From 219968c9b3cdb73d653800cc44efb4b2d7addd42 Mon Sep 17 00:00:00 2001
From: Yo Chiang <yochiang@google.com>
Date: Tue, 22 Sep 2020 18:45:04 +0800
Subject: [PATCH] soong: Exclude system shared libs from fix suggestions

Pass the value of system_shared_libs to the Android.mk world, so that
prebuilt ELF check can exclude them from fix suggestions.

Bug: 141925662
Test: Write a bad cc_prebuilt_library module and check fix suggestions
Change-Id: I0cc61821765507180ce6a582bf8125a192f83a57
---
 cc/androidmk.go |  7 +++++++
 cc/cc.go        |  8 ++++++++
 cc/linker.go    | 16 ++++++++--------
 3 files changed, 23 insertions(+), 8 deletions(-)

diff --git a/cc/androidmk.go b/cc/androidmk.go
index 380b4e92f..fcaff557d 100644
--- a/cc/androidmk.go
+++ b/cc/androidmk.go
@@ -83,6 +83,13 @@ func (c *Module) AndroidMkEntries() []android.AndroidMkEntries {
 				if len(c.Properties.Logtags) > 0 {
 					entries.AddStrings("LOCAL_LOGTAGS_FILES", c.Properties.Logtags...)
 				}
+				// Note: Pass the exact value of AndroidMkSystemSharedLibs to the Make
+				// world, even if it is an empty list. In the Make world,
+				// LOCAL_SYSTEM_SHARED_LIBRARIES defaults to "none", which is expanded
+				// to the default list of system shared libs by the build system.
+				// Soong computes the exact list of system shared libs, so we have to
+				// override the default value when the list of libs is actually empty.
+				entries.SetString("LOCAL_SYSTEM_SHARED_LIBRARIES", strings.Join(c.Properties.AndroidMkSystemSharedLibs, " "))
 				if len(c.Properties.AndroidMkSharedLibs) > 0 {
 					entries.AddStrings("LOCAL_SHARED_LIBRARIES", c.Properties.AndroidMkSharedLibs...)
 				}
diff --git a/cc/cc.go b/cc/cc.go
index 70229be5a..82321173c 100644
--- a/cc/cc.go
+++ b/cc/cc.go
@@ -99,6 +99,9 @@ type Deps struct {
 	// Used for data dependencies adjacent to tests
 	DataLibs []string
 
+	// Used by DepsMutator to pass system_shared_libs information to check_elf_file.py.
+	SystemSharedLibs []string
+
 	StaticUnwinderIfLegacy bool
 
 	ReexportSharedLibHeaders, ReexportStaticLibHeaders, ReexportHeaderLibHeaders []string
@@ -237,6 +240,9 @@ type BaseProperties struct {
 	PreventInstall            bool     `blueprint:"mutated"`
 	ApexesProvidingSharedLibs []string `blueprint:"mutated"`
 
+	// Set by DepsMutator.
+	AndroidMkSystemSharedLibs []string `blueprint:"mutated"`
+
 	ImageVariationPrefix string `blueprint:"mutated"`
 	VndkVersion          string `blueprint:"mutated"`
 	SubName              string `blueprint:"mutated"`
@@ -1815,6 +1821,8 @@ func (c *Module) DepsMutator(actx android.BottomUpMutatorContext) {
 
 	deps := c.deps(ctx)
 
+	c.Properties.AndroidMkSystemSharedLibs = deps.SystemSharedLibs
+
 	variantNdkLibs := []string{}
 	variantLateNdkLibs := []string{}
 	if ctx.Os() == android.Android {
diff --git a/cc/linker.go b/cc/linker.go
index 58f8a294e..12c8b2c59 100644
--- a/cc/linker.go
+++ b/cc/linker.go
@@ -278,19 +278,19 @@ func (linker *baseLinker) linkerDeps(ctx DepsContext, deps Deps) Deps {
 			deps.LateStaticLibs = append(deps.LateStaticLibs, "libatomic")
 		}
 
-		systemSharedLibs := linker.Properties.System_shared_libs
-		if systemSharedLibs == nil {
+		deps.SystemSharedLibs = linker.Properties.System_shared_libs
+		if deps.SystemSharedLibs == nil {
 			// Provide a default system_shared_libs if it is unspecified. Note: If an
 			// empty list [] is specified, it implies that the module declines the
 			// default system_shared_libs.
-			systemSharedLibs = []string{"libc", "libm", "libdl"}
+			deps.SystemSharedLibs = []string{"libc", "libm", "libdl"}
 		}
 
 		if inList("libdl", deps.SharedLibs) {
 			// If system_shared_libs has libc but not libdl, make sure shared_libs does not
 			// have libdl to avoid loading libdl before libc.
-			if inList("libc", systemSharedLibs) {
-				if !inList("libdl", systemSharedLibs) {
+			if inList("libc", deps.SystemSharedLibs) {
+				if !inList("libdl", deps.SystemSharedLibs) {
 					ctx.PropertyErrorf("shared_libs",
 						"libdl must be in system_shared_libs, not shared_libs")
 				}
@@ -300,12 +300,12 @@ func (linker *baseLinker) linkerDeps(ctx DepsContext, deps Deps) Deps {
 
 		// If libc and libdl are both in system_shared_libs make sure libdl comes after libc
 		// to avoid loading libdl before libc.
-		if inList("libdl", systemSharedLibs) && inList("libc", systemSharedLibs) &&
-			indexList("libdl", systemSharedLibs) < indexList("libc", systemSharedLibs) {
+		if inList("libdl", deps.SystemSharedLibs) && inList("libc", deps.SystemSharedLibs) &&
+			indexList("libdl", deps.SystemSharedLibs) < indexList("libc", deps.SystemSharedLibs) {
 			ctx.PropertyErrorf("system_shared_libs", "libdl must be after libc")
 		}
 
-		deps.LateSharedLibs = append(deps.LateSharedLibs, systemSharedLibs...)
+		deps.LateSharedLibs = append(deps.LateSharedLibs, deps.SystemSharedLibs...)
 	}
 
 	if ctx.Fuchsia() {