Add support for PRODUCT_RELEASE_CONFIG_MAPS

This allows product config to determine what build flags are present in
a product's build, as well as their value.

As product config moves to a declarative specification, this can be
handled with less unnecessary work.

Bug: b/302593603
Bug: b/308849337
Test: manual
Change-Id: If57622059bb7d1c33df7498321db621c0c2d30c0
diff --git a/cmd/soong_ui/main.go b/cmd/soong_ui/main.go
index 18cba77..df8101c 100644
--- a/cmd/soong_ui/main.go
+++ b/cmd/soong_ui/main.go
@@ -59,6 +59,9 @@
 
 	// run the command
 	run func(ctx build.Context, config build.Config, args []string)
+
+	// whether to do common setup before calling run.
+	doSetup bool
 }
 
 // list of supported commands (flags) supported by soong ui
@@ -69,6 +72,7 @@
 		config:      build.NewConfig,
 		stdio:       stdio,
 		run:         runMake,
+		doSetup:     true,
 	}, {
 		flag:         "--dumpvar-mode",
 		description:  "print the value of the legacy make variable VAR to stdout",
@@ -77,6 +81,7 @@
 		config:       dumpVarConfig,
 		stdio:        customStdio,
 		run:          dumpVar,
+		doSetup:      true,
 	}, {
 		flag:         "--dumpvars-mode",
 		description:  "dump the values of one or more legacy make variables, in shell syntax",
@@ -85,6 +90,7 @@
 		config:       dumpVarConfig,
 		stdio:        customStdio,
 		run:          dumpVars,
+		doSetup:      true,
 	}, {
 		flag:        "--build-mode",
 		description: "build modules based on the specified build action",
@@ -182,8 +188,12 @@
 		CriticalPath: criticalPath,
 	}}
 
-	config := c.config(buildCtx, args...)
-	config.SetLogsPrefix(c.logsPrefix)
+	freshConfig := func() build.Config {
+		config := c.config(buildCtx, args...)
+		config.SetLogsPrefix(c.logsPrefix)
+		return config
+	}
+	config := freshConfig()
 	logsDir := config.LogsDir()
 	buildStarted = config.BuildStartedTimeOrDefault(buildStarted)
 
@@ -213,6 +223,16 @@
 		log.Verbosef("  [%d] %s", i, arg)
 	}
 
+	if c.doSetup {
+		// We need to call logAndSymlinkSetup before we can do product
+		// config, which is how we get PRODUCT_CONFIG_RELEASE_MAPS set
+		// for the final product config for the build.
+		logAndSymlinkSetup(buildCtx, config)
+		if build.SetProductReleaseConfigMaps(buildCtx, config) {
+			config = freshConfig()
+		}
+
+	}
 	defer func() {
 		stat.Finish()
 		criticalPath.WriteToMetrics(met)
@@ -311,7 +331,6 @@
 }
 
 func dumpVar(ctx build.Context, config build.Config, args []string) {
-	logAndSymlinkSetup(ctx, config)
 	flags := flag.NewFlagSet("dumpvar", flag.ExitOnError)
 	flags.SetOutput(ctx.Writer)
 
@@ -364,7 +383,6 @@
 }
 
 func dumpVars(ctx build.Context, config build.Config, args []string) {
-	logAndSymlinkSetup(ctx, config)
 
 	flags := flag.NewFlagSet("dumpvars", flag.ExitOnError)
 	flags.SetOutput(ctx.Writer)
@@ -544,7 +562,6 @@
 }
 
 func runMake(ctx build.Context, config build.Config, _ []string) {
-	logAndSymlinkSetup(ctx, config)
 	logsDir := config.LogsDir()
 	if config.IsVerbose() {
 		writer := ctx.Writer
diff --git a/ui/build/config.go b/ui/build/config.go
index b228bb4..ac1bc7c 100644
--- a/ui/build/config.go
+++ b/ui/build/config.go
@@ -31,6 +31,7 @@
 	"time"
 
 	"android/soong/shared"
+	"android/soong/ui/metrics"
 
 	"google.golang.org/protobuf/proto"
 
@@ -465,6 +466,42 @@
 	return NewConfig(ctx, getConfigArgs(action, dir, ctx, args)...)
 }
 
+// Prepare for getting make variables.  For them to be accurate, we need to have
+// obtained PRODUCT_RELEASE_CONFIG_MAPS.
+//
+// Returns:
+//
+//	Whether config should be called again.
+//
+// TODO: when converting product config to a declarative language, make sure
+// that PRODUCT_RELEASE_CONFIG_MAPS is properly handled as a separate step in
+// that process.
+func SetProductReleaseConfigMaps(ctx Context, config Config) bool {
+	ctx.BeginTrace(metrics.RunKati, "SetProductReleaseConfigMaps")
+	defer ctx.EndTrace()
+
+	if config.SkipConfig() {
+		// This duplicates the logic from Build to skip product config
+		// if the user has explicitly said to.
+		return false
+	}
+
+	releaseConfigVars := []string{
+		"PRODUCT_RELEASE_CONFIG_MAPS",
+	}
+
+	origValue, _ := config.environ.Get("PRODUCT_RELEASE_CONFIG_MAPS")
+	// Get the PRODUCT_RELEASE_CONFIG_MAPS for this product, to avoid polluting the environment
+	// when we run product config to get the rest of the make vars.
+	releaseMapVars, err := dumpMakeVars(ctx, config, nil, releaseConfigVars, false, "")
+	if err != nil {
+		ctx.Fatalln("Error getting PRODUCT_RELEASE_CONFIG_MAPS:", err)
+	}
+	productReleaseConfigMaps := releaseMapVars["PRODUCT_RELEASE_CONFIG_MAPS"]
+	os.Setenv("PRODUCT_RELEASE_CONFIG_MAPS", productReleaseConfigMaps)
+	return origValue != productReleaseConfigMaps
+}
+
 // storeConfigMetrics selects a set of configuration information and store in
 // the metrics system for further analysis.
 func storeConfigMetrics(ctx Context, config Config) {
diff --git a/ui/build/dumpvars.go b/ui/build/dumpvars.go
index efe7478..d364542 100644
--- a/ui/build/dumpvars.go
+++ b/ui/build/dumpvars.go
@@ -191,6 +191,9 @@
 		"TARGET_BUILD_APPS",
 		"TARGET_BUILD_UNBUNDLED",
 
+		// Additional release config maps
+		"PRODUCT_RELEASE_CONFIG_MAPS",
+
 		// compiler wrappers set up by make
 		"CC_WRAPPER",
 		"CXX_WRAPPER",