Clang: the tip-of-tree version is now 12.0.0

Bug: 1105518
Change-Id: I267708d4990adbbdb7d9fe3642fb40d077cad7f8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2297525Reviewed-by: Nico Weber <thakis@chromium.org>
Commit-Queue: Hans Wennborg <hans@chromium.org>
Cr-Commit-Position: refs/heads/master@{#788567}

build/toolchain/toolchain.gni

@@ -39,7 +39,12 @@ if (generate_linker_map) {
 
 declare_args() {
   # Clang compiler version. Clang files are placed at version-dependent paths.
-  clang_version = "11.0.0"
+  if (llvm_force_head_revision) {
+    clang_version = "12.0.0"
+  } else {
+    # TODO(crbug.com/1105518): Remove in the next Clang roll.
+    clang_version = "11.0.0"
+  }
 }
 
 # Check target_os here instead of is_ios as this file is loaded for secondary

tools/clang/scripts/build.py

@@ -407,6 +407,15 @@ def main():
                       default=sys.platform in ('linux2', 'darwin'))
   args = parser.parse_args()
 
+  # TODO(crbug.com/1105518): Remove in the next Clang roll.
+  if args.llvm_force_head_revision:
+    global RELEASE_VERSION
+    RELEASE_VERSION = '12.0.0'
+    old_lib_dir = os.path.join(LLVM_BUILD_DIR, 'lib', 'clang', '11.0.0')
+    if (os.path.isdir(old_lib_dir)):
+      print('Removing old lib dir: ' + old_lib_dir)
+      RmTree(old_lib_dir
+
   if args.pgo and not args.bootstrap:
     print('--pgo requires --bootstrap')
     return 1

tools/clang/scripts/update.py

@@ -43,6 +43,7 @@ CLANG_SUB_REVISION = 1
 
 PACKAGE_VERSION = '%s-%s-%s' % (CLANG_SVN_REVISION, CLANG_REVISION[:8],
                                 CLANG_SUB_REVISION)
+# TODO(crbug.com/1105518): Bump to 12.0.0 in the next Clang roll.
 RELEASE_VERSION = '11.0.0'
 
 
@@ -299,6 +300,11 @@ def main():
                       help='Verify that clang has the passed-in version.')
   args = parser.parse_args()
 
+  # TODO(crbug.com/1042192): Remove in the next Clang roll.
+  if args.llvm_force_head_revision:
+    global RELEASE_VERSION
+    RELEASE_VERSION = '12.0.0'
+
   if args.force_local_build:
     print(('update.py --force-local-build is no longer used to build clang; '
            'use build.py instead.'))