Clang packaging script: don't do separate threads-enabled and disabled builds

This gets us off the hook from fixing failures in a build config which
is not well tested upstream, reduces the package build time, and
simplifies our build script.

It also make thinlto faster, due to lld now being built with PGO
(although we don't train on lld, it benefits from the training on clang).

Bug: 884608, 949626
Change-Id: I55859efbde9071da72c1057765d0d1900e069eea
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2095544Reviewed-by: Reid Kleckner <rnk@chromium.org>
Reviewed-by: Nico Weber <thakis@chromium.org>
Commit-Queue: Hans Wennborg <hans@chromium.org>
Cr-Commit-Position: refs/heads/master@{#749607}

tools/clang/scripts/build.py

@@ -38,8 +38,6 @@ LLVM_BOOTSTRAP_INSTALL_DIR = os.path.join(THIRD_PARTY_DIR,
 LLVM_INSTRUMENTED_DIR = os.path.join(THIRD_PARTY_DIR, 'llvm-instrumented')
 LLVM_PROFDATA_FILE = os.path.join(LLVM_INSTRUMENTED_DIR, 'profdata.prof')
 CHROME_TOOLS_SHIM_DIR = os.path.join(LLVM_DIR, 'llvm', 'tools', 'chrometools')
-THREADS_ENABLED_BUILD_DIR = os.path.join(THIRD_PARTY_DIR,
-                                         'llvm-threads-enabled')
 COMPILER_RT_BUILD_DIR = os.path.join(LLVM_BUILD_DIR, 'compiler-rt')
 LLVM_BUILD_TOOLS_DIR = os.path.abspath(
     os.path.join(LLVM_DIR, '..', 'llvm-build-tools'))
@@ -613,7 +611,6 @@ def main():
       projects += ';libcxx;compiler-rt'
 
     instrument_args = base_cmake_args + [
-        '-DLLVM_ENABLE_THREADS=OFF',
         '-DLLVM_ENABLE_PROJECTS=' + projects,
         '-DCMAKE_C_FLAGS=' + ' '.join(cflags),
         '-DCMAKE_CXX_FLAGS=' + ' '.join(cxxflags),
@@ -642,6 +639,9 @@ def main():
     # C++-y "Hello World" program only resulted in 14% faster builds.)
     # See https://crbug.com/966403#c16 for all numbers.
     #
+    # Although the training currently only exercises Clang, it does involve LLVM
+    # internals, and so LLD also benefits when used for ThinLTO links.
+    #
     # NOTE: Tidy uses binaries built with this profile, but doesn't seem to
     # gain much from it. If tidy's execution time becomes a concern, it might
     # be good to investigate that.
@@ -726,37 +726,6 @@ def main():
     deployment_env = os.environ.copy()
     deployment_env['MACOSX_DEPLOYMENT_TARGET'] = deployment_target
 
-  # Build lld and code coverage tools. This is done separately from the rest of
-  # the build because these tools require threading support.
-  print('Building thread-enabled tools.')
-  tools_with_threading = [ 'dsymutil', 'lld', 'llvm-cov', 'llvm-profdata' ]
-  print('Building the following tools with threading support: %s' %
-        str(tools_with_threading))
-
-  if os.path.exists(THREADS_ENABLED_BUILD_DIR):
-    RmTree(THREADS_ENABLED_BUILD_DIR)
-  EnsureDirExists(THREADS_ENABLED_BUILD_DIR)
-  os.chdir(THREADS_ENABLED_BUILD_DIR)
-
-  threads_enabled_cmake_args = base_cmake_args + [
-      '-DCMAKE_C_FLAGS=' + ' '.join(cflags),
-      '-DCMAKE_CXX_FLAGS=' + ' '.join(cxxflags),
-      '-DCMAKE_EXE_LINKER_FLAGS=' + ' '.join(ldflags),
-      '-DCMAKE_SHARED_LINKER_FLAGS=' + ' '.join(ldflags),
-      '-DCMAKE_MODULE_LINKER_FLAGS=' + ' '.join(ldflags)]
-  if cc is not None:
-    threads_enabled_cmake_args.append('-DCMAKE_C_COMPILER=' + cc)
-  if cxx is not None:
-    threads_enabled_cmake_args.append('-DCMAKE_CXX_COMPILER=' + cxx)
-  if lld is not None:
-    threads_enabled_cmake_args.append('-DCMAKE_LINKER=' + lld)
-
-  RunCommand(['cmake'] + threads_enabled_cmake_args +
-             [os.path.join(LLVM_DIR, 'llvm')],
-             msvc_arch='x64', env=deployment_env)
-  CopyLibstdcpp(args, THREADS_ENABLED_BUILD_DIR)
-  RunCommand(['ninja'] + tools_with_threading, msvc_arch='x64')
-
   print('Building final compiler.')
 
