package name for import at %s, (processed as %s)", - f.Position(spec.Path.Pos()), name)) - } - if spec.Name != nil { - name = spec.Name.Name - } - return &importStmt{ - name: name, - path: p, - aliased: spec.Name != nil, - } -} - -func (i *importStmt) String() string { - if i.aliased { - return fmt.Sprintf("%s \"%s\"", i.name, i.path) - } - return fmt.Sprintf("\"%s\"", i.path) -} - -func (i *importStmt) markUsed() { - i.used = true -} - -func (i *importStmt) equivalent(other *importStmt) bool { - return i.name == other.name && i.path == other.path && i.aliased == other.aliased -} - -// importTable represents a collection of importStmts. -type importTable struct { - // Map of imports and whether they should be copied to the output. - is map[string]*importStmt -} - -func newImportTable() *importTable { - return &importTable{ - is: make(map[string]*importStmt), - } -} - -// Merges import statements from other into i. Collisions in import statements -// result in a panic. -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 - } -} - -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 - return s -} - -func (i *importTable) add(s string) *importStmt { - n := newImport(s) - return i.addStmt(n) -} - -func (i *importTable) addFromSpec(spec *ast.ImportSpec, f *token.FileSet) *importStmt { - return i.addStmt(newImportFromSpec(spec, f)) -} - -// Marks the import named n as used. If no such import is in the table, returns -// false. -func (i *importTable) markUsed(n string) bool { - if n, ok := i.is[n]; ok { - n.markUsed() - return true - } - return false -} - -func (i *importTable) clear() { - for _, i := range i.is { - i.used = false - } -} - -func (i *importTable) write(out io.Writer) error { - if len(i.is) == 0 { - // Nothing to import, we're done. - return nil - } - - imports := make([]string, 0, len(i.is)) - for _, i := range i.is { - if i.used { - imports = append(imports, i.String()) - } - } - sort.Strings(imports) - - var b sourceBuffer - b.emit("import (\n") - b.incIndent() - for _, i := range imports { - b.emit("%s\n", i) - } - b.decIndent() - b.emit(")\n\n") - - return b.write(out) -} |