diff --git a/Android.bp b/Android.bp
index 8d0c1ea..c73c3da 100644
--- a/Android.bp
+++ b/Android.bp
@@ -206,6 +206,7 @@
     ],
     testSrcs: [
         "cc/cc_test.go",
+        "cc/compiler_test.go",
         "cc/gen_test.go",
         "cc/genrule_test.go",
         "cc/library_test.go",
diff --git a/cc/compiler.go b/cc/compiler.go
index bb40a5b..671861b 100644
--- a/cc/compiler.go
+++ b/cc/compiler.go
@@ -17,6 +17,7 @@
 import (
 	"fmt"
 	"path/filepath"
+	"regexp"
 	"strconv"
 	"strings"
 
@@ -252,6 +253,7 @@
 // per-target values, module type values, and per-module Blueprints properties
 func (compiler *baseCompiler) compilerFlags(ctx ModuleContext, flags Flags, deps PathDeps) Flags {
 	tc := ctx.toolchain()
+	modulePath := android.PathForModuleSrc(ctx).String()
 
 	compiler.srcsBeforeGen = android.PathsForModuleSrcExcludes(ctx, compiler.Properties.Srcs, compiler.Properties.Exclude_srcs)
 	compiler.srcsBeforeGen = append(compiler.srcsBeforeGen, deps.GeneratedSources...)
@@ -289,8 +291,8 @@
 
 	if compiler.Properties.Include_build_directory == nil ||
 		*compiler.Properties.Include_build_directory {
-		flags.Local.CommonFlags = append(flags.Local.CommonFlags, "-I"+android.PathForModuleSrc(ctx).String())
-		flags.Local.YasmFlags = append(flags.Local.YasmFlags, "-I"+android.PathForModuleSrc(ctx).String())
+		flags.Local.CommonFlags = append(flags.Local.CommonFlags, "-I"+modulePath)
+		flags.Local.YasmFlags = append(flags.Local.YasmFlags, "-I"+modulePath)
 	}
 
 	if !(ctx.useSdk() || ctx.useVndk()) || ctx.Host() {
@@ -381,7 +383,7 @@
 		"${config.CommonClangGlobalCflags}",
 		fmt.Sprintf("${config.%sClangGlobalCflags}", hod))
 
-	if strings.HasPrefix(android.PathForModuleSrc(ctx).String(), "external/") {
+	if isThirdParty(modulePath) {
 		flags.Global.CommonFlags = append([]string{"${config.ClangExternalCflags}"}, flags.Global.CommonFlags...)
 	}
 
@@ -438,7 +440,7 @@
 	// vendor/device specific things), we could extend this to be a ternary
 	// value.
 	strict := true
-	if strings.HasPrefix(android.PathForModuleSrc(ctx).String(), "external/") {
+	if strings.HasPrefix(modulePath, "external/") {
 		strict = false
 	}
 
@@ -580,3 +582,28 @@
 
 	return TransformSourceToObj(ctx, subdir, srcFiles, flags, pathDeps, cFlagsDeps)
 }
+
+var thirdPartyDirPrefixExceptions = []*regexp.Regexp{
+	regexp.MustCompile("^vendor/[^/]*google[^/]*/"),
+	regexp.MustCompile("^hardware/google/"),
+	regexp.MustCompile("^hardware/interfaces/"),
+	regexp.MustCompile("^hardware/libhardware[^/]*/"),
+	regexp.MustCompile("^hardware/ril/"),
+}
+
+func isThirdParty(path string) bool {
+	thirdPartyDirPrefixes := []string{"external/", "vendor/", "hardware/"}
+
+	for _, prefix := range thirdPartyDirPrefixes {
+		if strings.HasPrefix(path, prefix) {
+			for _, prefix := range thirdPartyDirPrefixExceptions {
+				if prefix.MatchString(path) {
+					return false
+				}
+			}
+			break
+		}
+	}
+
+	return true
+}
diff --git a/cc/compiler_test.go b/cc/compiler_test.go
new file mode 100644
index 0000000..c301388
--- /dev/null
+++ b/cc/compiler_test.go
@@ -0,0 +1,43 @@
+// Copyright 2019 Google Inc. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package cc
+
+import (
+	"testing"
+)
+
+func TestIsThirdParty(t *testing.T) {
+	shouldFail := []string{
+		"external/foo/",
+		"vendor/bar/",
+		"hardware/underwater_jaguar/",
+	}
+	shouldPass := []string{
+		"vendor/google/cts/",
+		"hardware/google/pixel",
+		"hardware/interfaces/camera",
+		"hardware/ril/supa_ril",
+	}
+	for _, path := range shouldFail {
+		if !isThirdParty(path) {
+			t.Errorf("Expected %s to be considered third party", path)
+		}
+	}
+	for _, path := range shouldPass {
+		if isThirdParty(path) {
+			t.Errorf("Expected %s to *not* be considered third party", path)
+		}
+	}
+}
diff --git a/cc/config/clang.go b/cc/config/clang.go
index 030a076..eddc341 100644
--- a/cc/config/clang.go
+++ b/cc/config/clang.go
@@ -163,8 +163,8 @@
 		"-Wno-tautological-type-limit-compare",
 	}, " "))
 
-	// Extra cflags for projects under external/ directory to disable warnings that are infeasible
-	// to fix in all the external projects and their upstream repos.
+	// Extra cflags for external third-party projects to disable warnings that
+	// are infeasible to fix in all the external projects and their upstream repos.
 	pctx.StaticVariable("ClangExtraExternalCflags", strings.Join([]string{
 		"-Wno-enum-compare",
 		"-Wno-enum-compare-switch",