Mixed bazel/soong build prototype for genrule
With this change, bazel_module is a specifiable property on
genrule module definitions. With bazel-enabled mode, soong_build will
defer to Bazel for information on these modules.
source build/soong/bazelenv.sh to enter bazel-enabled mode.
Test: Manually verified on bionic/libc genrules using aosp_cf_x86_phone-userdebug
Change-Id: I3619848186d50be7273a5eba31c79989b981d408
diff --git a/android/bazel_handler.go b/android/bazel_handler.go
new file mode 100644
index 0000000..d4f6e4c
--- /dev/null
+++ b/android/bazel_handler.go
@@ -0,0 +1,239 @@
+// Copyright 2020 Google Inc. 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.
+
+package android
+
+import (
+ "bytes"
+ "errors"
+ "fmt"
+ "os"
+ "os/exec"
+ "runtime"
+ "strings"
+ "sync"
+)
+
+// Map key to describe bazel cquery requests.
+type cqueryKey struct {
+ label string
+ starlarkExpr string
+}
+
+type BazelContext interface {
+ // The below methods involve queuing cquery requests to be later invoked
+ // by bazel. If any of these methods return (_, false), then the request
+ // has been queued to be run later.
+
+ // Returns result files built by building the given bazel target label.
+ GetAllFiles(label string) ([]string, bool)
+
+ // TODO(cparsons): Other cquery-related methods should be added here.
+ // ** End cquery methods
+
+ // Issues commands to Bazel to receive results for all cquery requests
+ // queued in the BazelContext.
+ InvokeBazel() error
+
+ // Returns true if bazel is enabled for the given configuration.
+ BazelEnabled() bool
+}
+
+// A context object which tracks queued requests that need to be made to Bazel,
+// and their results after the requests have been made.
+type bazelContext struct {
+ homeDir string
+ bazelPath string
+ outputBase string
+ workspaceDir string
+
+ requests map[cqueryKey]bool // cquery requests that have not yet been issued to Bazel
+ requestMutex sync.Mutex // requests can be written in parallel
+
+ results map[cqueryKey]string // Results of cquery requests after Bazel invocations
+}
+
+var _ BazelContext = &bazelContext{}
+
+// A bazel context to use when Bazel is disabled.
+type noopBazelContext struct{}
+
+var _ BazelContext = noopBazelContext{}
+
+// A bazel context to use for tests.
+type MockBazelContext struct {
+ AllFiles map[string][]string
+}
+
+func (m MockBazelContext) GetAllFiles(label string) ([]string, bool) {
+ result, ok := m.AllFiles[label]
+ return result, ok
+}
+
+func (m MockBazelContext) InvokeBazel() error {
+ panic("unimplemented")
+}
+
+func (m MockBazelContext) BazelEnabled() bool {
+ return true
+}
+
+var _ BazelContext = MockBazelContext{}
+
+func (bazelCtx *bazelContext) GetAllFiles(label string) ([]string, bool) {
+ starlarkExpr := "', '.join([f.path for f in target.files.to_list()])"
+ result, ok := bazelCtx.cquery(label, starlarkExpr)
+ if ok {
+ bazelOutput := strings.TrimSpace(result)
+ return strings.Split(bazelOutput, ", "), true
+ } else {
+ return nil, false
+ }
+}
+
+func (n noopBazelContext) GetAllFiles(label string) ([]string, bool) {
+ panic("unimplemented")
+}
+
+func (n noopBazelContext) InvokeBazel() error {
+ panic("unimplemented")
+}
+
+func (n noopBazelContext) BazelEnabled() bool {
+ return false
+}
+
+func NewBazelContext(c *config) (BazelContext, error) {
+ if c.Getenv("USE_BAZEL") != "1" {
+ return noopBazelContext{}, nil
+ }
+
+ bazelCtx := bazelContext{requests: make(map[cqueryKey]bool)}
+ missingEnvVars := []string{}
+ if len(c.Getenv("BAZEL_HOME")) > 1 {
+ bazelCtx.homeDir = c.Getenv("BAZEL_HOME")
