re PR go/65462 (Use of 'go get' with gccgo is not finding dependencies correctly)

PR go/65462
cmd: Fix dependencies for 'go get' with gccgo

Problem described in GCC BZ 65462.
Generate the list of the standard GO package names based on what was built into libgo in the libgo Makefile.
Change the var name from reqPkgSrc to reqStdPkgSrc to clarify it only affects standard GO packages.
Skip the attempted loading of a package only if it is a standard GO package and the flag is set indicating its source is not required to be available.
This requires a corresponding change to gotools to build and link in the new file containing the list of standard GO package names that was generated by the libgo Makefile.

gotools/:
	PR go/65462
	* Makefile.am (go_cmd_go_files): Add $(libgodir)/zstdpkglist.go.
	* Makefile.in: Rebuild.

From-SVN: r221643

gotools/ChangeLog

@@ -1,3 +1,9 @@
+2015-03-24  Ian Lance Taylor  <iant@google.com>
+
+	PR go/65462
+	* Makefile.am (go_cmd_go_files): Add $(libgodir)/zstdpkglist.go.
+	* Makefile.in: Rebuild.
+
 2015-03-12  Ian Lance Taylor  <iant@google.com>
 
 	* Makefile.am (GOLINK): Add GOCFLAGS.

gotools/Makefile.am

@@ -67,7 +67,8 @@ go_cmd_go_files = \
 	$(cmdsrcdir)/go/tool.go \
 	$(cmdsrcdir)/go/vcs.go \
 	$(cmdsrcdir)/go/version.go \
-	$(cmdsrcdir)/go/vet.go
+	$(cmdsrcdir)/go/vet.go \
+	$(libgodir)/zstdpkglist.go
 
 go_cmd_gofmt_files = \
 	$(cmdsrcdir)/gofmt/doc.go \

gotools/Makefile.in

@@ -257,7 +257,8 @@ go_cmd_go_files = \
 	$(cmdsrcdir)/go/tool.go \
 	$(cmdsrcdir)/go/vcs.go \
 	$(cmdsrcdir)/go/version.go \
-	$(cmdsrcdir)/go/vet.go
+	$(cmdsrcdir)/go/vet.go \
+	$(libgodir)/zstdpkglist.go
 
 go_cmd_gofmt_files = \
 	$(cmdsrcdir)/gofmt/doc.go \
@@ -518,8 +519,8 @@ distclean-generic:
 maintainer-clean-generic:
 	@echo "This command is intended for maintainers to use"
 	@echo "it deletes files that may require special tools to rebuild."
-@NATIVE_FALSE@install-exec-local:
 @NATIVE_FALSE@uninstall-local:
+@NATIVE_FALSE@install-exec-local:
 clean: clean-am
 
 clean-am: clean-binPROGRAMS clean-generic clean-noinstPROGRAMS \

libgo/Makefile.am

@@ -978,6 +978,20 @@ s-version: Makefile
 	$(SHELL) $(srcdir)/mvifdiff.sh version.go.tmp version.go
 	$(STAMP) $@
 
+noinst_DATA = zstdpkglist.go
+
+# Generate the list of go std packages that were included in libgo
+zstdpkglist.go: s-zstdpkglist; @true
+s-zstdpkglist: Makefile
+	rm -f zstdpkglist.go.tmp
+	echo 'package main' > zstdpkglist.go.tmp
+	echo "" >> zstdpkglist.go.tmp
+	echo 'var stdpkg = map[string]bool{' >> zstdpkglist.go.tmp
+	echo $(libgo_go_objs) 'unsafe.lo' | sed 's/\.lo /\": true,\n/g' | sed 's/\.lo/\": true,/' | sed 's/-go//' | grep -v _c | sed 's/^/\t\"/' | sort | uniq >> zstdpkglist.go.tmp
+	echo '}' >> zstdpkglist.go.tmp
+	$(SHELL) $(srcdir)/mvifdiff.sh zstdpkglist.go.tmp zstdpkglist.go
+	$(STAMP) $@
+
 go_sort_files = \
 	go/sort/search.go \
 	go/sort/sort.go

