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Diffstat (limited to 'tools/go_marshal/gomarshal/generator.go')
-rw-r--r--tools/go_marshal/gomarshal/generator.go378
1 files changed, 0 insertions, 378 deletions
diff --git a/tools/go_marshal/gomarshal/generator.go b/tools/go_marshal/gomarshal/generator.go
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index af90bdecb..000000000
--- a/tools/go_marshal/gomarshal/generator.go
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@@ -1,378 +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"
-)
-
-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 a
-// similarly-named source identifier. Avoid problems by refusing the generate
-// code when we see these.
-//
-// 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{
- "src", "srcs", "dst", "dsts", "blk", "buf", "err",
- // All single-letter identifiers.
-}
-
-// 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 they're always added to the generated code.
- g.imports.add(i).markUsed()
- }
- g.imports.add(marshalImport).markUsed()
- // The follow imports may or may not be used by the generated
- // code, depending what's required for the target types. Don't
- // mark these imports as used by default.
- g.imports.add(usermemImport)
- g.imports.add(safecopyImport)
- g.imports.add("unsafe")
-
- 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")
- 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
-}
-
-// collectMarshallabeTypes walks the parsed AST and collects a list of type
-// declarations for which we need to generate the Marshallable interface.
-func (g *Generator) collectMarshallabeTypes(a *ast.File, f *token.FileSet) []*ast.TypeSpec {
- var types []*ast.TypeSpec
- 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.
- t := spec.(*ast.TypeSpec)
- if _, ok := t.Type.(*ast.StructType); ok {
- debugfAt(f.Position(t.Pos()), "Collected marshallable type %s.\n", t.Name.Name)
- types = append(types, t)
- continue
- }
- debugf("Skipping declaration %v since it's not a struct declaration.\n", gdecl)
- }
- }
- 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 {
- badImportNames := make(map[string]bool)
- for _, i := range badIdents {
- badImportNames[i] = true
- }
-
- is := make(map[string]importStmt)
- for _, decl := range a.Decls {
- gdecl, ok := decl.(*ast.GenDecl)
- // 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 badImportNames[i.name] {
- 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 {
- // We're guaranteed to have only struct type specs by now. See
- // Generator.collectMarshallabeTypes.
- i := newInterfaceGenerator(t, fset)
- i.validate()
- i.emitMarshallable()
- 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.collectMarshallabeTypes(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))
- }
- }
-
- // Tool was invoked with input files with no data structures marked for code
- // generation. This is probably not what the user intended.
- if len(impls) == 0 {
- var buf bytes.Buffer
- fmt.Fprintf(&buf, "go_marshal invoked on these files, but they don't contain any types requiring code generation. Perhaps mark some with \"// +marshal\"?:\n")
- for _, i := range g.inputs {
- fmt.Fprintf(&buf, " %s\n", i)
- }
- abort(buf.String())
- }
-
- // Write output file header. These include things like package name and
- // import statements.
- if err := g.writeHeader(); err != nil {
- 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
- }
-
- imports := newImportTable()
- for _, t := range ts {
- imports.merge(t.imports)
- }
-
- if err := imports.write(g.outputTest); err != nil {
- return err
- }
-
- for _, t := range ts {
- if err := t.write(g.outputTest); err != nil {
- return err
- }
- }
- return nil
-}