Revert "Get the dex2oat host tool path from module dependency on..."

Revert submission 1211982-dex2oat-soong-dep

Reason for revert: Build failures. See b/148312086.

Reverted Changes:
Ibc427a9a8: Make dex2oat(d) visible for use as implicit dexpre...
I71df11c1e: Move the Once cache for dexpreopt.GlobalConfig int...
I38317f2d5: Get the dex2oat host tool path from module depende...
I440a09dba: Separate dexpreopt.GlobalSoongConfig to allow inde...

Bug: 148312086
Bug: 145934348
Exempt-From-Owner-Approval: Plain revert
Change-Id: I0cf6fef04434fd3c0b7957ee9abdcaabeb20b9d8
diff --git a/dexpreopt/config.go b/dexpreopt/config.go
index 72c01d0..cd74ec8 100644
--- a/dexpreopt/config.go
+++ b/dexpreopt/config.go
@@ -16,11 +16,8 @@
 
 import (
 	"encoding/json"
-	"fmt"
 	"strings"
 
-	"github.com/google/blueprint"
-
 	"android/soong/android"
 )
 
@@ -301,71 +298,6 @@
 	return config.ModuleConfig, nil
 }
 
-// dex2oatModuleName returns the name of the module to use for the dex2oat host
-// tool. It should be a binary module with public visibility that is compiled
-// and installed for host.
-func dex2oatModuleName(config android.Config) string {
-	// Default to the debug variant of dex2oat to help find bugs.
-	// Set USE_DEX2OAT_DEBUG to false for only building non-debug versions.
-	if config.Getenv("USE_DEX2OAT_DEBUG") == "false" {
-		return "dex2oat"
-	} else {
-		return "dex2oatd"
-	}
-}
-
-var dex2oatDepTag = struct {
-	blueprint.BaseDependencyTag
-}{}
-
-type DexPreoptModule interface {
-	dexPreoptModuleSignature() // Not called - only for type detection.
-}
-
-// RegisterToolDepsMutator registers a mutator that adds the necessary
-// dependencies to binary modules for tools that are required later when
-// Get(Cached)GlobalSoongConfig is called. It should be passed to
-// android.RegistrationContext.FinalDepsMutators, and module types that need
-// dependencies also need to embed DexPreoptModule.
-func RegisterToolDepsMutator(ctx android.RegisterMutatorsContext) {
-	ctx.BottomUp("dexpreopt_tool_deps", toolDepsMutator).Parallel()
-}
-
-func toolDepsMutator(ctx android.BottomUpMutatorContext) {
-	if GetGlobalConfig(ctx).DisablePreopt {
-		// Only register dependencies if dexpreopting is enabled. Necessary to avoid
-		// them in non-platform builds where dex2oat etc isn't available.
-		//
-		// It would be nice to not register this mutator at all then, but
-		// RegisterMutatorsContext available at registration doesn't have the state
-		// necessary to pass as PathContext to constructPath etc.
-		return
-	}
-	if _, ok := ctx.Module().(DexPreoptModule); !ok {
-		return
-	}
-	dex2oatBin := dex2oatModuleName(ctx.Config())
-	v := ctx.Config().BuildOSTarget.Variations()
-	ctx.AddFarVariationDependencies(v, dex2oatDepTag, dex2oatBin)
-}
-
-func dex2oatPathFromDep(ctx android.ModuleContext) android.Path {
-	dex2oatBin := dex2oatModuleName(ctx.Config())
-
-	dex2oatModule := ctx.GetDirectDepWithTag(dex2oatBin, dex2oatDepTag)
-	if dex2oatModule == nil {
-		// If this happens there's probably a missing call to AddToolDeps in DepsMutator.
-		panic(fmt.Sprintf("Failed to lookup %s dependency", dex2oatBin))
-	}
-
-	dex2oatPath := dex2oatModule.(android.HostToolProvider).HostToolPath()
-	if !dex2oatPath.Valid() {
-		panic(fmt.Sprintf("Failed to find host tool path in %s", dex2oatModule))
-	}
-
-	return dex2oatPath.Path()
-}
-
 // createGlobalSoongConfig creates a GlobalSoongConfig from the current context.
 // Should not be used in dexpreopt_gen.
 func createGlobalSoongConfig(ctx android.ModuleContext) GlobalSoongConfig {
@@ -376,9 +308,18 @@
 		panic("This should not be called from tests. Please call GlobalSoongConfigForTests somewhere in the test setup.")
 	}
 
+	// Default to debug version to help find bugs.
+	// Set USE_DEX2OAT_DEBUG to false for only building non-debug versions.
+	var dex2oatBinary string
+	if ctx.Config().Getenv("USE_DEX2OAT_DEBUG") == "false" {
+		dex2oatBinary = "dex2oat"
+	} else {
+		dex2oatBinary = "dex2oatd"
+	}
+
 	return GlobalSoongConfig{
 		Profman:          ctx.Config().HostToolPath(ctx, "profman"),
-		Dex2oat:          dex2oatPathFromDep(ctx),
+		Dex2oat:          ctx.Config().HostToolPath(ctx, dex2oatBinary),
 		Aapt:             ctx.Config().HostToolPath(ctx, "aapt"),
 		SoongZip:         ctx.Config().HostToolPath(ctx, "soong_zip"),
 		Zip2zip:          ctx.Config().HostToolPath(ctx, "zip2zip"),
@@ -387,16 +328,6 @@
 	}
 }
 
-// The main reason for this Once cache for GlobalSoongConfig is to make the
-// dex2oat path available to singletons. In ordinary modules we get it through a
-// dex2oatDepTag dependency, but in singletons there's no simple way to do the
-// same thing and ensure the right variant is selected, hence this cache to make
-// the resolved path available to singletons. This means we depend on there
-// being at least one ordinary module with a dex2oatDepTag dependency.
-//
-// TODO(b/147613152): Implement a way to deal with dependencies from singletons,
-// and then possibly remove this cache altogether (but the use in
-// GlobalSoongConfigForTests also needs to be rethought).
 var globalSoongConfigOnceKey = android.NewOnceKey("DexpreoptGlobalSoongConfig")
 
 // GetGlobalSoongConfig creates a GlobalSoongConfig the first time it's called,
@@ -405,14 +336,6 @@
 	globalSoong := ctx.Config().Once(globalSoongConfigOnceKey, func() interface{} {
 		return createGlobalSoongConfig(ctx)
 	}).(GlobalSoongConfig)
-
-	// Always resolve the tool path from the dependency, to ensure that every
-	// module has the dependency added properly.
-	myDex2oat := dex2oatPathFromDep(ctx)
-	if myDex2oat != globalSoong.Dex2oat {
-		panic(fmt.Sprintf("Inconsistent dex2oat path in cached config: expected %s, got %s", globalSoong.Dex2oat, myDex2oat))
-	}
-
 	return globalSoong
 }
 
@@ -460,10 +383,6 @@
 }
 
 func (s *globalSoongConfigSingleton) GenerateBuildActions(ctx android.SingletonContext) {
-	if GetGlobalConfig(ctx).DisablePreopt {
-		return
-	}
-
 	config := GetCachedGlobalSoongConfig(ctx)
 	jc := globalJsonSoongConfig{
 		Profman:          config.Profman.String(),
@@ -491,10 +410,6 @@
 }
 
 func (s *globalSoongConfigSingleton) MakeVars(ctx android.MakeVarsContext) {
-	if GetGlobalConfig(ctx).DisablePreopt {
-		return
-	}
-
 	config := GetCachedGlobalSoongConfig(ctx)
 
 	ctx.Strict("DEX2OAT", config.Dex2oat.String())