Add tidy_timeout_srcs property

Similar to `tidy_disabled_srcs`, a `tidy_timeout_srcs` list
can be used to include all source files that took long to compile
with clang-tidy. Files listed in `tidy_timeout_srcs` will not
be compiled by clang-tidy when `TIDY_TIMEOUT` is defined.

Bug: 201099167
Test: TIDY_TIME=90 make droid tidy-soong_subset
Change-Id: Ie0bfda66caae4445d10117ceefa1b5b8c1ecf256
diff --git a/cc/builder.go b/cc/builder.go
index 8e6f7cd..525b1a1 100644
--- a/cc/builder.go
+++ b/cc/builder.go
@@ -459,7 +459,7 @@
 }
 
 // Generate rules for compiling multiple .c, .cpp, or .S files to individual .o files
-func transformSourceToObj(ctx ModuleContext, subdir string, srcFiles, noTidySrcs android.Paths,
+func transformSourceToObj(ctx ModuleContext, subdir string, srcFiles, noTidySrcs, timeoutTidySrcs android.Paths,
 	flags builderFlags, pathDeps android.Paths, cFlagsDeps android.Paths) Objects {
 	// Source files are one-to-one with tidy, coverage, or kythe files, if enabled.
 	objFiles := make(android.Paths, len(srcFiles))
@@ -474,6 +474,10 @@
 		tidyTimeout := ctx.Config().Getenv("TIDY_TIMEOUT")
 		if len(tidyTimeout) > 0 {
 			tidyVars += "TIDY_TIMEOUT=" + tidyTimeout + " "
+			// add timeoutTidySrcs into noTidySrcsMap if TIDY_TIMEOUT is set
+			for _, path := range timeoutTidySrcs {
+				noTidySrcsMap[path.String()] = true
+			}
 		}
 	}
 	var coverageFiles android.Paths
diff --git a/cc/compiler.go b/cc/compiler.go
index d9a6bcd..7645cbb 100644
--- a/cc/compiler.go
+++ b/cc/compiler.go
@@ -42,6 +42,9 @@
 	// list of source files that should not be compiled with clang-tidy.
 	Tidy_disabled_srcs []string `android:"path,arch_variant"`
 
+	// list of source files that should not be compiled by clang-tidy when TIDY_TIMEOUT is set.
+	Tidy_timeout_srcs []string `android:"path,arch_variant"`
+
 	// list of source files that should not be used to build the C/C++ module.
 	// This is most useful in the arch/multilib variants to remove non-common files
 	Exclude_srcs []string `android:"path,arch_variant"`
@@ -663,6 +666,7 @@
 	// Compile files listed in c.Properties.Srcs into objects
 	objs := compileObjs(ctx, buildFlags, "", srcs,
 		android.PathsForModuleSrc(ctx, compiler.Properties.Tidy_disabled_srcs),
+		android.PathsForModuleSrc(ctx, compiler.Properties.Tidy_timeout_srcs),
 		pathDeps, compiler.cFlagsDeps)
 
 	if ctx.Failed() {
@@ -674,9 +678,9 @@
 
 // Compile a list of source files into objects a specified subdirectory
 func compileObjs(ctx ModuleContext, flags builderFlags, subdir string,
-	srcFiles, noTidySrcs, pathDeps android.Paths, cFlagsDeps android.Paths) Objects {
+	srcFiles, noTidySrcs, timeoutTidySrcs, pathDeps android.Paths, cFlagsDeps android.Paths) Objects {
 
-	return transformSourceToObj(ctx, subdir, srcFiles, noTidySrcs, flags, pathDeps, cFlagsDeps)
+	return transformSourceToObj(ctx, subdir, srcFiles, noTidySrcs, timeoutTidySrcs, flags, pathDeps, cFlagsDeps)
 }
 
 // Properties for rust_bindgen related to generating rust bindings.
diff --git a/cc/library.go b/cc/library.go
index 6aac7ae..5fa3471 100644
--- a/cc/library.go
+++ b/cc/library.go
@@ -145,6 +145,8 @@
 
 	Tidy_disabled_srcs []string `android:"path,arch_variant"`
 
+	Tidy_timeout_srcs []string `android:"path,arch_variant"`
+
 	Sanitized Sanitized `android:"arch_variant"`
 
 	Cflags []string `android:"arch_variant"`
@@ -1079,11 +1081,13 @@
 		srcs := android.PathsForModuleSrc(ctx, library.StaticProperties.Static.Srcs)
 		objs = objs.Append(compileObjs(ctx, buildFlags, android.DeviceStaticLibrary, srcs,
 			android.PathsForModuleSrc(ctx, library.StaticProperties.Static.Tidy_disabled_srcs),
+			android.PathsForModuleSrc(ctx, library.StaticProperties.Static.Tidy_timeout_srcs),
 			library.baseCompiler.pathDeps, library.baseCompiler.cFlagsDeps))
 	} else if library.shared() {
 		srcs := android.PathsForModuleSrc(ctx, library.SharedProperties.Shared.Srcs)
 		objs = objs.Append(compileObjs(ctx, buildFlags, android.DeviceSharedLibrary, srcs,
 			android.PathsForModuleSrc(ctx, library.SharedProperties.Shared.Tidy_disabled_srcs),
+			android.PathsForModuleSrc(ctx, library.SharedProperties.Shared.Tidy_timeout_srcs),
 			library.baseCompiler.pathDeps, library.baseCompiler.cFlagsDeps))
 	}
 
diff --git a/cc/ndk_library.go b/cc/ndk_library.go
index 7efe134..fc682ff 100644
--- a/cc/ndk_library.go
+++ b/cc/ndk_library.go
@@ -279,7 +279,7 @@
 
 func compileStubLibrary(ctx ModuleContext, flags Flags, src android.Path) Objects {
 	return compileObjs(ctx, flagsToBuilderFlags(flags), "",
-		android.Paths{src}, nil, nil, nil)
+		android.Paths{src}, nil, nil, nil, nil)
 }
 
 func (this *stubDecorator) findImplementationLibrary(ctx ModuleContext) android.Path {
diff --git a/docs/tidy.md b/docs/tidy.md
index 3140198..890c3a0 100644
--- a/docs/tidy.md
+++ b/docs/tidy.md
@@ -225,6 +225,16 @@
 in several Android continuous builds where `WITH_TIDY=1` and
 `CLANG_ANALYZER_CHECKS=1` are set.
 
+Similar to `tidy_disabled_srcs` a `tidy_timeout_srcs` list
+can be used to include all source files that took too much time to compile
+with clang-tidy. Files listed in `tidy_timeout_srcs` will not
+be compiled by clang-tidy when `TIDY_TIMEOUT` is defined.
+This can save global build time, when it is necessary to set some
+time limit globally to finish in an acceptable time.
+For developers who want to find all clang-tidy warnings and
+are willing to spend more time on all files in a project,
+they should not define `TIDY_TIMEOUT` and build only the wanted project directories.
+
 ## Capabilities for Android.bp and Android.mk
 
 Some of the previously mentioned features are defined only