Convert cc aidl to rule builder

This fixes an incremental build issue where we didn't clean up old aidl
header files (or necessarily notice that they were updated).

We do this by declaring the header files as outputs in the build graph,
but this means that the src file name needs to be convertible to the
aidl package name, as that's how the header file paths are created. In
many cases, filegroups can be used to strip path prefixes from the aidl
files.

Bug: 112114177
Test: treehugger
Change-Id: If534ff3dbfac329dea9a7402e30be74495754160

android/rule_builder.go

@@ -525,6 +525,15 @@ func (c *RuleBuilderCommand) Outputs(paths WritablePaths) *RuleBuilderCommand {
 	return c
 }
 
+// OutputDir adds the output directory to the command line. This is only available when used with RuleBuilder.Sbox,
+// and will be the temporary output directory managed by sbox, not the final one.
+func (c *RuleBuilderCommand) OutputDir() *RuleBuilderCommand {
+	if !c.sbox {
+		panic("OutputDir only valid with Sbox")
+	}
+	return c.Text("__SBOX_OUT_DIR__")
+}
+
 // DepFile adds the specified depfile path to the paths returned by RuleBuilder.DepFiles and adds it to the command
 // line, and causes RuleBuilder.Build file to set the depfile flag for ninja.  If multiple depfiles are added to
 // commands in a single RuleBuilder then RuleBuilder.Build will add an extra command to merge the depfiles together.

cc/gen.go

@@ -16,6 +16,7 @@ package cc
 
 import (
 	"path/filepath"
+	"strings"
 
 	"github.com/google/blueprint"
 
@@ -36,15 +37,6 @@ var (
 			CommandDeps: []string{"$lexCmd"},
 		})
 
-	aidl = pctx.AndroidStaticRule("aidl",
-		blueprint.RuleParams{
-			Command:     "$aidlCmd -d${out}.d --ninja $aidlFlags $in $outDir $out",
-			CommandDeps: []string{"$aidlCmd"},
-			Depfile:     "${out}.d",
-			Deps:        blueprint.DepsGCC,
-		},
-		"aidlFlags", "outDir")
-
 	sysprop = pctx.AndroidStaticRule("sysprop",
 		blueprint.RuleParams{
 			Command: "$syspropCmd --header-dir=$headerOutDir --system-header-dir=$systemOutDir " +
@@ -114,20 +106,37 @@ func genYacc(ctx android.ModuleContext, rule *android.RuleBuilder, yaccFile andr
 	return ret
 }
 
-func genAidl(ctx android.ModuleContext, aidlFile android.Path, outFile android.ModuleGenPath, aidlFlags string) android.Paths {
-	ctx.Build(pctx, android.BuildParams{
-		Rule:        aidl,
-		Description: "aidl " + aidlFile.Rel(),
-		Output:      outFile,
-		Input:       aidlFile,
-		Args: map[string]string{
-			"aidlFlags": aidlFlags,
-			"outDir":    android.PathForModuleGen(ctx, "aidl").String(),
-		},
-	})
+func genAidl(ctx android.ModuleContext, rule *android.RuleBuilder, aidlFile android.Path,
+	outFile, depFile android.ModuleGenPath, aidlFlags string) android.Paths {
 
-	// TODO: This should return the generated headers, not the source file.
-	return android.Paths{outFile}
+	aidlPackage := strings.TrimSuffix(aidlFile.Rel(), aidlFile.Base())
+	baseName := strings.TrimSuffix(aidlFile.Base(), aidlFile.Ext())
+	shortName := strings.TrimPrefix(baseName, "I")
+
+	outDir := android.PathForModuleGen(ctx, "aidl")
+	headerI := outDir.Join(ctx, aidlPackage, baseName+".h")
+	headerBn := outDir.Join(ctx, aidlPackage, "Bn"+shortName+".h")
+	headerBp := outDir.Join(ctx, aidlPackage, "Bp"+shortName+".h")
+
+	cmd := rule.Command()
+	cmd.Tool(ctx.Config().HostToolPath(ctx, "aidl-cpp")).
+		FlagWithDepFile("-d", depFile).
+		Flag("--ninja").
+		Flag(aidlFlags).
+		Input(aidlFile).
+		OutputDir().
+		Output(outFile).
+		ImplicitOutputs(android.WritablePaths{
+			headerI,
+			headerBn,
+			headerBp,
+		})
+
+	return android.Paths{
+		headerI,
+		headerBn,
+		headerBp,
+	}
 }
 
