Add autocomplete support for bazel mode.

config.go

@@ -21,6 +21,8 @@ import (
 type config struct {
 	ProposeBuiltins   bool   `json:"propose-builtins"`
 	LibPath           string `json:"lib-path"`
+	CustomPkgPrefix   string `json:"custom-pkg-prefix"`
+	CustomVendorDir   string `json:"custom-vendor-dir"`
 	Autobuild         bool   `json:"autobuild"`
 	ForceDebugOutput  string `json:"force-debug-output"`
 	PackageLookupMode string `json:"package-lookup-mode"`
@@ -30,6 +32,7 @@ type config struct {
 var g_config = config{
 	ProposeBuiltins:   false,
 	LibPath:           "",
+	CustomPkgPrefix:   "",
 	Autobuild:         false,
 	ForceDebugOutput:  "",
 	PackageLookupMode: "go",

declcache.go

@@ -273,6 +273,7 @@ func log_build_context(context *package_lookup_context) {
 	log.Printf(" GOPATH: %s\n", context.GOPATH)
 	log.Printf(" GOOS: %s\n", context.GOOS)
 	log.Printf(" GOARCH: %s\n", context.GOARCH)
+	log.Printf(" BzlProjectRoot: %q\n", context.BzlProjectRoot)
 	log.Printf(" GBProjectRoot: %q\n", context.GBProjectRoot)
 	log.Printf(" lib-path: %q\n", g_config.LibPath)
 }
@@ -320,6 +321,40 @@ func find_global_file(imp string, context *package_lookup_context) (string, bool
 		}
 	}
 
+	// bzl-specific lookup mode, only if the root dir was found
+	if g_config.PackageLookupMode == "bzl" && context.BzlProjectRoot != "" {
+		var root, impath string
+		if strings.HasPrefix(imp, g_config.CustomPkgPrefix+"/") {
+			root = filepath.Join(context.BzlProjectRoot, "bazel-bin")
+			impath = imp[len(g_config.CustomPkgPrefix)+1:]
+		} else if g_config.CustomVendorDir != "" {
+			// Try custom vendor dir.
+			root = filepath.Join(context.BzlProjectRoot, "bazel-bin", g_config.CustomVendorDir)
+			impath = imp
+		}
+
+		if root != "" && impath != "" {
+			// There might be more than one ".a" files in the pkg path with bazel.
+			// But the best practice is to keep one go_library build target in each
+			// pakcage directory so that it follows the standard Go package
+			// structure. Thus here we assume there is at most one ".a" file existing
+			// in the pkg path.
+			if d, err := os.Open(filepath.Join(root, impath)); err == nil {
+				defer d.Close()
+
+				if fis, err := d.Readdir(-1); err == nil {
+					for _, fi := range fis {
+						if !fi.IsDir() && filepath.Ext(fi.Name()) == ".a" {
+							pkg_path := filepath.Join(root, impath, fi.Name())
+							log_found_package_maybe(imp, pkg_path)
+							return pkg_path, true
+						}
+					}
+				}
+			}
+		}
+	}
+
 	if context.CurrentPackagePath != "" {
 		// Try vendor path first, see GO15VENDOREXPERIMENT.
 		// We don't check this environment variable however, seems like there is
@@ -382,6 +417,7 @@ func package_name(file *ast.File) string {
 
 type package_lookup_context struct {
 	build.Context
+	BzlProjectRoot     string
 	GBProjectRoot      string
 	CurrentPackagePath string
 }

server.go

@@ -151,6 +151,15 @@ func server_auto_complete(file []byte, filename string, cursor int, context_pack
 		g_daemon.drop_cache()
 	}
 	switch g_config.PackageLookupMode {
+	case "bzl":
+		// when package lookup mode is bzl, we set GOPATH to "" explicitly and
+		// BzlProjectRoot becomes valid (or empty)
+		var err error
+		g_daemon.context.GOPATH = ""
+		g_daemon.context.BzlProjectRoot, err = find_bzl_project_root(g_config.LibPath, filename)
+		if *g_debug && err != nil {
+			log.Printf("Bzl project root not found: %s", err)
+		}
 	case "gb":
 		// when package lookup mode is gb, we set GOPATH to "" explicitly and
 		// GBProjectRoot becomes valid (or empty)

utils.go

@@ -95,6 +95,32 @@ func has_prefix(s, prefix string, ignorecase bool) bool {
 	return strings.HasPrefix(s, prefix)
 }
 
+func find_bzl_project_root(libpath, path string) (string, error) {
+	if libpath == "" {
+		return "", fmt.Errorf("could not find project root, libpath is empty")
+	}
+
+	pathMap := map[string]struct{}{}
+	for _, lp := range strings.Split(libpath, ":") {
+		lp := strings.TrimSpace(lp)
+		pathMap[filepath.Clean(lp)] = struct{}{}
+	}
+
+	path = filepath.Dir(path)
+	if path == "" {
+		return "", fmt.Errorf("project root is blank")
+	}
+
+	start := path
+	for path != "/" {
+		if _, ok := pathMap[filepath.Clean(path)]; ok {
+			return path, nil
+		}
+		path = filepath.Dir(path)
+	}
+	return "", fmt.Errorf("could not find project root in %q or its parents", start)
+}
+
 // Code taken directly from `gb`, I hope author doesn't mind.
 func find_gb_project_root(path string) (string, error) {
 	path = filepath.Dir(path)