Revert "Remove --noexperimental_platform_in_output_dir"

This reverts commit 24af24e0f2.

Reason for revert: Breaks kernel build tools build https://ci.android.com/builds/branches/aosp_kernel-build-tools/grid?head=10282004&tail=10282004

Change-Id: I486d7f305d44cfecc51a0e039cc41c0afa6495f3

android/bazel_handler.go

@@ -665,20 +665,26 @@ func (r *builtinBazelRunner) issueBazelCommand(cmdRequest bazel.CmdRequest, path
 
 func (context *mixedBuildBazelContext) createBazelCommand(config Config, runName bazel.RunName, command bazelCommand,
 	extraFlags ...string) bazel.CmdRequest {
-	if runtime.GOOS != "linux" && runtime.GOOS != "darwin" {
-		panic("Unknown GOOS: " + runtime.GOOS)
-	}
 	cmdFlags := []string{
 		"--output_base=" + absolutePath(context.paths.outputBase),
 		command.command,
 		command.expression,
 		"--profile=" + shared.BazelMetricsFilename(context.paths, runName),
 
-		"--host_platform=@soong_injection//product_config_platforms:mixed_builds_product-" + context.targetBuildVariant + "_" + runtime.GOOS + "_x86_64",
-		// This --platforms flag largely doesn't matter, because the config_nodes will
-		// transition into the right configuration. This is just to make sure we use the
-		// mixed_builds_product everywhere.
-		"--platforms=@soong_injection//product_config_platforms:mixed_builds_product-" + context.targetBuildVariant,
+		// We don't need to set --host_platforms because it's set in bazelrc files
+		// that the bazel shell script wrapper passes
+
+		// Optimize Ninja rebuilds by ensuring Bazel write into product-agnostic
+		// output paths for the configured targets that shouldn't be affected by
+		// TARGET_PRODUCT. Otherwise product agnostic modules will be rebuilt by
+		// Ninja when the product changes, unconditionally.
+		//
+		// For example, Mainline APEXes should be identical regardless of the
+		// product (modulo arch/cpu).
+		//
+		// This flag forcibly disables the platform prefix in the intermediate
+		// outputs during a mixed build.
+		"--noexperimental_platform_in_output_dir",
 
 		// Suppress noise
 		"--ui_event_filters=-INFO",
@@ -725,9 +731,9 @@ func (context *mixedBuildBazelContext) mainBzlFileContents() []byte {
 #####################################################
 def _config_node_transition_impl(settings, attr):
     if attr.os == "android" and attr.arch == "target":
-        target = "mixed_builds_product-{VARIANT}"
+        target = "current_product-{VARIANT}"
     else:
-        target = "mixed_builds_product-{VARIANT}_%s_%s" % (attr.os, attr.arch)
+        target = "current_product-{VARIANT}_%s_%s" % (attr.os, attr.arch)
     apex_name = ""
     if attr.within_apex:
         # //build/bazel/rules/apex:apex_name has to be set to a non_empty value,
@@ -964,9 +970,9 @@ def get_arch(target):
   platform_name = platforms[0].name
   if platform_name == "host":
     return "HOST"
-  if not platform_name.startswith("mixed_builds_product-{TARGET_BUILD_VARIANT}"):
-    fail("expected platform name of the form 'mixed_builds_product-{TARGET_BUILD_VARIANT}_android_<arch>' or 'mixed_builds_product-{TARGET_BUILD_VARIANT}_linux_<arch>', but was " + str(platforms))
-  platform_name = platform_name.removeprefix("mixed_builds_product-{TARGET_BUILD_VARIANT}").removeprefix("_")
+  if not platform_name.startswith("current_product-{TARGET_BUILD_VARIANT}"):
+    fail("expected platform name of the form 'current_product-{TARGET_BUILD_VARIANT}_android_<arch>' or 'current_product-{TARGET_BUILD_VARIANT}_linux_<arch>', but was " + str(platforms))
+  platform_name = platform_name.removeprefix("current_product-{TARGET_BUILD_VARIANT}").removeprefix("_")
   config_key = ""
   if not platform_name:
     config_key = "target|android"
@@ -975,7 +981,7 @@ def get_arch(target):
   elif platform_name.startswith("linux_"):
     config_key = platform_name.removeprefix("linux_") + "|linux"
   else:
-    fail("expected platform name of the form 'mixed_builds_product-{TARGET_BUILD_VARIANT}_android_<arch>' or 'mixed_builds_product-{TARGET_BUILD_VARIANT}_linux_<arch>', but was " + str(platforms))
+    fail("expected platform name of the form 'current_product-{TARGET_BUILD_VARIANT}_android_<arch>' or 'current_product-{TARGET_BUILD_VARIANT}_linux_<arch>', but was " + str(platforms))
 
   within_apex = buildoptions.get("//build/bazel/rules/apex:within_apex")
   apex_sdk_version = buildoptions.get("//build/bazel/rules/apex:min_sdk_version")

bp2build/bp2build_product_config.go

@@ -72,13 +72,8 @@ package(default_visibility = [
 load("//{PRODUCT_FOLDER}:soong.variables.bzl", _soong_variables = "variables")
 load("@//build/bazel/product_config:android_product.bzl", "android_product")
 