   default_tools = ['plugins', 'blink_gc_plugin', 'translation_unit']
@@ -765,7 +734,6 @@ def main():
   if cxx is not None: base_cmake_args.append('-DCMAKE_CXX_COMPILER=' + cxx)
   if lld is not None: base_cmake_args.append('-DCMAKE_LINKER=' + lld)
   cmake_args = base_cmake_args + compiler_rt_args + [
-      '-DLLVM_ENABLE_THREADS=OFF',
       '-DCMAKE_C_FLAGS=' + ' '.join(cflags),
       '-DCMAKE_CXX_FLAGS=' + ' '.join(cxxflags),
       '-DCMAKE_EXE_LINKER_FLAGS=' + ' '.join(ldflags),
@@ -792,17 +760,6 @@ def main():
   CopyLibstdcpp(args, LLVM_BUILD_DIR)
   RunCommand(['ninja'], msvc_arch='x64')
 
-  # Copy in the threaded versions of lld and other tools.
-  if sys.platform == 'win32':
-    CopyFile(os.path.join(THREADS_ENABLED_BUILD_DIR, 'bin', 'lld-link.exe'),
-             os.path.join(LLVM_BUILD_DIR, 'bin'))
-    CopyFile(os.path.join(THREADS_ENABLED_BUILD_DIR, 'bin', 'lld.pdb'),
-             os.path.join(LLVM_BUILD_DIR, 'bin'))
-  else:
-    for tool in tools_with_threading:
-      CopyFile(os.path.join(THREADS_ENABLED_BUILD_DIR, 'bin', tool),
-               os.path.join(LLVM_BUILD_DIR, 'bin'))
-
   if chrome_tools:
     # If any Chromium tools were built, install those now.
     RunCommand(['ninja', 'cr-install'], msvc_arch='x64')
@@ -830,7 +787,6 @@ def main():
       cflags += ['-m32']
       cxxflags += ['-m32']
     compiler_rt_args = base_cmake_args + [
-        '-DLLVM_ENABLE_THREADS=OFF',
         '-DCMAKE_C_FLAGS=' + ' '.join(cflags),
         '-DCMAKE_CXX_FLAGS=' + ' '.join(cxxflags),
         '-DCOMPILER_RT_BUILD_BUILTINS=OFF',
@@ -887,7 +843,6 @@ def main():
                 '--sysroot=%s/sysroot' % toolchain_dir,
                 '-B%s' % toolchain_dir]
       android_args = base_cmake_args + [
-        '-DLLVM_ENABLE_THREADS=OFF',
         '-DCMAKE_C_COMPILER=' + os.path.join(LLVM_BUILD_DIR, 'bin/clang'),
         '-DCMAKE_CXX_COMPILER=' + os.path.join(LLVM_BUILD_DIR, 'bin/clang++'),
         '-DLLVM_CONFIG_PATH=' + os.path.join(LLVM_BUILD_DIR, 'bin/llvm-config'),
@@ -936,7 +891,6 @@ def main():
       # TODO(thakis): Might have to pass -B here once sysroot contains
       # binaries (e.g. gas for arm64?)
       fuchsia_args = base_cmake_args + [
-        '-DLLVM_ENABLE_THREADS=OFF',
         '-DCMAKE_C_COMPILER=' + os.path.join(LLVM_BUILD_DIR, 'bin/clang'),
         '-DCMAKE_CXX_COMPILER=' + os.path.join(LLVM_BUILD_DIR, 'bin/clang++'),
         '-DCMAKE_LINKER=' + os.path.join(LLVM_BUILD_DIR, 'bin/clang'),

tools/clang/scripts/update.py

@@ -41,7 +41,7 @@ import zipfile
 # Reverting problematic clang rolls is safe, though.
 CLANG_REVISION = '9284abd0040afecfd619dbcf1b244a8b533291c9'
 CLANG_SVN_REVISION = 'n344329'
-CLANG_SUB_REVISION = 4
+CLANG_SUB_REVISION = 5
 
 PACKAGE_VERSION = '%s-%s-%s' % (CLANG_SVN_REVISION, CLANG_REVISION[:8],
                                 CLANG_SUB_REVISION)