soong: add support for module specific lexer flags

To support module specific lexer flags, this follows the same strategy
as the yacc flags:
 - add LexProperties to the BaseCompilerProperties
 - propagate those flags to the generator generation (i.e. genLex)
 - add a placeholder for custom flags
 - replace the placeholder with the concatenated flags

This might not support escaping very well, but I figured that this is a
very edge case. Support for escaping etc. could be added later on.

Bug: 159682555
Signed-off-by: Matthias Maennich <maennich@google.com>
Change-Id: I31a3b783bb05213fe1621191031952b41b318103

cc/builder.go

@@ -361,6 +361,7 @@ type builderFlags struct {
 	protoOptionsFile bool
 
 	yacc *YaccProperties
+	lex  *LexProperties
 }
 
 type Objects struct {

cc/cc.go

@@ -210,6 +210,7 @@ type Flags struct {
 	protoOptionsFile bool // Whether to look for a .options file next to the .proto
 
 	Yacc *YaccProperties
+	Lex  *LexProperties
 }
 
 // Properties used to compile all C or C++ modules

cc/compiler.go

@@ -111,6 +111,7 @@ type BaseCompilerProperties struct {
 	Gnu_extensions *bool
 
 	Yacc *YaccProperties
+	Lex  *LexProperties
 
 	Aidl struct {
 		// list of directories that will be added to the aidl include paths.
@@ -289,6 +290,7 @@ func (compiler *baseCompiler) compilerFlags(ctx ModuleContext, flags Flags, deps
 	flags.Local.YasmFlags = append(flags.Local.YasmFlags, esc(compiler.Properties.Asflags)...)
 
 	flags.Yacc = compiler.Properties.Yacc
+	flags.Lex = compiler.Properties.Lex
 
 	// Include dir cflags
 	localIncludeDirs := android.PathsForModuleSrc(ctx, compiler.Properties.Local_include_dirs)

cc/gen.go

@@ -34,9 +34,9 @@ func init() {
 var (
 	lex = pctx.AndroidStaticRule("lex",
 		blueprint.RuleParams{
-			Command:     "M4=$m4Cmd $lexCmd -o$out $in",
+			Command:     "M4=$m4Cmd $lexCmd $flags -o$out $in",
 			CommandDeps: []string{"$lexCmd", "$m4Cmd"},
-		})
+		}, "flags")
 
 	sysprop = pctx.AndroidStaticRule("sysprop",
 		blueprint.RuleParams{
@@ -153,12 +153,23 @@ func genAidl(ctx android.ModuleContext, rule *android.RuleBuilder, aidlFile andr
 	}
 }
 
-func genLex(ctx android.ModuleContext, lexFile android.Path, outFile android.ModuleGenPath) {
+type LexProperties struct {
+	// list of module-specific flags that will be used for .l and .ll compiles
+	Flags []string
+}
+
+func genLex(ctx android.ModuleContext, lexFile android.Path, outFile android.ModuleGenPath, props *LexProperties) {
+	var flags []string
+	if props != nil {
+		flags = props.Flags
+	}
+	flagsString := strings.Join(flags[:], " ")
 	ctx.Build(pctx, android.BuildParams{
 		Rule:        lex,
 		Description: "lex " + lexFile.Rel(),
 		Output:      outFile,
 		Input:       lexFile,
+		Args:        map[string]string{"flags": flagsString},
 	})
 }
 
@@ -235,11 +246,11 @@ func genSources(ctx android.ModuleContext, srcFiles android.Paths,
 		case ".l":
 			cFile := android.GenPathWithExt(ctx, "lex", srcFile, "c")
 			srcFiles[i] = cFile
-			genLex(ctx, srcFile, cFile)
+			genLex(ctx, srcFile, cFile, buildFlags.lex)
 		case ".ll":
 			cppFile := android.GenPathWithExt(ctx, "lex", srcFile, "cpp")
 			srcFiles[i] = cppFile
-			genLex(ctx, srcFile, cppFile)
+			genLex(ctx, srcFile, cppFile, buildFlags.lex)
 		case ".proto":
 			ccFile, headerFile := genProto(ctx, srcFile, buildFlags)
 			srcFiles[i] = ccFile

cc/util.go

@@ -97,6 +97,7 @@ func flagsToBuilderFlags(in Flags) builderFlags {
 		protoOptionsFile: in.protoOptionsFile,
 
 		yacc: in.Yacc,
+		lex:  in.Lex,
 	}
 }