From eefc9e6a624e78e1c1565656f7ec5e0a655590b0 Mon Sep 17 00:00:00 2001
From: Chris Parsons <cparsons@google.com>
Date: Fri, 2 Apr 2021 17:36:47 -0400
Subject: [PATCH] Fix note_memtag bionic libraries in mixed builds

Required fixes:
  - Set MakeLinkType for libraries, even in mixed build mode.
  - Set snapshot header information to empty list, which passes
        validation logic for depending modules

Fixing these libraries also requires a Starlark change to
cc_library_static.bzl, which will be submitted separately.

Additionally, this adds better error messaging in the event that
output files are missing from a mixed-build library.

Test: USE_BAZEL_ANALYSIS=1 m libc
Test: USE_BAZEL_ANALYSIS=1 m runtime-module-sdk
Change-Id: Iad2c4d46359986fb0a43263292a15ed45fabbac7
---
 android/bazel.go             |  2 --
 bazel/cquery/request_type.go | 14 ++++++++++++--
 cc/cc.go                     |  4 ++--
 cc/library.go                | 17 ++++++++++++++---
 4 files changed, 28 insertions(+), 9 deletions(-)

diff --git a/android/bazel.go b/android/bazel.go
index a08da0e7b..b2170be79 100644
--- a/android/bazel.go
+++ b/android/bazel.go
@@ -174,8 +174,6 @@ var (
 		"liblinker_debuggerd_stub",      // ruperts@, cc_library_static, depends on //system/libbase
 		"libbionic_tests_headers_posix", // ruperts@, cc_library_static
 		"libc_dns",                      // ruperts@, cc_library_static
-		"note_memtag_heap_async",        // cparsons@, cc_library_static
-		"note_memtag_heap_sync",         // cparsons@, cc_library_static
 	}
 
 	// Used for quicker lookups
diff --git a/bazel/cquery/request_type.go b/bazel/cquery/request_type.go
index bd1ece177..c4ab36c35 100644
--- a/bazel/cquery/request_type.go
+++ b/bazel/cquery/request_type.go
@@ -83,7 +83,17 @@ func (g getOutputFilesAndCcObjectFilesType) ParseResult(rawString string) interf
 	splitString := strings.Split(rawString, "|")
 	outputFilesString := splitString[0]
 	ccObjectsString := splitString[1]
-	outputFiles = strings.Split(outputFilesString, ", ")
-	ccObjects = strings.Split(ccObjectsString, ", ")
+	outputFiles = splitOrEmpty(outputFilesString, ", ")
+	ccObjects = splitOrEmpty(ccObjectsString, ", ")
 	return GetOutputFilesAndCcObjectFiles_Result{outputFiles, ccObjects}
 }
+
+// splitOrEmpty is a modification of strings.Split() that returns an empty list
+// if the given string is empty.
+func splitOrEmpty(s string, sep string) []string {
+	if len(s) < 1 {
+		return []string{}
+	} else {
+		return strings.Split(s, sep)
+	}
+}
diff --git a/cc/cc.go b/cc/cc.go
index 0f9a55668..1ce83a95c 100644
--- a/cc/cc.go
+++ b/cc/cc.go
@@ -1646,12 +1646,12 @@ func (c *Module) GenerateAndroidBuildActions(actx android.ModuleContext) {
 		c.hideApexVariantFromMake = true
 	}
 
+	c.makeLinkType = GetMakeLinkType(actx, c)
+
 	if c.maybeGenerateBazelActions(actx) {
 		return
 	}
 
-	c.makeLinkType = GetMakeLinkType(actx, c)
-
 	ctx := &moduleContext{
 		ModuleContext: actx,
 		moduleContextImpl: moduleContextImpl{
diff --git a/cc/library.go b/cc/library.go
index 50fff7f9d..11b673742 100644
--- a/cc/library.go
+++ b/cc/library.go
@@ -425,11 +425,14 @@ func (handler *staticLibraryBazelHandler) generateBazelBuildActions(ctx android.
 	if !ok {
 		return ok
 	}
-	if len(outputPaths) != 1 {
+	if len(outputPaths) > 1 {
 		// TODO(cparsons): This is actually expected behavior for static libraries with no srcs.
 		// We should support this.
-		ctx.ModuleErrorf("expected exactly one output file for '%s', but got %s", label, objPaths)
+		ctx.ModuleErrorf("expected at most one output file for '%s', but got %s", label, objPaths)
 		return false
+	} else if len(outputPaths) == 0 {
+		handler.module.outputFile = android.OptionalPath{}
+		return true
 	}
 	outputFilePath := android.PathForBazelOut(ctx, outputPaths[0])
 	handler.module.outputFile = android.OptionalPathForPath(outputFilePath)
@@ -453,7 +456,15 @@ func (handler *staticLibraryBazelHandler) generateBazelBuildActions(ctx android.
 			Direct(outputFilePath).
 			Build(),
 	})
-	handler.module.outputFile = android.OptionalPathForPath(android.PathForBazelOut(ctx, objPaths[0]))
+	if i, ok := handler.module.linker.(snapshotLibraryInterface); ok {
+		// Dependencies on this library will expect collectedSnapshotHeaders to
+		// be set, otherwise validation will fail. For now, set this to an empty
+		// list.
+		// TODO(cparsons): More closely mirror the collectHeadersForSnapshot
+		// implementation.
+		i.(*libraryDecorator).collectedSnapshotHeaders = android.Paths{}
+	}
+
 	return ok
 }