From db7dda89f3c1cd1267b50e65a6a9385484bcee3e Mon Sep 17 00:00:00 2001
From: Yabin Cui <yabinc@google.com>
Date: Mon, 30 Nov 2020 15:47:45 -0800
Subject: [PATCH] Switch to clang-r407598 (12.0.1).

Also suppress a clang-tidy warning and a ubsan check to pass compilation.

Bug: 171348143
Test: build.
Change-Id: Ie5162c15df172cefd7cff9776e54531fd620bc23
---
 cc/config/clang.go  |  3 +++
 cc/config/global.go |  4 ++--
 cc/sanitize.go      | 20 ++++++++++++++++++++
 3 files changed, 25 insertions(+), 2 deletions(-)

diff --git a/cc/config/clang.go b/cc/config/clang.go
index 519a9e2d2..328295896 100644
--- a/cc/config/clang.go
+++ b/cc/config/clang.go
@@ -94,6 +94,7 @@ var ClangLibToolingUnknownCflags = sorted([]string{})
 // `modernize-*`.
 var ClangTidyDisableChecks = []string{
 	"misc-no-recursion",
+	"readability-function-cognitive-complexity", // http://b/175055536
 }
 
 func init() {
@@ -190,6 +191,8 @@ func init() {
 		"-Wno-pessimizing-move",                     // http://b/154270751
 		// New warnings to be fixed after clang-r399163
 		"-Wno-non-c-typedef-for-linkage", // http://b/161304145
+		// New warnings to be fixed after clang-r407598
+		"-Wno-string-concatenation", // http://b/175068488
 	}, " "))
 
 	// Extra cflags for external third-party projects to disable warnings that
diff --git a/cc/config/global.go b/cc/config/global.go
index e5cb7eefd..fa8e0fba2 100644
--- a/cc/config/global.go
+++ b/cc/config/global.go
@@ -135,8 +135,8 @@ var (
 
 	// prebuilts/clang default settings.
 	ClangDefaultBase         = "prebuilts/clang/host"
-	ClangDefaultVersion      = "clang-r399163b"
-	ClangDefaultShortVersion = "11.0.5"
+	ClangDefaultVersion      = "clang-r407598"
+	ClangDefaultShortVersion = "12.0.1"
 
 	// Directories with warnings from Android.bp files.
 	WarningAllowedProjects = []string{
diff --git a/cc/sanitize.go b/cc/sanitize.go
index 0e2d01a45..bb92a882d 100644
--- a/cc/sanitize.go
+++ b/cc/sanitize.go
@@ -458,6 +458,22 @@ func toDisableImplicitIntegerChange(flags []string) bool {
 	return false
 }
 
+func toDisableUnsignedShiftBaseChange(flags []string) bool {
+	// Returns true if any flag is fsanitize*integer, and there is
+	// no explicit flag about sanitize=unsigned-shift-base.
+	for _, f := range flags {
+		if strings.Contains(f, "sanitize=unsigned-shift-base") {
+			return false
+		}
+	}
+	for _, f := range flags {
+		if strings.HasPrefix(f, "-fsanitize") && strings.Contains(f, "integer") {
+			return true
+		}
+	}
+	return false
+}
+
 func (sanitize *sanitize) flags(ctx ModuleContext, flags Flags) Flags {
 	minimalRuntimeLib := config.UndefinedBehaviorSanitizerMinimalRuntimeLibrary(ctx.toolchain()) + ".a"
 	minimalRuntimePath := "${config.ClangAsanLibDir}/" + minimalRuntimeLib
@@ -614,6 +630,10 @@ func (sanitize *sanitize) flags(ctx ModuleContext, flags Flags) Flags {
 		if toDisableImplicitIntegerChange(flags.Local.CFlags) {
 			flags.Local.CFlags = append(flags.Local.CFlags, "-fno-sanitize=implicit-integer-sign-change")
 		}
+		// http://b/171275751, Android doesn't build with this sanitizer yet.
+		if toDisableUnsignedShiftBaseChange(flags.Local.CFlags) {
+			flags.Local.CFlags = append(flags.Local.CFlags, "-fno-sanitize=unsigned-shift-base")
+		}
 	}
 
 	if len(sanitize.Properties.DiagSanitizers) > 0 {