Merge "Add Darwin x86_64+arm64 universal binary support" am: ce69757379

Original change: https://android-review.googlesource.com/c/platform/build/soong/+/1884611

Change-Id: I54226fc10b6e7265c9378df3e9634c793a61a12e

android/arch.go

@@ -566,6 +566,8 @@ func GetOsSpecificVariantsOfCommonOSVariant(mctx BaseModuleContext) []Module {
 	return variants
 }
 
+var DarwinUniversalVariantTag = archDepTag{name: "darwin universal binary"}
+
 // archMutator splits a module into a variant for each Target requested by the module.  Target selection
 // for a module is in three levels, OsClass, multilib, and then Target.
 // OsClass selection is determined by:
@@ -652,7 +654,7 @@ func archMutator(bpctx blueprint.BottomUpMutatorContext) {
 	prefer32 := os == Windows
 
 	// Determine the multilib selection for this module.
-	multilib, extraMultilib := decodeMultilib(base, os.Class)
+	multilib, extraMultilib := decodeMultilib(base, os)
 
 	// Convert the multilib selection into a list of Targets.
 	targets, err := decodeMultilibTargets(multilib, osTargets, prefer32)
@@ -702,6 +704,16 @@ func archMutator(bpctx blueprint.BottomUpMutatorContext) {
 			m.base().commonProperties.SkipInstall = true
 		}
 	}
+
+	// Create a dependency for Darwin Universal binaries from the primary to secondary
+	// architecture. The module itself will be responsible for calling lipo to merge the outputs.
+	if os == Darwin {
+		if multilib == "darwin_universal" && len(modules) == 2 {
+			mctx.AddInterVariantDependency(DarwinUniversalVariantTag, modules[1], modules[0])
+		} else if multilib == "darwin_universal_common_first" && len(modules) == 3 {
+			mctx.AddInterVariantDependency(DarwinUniversalVariantTag, modules[2], modules[1])
+		}
+	}
 }
 
 // addTargetProperties annotates a variant with the Target is is being compiled for, the list
@@ -717,9 +729,9 @@ func addTargetProperties(m Module, target Target, multiTargets []Target, primary
 // multilib from the factory's call to InitAndroidArchModule if none was set.  For modules that
 // called InitAndroidMultiTargetsArchModule it always returns "common" for multilib, and returns
 // the actual multilib in extraMultilib.
-func decodeMultilib(base *ModuleBase, class OsClass) (multilib, extraMultilib string) {
+func decodeMultilib(base *ModuleBase, os OsType) (multilib, extraMultilib string) {
 	// First check the "android.compile_multilib" or "host.compile_multilib" properties.
-	switch class {
+	switch os.Class {
 	case Device:
 		multilib = String(base.commonProperties.Target.Android.Compile_multilib)
 	case Host:
@@ -737,6 +749,26 @@ func decodeMultilib(base *ModuleBase, class OsClass) (multilib, extraMultilib st
 	}
 
 	if base.commonProperties.UseTargetVariants {
+		// Darwin has the concept of "universal binaries" which is implemented in Soong by
+		// building both x86_64 and arm64 variants, and having select module types know how to
+		// merge the outputs of their corresponding variants together into a final binary. Most
+		// module types don't need to understand this logic, as we only build a small portion
+		// of the tree for Darwin, and only module types writing macho files need to do the
+		// merging.
+		//
+		// This logic is not enabled for:
+		//  "common", as it's not an arch-specific variant
+		//  "32", as Darwin never has a 32-bit variant
+		//  !UseTargetVariants, as the module has opted into handling the arch-specific logic on
+		//    its own.
+		if os == Darwin && multilib != "common" && multilib != "32" {
+			if multilib == "common_first" {
+				multilib = "darwin_universal_common_first"
+			} else {
+				multilib = "darwin_universal"
+			}
+		}
+
 		return multilib, ""
 	} else {
 		// For app modules a single arch variant will be created per OS class which is expected to handle all the
@@ -1793,6 +1825,15 @@ func decodeMultilibTargets(multilib string, targets []Target, prefer32 bool) ([]
 		if len(buildTargets) == 0 {
 			buildTargets = filterMultilibTargets(targets, "lib64")
 		}
+	case "darwin_universal":
+		buildTargets = filterMultilibTargets(targets, "lib64")
+		// Reverse the targets so that the first architecture can depend on the second
+		// architecture module in order to merge the outputs.
+		reverseSliceInPlace(buildTargets)
+	case "darwin_universal_common_first":
+		archTargets := filterMultilibTargets(targets, "lib64")
+		reverseSliceInPlace(archTargets)
+		buildTargets = append(getCommonTargets(targets), archTargets...)
 	default:
 		return nil, fmt.Errorf(`compile_multilib must be "both", "first", "32", "64", "prefer32" or "first_prefer32" found %q`,
 			multilib)

apex/apex.go

@@ -2015,6 +2015,8 @@ func (a *apexBundle) GenerateAndroidBuildActions(ctx android.ModuleContext) {
 					}
 				} else if _, ok := depTag.(android.CopyDirectlyInAnyApexTag); ok {
 					// nothing
+				} else if depTag == android.DarwinUniversalVariantTag {
+					// nothing
 				} else if am.CanHaveApexVariants() && am.IsInstallableToApex() {
 					ctx.ModuleErrorf("unexpected tag %s for indirect dependency %q", android.PrettyPrintTag(depTag), depName)
 				}

cc/binary.go

@@ -345,6 +345,12 @@ func (binary *binaryDecorator) link(ctx ModuleContext,
 		flags.Local.LdFlags = append(flags.Local.LdFlags, "-Wl,--no-dynamic-linker")
 	}
 
