roll clang 138187:138188

tools/clang/scripts/update.sh

Index: tools/clang/scripts/update.sh
diff --git a/tools/clang/scripts/update.sh b/tools/clang/scripts/update.sh
index 352eff173175e1307842d2e7c49b4dce3940fe17..27abeab2e10b2965ebb401a83758dfd43aeab83f 100755
--- a/tools/clang/scripts/update.sh
+++ b/tools/clang/scripts/update.sh
@@ -34,11 +34,37 @@ fi
 # To always force a new build if someone interrupts their build half way.
 rm -f "${STAMP_FILE}"
 
+# Check if there's a prebuilt binary and if so just fetch that. That's faster,
+# and goma relies on having matching binary hashes on client and server too.
+CDS_URL=http://commondatastorage.googleapis.com/chromium-browser-clang

[Mark Mentovai, 2011/08/26 16:55:19]

Can you skip the “try to download binary” step if a special environment variable
is set? Maybe stick this entire block inside

if [[ -z "${CLANG_FORCE_BUILD_FROM_SOURCE}" ]]; then

[Nico, 2011/08/27 05:25:33]

I wanted to add some flag for that, and I'm waiting on
http://codereview.chromium.org/7741026/ to land so that I can build on the flag
processing code in their.

+CDS_FILE="clang-${CLANG_REVISION}.tgz"
+echo Trying to download prebuilt clang

[Mark Mentovai, 2011/08/26 16:55:19]

It’s good practice to quote the entire string you’re passing to echo. Also in
cases like the ones you have on lines 51 and 55, you can put the quotes around
the entire string you want to print, not just around ${CLANG_REVISION}.

[Nico, 2011/08/27 05:25:33]

Done.

+if [ "$(uname -s)" = "Linux" ]; then

[Mark Mentovai, 2011/08/26 16:55:19]

You run |uname -s| repeatedly to check the same thing. Just run it once and save
the result in a variable.

[Nico, 2011/08/27 05:25:33]

It's cheap to run and its result is unlikely to change.

+  wget "${CDS_URL}/Linux_x64/${CDS_FILE}" || rm -f "${CDS_FILE}"
+elif [ "$(uname -s)" = "Darwin" ]; then
+  curl -L --fail -O "${CDS_URL}/Mac/${CDS_FILE}" || rm -f "${CDS_FILE}"
+fi
+if [ -f "${CDS_FILE}" ]; then
+  rm -rf "${LLVM_BUILD_DIR}/Release+Asserts"
+  mkdir -p "${LLVM_BUILD_DIR}/Release+Asserts"
+  tar -xzf "${CDS_FILE}" -C "${LLVM_BUILD_DIR}/Release+Asserts"
+  echo clang "${CLANG_REVISION}" unpacked
+  echo "${CLANG_REVISION}" > "${STAMP_FILE}"
+  exit 0
+else
+  echo Did not find prebuilt clang at r"${CLANG_REVISION}", building
+fi
+
 if grep -q 'src/third_party/llvm":' "${DEPS_FILE}"; then
   echo LLVM pulled in through DEPS, skipping LLVM update step
 else
   echo Getting LLVM r"${CLANG_REVISION}" in "${LLVM_DIR}"
-  svn co --force "${LLVM_REPO_URL}/llvm/trunk@${CLANG_REVISION}" "${LLVM_DIR}"
+  if ! svn co --force "${LLVM_REPO_URL}/llvm/trunk@${CLANG_REVISION}" \
+                      "${LLVM_DIR}"; then
+    echo Checkout failed, retrying

[Mark Mentovai, 2011/08/26 16:55:19]

Why do you retry this one but not the one to check out tools/clang?

[Nico, 2011/08/27 05:25:33]

clang's checked out to llvm/tools/clang. It's very unlikely that one checkout is
from the internal mirror and the other isn't (since llvm is checked out first,
and since LLVM_REPO_URL doesn't change during the execution of this script, it
can only happen if someone mucks around manually on the bots)

+    rm -rf "${LLVM_DIR}"
+    svn co --force "${LLVM_REPO_URL}/llvm/trunk@${CLANG_REVISION}" "${LLVM_DIR}"
+  fi
 fi
 
 if grep -q 'src/third_party/llvm/tools/clang":' "${DEPS_FILE}"; then
@@ -59,6 +85,8 @@ cd "${LLVM_BUILD_DIR}"
 if [ ! -f ./config.status ]; then
   ../llvm/configure \
       --enable-optimized \
+      --disable-threads \

[Mark Mentovai, 2011/08/26 16:55:19]

Curious about what GOMA’s requirements are that make this necessary.

Also curious about what impact this has on the built-up compiler.

[Nico, 2011/08/27 05:25:33]

They run gcc in a fake chrooted sandbox, and I'm guessing that sandbox doesn't
permit threads.
Me too! If I read the source correctly, the only effect of this is to replace
all methods on llvm's Mutex class with no-ops. This class isn't used at all in
tools/clang, and is only used in the JIT part of llvm (I think). I don't think
clang uses multiple threads when compiling.

I relanded this CL with a clang revision increment of 1, so if ld crashes again
on the waterfall, it's pretty likely it's caused by this configure change. So
far, everything looks good though.

+      --disable-pthreads \
       --without-llvmgcc \
       --without-llvmgxx
 fi