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// Copyright 2023 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 (
"crypto/sha1"
"encoding/hex"
"fmt"
"github.com/google/blueprint"
"io"
"io/fs"
"os"
"path/filepath"
"strings"
"testing"
"github.com/google/blueprint/proptools"
)
// WriteFileRule creates a ninja rule to write contents to a file by immediately writing the
// contents, plus a trailing newline, to a file in out/soong/raw-${TARGET_PRODUCT}, and then creating
// a ninja rule to copy the file into place.
func WriteFileRule(ctx BuilderContext, outputFile WritablePath, content string) {
writeFileRule(ctx, outputFile, content, true, false)
}
// WriteFileRuleVerbatim creates a ninja rule to write contents to a file by immediately writing the
// contents to a file in out/soong/raw-${TARGET_PRODUCT}, and then creating a ninja rule to copy the file into place.
func WriteFileRuleVerbatim(ctx BuilderContext, outputFile WritablePath, content string) {
writeFileRule(ctx, outputFile, content, false, false)
}
// WriteExecutableFileRuleVerbatim is the same as WriteFileRuleVerbatim, but runs chmod +x on the result
func WriteExecutableFileRuleVerbatim(ctx BuilderContext, outputFile WritablePath, content string) {
writeFileRule(ctx, outputFile, content, false, true)
}
// tempFile provides a testable wrapper around a file in out/soong/.temp. It writes to a temporary file when
// not in tests, but writes to a buffer in memory when used in tests.
type tempFile struct {
// tempFile contains wraps an io.Writer, which will be file if testMode is false, or testBuf if it is true.
io.Writer
file *os.File
testBuf *strings.Builder
}
func newTempFile(ctx BuilderContext, pattern string, testMode bool) *tempFile {
if testMode {
testBuf := &strings.Builder{}
return &tempFile{
Writer: testBuf,
testBuf: testBuf,
}
} else {
f, err := os.CreateTemp(absolutePath(ctx.Config().tempDir()), pattern)
if err != nil {
panic(fmt.Errorf("failed to open temporary raw file: %w", err))
}
return &tempFile{
Writer: f,
file: f,
}
}
}
func (t *tempFile) close() error {
if t.file != nil {
return t.file.Close()
}
return nil
}
func (t *tempFile) name() string {
if t.file != nil {
return t.file.Name()
}
return "temp_file_in_test"
}
func (t *tempFile) rename(to string) {
if t.file != nil {
os.MkdirAll(filepath.Dir(to), 0777)
err := os.Rename(t.file.Name(), to)
if err != nil {
panic(fmt.Errorf("failed to rename %s to %s: %w", t.file.Name(), to, err))
}
}
}
func (t *tempFile) remove() error {
if t.file != nil {
return os.Remove(t.file.Name())
}
return nil
}
func writeContentToTempFileAndHash(ctx BuilderContext, content string, newline bool) (*tempFile, string) {
tempFile := newTempFile(ctx, "raw", ctx.Config().captureBuild)
defer tempFile.close()
hash := sha1.New()
w := io.MultiWriter(tempFile, hash)
_, err := io.WriteString(w, content)
if err == nil && newline {
_, err = io.WriteString(w, "\n")
}
if err != nil {
panic(fmt.Errorf("failed to write to temporary raw file %s: %w", tempFile.name(), err))
}
return tempFile, hex.EncodeToString(hash.Sum(nil))
}
func writeFileRule(ctx BuilderContext, outputFile WritablePath, content string, newline bool, executable bool) {
// Write the contents to a temporary file while computing its hash.
tempFile, hash := writeContentToTempFileAndHash(ctx, content, newline)
// Shard the final location of the raw file into a subdirectory based on the first two characters of the
// hash to avoid making the raw directory too large and slowing down accesses.
relPath := filepath.Join(hash[0:2], hash)
// These files are written during soong_build. If something outside the build deleted them there would be no
// trigger to rerun soong_build, and the build would break with dependencies on missing files. Writing them
// to their final locations would risk having them deleted when cleaning a module, and would also pollute the
// output directory with files for modules that have never been built.
// Instead, the files are written to a separate "raw" directory next to the build.ninja file, and a ninja
// rule is created to copy the files into their final location as needed.
