Add functionality to sandbox mixed build actions
The use case for this is for building rules_go's root builder which runs
into issues when built in a directory that contains a symlink to
prebuilts/go
The implementation will involve two changes of working dir
- `sbox` to change the working directory to
__SBOX_SANDBOX_DIR__
- the generated manifest will change the working
directory to mixed build execution root relative to that
Implemenation details
1. Create a unique intermediate path by hashing the outputs of a buildAction.
"out/bazel/output/execroot/__main__/" was deliberately not chosen as
the outpuDir for the sandbox because ruleBuilder would wipe it.
`sbox` will generate the files in __SBOX_SANDBOX_DIR__ and then place
the files in this intermediate directory.
2. After the files have been generated in (1), copy them to
out/bazel/output/execroot/__main__/...
3. For bazel depsets that are inputs of an action, copy the direct
artifacts into the sandbox instead of the phony target
4. Make sandboxing an opt-in. Currently we will only use it for
`GoToolchainBinaryBuild`
In the current implementation, (3) will increase the size of the ninja
file. With sboxing turned on for only GoToolchainBinaryBuild, this will
increase the size of the ninja file by around 1.3% on aosp's cf
Test: m com.android.neuralnetworks (will build soong_zip from source
using rules_go)
Test: OUT_DIR=out.other m com.android.neuralnetworks
Bug: 289102849
Change-Id: I7addda9af583ba0ff306e50c1dfa16ed16c29799
diff --git a/android/bazel_handler.go b/android/bazel_handler.go
index 5d93f06..94bc88b 100644
--- a/android/bazel_handler.go
+++ b/android/bazel_handler.go
@@ -16,6 +16,8 @@
import (
"bytes"
+ "crypto/sha1"
+ "encoding/hex"
"fmt"
"os"
"path"
@@ -1222,7 +1224,11 @@
ctx.AddNinjaFileDeps(file)
}
+ depsetHashToDepset := map[string]bazel.AqueryDepset{}
+
for _, depset := range ctx.Config().BazelContext.AqueryDepsets() {
+ depsetHashToDepset[depset.ContentHash] = depset
+
var outputs []Path
var orderOnlies []Path
for _, depsetDepHash := range depset.TransitiveDepSetHashes {
@@ -1257,7 +1263,30 @@
}
if len(buildStatement.Command) > 0 {
rule := NewRuleBuilder(pctx, ctx)
- createCommand(rule.Command(), buildStatement, executionRoot, bazelOutDir, ctx)
+ intermediateDir, intermediateDirHash := intermediatePathForSboxMixedBuildAction(ctx, buildStatement)
+ if buildStatement.ShouldRunInSbox {
+ // Create a rule to build the output inside a sandbox
+ // This will create two changes of working directory
+ // 1. From ANDROID_BUILD_TOP to sbox top
+ // 2. From sbox top to a a synthetic mixed build execution root relative to it
+ // Finally, the outputs will be copied to intermediateDir
+ rule.Sbox(intermediateDir,
+ PathForOutput(ctx, "mixed_build_sbox_intermediates", intermediateDirHash+".textproto")).
+ SandboxInputs().
+ // Since we will cd to mixed build execution root, set sbox's out subdir to empty
+ // Without this, we will try to copy from $SBOX_SANDBOX_DIR/out/out/bazel/output/execroot/__main__/...
+ SetSboxOutDirDirAsEmpty()
+
+ // Create another set of rules to copy files from the intermediate dir to mixed build execution root
+ for _, outputPath := range buildStatement.OutputPaths {
+ ctx.Build(pctx, BuildParams{
+ Rule: CpIfChanged,
+ Input: intermediateDir.Join(ctx, executionRoot, outputPath),
+ Output: PathForBazelOut(ctx, outputPath),
+ })
+ }
+ }
+ createCommand(rule.Command(), buildStatement, executionRoot, bazelOutDir, ctx, depsetHashToDepset)
desc := fmt.Sprintf("%s: %s", buildStatement.Mnemonic, buildStatement.OutputPaths)
rule.Build(fmt.Sprintf("bazel %d", index), desc)
continue
@@ -1304,10 +1333,25 @@
}
}
+// Returns a out dir path for a sandboxed mixed build action
+func intermediatePathForSboxMixedBuildAction(ctx PathContext, statement *bazel.BuildStatement) (OutputPath, string) {
+ // An artifact can be generated by a single buildstatement.
+ // Use the hash of the first artifact to create a unique path
+ uniqueDir := sha1.New()
+ uniqueDir.Write([]byte(statement.OutputPaths[0]))
+ uniqueDirHashString := hex.EncodeToString(uniqueDir.Sum(nil))
+ return PathForOutput(ctx, "mixed_build_sbox_intermediates", uniqueDirHashString), uniqueDirHashString
+}
+
// Register bazel-owned build statements (obtained from the aquery invocation).
-func createCommand(cmd *RuleBuilderCommand, buildStatement *bazel.BuildStatement, executionRoot string, bazelOutDir string, ctx BuilderContext) {
+func createCommand(cmd *RuleBuilderCommand, buildStatement *bazel.BuildStatement, executionRoot string, bazelOutDir string, ctx BuilderContext, depsetHashToDepset map[string]bazel.AqueryDepset) {
// executionRoot is the action cwd.
- cmd.Text(fmt.Sprintf("cd '%s' &&", executionRoot))
+ if buildStatement.ShouldRunInSbox {
+ // mkdir -p ensures that the directory exists when run via sbox
+ cmd.Text(fmt.Sprintf("mkdir -p '%s' && cd '%s' &&", executionRoot, executionRoot))
+ } else {
+ cmd.Text(fmt.Sprintf("cd '%s' &&", executionRoot))
+ }
// Remove old outputs, as some actions might not rerun if the outputs are detected.
if len(buildStatement.OutputPaths) > 0 {
@@ -1334,14 +1378,30 @@
}
for _, outputPath := range buildStatement.OutputPaths {
- cmd.ImplicitOutput(PathForBazelOut(ctx, outputPath))
+ if buildStatement.ShouldRunInSbox {
+ // The full path has three components that get joined together
+ // 1. intermediate output dir that `sbox` will place the artifacts at
+ // 2. mixed build execution root
+ // 3. artifact path returned by aquery
+ intermediateDir, _ := intermediatePathForSboxMixedBuildAction(ctx, buildStatement)
+ cmd.ImplicitOutput(intermediateDir.Join(ctx, executionRoot, outputPath))
+ } else {
+ cmd.ImplicitOutput(PathForBazelOut(ctx, outputPath))
+ }
}
for _, inputPath := range buildStatement.InputPaths {
cmd.Implicit(PathForBazelOut(ctx, inputPath))
}
for _, inputDepsetHash := range buildStatement.InputDepsetHashes {
- otherDepsetName := bazelDepsetName(inputDepsetHash)
- cmd.Implicit(PathForPhony(ctx, otherDepsetName))
+ if buildStatement.ShouldRunInSbox {
+ // Bazel depsets are phony targets that are used to group files.
+ // We need to copy the grouped files into the sandbox
+ ds, _ := depsetHashToDepset[inputDepsetHash]
+ cmd.Implicits(PathsForBazelOut(ctx, ds.DirectArtifacts))
+ } else {
+ otherDepsetName := bazelDepsetName(inputDepsetHash)
+ cmd.Implicit(PathForPhony(ctx, otherDepsetName))
+ }
}
if depfile := buildStatement.Depfile; depfile != nil {