libgo/Makefile.in

@@ -269,23 +269,24 @@ RECURSIVE_TARGETS = all-recursive check-recursive dvi-recursive \
 	install-pdf-recursive install-ps-recursive install-recursive \
 	installcheck-recursive installdirs-recursive pdf-recursive \
 	ps-recursive uninstall-recursive
-DATA = $(toolexeclibgo_DATA) $(toolexeclibgoarchive_DATA) \
-	$(toolexeclibgocompress_DATA) $(toolexeclibgocontainer_DATA) \
-	$(toolexeclibgocrypto_DATA) $(toolexeclibgocryptox509_DATA) \
-	$(toolexeclibgodatabase_DATA) $(toolexeclibgodatabasesql_DATA) \
-	$(toolexeclibgodebug_DATA) $(toolexeclibgoencoding_DATA) \
-	$(toolexeclibgoexp_DATA) $(toolexeclibgogo_DATA) \
-	$(toolexeclibgohash_DATA) $(toolexeclibgohtml_DATA) \
-	$(toolexeclibgoimage_DATA) $(toolexeclibgoimagecolor_DATA) \
-	$(toolexeclibgoindex_DATA) $(toolexeclibgoio_DATA) \
-	$(toolexeclibgolog_DATA) $(toolexeclibgomath_DATA) \
-	$(toolexeclibgomime_DATA) $(toolexeclibgonet_DATA) \
-	$(toolexeclibgonethttp_DATA) $(toolexeclibgonetrpc_DATA) \
-	$(toolexeclibgoold_DATA) $(toolexeclibgoos_DATA) \
-	$(toolexeclibgopath_DATA) $(toolexeclibgoregexp_DATA) \
-	$(toolexeclibgoruntime_DATA) $(toolexeclibgosync_DATA) \
-	$(toolexeclibgotesting_DATA) $(toolexeclibgotext_DATA) \
-	$(toolexeclibgotexttemplate_DATA) $(toolexeclibgounicode_DATA)
+DATA = $(noinst_DATA) $(toolexeclibgo_DATA) \
+	$(toolexeclibgoarchive_DATA) $(toolexeclibgocompress_DATA) \
+	$(toolexeclibgocontainer_DATA) $(toolexeclibgocrypto_DATA) \
+	$(toolexeclibgocryptox509_DATA) $(toolexeclibgodatabase_DATA) \
+	$(toolexeclibgodatabasesql_DATA) $(toolexeclibgodebug_DATA) \
+	$(toolexeclibgoencoding_DATA) $(toolexeclibgoexp_DATA) \
+	$(toolexeclibgogo_DATA) $(toolexeclibgohash_DATA) \
+	$(toolexeclibgohtml_DATA) $(toolexeclibgoimage_DATA) \
+	$(toolexeclibgoimagecolor_DATA) $(toolexeclibgoindex_DATA) \
+	$(toolexeclibgoio_DATA) $(toolexeclibgolog_DATA) \
+	$(toolexeclibgomath_DATA) $(toolexeclibgomime_DATA) \
+	$(toolexeclibgonet_DATA) $(toolexeclibgonethttp_DATA) \
+	$(toolexeclibgonetrpc_DATA) $(toolexeclibgoold_DATA) \
+	$(toolexeclibgoos_DATA) $(toolexeclibgopath_DATA) \
+	$(toolexeclibgoregexp_DATA) $(toolexeclibgoruntime_DATA) \
+	$(toolexeclibgosync_DATA) $(toolexeclibgotesting_DATA) \
+	$(toolexeclibgotext_DATA) $(toolexeclibgotexttemplate_DATA) \
+	$(toolexeclibgounicode_DATA)
 RECURSIVE_CLEAN_TARGETS = mostlyclean-recursive clean-recursive	\
   distclean-recursive maintainer-clean-recursive
 AM_RECURSIVE_TARGETS = $(RECURSIVE_TARGETS:-recursive=) \
@@ -1154,6 +1155,7 @@ go_runtime_files = \
 	go/runtime/softfloat64.go \
 	version.go
 
+noinst_DATA = zstdpkglist.go
 go_sort_files = \
 	go/sort/search.go \
 	go/sort/sort.go
@@ -4394,6 +4396,18 @@ s-version: Makefile
 	$(SHELL) $(srcdir)/mvifdiff.sh version.go.tmp version.go
 	$(STAMP) $@
 
+# Generate the list of go std packages that were included in libgo
+zstdpkglist.go: s-zstdpkglist; @true
+s-zstdpkglist: Makefile
+	rm -f zstdpkglist.go.tmp
+	echo 'package main' > zstdpkglist.go.tmp
+	echo "" >> zstdpkglist.go.tmp
+	echo 'var stdpkg = map[string]bool{' >> zstdpkglist.go.tmp
+	echo $(libgo_go_objs) 'unsafe.lo' | sed 's/\.lo /\": true,\n/g' | sed 's/\.lo/\": true,/' | sed 's/-go//' | grep -v _c | sed 's/^/\t\"/' | sort | uniq >> zstdpkglist.go.tmp
+	echo '}' >> zstdpkglist.go.tmp
+	$(SHELL) $(srcdir)/mvifdiff.sh zstdpkglist.go.tmp zstdpkglist.go
+	$(STAMP) $@
+
 libcalls.go: s-libcalls; @true
 s-libcalls: libcalls-list go/syscall/mksyscall.awk $(go_base_syscall_files)
 	rm -f libcalls.go.tmp

libgo/go/cmd/go/build.go

@@ -132,7 +132,8 @@ var buildLdflags []string    // -ldflags flag
 var buildGccgoflags []string // -gccgoflags flag
 var buildRace bool           // -race flag
 
