Treat GOPATH as a list of workspaces; use first workspace.

dmitshur · neelance · commit 849fd25ac7bd · 2014-07-06T12:28:23.000+02:00
Fixes #60. The behavior should be improved (fixes #60) if user has multiple GOPATH workspaces. The behavior should be unchanged if user has a single GOPATH workspace. First cut at correct GOPATH handling as a list, rather than assuming it contains no more than 1 entry. It's unfinished and needs more work to correctly handle all scenarios with multiple GOPATH workspaces, but it's an improvement over the original version. Use filepath.Join instead of concatenating strings for path manipulation.
diff --git a/build/build.go b/build/build.go
@@ -59,7 +59,8 @@ func Import(path string, mode build.ImportMode, archSuffix string) (*build.Packa
 	}
 	if _, err := os.Stat(pkg.PkgObj); os.IsNotExist(err) && strings.HasPrefix(pkg.PkgObj, build.Default.GOROOT) {
 		// fall back to GOPATH
-		gopathPkgObj := build.Default.GOPATH + pkg.PkgObj[len(build.Default.GOROOT):]
+		firstGopathWorkspace := filepath.SplitList(build.Default.GOPATH)[0] // TODO: Need to check inside all GOPATH workspaces.
+		gopathPkgObj := filepath.Join(firstGopathWorkspace, pkg.PkgObj[len(build.Default.GOROOT):])
 		if _, err := os.Stat(gopathPkgObj); err == nil {
 			pkg.PkgObj = gopathPkgObj
 		}
@@ -401,8 +402,9 @@ func (s *Session) BuildPackage(pkg *PackageData) error {
 
 	if err := s.writeLibraryPackage(pkg, pkg.PkgObj); err != nil {
 		if strings.HasPrefix(pkg.PkgObj, s.options.GOROOT) {
-			// fall back to GOPATH
-			if err := s.writeLibraryPackage(pkg, s.options.GOPATH+pkg.PkgObj[len(s.options.GOROOT):]); err != nil {
+			// fall back to first GOPATH workspace
+			firstGopathWorkspace := filepath.SplitList(s.options.GOPATH)[0]
+			if err := s.writeLibraryPackage(pkg, filepath.Join(firstGopathWorkspace, pkg.PkgObj[len(s.options.GOROOT):])); err != nil {
 				return err
 			}
 			return nil
@@ -461,9 +463,9 @@ func (s *Session) WriteCommandPackage(pkg *PackageData, pkgObj string) error {
 			}
 			pos := fileSet.Position(originalPos)
 			file := pos.Filename
-			switch {
-			case strings.HasPrefix(file, s.options.GOPATH):
-				file = filepath.ToSlash(filepath.Join("/gopath", file[len(s.options.GOPATH):]))
+			switch hasGopathPrefix, prefixLen := hasGopathPrefix(file, s.options.GOPATH); {
+			case hasGopathPrefix:
+				file = filepath.ToSlash(filepath.Join("/gopath", file[prefixLen:]))
 			case strings.HasPrefix(file, s.options.GOROOT):
 				file = filepath.ToSlash(filepath.Join("/goroot", file[len(s.options.GOROOT):]))
 			default:
@@ -480,6 +482,18 @@ func (s *Session) WriteCommandPackage(pkg *PackageData, pkgObj string) error {
 	return compiler.WriteProgramCode(deps, s.ImportContext, sourceMapFilter)
 }
 
+// hasGopathPrefix returns true and the length of the matched GOPATH workspace,
+// iff file has a prefix that matches one of the GOPATH workspaces.
+func hasGopathPrefix(file, gopath string) (hasGopathPrefix bool, prefixLen int) {
+	gopathWorkspaces := filepath.SplitList(gopath)
+	for _, gopathWorkspace := range gopathWorkspaces {
+		if strings.HasPrefix(file, gopathWorkspace) {
+			return true, len(gopathWorkspace)
+		}
+	}
+	return false, 0
+}
+
 func (s *Session) WaitForChange() {
 	fmt.Println("\x1B[32mwatching for changes...\x1B[39m")
 	select {
diff --git a/tool.go b/tool.go
@@ -136,7 +136,8 @@ func main() {
 			exitCode := handleError(func() error {
 				pkgs := installFlags.Args()
 				if len(pkgs) == 0 {
-					srcDir, err := filepath.EvalSymlinks(filepath.Join(build.Default.GOPATH, "src"))
+					firstGopathWorkspace := filepath.SplitList(build.Default.GOPATH)[0] // TODO: The GOPATH workspace that contains the package source should be chosen.
+					srcDir, err := filepath.EvalSymlinks(filepath.Join(firstGopathWorkspace, "src"))
 					if err != nil {
 						return err
 					}
@@ -220,7 +221,8 @@ func main() {
 				}
 			}
 			if len(pkgs) == 0 {
-				srcDir, err := filepath.EvalSymlinks(filepath.Join(build.Default.GOPATH, "src"))
+				firstGopathWorkspace := filepath.SplitList(build.Default.GOPATH)[0] // TODO: Not sure if always picking first GOPATH workspace here is the right thing.
+				srcDir, err := filepath.EvalSymlinks(filepath.Join(firstGopathWorkspace, "src"))
 				if err != nil {
 					return err
 				}

Original file line number	Diff line number	Diff line change
`@@ -136,7 +136,8 @@ func main() {`
`136`	`136`	`exitCode := handleError(func() error {`
`137`	`137`	`pkgs := installFlags.Args()`
`138`	`138`	`if len(pkgs) == 0 {`
`139`		`- srcDir, err := filepath.EvalSymlinks(filepath.Join(build.Default.GOPATH, "src"))`
	`139`	`+ firstGopathWorkspace := filepath.SplitList(build.Default.GOPATH)[0] // TODO: The GOPATH workspace that contains the package source should be chosen.`
	`140`	`+ srcDir, err := filepath.EvalSymlinks(filepath.Join(firstGopathWorkspace, "src"))`
`140`	`141`	`if err != nil {`
`141`	`142`	`return err`
`142`	`143`	`}`
`@@ -220,7 +221,8 @@ func main() {`
`220`	`221`	`}`
`221`	`222`	`}`
`222`	`223`	`if len(pkgs) == 0 {`
`223`		`- srcDir, err := filepath.EvalSymlinks(filepath.Join(build.Default.GOPATH, "src"))`
	`224`	`+ firstGopathWorkspace := filepath.SplitList(build.Default.GOPATH)[0] // TODO: Not sure if always picking first GOPATH workspace here is the right thing.`
	`225`	`+ srcDir, err := filepath.EvalSymlinks(filepath.Join(firstGopathWorkspace, "src"))`
`224`	`226`	`if err != nil {`
`225`	`227`	`return err`
`226`	`228`	`}`