diff options
author | Thomas Voss <mail@thomasvoss.com> | 2024-09-13 13:01:48 +0200 |
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committer | Thomas Voss <mail@thomasvoss.com> | 2024-09-13 13:01:48 +0200 |
commit | 548090e67f66acf84385c4152ca464e52d3e3319 (patch) | |
tree | 9b6de528bd7b0aa63362fa83f5c8e6a97f68a5d8 /vendor/golang.org/x/tools/go/internal/cgo | |
parent | a1d809960bee74df19c7e5fc34ffd1e4757cfdcb (diff) |
Migrate away from templ and towards html/template
Diffstat (limited to 'vendor/golang.org/x/tools/go/internal/cgo')
-rw-r--r-- | vendor/golang.org/x/tools/go/internal/cgo/cgo.go | 219 | ||||
-rw-r--r-- | vendor/golang.org/x/tools/go/internal/cgo/cgo_pkgconfig.go | 42 |
2 files changed, 261 insertions, 0 deletions
diff --git a/vendor/golang.org/x/tools/go/internal/cgo/cgo.go b/vendor/golang.org/x/tools/go/internal/cgo/cgo.go new file mode 100644 index 0000000..697974b --- /dev/null +++ b/vendor/golang.org/x/tools/go/internal/cgo/cgo.go @@ -0,0 +1,219 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Package cgo handles cgo preprocessing of files containing `import "C"`. +// +// DESIGN +// +// The approach taken is to run the cgo processor on the package's +// CgoFiles and parse the output, faking the filenames of the +// resulting ASTs so that the synthetic file containing the C types is +// called "C" (e.g. "~/go/src/net/C") and the preprocessed files +// have their original names (e.g. "~/go/src/net/cgo_unix.go"), +// not the names of the actual temporary files. +// +// The advantage of this approach is its fidelity to 'go build'. The +// downside is that the token.Position.Offset for each AST node is +// incorrect, being an offset within the temporary file. Line numbers +// should still be correct because of the //line comments. +// +// The logic of this file is mostly plundered from the 'go build' +// tool, which also invokes the cgo preprocessor. +// +// +// REJECTED ALTERNATIVE +// +// An alternative approach that we explored is to extend go/types' +// Importer mechanism to provide the identity of the importing package +// so that each time `import "C"` appears it resolves to a different +// synthetic package containing just the objects needed in that case. +// The loader would invoke cgo but parse only the cgo_types.go file +// defining the package-level objects, discarding the other files +// resulting from preprocessing. +// +// The benefit of this approach would have been that source-level +// syntax information would correspond exactly to the original cgo +// file, with no preprocessing involved, making source tools like +// godoc, guru, and eg happy. However, the approach was rejected +// due to the additional complexity it would impose on go/types. (It +// made for a beautiful demo, though.) +// +// cgo files, despite their *.go extension, are not legal Go source +// files per the specification since they may refer to unexported +// members of package "C" such as C.int. Also, a function such as +// C.getpwent has in effect two types, one matching its C type and one +// which additionally returns (errno C.int). The cgo preprocessor +// uses name mangling to distinguish these two functions in the +// processed code, but go/types would need to duplicate this logic in +// its handling of function calls, analogous to the treatment of map +// lookups in which y=m[k] and y,ok=m[k] are both legal. + +package cgo + +import ( + "fmt" + "go/ast" + "go/build" + "go/parser" + "go/token" + "log" + "os" + "os/exec" + "path/filepath" + "regexp" + "strings" +) + +// ProcessFiles invokes the cgo preprocessor on bp.CgoFiles, parses +// the output and returns the resulting ASTs. +func ProcessFiles(bp *build.Package, fset *token.FileSet, DisplayPath func(path string) string, mode parser.Mode) ([]*ast.File, error) { + tmpdir, err := os.MkdirTemp("", strings.Replace(bp.ImportPath, "/", "_", -1)+"_C") + if err != nil { + return nil, err + } + defer os.RemoveAll(tmpdir) + + pkgdir := bp.Dir + if DisplayPath != nil { + pkgdir = DisplayPath(pkgdir) + } + + cgoFiles, cgoDisplayFiles, err := Run(bp, pkgdir, tmpdir, false) + if err != nil { + return nil, err + } + var files []*ast.File + for i := range cgoFiles { + rd, err := os.Open(cgoFiles[i]) + if err != nil { + return nil, err + } + display := filepath.Join(bp.Dir, cgoDisplayFiles[i]) + f, err := parser.ParseFile(fset, display, rd, mode) + rd.Close() + if err != nil { + return nil, err + } + files = append(files, f) + } + return files, nil +} + +var cgoRe = regexp.MustCompile(`[/\\:]`) + +// Run invokes the cgo preprocessor on bp.CgoFiles and returns two +// lists of files: the resulting processed files (in temporary +// directory tmpdir) and the corresponding names of the unprocessed files. +// +// Run is adapted from (*builder).cgo in +// $GOROOT/src/cmd/go/build.go, but these features are unsupported: +// Objective