-var reqPkgSrc bool // req src for Imports
+// Require the source for go std packages
+var reqStdPkgSrc bool
 var buildContext = build.Default
 var buildToolchain toolchain = noToolchain{}
 
@@ -187,9 +188,9 @@ func addBuildFlags(cmd *Command) {
 	cmd.Flag.BoolVar(&buildRace, "race", false, "")
 	switch build.Default.Compiler {
 	case "gc":
-		reqPkgSrc = true
+		reqStdPkgSrc = true
 	case "gccgo":
-		reqPkgSrc = false
+		reqStdPkgSrc = false
 	}
 }
 
@@ -579,7 +580,7 @@ func (b *builder) action(mode buildMode, depMode buildMode, p *Package) *action
 	// are writing is not the cgo we need to use.
 
 	if goos == runtime.GOOS && goarch == runtime.GOARCH && !buildRace {
-		if reqPkgSrc {
+		if reqStdPkgSrc {
 			if len(p.CgoFiles) > 0 || p.Standard && p.ImportPath == "runtime/cgo" {
 				var stk importStack
 				p1 := loadPackage("cmd/cgo", &stk)

libgo/go/cmd/go/pkg.go

@@ -112,7 +112,11 @@ func (p *Package) copyBuild(pp *build.Package) {
 	p.ConflictDir = pp.ConflictDir
 	// TODO? Target
 	p.Goroot = pp.Goroot
-	p.Standard = p.Goroot && p.ImportPath != "" && !strings.Contains(p.ImportPath, ".")
+	if buildContext.Compiler == "gccgo" {
+		p.Standard = stdpkg[p.ImportPath]
+	} else {
+		p.Standard = p.Goroot && p.ImportPath != "" && !strings.Contains(p.ImportPath, ".")
+	}
 	p.GoFiles = pp.GoFiles
 	p.CgoFiles = pp.CgoFiles
 	p.IgnoredGoFiles = pp.IgnoredGoFiles
@@ -582,7 +586,7 @@ func (p *Package) load(stk *importStack, bp *build.Package, err error) *Package
 			continue
 		}
 		p1 := loadImport(path, p.Dir, stk, p.build.ImportPos[path])
-		if !reqPkgSrc && p1.Root == "" {
+		if !reqStdPkgSrc && p1.Standard {
 			continue
 		}
 		if p1.local {

libgo/go/cmd/go/test.go

@@ -384,17 +384,18 @@ func runTest(cmd *Command, args []string) {
 		delete(deps, "unsafe")
 
 		all := []string{}
-		if reqPkgSrc {
-			for path := range deps {
-				if !build.IsLocalImport(path) {
-					all = append(all, path)
-				}
+		for path := range deps {
+			if !build.IsLocalImport(path) {
+				all = append(all, path)
 			}
 		}
 		sort.Strings(all)
 
 		a := &action{}
 		for _, p := range packagesForBuild(all) {
+			if !reqStdPkgSrc && p.Standard {
+				continue
+			}
 			a.deps = append(a.deps, b.action(modeInstall, modeInstall, p))
 		}
 		b.do(a)
@@ -563,7 +564,7 @@ func (b *builder) test(p *Package) (buildAction, runAction, printAction *action,
 	stk.push(p.ImportPath + " (test)")
 	for _, path := range p.TestImports {
 		p1 := loadImport(path, p.Dir, &stk, p.build.TestImportPos[path])
-		if !reqPkgSrc && p1.Root == "" {
+		if !reqStdPkgSrc && p1.Standard {
 			continue
 		}
 		if p1.Error != nil {
@@ -591,7 +592,7 @@ func (b *builder) test(p *Package) (buildAction, runAction, printAction *action,
 			continue
 		}
 		p1 := loadImport(path, p.Dir, &stk, p.build.XTestImportPos[path])
-		if !reqPkgSrc && p1.Root == "" {
+		if !reqStdPkgSrc && p1.Standard {
 			continue
 		}
 		if p1.Error != nil {
@@ -722,7 +723,7 @@ func (b *builder) test(p *Package) (buildAction, runAction, printAction *action,
 			pmain.imports = append(pmain.imports, ptest)
 		} else {
 			p1 := loadImport(dep, "", &stk, nil)
-			if !reqPkgSrc && p1.Root == "" {
+			if !reqStdPkgSrc && p1.Standard {
 				continue
 			}
 			if p1.Error != nil {