Add prototype gopackagesdriver based on bazel query.

AUTHORS

@@ -9,6 +9,7 @@
 Benjamin Staffin <[email protected]>
 Brian Silverman <[email protected]>
 David Santiago <[email protected]>
+Derivita Inc.
 Google Inc.
 Jake Voytko <[email protected]>
 Yuki Yugui Sonoda <[email protected]>

go/private/repositories.bzl

@@ -120,6 +120,18 @@ def go_rules_dependencies(is_rules_go = False):
         strip_prefix = "rules_cc-b1c40e1de81913a3c40e5948f78719c28152486d",
     )
 
+    # Needed for gopackagesdriver
+    _maybe(
+        http_archive,
+        name = "com_github_bazelbuild_bazel_watcher",
+        # master, as of 2021-03-03
+        urls = [
+            "https://github.com/bazelbuild/bazel-watcher/archive/512875a4a20b48d7539151e55b896f00be8c4a60.zip",
+        ],
+        sha256 = "e822f17ff2c533a068c48fd75764028aaee99f65381469c1b2f269e602e8fad7",
+        strip_prefix = "bazel-watcher-512875a4a20b48d7539151e55b896f00be8c4a60",
+    )
+
     # Proto dependencies
     # These are limited as much as possible. In most cases, users need to
     # declare these on their own (probably via go_repository rules generated

go/tools/gopackagesdriver/BUILD.bazel

@@ -0,0 +1,11 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_binary")
+
+go_binary(
+    name = "gopackagesdriver",
+    srcs = ["gopackagesdriver.go"],
+    visibility = ["//visibility:public"],
+    deps = [
+        "//go/tools/gopackagesdriver/protocol",
+        "//go/tools/gopackagesdriver/bazelquerydriver",
+    ],
+)

go/tools/gopackagesdriver/bazelquerydriver/BUILD.bazel

@@ -0,0 +1,18 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_library")
+
+go_library(
+    name = "bazelquerydriver",
+    srcs = [
+        "driver.go",
+        "sdk.go",
+    ],
+    importpath = "github.com/bazelbuild/rules_go/go/tools/gopackagesdriver/bazelquerydriver",
+    visibility = ["//go/tools/gopackagesdriver:__subpackages__"],
+    deps = [
+        "//go/tools/gopackagesdriver/bazelquerydriver/pkgconv",
+        "//go/tools/gopackagesdriver/protocol",
+        "@com_github_bazelbuild_bazel_watcher//third_party/bazel/master/src/main/protobuf/blaze_query:go_default_library",
+        "@com_github_bazelbuild_bazel_watcher//bazel:go_default_library",
+        "@org_golang_x_tools//go/packages:go_default_library",
+    ],
+)