+ } else {
+ missingEnvVars = append(missingEnvVars, "BAZEL_HOME")
+ }
+ if len(c.Getenv("BAZEL_PATH")) > 1 {
+ bazelCtx.bazelPath = c.Getenv("BAZEL_PATH")
+ } else {
+ missingEnvVars = append(missingEnvVars, "BAZEL_PATH")
+ }
+ if len(c.Getenv("BAZEL_OUTPUT_BASE")) > 1 {
+ bazelCtx.outputBase = c.Getenv("BAZEL_OUTPUT_BASE")
+ } else {
+ missingEnvVars = append(missingEnvVars, "BAZEL_OUTPUT_BASE")
+ }
+ if len(c.Getenv("BAZEL_WORKSPACE")) > 1 {
+ bazelCtx.workspaceDir = c.Getenv("BAZEL_WORKSPACE")
+ } else {
+ missingEnvVars = append(missingEnvVars, "BAZEL_WORKSPACE")
+ }
+ if len(missingEnvVars) > 0 {
+ return nil, errors.New(fmt.Sprintf("missing required env vars to use bazel: %s", missingEnvVars))
+ } else {
+ return &bazelCtx, nil
+ }
+}
+
+func (context *bazelContext) BazelEnabled() bool {
+ return true
+}
+
+// Adds a cquery request to the Bazel request queue, to be later invoked, or
+// returns the result of the given request if the request was already made.
+// If the given request was already made (and the results are available), then
+// returns (result, true). If the request is queued but no results are available,
+// then returns ("", false).
+func (context *bazelContext) cquery(label string, starlarkExpr string) (string, bool) {
+ key := cqueryKey{label, starlarkExpr}
+ if result, ok := context.results[key]; ok {
+ return result, true
+ } else {
+ context.requestMutex.Lock()
+ defer context.requestMutex.Unlock()
+ context.requests[key] = true
+ return "", false
+ }
+}
+
+func pwdPrefix() string {
+ // Darwin doesn't have /proc
+ if runtime.GOOS != "darwin" {
+ return "PWD=/proc/self/cwd"
+ }
+ return ""
+}
+
+func (context *bazelContext) issueBazelCommand(command string, labels []string,
+ extraFlags ...string) (string, error) {
+
+ cmdFlags := []string{"--output_base=" + context.outputBase, command}
+ cmdFlags = append(cmdFlags, labels...)
+ cmdFlags = append(cmdFlags, extraFlags...)
+
+ bazelCmd := exec.Command(context.bazelPath, cmdFlags...)
+ bazelCmd.Dir = context.workspaceDir
+ bazelCmd.Env = append(os.Environ(), "HOME="+context.homeDir, pwdPrefix())
+
+ var stderr bytes.Buffer
+ bazelCmd.Stderr = &stderr
+
+ if output, err := bazelCmd.Output(); err != nil {
+ return "", fmt.Errorf("bazel command failed. command: [%s], error [%s]", bazelCmd, stderr)
+ } else {
+ return string(output), nil
+ }
+}
+
+// Issues commands to Bazel to receive results for all cquery requests
+// queued in the BazelContext.
+func (context *bazelContext) InvokeBazel() error {
+ context.results = make(map[cqueryKey]string)
+
+ var labels []string
+ var cqueryOutput string
+ var err error
+ for val, _ := range context.requests {
+ labels = append(labels, val.label)
+
+ // TODO(cparsons): Combine requests into a batch cquery request.
+ // TODO(cparsons): Use --query_file to avoid command line limits.
+ cqueryOutput, err = context.issueBazelCommand("cquery", []string{val.label},
+ "--output=starlark",
+ "--starlark:expr="+val.starlarkExpr)
+
+ if err != nil {
+ return err
+ } else {
+ context.results[val] = string(cqueryOutput)
+ }
+ }
+
+ // Issue a build command.
+ // TODO(cparsons): Invoking bazel execution during soong_build should be avoided;
+ // bazel actions should either be added to the Ninja file and executed later,
+ // or bazel should handle execution.
+ // TODO(cparsons): Use --target_pattern_file to avoid command line limits.
+ _, err = context.issueBazelCommand("build", labels)
+
+ if err != nil {
+ return err
+ }
+
+ // Clear requests.
+ context.requests = map[cqueryKey]bool{}
+ return nil
+}