 func genLex(ctx android.ModuleContext, lexFile android.Path, outFile android.ModuleGenPath) {
@@ -187,6 +196,8 @@ func genSources(ctx android.ModuleContext, srcFiles android.Paths,
 	var deps android.Paths
 	var rsFiles android.Paths
 
+	var aidlRule *android.RuleBuilder
+
 	var yaccRule_ *android.RuleBuilder
 	yaccRule := func() *android.RuleBuilder {
 		if yaccRule_ == nil {
@@ -218,9 +229,13 @@ func genSources(ctx android.ModuleContext, srcFiles android.Paths,
 			srcFiles[i] = ccFile
 			deps = append(deps, headerFile)
 		case ".aidl":
+			if aidlRule == nil {
+				aidlRule = android.NewRuleBuilder().Sbox(android.PathForModuleGen(ctx, "aidl"))
+			}
 			cppFile := android.GenPathWithExt(ctx, "aidl", srcFile, "cpp")
+			depFile := android.GenPathWithExt(ctx, "aidl", srcFile, "cpp.d")
 			srcFiles[i] = cppFile
-			deps = append(deps, genAidl(ctx, srcFile, cppFile, buildFlags.aidlFlags)...)
+			deps = append(deps, genAidl(ctx, aidlRule, srcFile, cppFile, depFile, buildFlags.aidlFlags)...)
 		case ".rs", ".fs":
 			cppFile := rsGeneratedCppFile(ctx, srcFile)
 			rsFiles = append(rsFiles, srcFiles[i])
@@ -236,6 +251,10 @@ func genSources(ctx android.ModuleContext, srcFiles android.Paths,
 		}
 	}
 
+	if aidlRule != nil {
+		aidlRule.Build(pctx, ctx, "aidl", "gen aidl")
+	}
+
 	if yaccRule_ != nil {
 		yaccRule_.Build(pctx, ctx, "yacc", "gen yacc")
 	}

cc/gen_test.go

@@ -15,6 +15,7 @@
 package cc
 
 import (
+	"path/filepath"
 	"testing"
 )
 
@@ -32,7 +33,7 @@ func TestGen(t *testing.T) {
 		aidl := ctx.ModuleForTests("libfoo", "android_arm_armv7-a-neon_core_shared").Rule("aidl")
 		libfoo := ctx.ModuleForTests("libfoo", "android_arm_armv7-a-neon_core_shared").Module().(*Module)
 
-		if !inList("-I"+aidl.Args["outDir"], libfoo.flags.GlobalFlags) {
+		if !inList("-I"+filepath.Dir(aidl.Output.String()), libfoo.flags.GlobalFlags) {
 			t.Errorf("missing aidl includes in global flags")
 		}
 	})
@@ -55,7 +56,7 @@ func TestGen(t *testing.T) {
 		aidl := ctx.ModuleForTests("libfoo", "android_arm_armv7-a-neon_core_shared").Rule("aidl")
 		libfoo := ctx.ModuleForTests("libfoo", "android_arm_armv7-a-neon_core_shared").Module().(*Module)
 
-		if !inList("-I"+aidl.Args["outDir"], libfoo.flags.GlobalFlags) {
+		if !inList("-I"+filepath.Dir(aidl.Output.String()), libfoo.flags.GlobalFlags) {
 			t.Errorf("missing aidl includes in global flags")
 		}
 	})