C, CGOPKGPATH, CGO_FLAGS. +// +// If useabs is set to true, absolute paths of the bp.CgoFiles will be passed in +// to the cgo preprocessor. This in turn will set the // line comments +// referring to those files to use absolute paths. This is needed for +// go/packages using the legacy go list support so it is able to find +// the original files. +func Run(bp *build.Package, pkgdir, tmpdir string, useabs bool) (files, displayFiles []string, err error) { + cgoCPPFLAGS, _, _, _ := cflags(bp, true) + _, cgoexeCFLAGS, _, _ := cflags(bp, false) + + if len(bp.CgoPkgConfig) > 0 { + pcCFLAGS, err := pkgConfigFlags(bp) + if err != nil { + return nil, nil, err + } + cgoCPPFLAGS = append(cgoCPPFLAGS, pcCFLAGS...) + } + + // Allows including _cgo_export.h from .[ch] files in the package. + cgoCPPFLAGS = append(cgoCPPFLAGS, "-I", tmpdir) + + // _cgo_gotypes.go (displayed "C") contains the type definitions. + files = append(files, filepath.Join(tmpdir, "_cgo_gotypes.go")) + displayFiles = append(displayFiles, "C") + for _, fn := range bp.CgoFiles { + // "foo.cgo1.go" (displayed "foo.go") is the processed Go source. + f := cgoRe.ReplaceAllString(fn[:len(fn)-len("go")], "_") + files = append(files, filepath.Join(tmpdir, f+"cgo1.go")) + displayFiles = append(displayFiles, fn) + } + + var cgoflags []string + if bp.Goroot && bp.ImportPath == "runtime/cgo" { + cgoflags = append(cgoflags, "-import_runtime_cgo=false") + } + if bp.Goroot && bp.ImportPath == "runtime/race" || bp.ImportPath == "runtime/cgo" { + cgoflags = append(cgoflags, "-import_syscall=false") + } + + var cgoFiles []string = bp.CgoFiles + if useabs { + cgoFiles = make([]string, len(bp.CgoFiles)) + for i := range cgoFiles { + cgoFiles[i] = filepath.Join(pkgdir, bp.CgoFiles[i]) + } + } + + args := stringList( + "go", "tool", "cgo", "-objdir", tmpdir, cgoflags, "--", + cgoCPPFLAGS, cgoexeCFLAGS, cgoFiles, + ) + if false { + log.Printf("Running cgo for package %q: %s (dir=%s)", bp.ImportPath, args, pkgdir) + } + cmd := exec.Command(args[0], args[1:]...) + cmd.Dir = pkgdir + cmd.Env = append(os.Environ(), "PWD="+pkgdir) + cmd.Stdout = os.Stderr + cmd.Stderr = os.Stderr + if err := cmd.Run(); err != nil { + return nil, nil, fmt.Errorf("cgo failed: %s: %s", args, err) + } + + return files, displayFiles, nil +} + +// -- unmodified from 'go build' --------------------------------------- + +// Return the flags to use when invoking the C or C++ compilers, or cgo. +func cflags(p *build.Package, def bool) (cppflags, cflags, cxxflags, ldflags []string) { + var defaults string + if def { + defaults = "-g -O2" + } + + cppflags = stringList(envList("CGO_CPPFLAGS", ""), p.CgoCPPFLAGS) + cflags = stringList(envList("CGO_CFLAGS", defaults), p.CgoCFLAGS) + cxxflags = stringList(envList("CGO_CXXFLAGS", defaults), p.CgoCXXFLAGS) + ldflags = stringList(envList("CGO_LDFLAGS", defaults), p.CgoLDFLAGS) + return +} + +// envList returns the value of the given environment variable broken +// into fields, using the default value when the variable is empty. +func envList(key, def string) []string { + v := os.Getenv(key) + if v == "" { + v = def + } + return strings.Fields(v) +} + +// stringList's arguments should be a sequence of string or []string values. +// stringList flattens them into a single []string. +func stringList(args ...interface{}) []string { + var x []string + for _, arg := range args { + switch arg := arg.(type) { + case []string: + x = append(x, arg...) + case string: + x = append(x, arg) + default: + panic("stringList: invalid argument") + } + } + return x +} diff --git a/vendor/golang.org/x/tools/go/internal/cgo/cgo_pkgconfig.go b/vendor/golang.org/x/tools/go/internal/cgo/cgo_pkgconfig.go new file mode 100644 index 0000000..2455be5 --- /dev/null +++ b/vendor/golang.org/x/tools/go/internal/cgo/cgo_pkgconfig.go @@ -0,0 +1,42 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package cgo + +import ( + "errors" + "fmt" + "go/build" + "os/exec" + "strings" +) + +// pkgConfig runs pkg-config with the specified arguments and returns the flags it prints. +func pkgConfig(mode string, pkgs []string) (flags []string, err error) { + cmd := exec.Command("pkg-config", append([]string{mode}, pkgs...)...) + out, err := cmd.Output() + if err != nil { + s := fmt.Sprintf("%s failed: %v", strings.Join(cmd.Args, " "), err) + if len(out) > 0 { + s = fmt.Sprintf("%s: %s", s, out) + } + if err, ok := err.(*exec.ExitError); ok && len(err.Stderr) > 0 { + s = fmt.Sprintf("%s\nstderr:\n%s", s, err.Stderr) + } + return nil, errors.New(s) + } + if len(out) > 0 { + flags = strings.Fields(string(out)) + } + return +} + +// pkgConfigFlags calls pkg-config if needed and returns the cflags +// needed to build the package. +func pkgConfigFlags(p *build.Package) (cflags []string, err error) { + if len(p.CgoPkgConfig) == 0 { + return nil, nil + } + return pkgConfig("--cflags", p.CgoPkgConfig) +} |