go/tools/gopackagesdriver/bazelquerydriver/driver.go

@@ -0,0 +1,310 @@
+// Copyright 2021 The Bazel Go Rules Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// bazelquerydriver implements the driver interface for
+// golang.org/x/tools/go/packages. It uses `bazel query` to gather
+// information about packages built using bazel.
+package bazelquerydriver
+
+import (
+	"fmt"
+	"go/ast"
+	"go/parser"
+	"go/token"
+	"go/types"
+	"log"
+	"os"
+	"path/filepath"
+	"runtime"
+	"strconv"
+	"strings"
+
+	"github.com/bazelbuild/bazel-watcher/bazel"
+	"github.com/bazelbuild/bazel-watcher/third_party/bazel/master/src/main/protobuf/blaze_query"
+	"github.com/bazelbuild/rules_go/go/tools/gopackagesdriver/bazelquerydriver/pkgconv"
+	"github.com/bazelbuild/rules_go/go/tools/gopackagesdriver/protocol"
+	"golang.org/x/tools/go/packages"
+)
+
+const fileQueryPrefix = "file="
+
+const supportedModes = packages.NeedName | packages.NeedFiles | packages.NeedCompiledGoFiles | packages.NeedImports | packages.NeedDeps | packages.NeedTypesSizes | packages.NeedModule
+
+type bazelDriver struct {
+	cfg           protocol.Request
+	resp          protocol.Response
+	bazel         bazel.Bazel
+	sdk           *gosdk
+	workspaceRoot string
+	bazelQueries  []string
+	stdlibImports map[string]bool
+	fileQueries   map[string]bool
+	importQueries map[string]bool
+	wildcardQuery bool
+}
+
+// LoadPackages uses bazel query to answer a gopackagesdriver request.
+func LoadPackages(cfg protocol.Request, patterns ...string) (*protocol.Response, error) {
+	bzl := bazel.New()
+	sdk, err := newGoSDK(bzl)
+	if err != nil {
+		return nil, err
+	}
+	driver := &bazelDriver{
+		cfg:           cfg,
+		bazel:         bzl,
+		sdk:           sdk,
+		stdlibImports: make(map[string]bool),
+		fileQueries:   make(map[string]bool),
+		importQueries: make(map[string]bool),
+	}
+	return driver.loadPackages(patterns...)
+}
+
+func (d *bazelDriver) loadPackages(patterns ...string) (*protocol.Response, error) {
+	if info, err := d.bazel.Info(); err != nil {
+		return &protocol.Response{NotHandled: true}, nil
+	} else {
+		d.workspaceRoot = info["workspace"]
+	}
+
+	log.Printf("mode: %v", d.cfg.Mode)
+	unsupportedModes := d.cfg.Mode &^ supportedModes
+	if unsupportedModes != 0 {
+		return nil, fmt.Errorf("%v (%b) not implemented", unsupportedModes, unsupportedModes)
+	}
+
+	if len(patterns) == 0 {
+		patterns = append(patterns, ".")
+	}
+
+	for _, patt := range patterns {
+		switch {
+		case strings.HasPrefix(patt, fileQueryPrefix):
+			fp := strings.TrimPrefix(patt, fileQueryPrefix)
+			if err := d.prepareFileQuery(fp); err != nil {
+				return nil, err
+			}
+		case patt == ".":
+			d.bazelQueries = append(d.bazelQueries, goFilter(":all"))
+			d.wildcardQuery = true
+		case patt == "./...":
+			d.bazelQueries = append(d.bazelQueries, goFilter("..."))
+			d.wildcardQuery = true
+		case d.sdk.packages[patt]:
+			d.stdlibImports[patt] = true
+		default:
+			// TODO: do we need to check for a package ID instead of import path?
+			d.importQueries[patt] = true
+			d.bazelQueries = append(d.bazelQueries, fmt.Sprintf("attr(importpath, '%v', deps(%v))", patt, goFilter("//...")))
+		}
+	}
+
+	var resp protocol.Response
+
+	for pkg := range d.stdlibImports {
+		resp.Roots = append(resp.Roots, pkg)
+	}
+
+	if len(d.bazelQueries) != 0 {
+		pkgs, roots, err := d.packagesFromQueries(d.bazelQueries)
+		if err != nil {
+			return nil, err
+		}
+		resp.Packages = append(resp.Packages, pkgs...)
+		resp.Roots = append(resp.Roots, roots...)
+	}
+
+	stdlib, err := d.sdk.loadPackages(&d.cfg, d.stdlibImports)
+	if err != nil {
+		return nil, err
+	}
+	resp.Packages = append(resp.Packages, stdlib...)
+
+	if d.cfg.Mode&packages.NeedTypesSizes != 0 {
+		goarch := protocol.GetEnv(&d.cfg, "GOARCH", runtime.GOARCH)
+		// SizesFor always return StdSizesm,
+		resp.Sizes = types.SizesFor("gc", goarch).(*types.StdSizes)
+	}
+
+	return &resp, nil
+}
+
+// prepareFileQuery parses queries starting with file=.
+// It determines whether the file is inside the standard library,
+// and adds the appropriate stdlib or bazel query to `d`.
+// TODO: handle queries for generated files
+func (d *bazelDriver) prepareFileQuery(fp string) error {
+	if len(fp) == 0 {
+		return fmt.Errorf("\"file=\" prefix given with no query after it")
+	}
+	stdlibRoot := filepath.Join(d.sdk.goroot, "src") + string(filepath.Separator)
+
+	if filepath.IsAbs(fp) {
+		if strings.HasPrefix(fp, stdlibRoot) {
+			if rel, err := filepath.Rel(stdlibRoot, fp); err == nil {
+				pkg := filepath.Dir(rel)
+				if d.sdk.packages[pkg] {
+					d.stdlibImports[pkg] = true
+				}
+			}
+			return nil
+		}
