Move proto compilation to RuleBuilder

Using blueprint.Rule for protoc commands was causing code duplication
because there was no good way to run the same protoc for cc, java and
python but then run custom source packaging steps for java and python.
Move most of the code into a common function that returns a
RuleBuilder, and then let java and python add their own commands at
the end of the rule.

Bug: 70706119
Test: All Soong tests
Test: m checkbuild
Change-Id: Ic692136775d273bcc4f4de99620ab4878667c83a

1 files changed, 46 insertions, 19 deletions

diff --git a/android/proto.go b/android/proto.go
index 801837e0..83dc32a9 100644
--- a/android/proto.go
+++ b/android/proto.go
@@ -14,6 +14,12 @@
 
 package android
 
+import (
+	"strings"
+
+	"github.com/google/blueprint/proptools"
+)
+
 // TODO(ccross): protos are often used to communicate between multiple modules.  If the only
 // way to convert a proto to source is to reference it as a source file, and external modules cannot
 // reference source files in other modules, then every module that owns a proto file will need to
@@ -22,9 +28,17 @@ package android
 // and then external modules could depend on the proto module but use their own settings to
 // generate the source.
 
-func ProtoFlags(ctx ModuleContext, p *ProtoProperties) []string {
-	protoFlags := []string{}
+type ProtoFlags struct {
+	Flags                 []string
+	CanonicalPathFromRoot bool
+	Dir                   ModuleGenPath
+	SubDir                ModuleGenPath
+	OutTypeFlag           string
+	OutParams             []string
+}
 
+func GetProtoFlags(ctx ModuleContext, p *ProtoProperties) ProtoFlags {
+	var protoFlags []string
 	if len(p.Proto.Local_include_dirs) > 0 {
 		localProtoIncludeDirs := PathsForModuleSrc(ctx, p.Proto.Local_include_dirs)
 		protoFlags = append(protoFlags, JoinWithPrefix(localProtoIncludeDirs.Strings(), "-I"))
@@ -34,24 +48,12 @@ func ProtoFlags(ctx ModuleContext, p *ProtoProperties) []string {
 		protoFlags = append(protoFlags, JoinWithPrefix(rootProtoIncludeDirs.Strings(), "-I"))
 	}
 
-	return protoFlags
-}
-
-func ProtoCanonicalPathFromRoot(ctx ModuleContext, p *ProtoProperties) bool {
-	if p.Proto.Canonical_path_from_root == nil {
-		return true
+	return ProtoFlags{
+		Flags:                 protoFlags,
+		CanonicalPathFromRoot: proptools.BoolDefault(p.Proto.Canonical_path_from_root, true),
+		Dir:                   PathForModuleGen(ctx, "proto"),
+		SubDir:                PathForModuleGen(ctx, "proto", ctx.ModuleDir()),
 	}
-	return *p.Proto.Canonical_path_from_root
-}
-
-// ProtoDir returns the module's "gen/proto" directory
-func ProtoDir(ctx ModuleContext) ModuleGenPath {
-	return PathForModuleGen(ctx, "proto")
-}
-
-// ProtoSubDir returns the module's "gen/proto/path/to/module" directory
-func ProtoSubDir(ctx ModuleContext) ModuleGenPath {
-	return PathForModuleGen(ctx, "proto", ctx.ModuleDir())
 }
 
 type ProtoProperties struct {
@@ -76,3 +78,28 @@ type ProtoProperties struct {
 		Canonical_path_from_root *bool
 	} `android:"arch_variant"`
 }
+
+func ProtoRule(ctx ModuleContext, rule *RuleBuilder, protoFile Path, flags ProtoFlags, deps Paths,
+	outDir WritablePath, depFile WritablePath, outputs WritablePaths) {
+
+	var protoBase string
+	if flags.CanonicalPathFromRoot {
+		protoBase = "."
+	} else {
+		rel := protoFile.Rel()
+		protoBase = strings.TrimSuffix(protoFile.String(), rel)
+	}
+
+	rule.Command().
+		Tool(ctx.Config().HostToolPath(ctx, "aprotoc")).
+		FlagWithArg(flags.OutTypeFlag+"=", strings.Join(flags.OutParams, ",")+":"+outDir.String()).
+		FlagWithDepFile("--dependency_out=", depFile).
+		FlagWithArg("-I ", protoBase).
+		Flags(flags.Flags).
+		Input(protoFile).
+		Implicits(deps).
+		ImplicitOutputs(outputs)
+
+	rule.Command().
+		Tool(ctx.Config().HostToolPath(ctx, "dep_fixer")).Flag(depFile.String())
+}