Update libgo so that the vet tool works with gccgo. This is a backport of https://golang.org/cl/113715 and https://golang.org/cl/113716:
cmd/go: don't pass -compiler flag to vet Without this running go vet -compiler=gccgo causes vet to fail. The vet tool does need to know the compiler, but it is passed in vetConfig.Compiler. cmd/go, cmd/vet, go/internal/gccgoimport: make vet work with gccgo When using libgo, there is no package file for a standard library package. Since it is impossible for the go tool to rebuild the package, and since the package file exists only in the form of a .gox file, this seems like the best choice. Unfortunately it was confusing vet, which wanted to see a real file. This caused vet to report errors about missing package files for standard library packages. The gccgoimporter knows how to correctly handle this case. Fix this by 1) telling vet which packages are standard; 2) letting vet skip those packages; 3) letting the gccgoimporter handle this case. As a separate required fix, libgo has no runtime/cgo package, so don't try to depend on it (as it happens, this fixes https://golang.org/issue/25324). Bootstrapped and ran Go tests on x86_64-pc-linux-gnu. Committed to mainline. Ian
Index: gcc/go/gofrontend/MERGE =================================================================== --- gcc/go/gofrontend/MERGE (revision 260908) +++ gcc/go/gofrontend/MERGE (working copy) @@ -1,4 +1,4 @@ -572b19513766e9e5cc4aa8d984a89c93880726ba +9731580e76c065b76e3a103356bb8920da05a685 The first line of this file holds the git revision number of the last merge done from the gofrontend repository. Index: libgo/go/cmd/go/internal/load/pkg.go =================================================================== --- libgo/go/cmd/go/internal/load/pkg.go (revision 260097) +++ libgo/go/cmd/go/internal/load/pkg.go (working copy) @@ -1010,7 +1010,7 @@ func (p *Package) load(stk *ImportStack, // Cgo translation adds imports of "runtime/cgo" and "syscall", // except for certain packages, to avoid circular dependencies. - if p.UsesCgo() && (!p.Standard || !cgoExclude[p.ImportPath]) { + if p.UsesCgo() && (!p.Standard || !cgoExclude[p.ImportPath]) && cfg.BuildContext.Compiler != "gccgo" { addImport("runtime/cgo") } if p.UsesCgo() && (!p.Standard || !cgoSyscallExclude[p.ImportPath]) { @@ -1019,7 +1019,9 @@ func (p *Package) load(stk *ImportStack, // SWIG adds imports of some standard packages. if p.UsesSwig() { - addImport("runtime/cgo") + if cfg.BuildContext.Compiler != "gccgo" { + addImport("runtime/cgo") + } addImport("syscall") addImport("sync") @@ -1225,7 +1227,7 @@ func LinkerDeps(p *Package) []string { deps := []string{"runtime"} // External linking mode forces an import of runtime/cgo. - if externalLinkingForced(p) { + if externalLinkingForced(p) && cfg.BuildContext.Compiler != "gccgo" { deps = append(deps, "runtime/cgo") } // On ARM with GOARM=5, it forces an import of math, for soft floating point. Index: libgo/go/cmd/go/internal/vet/vetflag.go =================================================================== --- libgo/go/cmd/go/internal/vet/vetflag.go (revision 260048) +++ libgo/go/cmd/go/internal/vet/vetflag.go (working copy) @@ -90,7 +90,7 @@ func vetFlags(args []string) (passToVet, } switch f.Name { // Flags known to the build but not to vet, so must be dropped. - case "x", "n", "vettool": + case "x", "n", "vettool", "compiler": if extraWord { args = append(args[:i], args[i+2:]...) extraWord = false Index: libgo/go/cmd/go/internal/work/exec.go =================================================================== --- libgo/go/cmd/go/internal/work/exec.go (revision 260097) +++ libgo/go/cmd/go/internal/work/exec.go (working copy) @@ -512,6 +512,7 @@ func (b *Builder) build(a *Action) (err ImportPath: a.Package.ImportPath, ImportMap: make(map[string]string), PackageFile: make(map[string]string), + Standard: make(map[string]bool), } a.vetCfg = vcfg for i, raw := range a.Package.Internal.RawImports { @@ -548,17 +549,24 @@ func (b *Builder) build(a *Action) (err for _, a1 := range a.Deps { p1 := a1.Package - if p1 == nil || p1.ImportPath == "" || a1.built == "" { + if p1 == nil || p1.ImportPath == "" { continue } - fmt.Fprintf(&icfg, "packagefile %s=%s\n", p1.ImportPath, a1.built) + if a1.built != "" { + fmt.Fprintf(&icfg, "packagefile %s=%s\n", p1.ImportPath, a1.built) + } if vcfg != nil { // Add import mapping if needed // (for imports like "runtime/cgo" that appear only in generated code). if !vcfgMapped[p1.ImportPath] { vcfg.ImportMap[p1.ImportPath] = p1.ImportPath } - vcfg.PackageFile[p1.ImportPath] = a1.built + if a1.built != "" { + vcfg.PackageFile[p1.ImportPath] = a1.built + } + if p1.Standard { + vcfg.Standard[p1.ImportPath] = true + } } } @@ -693,6 +701,7 @@ type vetConfig struct { GoFiles []string ImportMap map[string]string PackageFile map[string]string + Standard map[string]bool ImportPath string SucceedOnTypecheckFailure bool @@ -722,7 +731,10 @@ func (b *Builder) vet(a *Action) error { if vcfg.ImportMap["fmt"] == "" { a1 := a.Deps[1] vcfg.ImportMap["fmt"] = "fmt" - vcfg.PackageFile["fmt"] = a1.built + if a1.built != "" { + vcfg.PackageFile["fmt"] = a1.built + } + vcfg.Standard["fmt"] = true } // During go test, ignore type-checking failures during vet. Index: libgo/go/cmd/vet/main.go =================================================================== --- libgo/go/cmd/vet/main.go (revision 260048) +++ libgo/go/cmd/vet/main.go (working copy) @@ -292,6 +292,7 @@ type vetConfig struct { GoFiles []string ImportMap map[string]string PackageFile map[string]string + Standard map[string]bool SucceedOnTypecheckFailure bool @@ -309,7 +310,12 @@ func (v *vetConfig) Import(path string) if p == "" { return nil, fmt.Errorf("unknown import path %q", path) } - if v.PackageFile[p] == "" && v.Compiler != "gccgo" { + if v.PackageFile[p] == "" { + if v.Compiler == "gccgo" && v.Standard[path] { + // gccgo doesn't have sources for standard library packages, + // but the importer will do the right thing. + return v.imp.Import(path) + } return nil, fmt.Errorf("unknown package file for import %q", path) } return v.imp.Import(p) @@ -318,6 +324,10 @@ func (v *vetConfig) Import(path string) func (v *vetConfig) openPackageFile(path string) (io.ReadCloser, error) { file := v.PackageFile[path] if file == "" { + if v.Compiler == "gccgo" && v.Standard[path] { + // The importer knows how to handle this. + return nil, nil + } // Note that path here has been translated via v.ImportMap, // unlike in the error in Import above. We prefer the error in // Import, but it's worth diagnosing this one too, just in case. Index: libgo/go/go/internal/gccgoimporter/importer.go =================================================================== --- libgo/go/go/internal/gccgoimporter/importer.go (revision 260048) +++ libgo/go/go/internal/gccgoimporter/importer.go (working copy) @@ -176,7 +176,7 @@ func GetImporter(searchpaths []string, i return p, nil } rc, err := lookup(pkgpath) - if err == nil { + if err == nil && rc != nil { defer rc.Close() rs, ok := rc.(io.ReadSeeker) if !ok {