From 7130fabd20530f4809320e38a994f1aba2d39ad7 Mon Sep 17 00:00:00 2001
From: Martin Stjernholm <mast@google.com>
Date: Thu, 28 May 2020 22:58:01 +0100
Subject: [PATCH] Propagate flags necessary for a prebuilt of the Bionic
 linker.

The flags are necessary to avoid implicit dependencies on crt libs,
libc, and the linker (recursively). The reason cc_prebuilt_binary react
to these flags is that they can affect the install rules.

Test: m nothing
Test: art/test/testrunner/run_build_test_target.py art-linux-bionic-x64
  on a master-art branch using snapshot built from runtime-module-sdk
  and runtime-module-host-exports
Bug: 152255951
Change-Id: I6b2fe92d105d1f446fffd00bd3267a416f75efb7
---
 cc/binary_sdk_member.go | 26 +++++++++++-
 sdk/cc_sdk_test.go      | 87 ++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 111 insertions(+), 2 deletions(-)

diff --git a/cc/binary_sdk_member.go b/cc/binary_sdk_member.go
index 88ac51349..372a72e2c 100644
--- a/cc/binary_sdk_member.go
+++ b/cc/binary_sdk_member.go
@@ -20,6 +20,7 @@ import (
 	"android/soong/android"
 
 	"github.com/google/blueprint"
+	"github.com/google/blueprint/proptools"
 )
 
 func init() {
@@ -65,7 +66,15 @@ func (mt *binarySdkMemberType) IsInstance(module android.Module) bool {
 }
 
 func (mt *binarySdkMemberType) AddPrebuiltModule(ctx android.SdkMemberContext, member android.SdkMember) android.BpModule {
-	return ctx.SnapshotBuilder().AddPrebuiltModule(member, "cc_prebuilt_binary")
+	pbm := ctx.SnapshotBuilder().AddPrebuiltModule(member, "cc_prebuilt_binary")
+
+	ccModule := member.Variants()[0].(*Module)
+
+	if stl := ccModule.stl.Properties.Stl; stl != nil {
+		pbm.AddProperty("stl", proptools.String(stl))
+	}
+
+	return pbm
 }
 
 func (mt *binarySdkMemberType) CreateVariantPropertiesStruct() android.SdkMemberProperties {
@@ -105,6 +114,10 @@ type nativeBinaryInfoProperties struct {
 	//
 	// This field is exported as its contents may not be arch specific.
 	SystemSharedLibs []string
+
+	// Arch specific flags.
+	StaticExecutable bool
+	Nocrt            bool
 }
 
 func (p *nativeBinaryInfoProperties) PopulateFromVariant(ctx android.SdkMemberContext, variant android.Module) {
@@ -113,6 +126,10 @@ func (p *nativeBinaryInfoProperties) PopulateFromVariant(ctx android.SdkMemberCo
 	p.archType = ccModule.Target().Arch.ArchType.String()
 	p.outputFile = getRequiredMemberOutputFile(ctx, ccModule)
 
+	binaryLinker := ccModule.linker.(*binaryDecorator)
+	p.StaticExecutable = binaryLinker.static()
+	p.Nocrt = Bool(binaryLinker.baseLinker.Properties.Nocrt)
+
 	if ccModule.linker != nil {
 		specifiedDeps := specifiedDeps{}
 		specifiedDeps = ccModule.linker.linkerSpecifiedDeps(specifiedDeps)
@@ -143,4 +160,11 @@ func (p *nativeBinaryInfoProperties) AddToPropertySet(ctx android.SdkMemberConte
 	if p.SystemSharedLibs != nil {
 		propertySet.AddPropertyWithTag("system_shared_libs", p.SystemSharedLibs, builder.SdkMemberReferencePropertyTag(false))
 	}
+
+	if p.StaticExecutable {
+		propertySet.AddProperty("static_executable", p.StaticExecutable)
+	}
+	if p.Nocrt {
+		propertySet.AddProperty("nocrt", p.Nocrt)
+	}
 }
diff --git a/sdk/cc_sdk_test.go b/sdk/cc_sdk_test.go
index dded15360..4a090814d 100644
--- a/sdk/cc_sdk_test.go
+++ b/sdk/cc_sdk_test.go
@@ -401,7 +401,6 @@ func TestSnapshotWithCcBinary(t *testing.T) {
 				"Test.cpp",
 			],
 			compile_multilib: "both",
-			stl: "none",
 		}
 	`)
 
@@ -494,6 +493,7 @@ cc_prebuilt_binary {
     device_supported: false,
     host_supported: true,
     installable: false,
+    stl: "none",
     target: {
         linux_glibc: {
             compile_multilib: "both",
@@ -518,6 +518,7 @@ cc_prebuilt_binary {
     prefer: false,
     device_supported: false,
     host_supported: true,
+    stl: "none",
     target: {
         linux_glibc: {
             compile_multilib: "both",
@@ -557,6 +558,90 @@ module_exports_snapshot {
 	)
 }
 
+// Test that we support the necessary flags for the linker binary, which is
+// special in several ways.
+func TestSnapshotWithCcStaticNocrtBinary(t *testing.T) {
+	// b/145598135 - Generating host snapshots for anything other than linux is not supported.
+	SkipIfNotLinux(t)
+
+	result := testSdkWithCc(t, `
+		module_exports {
+			name: "mymodule_exports",
+			host_supported: true,
+			device_supported: false,
+			native_binaries: ["linker"],
+		}
+
+		cc_binary {
+			name: "linker",
+			host_supported: true,
+			static_executable: true,
+			nocrt: true,
+			stl: "none",
+			srcs: [
+				"Test.cpp",
+			],
+			compile_multilib: "both",
+		}
+	`)
+
+	result.CheckSnapshot("mymodule_exports", "",
+		checkAndroidBpContents(`
+// This is auto-generated. DO NOT EDIT.
+
+cc_prebuilt_binary {
+    name: "mymodule_exports_linker@current",
+    sdk_member_name: "linker",
+    device_supported: false,
+    host_supported: true,
+    installable: false,
+    stl: "none",
+    static_executable: true,
+    nocrt: true,
+    compile_multilib: "both",
+    arch: {
+        x86_64: {
+            srcs: ["x86_64/bin/linker"],
+        },
+        x86: {
+            srcs: ["x86/bin/linker"],
+        },
+    },
+}
+
+cc_prebuilt_binary {
+    name: "linker",
+    prefer: false,
+    device_supported: false,
+    host_supported: true,
+    stl: "none",
+    static_executable: true,
+    nocrt: true,
+    compile_multilib: "both",
+    arch: {
+        x86_64: {
+            srcs: ["x86_64/bin/linker"],
+        },
+        x86: {
+            srcs: ["x86/bin/linker"],
+        },
+    },
+}
+
+module_exports_snapshot {
+    name: "mymodule_exports@current",
+    device_supported: false,
+    host_supported: true,
+    native_binaries: ["mymodule_exports_linker@current"],
+}
+`),
+		checkAllCopyRules(`
+.intermediates/linker/linux_glibc_x86_64/linker -> x86_64/bin/linker
+.intermediates/linker/linux_glibc_x86/linker -> x86/bin/linker
+`),
+	)
+}
+
 func TestSnapshotWithCcSharedLibrary(t *testing.T) {
 	result := testSdkWithCc(t, `
 		sdk {