+		if rel, err := filepath.Rel(d.workspaceRoot, fp); err == nil {
+			fp = rel
+		}
+	}
+
+	query, err := d.convertFileQuery(fp)
+	if err != nil {
+		return err
+	}
+	d.bazelQueries = append(d.bazelQueries, query)
+	d.fileQueries[fp] = true
+	return nil
+}
+
+// convertFileQuery returns a bazel query expression to find targets where `srcs` includes `path`.
+func (d *bazelDriver) convertFileQuery(path string) (string, error) {
+	log.Printf("bazel query %#v", path)
+	result, err := d.bazel.Query(path)
+	if err != nil {
+		return "", err
+	}
+	if len(result.Target) == 0 {
+		return "", fmt.Errorf("no source file %#v", path)
+	} else if len(result.Target) > 1 {
+		return "", fmt.Errorf("multiple results for %#v", path)
+	}
+
+	t := result.Target[0]
+	if t.GetType() != blaze_query.Target_SOURCE_FILE {
+		return "", fmt.Errorf("wanted SOURCE_FILE, but %v is %v", path, t.GetType())
+	}
+	name := t.GetSourceFile().GetName()
+	pkg := strings.Split(name, ":")[0]
+	return fmt.Sprintf("attr(srcs, '%v', '%v:*')", name, pkg), nil
+}
+
+func (d *bazelDriver) packagesFromQueries(queries []string) (pkgs []*packages.Package, roots []string, err error) {
+	query := strings.Join(queries, "+")
+	if d.cfg.Mode&packages.NeedDeps != 0 {
+		query = goFilter(fmt.Sprintf("deps(%v)", query))
+	}
+
+	log.Printf("bazel query %#v", query)
+	results, err := d.bazel.Query(query)
+	if err != nil {
+		return
+	}
+
+	pkgs = pkgconv.Load(results.GetTarget())
+
+	log.Printf("file queries: %v", d.fileQueries)
+	for _, p := range pkgs {
+		if d.includeInRoots(p) {
+			roots = append(roots, p.ID)
+		}
+	}
+
+	if d.cfg.Mode&packages.NeedCompiledGoFiles != 0 {
+		for _, pkg := range pkgs {
+			pkg.CompiledGoFiles = pkg.GoFiles
+		}
+	}
+	if d.cfg.Mode&(packages.NeedImports|packages.NeedName) != 0 {
+		for _, pkg := range pkgs {
+			name, imports, err := d.parsePackage(pkg)
+			if err != nil {
+				return nil, nil, fmt.Errorf("parsePackage: %w", err)
+			}
+			pkg.Name = name
+			for _, i := range imports {
+				if i, err = strconv.Unquote(i); err == nil {
+					if d.sdk.packages[i] {
+						if pkg.Imports == nil {
+							pkg.Imports = make(map[string]*packages.Package)
+						}
+						pkg.Imports[i] = &packages.Package{ID: i}
+						d.stdlibImports[i] = true
+					}
+				}
+			}
+		}
+	}
+	return
+}
+
+func (d *bazelDriver) includeInRoots(pkg *packages.Package) bool {
+	if d.wildcardQuery {
+		return strings.HasPrefix(pkg.ID, "//")
+	}
+	if pkg.PkgPath != "" && d.importQueries[pkg.PkgPath] {
+		return true
+	} else if len(d.fileQueries) > 0 && !strings.HasPrefix(pkg.ID, "@") {
+		for _, f := range pkg.GoFiles {
+			if d.fileQueries[f] {
+				return true
+			}
+			if rel, err := filepath.Rel(d.workspaceRoot, f); err == nil && d.fileQueries[rel] {
+				return true
+			}
+		}
+	}
+	return false
+}
+
+func (d *bazelDriver) parsePackage(pkg *packages.Package) (packageName string, imports []string, err error) {
+	triedBuild := false
+	dedupe := make(map[string]bool)
+	fset := token.NewFileSet()
+
+	for _, filename := range pkg.GoFiles {
+		var f *os.File
+		f, err = os.Open(filename)
+		if os.IsNotExist(err) && !triedBuild {
+			triedBuild = true
+			log.Printf("bazel build %v\n", pkg.ID)
+			d.bazel.Build(pkg.ID)
+			f, err = os.Open(filename)
+		}
+		if err != nil {
+			return
+		}
+		defer f.Close()
+		var syntax *ast.File
+		if syntax, err = parser.ParseFile(fset, filename, f, parser.ImportsOnly); err == nil {
+			packageName = syntax.Name.Name
+			for _, i := range syntax.Imports {
+				pkg := i.Path.Value
+				if !dedupe[pkg] {
+					dedupe[pkg] = true
+					imports = append(imports, pkg)
+				}
+			}
+			if d.cfg.Mode&packages.NeedImports == 0 {
+				// We don't need to parse all the files just to get the package name.
+				return
+			}
+		}
+	}
+	if packageName == "" {
+		packageName = filepath.Base(pkg.PkgPath)
+	}
+	return
+}
+
+func goFilter(expr string) string {
+	return fmt.Sprintf("kind(\"alias|proto_library|go_\", %s)", expr)
+}

go/tools/gopackagesdriver/bazelquerydriver/pkgconv/BUILD.bazel

@@ -0,0 +1,18 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_library")
+
+go_library(
+    name = "pkgconv",
+    srcs = [
+        "go_embed_data.go",
+        "go_library.go",
+        "go_proto_library.go",
+        "gotest.go",
+        "pkgconv.go",
+    ],
+    importpath = "github.com/bazelbuild/rules_go/go/tools/gopackagesdriver/bazelquerydriver/pkgconv",
+    visibility = ["//go/tools/gopackagesdriver:__subpackages__"],
+    deps = [
+        "@org_golang_x_tools//go/packages:go_default_library",
+        "@com_github_bazelbuild_bazel_watcher//third_party/bazel/master/src/main/protobuf/blaze_query:go_default_library",
+    ],
+)