+	if ctx.Darwin() && deps.DarwinSecondArchOutput.Valid() {
+		fatOutputFile := outputFile
+		outputFile = android.PathForModuleOut(ctx, "pre-fat", fileName)
+		transformDarwinUniversalBinary(ctx, fatOutputFile, outputFile, deps.DarwinSecondArchOutput.Path())
+	}
+
 	builderFlags := flagsToBuilderFlags(flags)
 	stripFlags := flagsToStripFlags(flags)
 	if binary.stripper.NeedsStrip(ctx) {

cc/builder.go

@@ -165,6 +165,12 @@ var (
 		}
 	}()
 
+	darwinLipo = pctx.AndroidStaticRule("darwinLipo",
+		blueprint.RuleParams{
+			Command:     "${config.MacLipoPath} -create -output $out $in",
+			CommandDeps: []string{"${config.MacLipoPath}"},
+		})
+
 	_ = pctx.SourcePathVariable("archiveRepackPath", "build/soong/scripts/archive_repack.sh")
 
 	// Rule to repack an archive (.a) file with a subset of object files.
@@ -1059,6 +1065,15 @@ func transformDarwinStrip(ctx android.ModuleContext, inputFile android.Path,
 	})
 }
 
+func transformDarwinUniversalBinary(ctx android.ModuleContext, outputFile android.WritablePath, inputFiles ...android.Path) {
+	ctx.Build(pctx, android.BuildParams{
+		Rule:        darwinLipo,
+		Description: "lipo " + outputFile.Base(),
+		Output:      outputFile,
+		Inputs:      inputFiles,
+	})
+}
+
 // Registers build statement to zip one or more coverage files.
 func transformCoverageFilesToZip(ctx android.ModuleContext,
 	inputs Objects, baseName string) android.OptionalPath {

cc/cc.go

@@ -167,6 +167,10 @@ type PathDeps struct {
 
 	// Path to the dynamic linker binary
 	DynamicLinker android.OptionalPath
+
+	// For Darwin builds, the path to the second architecture's output that should
+	// be combined with this architectures's output into a FAT MachO file.
+	DarwinSecondArchOutput android.OptionalPath
 }
 
 // LocalOrGlobalFlags contains flags that need to have values set globally by the build system or locally by the module
@@ -2584,6 +2588,11 @@ func (c *Module) depsToPaths(ctx android.ModuleContext) PathDeps {
 		depName := ctx.OtherModuleName(dep)
 		depTag := ctx.OtherModuleDependencyTag(dep)
 
+		if depTag == android.DarwinUniversalVariantTag {
+			depPaths.DarwinSecondArchOutput = dep.(*Module).OutputFile()
+			return
+		}
+
 		ccDep, ok := dep.(LinkableInterface)
 		if !ok {
 

cc/config/darwin_host.go

@@ -87,6 +87,10 @@ func init() {
 		return getMacTools(ctx).arPath
 	})
 
+	pctx.VariableFunc("MacLipoPath", func(ctx android.PackageVarContext) string {
+		return getMacTools(ctx).lipoPath
+	})
+
 	pctx.VariableFunc("MacStripPath", func(ctx android.PackageVarContext) string {
 		return getMacTools(ctx).stripPath
 	})
@@ -118,6 +122,7 @@ type macPlatformTools struct {
 
 	sdkRoot   string
 	arPath    string
+	lipoPath  string
 	stripPath string
 	toolPath  string
 }
@@ -157,6 +162,7 @@ func getMacTools(ctx android.PathContext) *macPlatformTools {
 		macTools.sdkRoot = xcrun("--show-sdk-path")
 
 		macTools.arPath = xcrun("--find", "ar")
+		macTools.lipoPath = xcrun("--find", "lipo")
 		macTools.stripPath = xcrun("--find", "strip")
 		macTools.toolPath = filepath.Dir(xcrun("--find", "ld"))
 	})

cc/library.go

@@ -1429,6 +1429,12 @@ func (library *libraryDecorator) linkShared(ctx ModuleContext,
 
 	builderFlags := flagsToBuilderFlags(flags)
 
+	if ctx.Darwin() && deps.DarwinSecondArchOutput.Valid() {
+		fatOutputFile := outputFile
+		outputFile = android.PathForModuleOut(ctx, "pre-fat", fileName)
+		transformDarwinUniversalBinary(ctx, fatOutputFile, outputFile, deps.DarwinSecondArchOutput.Path())
+	}
+
 	// Optimize out relinking against shared libraries whose interface hasn't changed by
 	// depending on a table of contents file instead of the library itself.
 	tocFile := outputFile.ReplaceExtension(ctx, flags.Toolchain.ShlibSuffix()[1:]+".toc")