From 8d8253f5257e7ab8ffa001d2e491bd0934d9119e Mon Sep 17 00:00:00 2001
From: Spandan Das <spandandas@google.com>
Date: Mon, 24 Jun 2024 17:38:27 +0000
Subject: [PATCH] Enforce that output files are created in primary ninja
 execution

Missing output files in ninja execution will be treated as errors.
Products can bypass this using the newly introduced
BUILD_BROKEN_MISSING_OUTPUTS flag.

Test: m nothing # verified missingoutfile appears in out/soong.log
Test: checkbuild passes on presubmits

Change-Id: I4eebcd08aa57fc6ccf1688c32e0d1fe06d66ab9a
---
 ui/build/config.go   | 15 ++++++++++++---
 ui/build/dumpvars.go |  6 ++++++
 ui/build/ninja.go    |  8 ++++++++
 3 files changed, 26 insertions(+), 3 deletions(-)

diff --git a/ui/build/config.go b/ui/build/config.go
index feded1c85..3b2f2c5bb 100644
--- a/ui/build/config.go
+++ b/ui/build/config.go
@@ -98,9 +98,10 @@ type configImpl struct {
 	// Autodetected
 	totalRAM uint64
 
-	brokenDupRules     bool
-	brokenUsesNetwork  bool
-	brokenNinjaEnvVars []string
+	brokenDupRules       bool
+	brokenUsesNetwork    bool
+	brokenNinjaEnvVars   []string
+	brokenMissingOutputs bool
 
 	pathReplaced bool
 
@@ -1591,6 +1592,14 @@ func (c *configImpl) BuildBrokenNinjaUsesEnvVars() []string {
 	return c.brokenNinjaEnvVars
 }
 
+func (c *configImpl) SetBuildBrokenMissingOutputs(val bool) {
+	c.brokenMissingOutputs = val
+}
+
+func (c *configImpl) BuildBrokenMissingOutputs() bool {
+	return c.brokenMissingOutputs
+}
+
 func (c *configImpl) SetTargetDeviceDir(dir string) {
 	c.targetDeviceDir = dir
 }
diff --git a/ui/build/dumpvars.go b/ui/build/dumpvars.go
index eba86a0fc..e77df44a5 100644
--- a/ui/build/dumpvars.go
+++ b/ui/build/dumpvars.go
@@ -235,6 +235,11 @@ func runMakeProductConfig(ctx Context, config Config) {
 		"BUILD_BROKEN_SRC_DIR_IS_WRITABLE",
 		"BUILD_BROKEN_SRC_DIR_RW_ALLOWLIST",
 
+		// Whether missing outputs should be treated as warnings
+		// instead of errors.
+		// `true` will relegate missing outputs to warnings.
+		"BUILD_BROKEN_MISSING_OUTPUTS",
+
 		// Not used, but useful to be in the soong.log
 		"TARGET_BUILD_TYPE",
 		"HOST_ARCH",
@@ -301,4 +306,5 @@ func runMakeProductConfig(ctx Context, config Config) {
 	config.SetBuildBrokenUsesNetwork(makeVars["BUILD_BROKEN_USES_NETWORK"] == "true")
 	config.SetBuildBrokenNinjaUsesEnvVars(strings.Fields(makeVars["BUILD_BROKEN_NINJA_USES_ENV_VARS"]))
 	config.SetSourceRootDirs(strings.Fields(makeVars["PRODUCT_SOURCE_ROOT_DIRS"]))
+	config.SetBuildBrokenMissingOutputs(makeVars["BUILD_BROKEN_MISSING_OUTPUTS"] == "true")
 }
diff --git a/ui/build/ninja.go b/ui/build/ninja.go
index 551b8ab41..ae27330a9 100644
--- a/ui/build/ninja.go
+++ b/ui/build/ninja.go
@@ -77,6 +77,14 @@ func runNinjaForBuild(ctx Context, config Config) {
 		"-w", "dupbuild=err",
 		"-w", "missingdepfile=err")
 
+	if !config.BuildBrokenMissingOutputs() {
+		// Missing outputs will be treated as errors.
+		// BUILD_BROKEN_MISSING_OUTPUTS can be used to bypass this check.
+		args = append(args,
+			"-w", "missingoutfile=err",
+		)
+	}
+
 	cmd := Command(ctx, config, "ninja", executable, args...)
 
 	// Set up the nsjail sandbox Ninja runs in.