-# Bazel will qualify its outputs by the platform name. When switching between products, this
-# means that soong-built files that depend on bazel-built files will suddenly get different
-# dependency files, because the path changes, and they will be rebuilt. In order to avoid this
-# extra rebuilding, make mixed builds always use a single platform so that the bazel artifacts
-# are always under the same path.
 android_product(
-    name = "mixed_builds_product-{VARIANT}",
+    name = "current_product-{VARIANT}",
     soong_variables = _soong_variables,
 )
 `)),
@@ -91,7 +86,7 @@ android_product(
 # TODO: When we start generating the platforms for more than just the
 # currently lunched product, they should all be listed here
 product_labels = [
-  "@soong_injection//product_config_platforms:mixed_builds_product-{VARIANT}",
+  "@soong_injection//product_config_platforms:current_product-{VARIANT}",
   "@soong_injection//{PRODUCT_FOLDER}:{PRODUCT}-{VARIANT}"
 ]
 `)),
@@ -99,25 +94,38 @@ product_labels = [
 			"product_config_platforms",
 			"common.bazelrc",
 			productReplacer.Replace(`
-build --platforms @soong_injection//{PRODUCT_FOLDER}:{PRODUCT}-{VARIANT}_linux_x86_64
+# current_product refers to the current TARGET_PRODUCT set, usually through
+# 'lunch' or 'banchan'.  Every build will have a primary TARGET_PRODUCT, but
+# bazel supports using other products in tests or configuration transitions. The
+# other products can be found in
+# @soong_injection//product_config_platforms/products/...
+build --platforms @soong_injection//product_config_platforms:current_product-{VARIANT}_linux_x86_64
 
-build:android --platforms=@soong_injection//{PRODUCT_FOLDER}:{PRODUCT}-{VARIANT}
-build:linux_x86_64 --platforms=@soong_injection//{PRODUCT_FOLDER}:{PRODUCT}-{VARIANT}_linux_x86_64
-build:linux_bionic_x86_64 --platforms=@soong_injection//{PRODUCT_FOLDER}:{PRODUCT}-{VARIANT}_linux_bionic_x86_64
-build:linux_musl_x86 --platforms=@soong_injection//{PRODUCT_FOLDER}:{PRODUCT}-{VARIANT}_linux_musl_x86
-build:linux_musl_x86_64 --platforms=@soong_injection//{PRODUCT_FOLDER}:{PRODUCT}-{VARIANT}_linux_musl_x86_64
+build:android --platforms=@soong_injection//product_config_platforms:current_product-{VARIANT}
+build:linux_x86_64 --platforms=@soong_injection//product_config_platforms:current_product-{VARIANT}_linux_x86_64
+build:linux_bionic_x86_64 --platforms=@soong_injection//product_config_platforms:current_product-{VARIANT}_linux_bionic_x86_64
+build:linux_musl_x86 --platforms=@soong_injection//product_config_platforms:current_product-{VARIANT}_linux_musl_x86
+build:linux_musl_x86_64 --platforms=@soong_injection//product_config_platforms:current_product-{VARIANT}_linux_musl_x86_64
 `)),
 		newFile(
 			"product_config_platforms",
 			"linux.bazelrc",
 			productReplacer.Replace(`
-build --host_platform @soong_injection//{PRODUCT_FOLDER}:{PRODUCT}-{VARIANT}_linux_x86_64
+build --host_platform @soong_injection//product_config_platforms:current_product-{VARIANT}_linux_x86_64
 `)),
 		newFile(
 			"product_config_platforms",
 			"darwin.bazelrc",
 			productReplacer.Replace(`
-build --host_platform @soong_injection//{PRODUCT_FOLDER}:{PRODUCT}-{VARIANT}_darwin_x86_64
+build --host_platform product_config_platforms:current_product-{VARIANT}_darwin_x86_64
+`)),
+		newFile(
+			"product_config_platforms",
+			"platform_mappings",
+			productReplacer.Replace(`
+flags:
+  --cpu=k8
+	@soong_injection//product_config_platforms:current_product-{VARIANT}
 `)),
 	}
 

tests/bp2build_bazel_test.sh

@@ -382,39 +382,4 @@ EOF
   run_bazel build --config=android --config=api_bp2build //foo:libfoo.contribution
 }
 
-function test_bazel_standalone_output_paths_contain_product_name {
-  setup
-  mkdir -p a
-  cat > a/Android.bp <<EOF
-cc_object {
-  name: "qq",
-  srcs: ["qq.cc"],
-  bazel_module: {
-    bp2build_available: true,
-  },
-  stl: "none",
-  system_shared_libs: [],
-}
-EOF
-
-  cat > a/qq.cc <<EOF
-#include "qq.h"
-int qq() {
-  return QQ;
-}
-EOF
-
-  cat > a/qq.h <<EOF
-#define QQ 1
-EOF
-
-  export TARGET_PRODUCT=aosp_arm; run_soong bp2build
-  local -r output=$(run_bazel cquery //a:qq --output=files --config=android --config=bp2build --config=ci)
-  if [[ ! $(echo ${output} | grep "bazel-out/aosp_arm") ]]; then
-    fail "Did not find the product name '${TARGET_PRODUCT}' in the output path. This can cause " \
-      "unnecessary rebuilds when toggling between products as bazel outputs for different products will " \
-      "clobber each other. Output paths are: \n${output}"
-  fi
-}
-
 scan_and_run_tests