From 611e14004382d52af11eae5e97595987215fe3f9 Mon Sep 17 00:00:00 2001
From: Martin Stjernholm <mast@google.com>
Date: Tue, 30 Nov 2021 18:37:16 +0000
Subject: [PATCH 1/2] Reduce code duplication for testing the two header
 modules.

Preparation for adding more tests to them.

Test: m nothing
Bug: 202192894
Change-Id: Ica29c649c4669e821371fbf8360f437871b7d041
---
 cc/library_headers_test.go | 55 +++++++++++++-------------------------
 1 file changed, 18 insertions(+), 37 deletions(-)

diff --git a/cc/library_headers_test.go b/cc/library_headers_test.go
index 9789ab04b..79d229142 100644
--- a/cc/library_headers_test.go
+++ b/cc/library_headers_test.go
@@ -16,7 +16,6 @@ package cc
 
 import (
 	"fmt"
-	"strings"
 	"testing"
 
 	"android/soong/android"
@@ -25,44 +24,26 @@ import (
 )
 
 func TestLibraryHeaders(t *testing.T) {
-	ctx := testCc(t, `
-	cc_library_headers {
-		name: "headers",
-		export_include_dirs: ["my_include"],
-	}
-	cc_library_static {
-		name: "lib",
-		srcs: ["foo.c"],
-		header_libs: ["headers"],
-	}
-	`)
+	bp := `
+		%s {
+			name: "headers",
+			export_include_dirs: ["my_include"],
+		}
+		cc_library_static {
+			name: "lib",
+			srcs: ["foo.c"],
+			header_libs: ["headers"],
+		}
+	`
 
-	// test if header search paths are correctly added
-	cc := ctx.ModuleForTests("lib", "android_arm64_armv8-a_static").Rule("cc")
-	cflags := cc.Args["cFlags"]
-	if !strings.Contains(cflags, " -Imy_include ") {
-		t.Errorf("cflags for libsystem must contain -Imy_include, but was %#v.", cflags)
-	}
-}
+	for _, headerModule := range []string{"cc_library_headers", "cc_prebuilt_library_headers"} {
+		t.Run(headerModule, func(t *testing.T) {
+			ctx := testCc(t, fmt.Sprintf(bp, headerModule))
 
-func TestPrebuiltLibraryHeaders(t *testing.T) {
-	ctx := testCc(t, `
-	cc_prebuilt_library_headers {
-		name: "headers",
-		export_include_dirs: ["my_include"],
-	}
-	cc_library_static {
-		name: "lib",
-		srcs: ["foo.c"],
-		header_libs: ["headers"],
-	}
-	`)
-
-	// test if header search paths are correctly added
-	cc := ctx.ModuleForTests("lib", "android_arm64_armv8-a_static").Rule("cc")
-	cflags := cc.Args["cFlags"]
-	if !strings.Contains(cflags, " -Imy_include ") {
-		t.Errorf("cflags for libsystem must contain -Imy_include, but was %#v.", cflags)
+			// test if header search paths are correctly added
+			cc := ctx.ModuleForTests("lib", "android_arm64_armv8-a_static").Rule("cc")
+			android.AssertStringDoesContain(t, "cFlags for lib module", cc.Args["cFlags"], " -Imy_include ")
+		})
 	}
 }
 

From d51cb5c130700cc4442ee53187e15181d5eabaa2 Mon Sep 17 00:00:00 2001
From: Martin Stjernholm <mast@google.com>
Date: Tue, 30 Nov 2021 18:49:03 +0000
Subject: [PATCH 2/2] Fix prebuilt header files to produce proper AndroidMk
 entries.

Necessary for modules that depend on headers through
LOCAL_HEADER_LIBRARIES in legacy Android.mk files.

Test: m nothing
Test: m nothing SOONG_CONFIG_art_module_source_build=false
  on internal master
Test: m droid checkbuild SOONG_CONFIG_art_module_source_build=false
Test: m SOONG_CONFIG_art_module_source_build=false \
        out/soong/.intermediates/prebuilts/module_sdk/art/current/sdk/prebuilt_jni_headers/linux_glibc_x86_64/prebuilt_jni_headers.a
      ar t out/soong/.intermediates/prebuilts/module_sdk/art/current/sdk/prebuilt_jni_headers/linux_glibc_x86_64/prebuilt_jni_headers.a \
        && echo ok
Bug: 202192894
Change-Id: Ied267053d1fc3563870a3faaf41d79983a22815a
---
 cc/library_headers_test.go | 11 +++++++++++
 cc/prebuilt.go             |  8 +++++++-
 2 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/cc/library_headers_test.go b/cc/library_headers_test.go
index 79d229142..3e448ba26 100644
--- a/cc/library_headers_test.go
+++ b/cc/library_headers_test.go
@@ -43,6 +43,17 @@ func TestLibraryHeaders(t *testing.T) {
 			// test if header search paths are correctly added
 			cc := ctx.ModuleForTests("lib", "android_arm64_armv8-a_static").Rule("cc")
 			android.AssertStringDoesContain(t, "cFlags for lib module", cc.Args["cFlags"], " -Imy_include ")
+
+			// Test that there's a valid AndroidMk entry.
+			headers := ctx.ModuleForTests("headers", "android_arm64_armv8-a").Module()
+			e := android.AndroidMkEntriesForTest(t, ctx, headers)[0]
+
+			// This duplicates the tests done in AndroidMkEntries.write. It would be
+			// better to test its output, but there are no test functions that capture that.
+			android.AssertBoolEquals(t, "AndroidMkEntries.Disabled", false, e.Disabled)
+			android.AssertBoolEquals(t, "AndroidMkEntries.OutputFile.Valid()", true, e.OutputFile.Valid())
+
+			android.AssertStringListContains(t, "LOCAL_EXPORT_CFLAGS for headers module", e.EntryMap["LOCAL_EXPORT_CFLAGS"], "-Imy_include")
 		})
 	}
 }
diff --git a/cc/prebuilt.go b/cc/prebuilt.go
index a279054c3..c303fda99 100644
--- a/cc/prebuilt.go
+++ b/cc/prebuilt.go
@@ -197,7 +197,13 @@ func (p *prebuiltLibraryLinker) link(ctx ModuleContext,
 	if p.header() {
 		ctx.SetProvider(HeaderLibraryInfoProvider, HeaderLibraryInfo{})
 
-		return nil
+		// Need to return an output path so that the AndroidMk logic doesn't skip
+		// the prebuilt header. For compatibility, in case Android.mk files use a
+		// header lib in LOCAL_STATIC_LIBRARIES, create an empty ar file as
+		// placeholder, just like non-prebuilt header modules do in linkStatic().
+		ph := android.PathForModuleOut(ctx, ctx.ModuleName()+staticLibraryExtension)
+		transformObjToStaticLib(ctx, nil, nil, builderFlags{}, ph, nil, nil)
+		return ph
 	}
 
 	return nil