// Obsolete files written by previous runs of soong_build must be cleaned up to avoid continually growing
// disk usage as the hashes of the files change over time. The cleanup must not remove files that were
// created by previous runs of soong_build for other products, as the build.ninja files for those products
// may still exist and still reference those files. The raw files from different products are kept
// separate by appending the Make_suffix to the directory name.
rawPath := PathForOutput(ctx, "raw"+proptools.String(ctx.Config().productVariables.Make_suffix), relPath)
rawFileInfo := rawFileInfo{
relPath: relPath,
}
if ctx.Config().captureBuild {
// When running tests tempFile won't write to disk, instead store the contents for later retrieval by
// ContentFromFileRuleForTests.
rawFileInfo.contentForTests = tempFile.testBuf.String()
}
rawFileSet := getRawFileSet(ctx.Config())
if _, exists := rawFileSet.LoadOrStore(hash, rawFileInfo); exists {
// If a raw file with this hash has already been created delete the temporary file.
tempFile.remove()
} else {
// If this is the first time this hash has been seen then move it from the temporary directory
// to the raw directory. If the file already exists in the raw directory assume it has the correct
// contents.
absRawPath := absolutePath(rawPath.String())
_, err := os.Stat(absRawPath)
if os.IsNotExist(err) {
tempFile.rename(absRawPath)
} else if err != nil {
panic(fmt.Errorf("failed to stat %q: %w", absRawPath, err))
} else {
tempFile.remove()
}
}
// Emit a rule to copy the file from raw directory to the final requested location in the output tree.
// Restat is used to ensure that two different products that produce identical files copied from their
// own raw directories they don't cause everything downstream to rebuild.
rule := rawFileCopy
if executable {
rule = rawFileCopyExecutable
}
ctx.Build(pctx, BuildParams{
Rule: rule,
Input: rawPath,
Output: outputFile,
Description: "raw " + outputFile.Base(),
})
}
var (
rawFileCopy = pctx.AndroidStaticRule("rawFileCopy",
blueprint.RuleParams{
Command: "if ! cmp -s $in $out; then cp $in $out; fi",
Description: "copy raw file $out",
Restat: true,
})
rawFileCopyExecutable = pctx.AndroidStaticRule("rawFileCopyExecutable",
blueprint.RuleParams{
Command: "if ! cmp -s $in $out; then cp $in $out; fi && chmod +x $out",
Description: "copy raw exectuable file $out",
Restat: true,
})
)
type rawFileInfo struct {
relPath string
contentForTests string
}
var rawFileSetKey OnceKey = NewOnceKey("raw file set")
func getRawFileSet(config Config) *SyncMap[string, rawFileInfo] {
return config.Once(rawFileSetKey, func() any {
return &SyncMap[string, rawFileInfo]{}
}).(*SyncMap[string, rawFileInfo])
}
// ContentFromFileRuleForTests returns the content that was passed to a WriteFileRule for use
// in tests.
func ContentFromFileRuleForTests(t *testing.T, ctx *TestContext, params TestingBuildParams) string {
t.Helper()
if params.Rule != rawFileCopy && params.Rule != rawFileCopyExecutable {
t.Errorf("expected params.Rule to be rawFileCopy or rawFileCopyExecutable, was %q", params.Rule)
return ""
}
key := filepath.Base(params.Input.String())
rawFileSet := getRawFileSet(ctx.Config())
rawFileInfo, _ := rawFileSet.Load(key)
return rawFileInfo.contentForTests
}
func rawFilesSingletonFactory() Singleton {
return &rawFilesSingleton{}
}
type rawFilesSingleton struct{}
func (rawFilesSingleton) GenerateBuildActions(ctx SingletonContext) {
if ctx.Config().captureBuild {
// Nothing to do when running in tests, no temporary files were created.
return
}
rawFileSet := getRawFileSet(ctx.Config())
rawFilesDir := PathForOutput(ctx, "raw"+proptools.String(ctx.Config().productVariables.Make_suffix)).String()
absRawFilesDir := absolutePath(rawFilesDir)
err := filepath.WalkDir(absRawFilesDir, func(path string, d fs.DirEntry, err error) error {
if err != nil {
return err
}
if d.IsDir() {
// Ignore obsolete directories for now.
return nil
}
// Assume the basename of the file is a hash
key := filepath.Base(path)
relPath, err := filepath.Rel(absRawFilesDir, path)
if err != nil {
return err
}
// Check if a file with the same hash was written by this run of soong_build. If the file was not written,
// or if a file with the same hash was written but to a different path in the raw directory, then delete it.
// Checking that the path matches allows changing the structure of the raw directory, for example to increase
// the sharding.
rawFileInfo, written := rawFileSet.Load(key)
if !written || rawFileInfo.relPath != relPath {
os.Remove(path)
}
return nil
})
if err != nil {
panic(fmt.Errorf("failed to clean %q: %w", rawFilesDir, err))
}
}