clang build.py: set -DLLVM_ENABLE_DIA_SDK=OFF to use the native symbolizer,

and also remove DIA dependencies.

Setting DLLVM_ENABLE_DIA_SDK=OFF makes LLVM default to the native symbolizer,
which was recently implemented, and allows us to remove the DIA dependency.

There aren't many existing test cases for this, so at the moment it's possible
there are edge cases where the native symbolizer doesn't work.

Change-Id: I8ff395f47869296b01bc3c11f3afdeae102664d5
Bug: 1126219
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2399515
Commit-Queue: Nico Weber <thakis@chromium.org>
Reviewed-by: Nico Weber <thakis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#806243}

tools/clang/scripts/build.py

@@ -52,22 +52,12 @@ BUG_REPORT_URL = ('https://crbug.com and run'
 
 
 win_sdk_dir = None
-dia_dll = None
 def GetWinSDKDir():
-  """Get the location of the current SDK. Sets dia_dll as a side-effect."""
+  """Get the location of the current SDK."""
   global win_sdk_dir
-  global dia_dll
   if win_sdk_dir:
     return win_sdk_dir
 
-  # Bump after VC updates.
-  DIA_DLL = {
-      '2013': 'msdia120.dll',
-      '2015': 'msdia140.dll',
-      '2017': 'msdia140.dll',
-      '2019': 'msdia140.dll',
-  }
-
   # Don't let vs_toolchain overwrite our environment.
   environ_bak = os.environ
 
@@ -85,8 +75,6 @@ def GetWinSDKDir():
       vs_path = os.environ['GYP_MSVS_OVERRIDE_PATH']
     dia_path = os.path.join(vs_path, 'DIA SDK', 'bin', 'amd64')
 
-  dia_dll = os.path.join(dia_path, DIA_DLL[msvs_version])
-
   os.environ = environ_bak
   return win_sdk_dir
 
@@ -130,11 +118,6 @@ def CopyFile(src, dst):
   shutil.copy(src, dst)
 
 
-def CopyDiaDllTo(target_dir):
-  GetWinSDKDir()
-  CopyFile(dia_dll, target_dir)
-
-
 def CopyDirectoryContents(src, dst):
   """Copy the files from directory src to dst."""
   dst = os.path.realpath(dst)  # realpath() in case dst ends in /..
@@ -543,6 +526,8 @@ def main():
       '-DLLVM_INCLUDE_GO_TESTS=OFF',
       # TODO(crbug.com/1113475): Update binutils.
       '-DENABLE_X86_RELAX_RELOCATIONS=NO',
+      # See crbug.com/1126219: Use native symbolizer instead of DIA
+      '-DLLVM_ENABLE_DIA_SDK=OFF',
   ]
 
   if args.gcc_toolchain:
@@ -661,8 +646,6 @@ def main():
       if sys.platform == 'darwin':
         # TODO(crbug.com/731375): Run check-all on Darwin too.
         test_targets = [ 'check-llvm', 'check-clang', 'check-builtins' ]
-      if sys.platform == 'win32':
-        CopyDiaDllTo(os.path.join(LLVM_BOOTSTRAP_DIR, 'bin'))
       RunCommand(['ninja'] + test_targets, msvc_arch='x64')
     RunCommand(['ninja', 'install'], msvc_arch='x64')
 
@@ -1061,8 +1044,6 @@ def main():
     RunCommand(['ninja', '-C', LLVM_BUILD_DIR, 'cr-check-all'], msvc_arch='x64')
 
   if args.run_tests:
-    if sys.platform == 'win32':
-      CopyDiaDllTo(os.path.join(LLVM_BUILD_DIR, 'bin'))
     test_targets = [ 'check-all' ]
     if sys.platform == 'darwin':
       # TODO(thakis): Run check-all on Darwin too, https://crbug.com/959361

tools/clang/scripts/update.py

@@ -39,7 +39,7 @@ import zipfile
 # Reverting problematic clang rolls is safe, though.
 # This is the output of `git describe` and is usable as a commit-ish.
 CLANG_REVISION = 'llvmorg-12-init-5035-gd0abc757'
-CLANG_SUB_REVISION = 1
+CLANG_SUB_REVISION = 2
 
 PACKAGE_VERSION = '%s-%s' % (CLANG_REVISION, CLANG_SUB_REVISION)
 RELEASE_VERSION = '12.0.0'