This hack is necessary under ubuntu precise to produce a gold plugin which has a

proper dt_needed entry for LTO.

Without this the linkline looks like:

g++ -I../native_client/pnacl/build/llvm/include
-I.../native_client/pnacl/build/llvm/tools/gold
-I.../native_client/pnacl/src/upstream/llvm/include
-I.../native_client/pnacl/src/upstream/llvm/tools/gold
-D_DEBUG -D_GNU_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS
-D__STDC_LIMIT_MACROS -O3 -fomit-frame-pointer -fvisibility-inlines-hidden
-fno-exceptions -fno-rtti -fPIC -Woverloaded-virtual -Wcast-qual
-I.../native_client/pnacl/src/binutils/binutils-2.20/include
-D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64
-L.../native_client/pnacl/build/llvm/Release+Asserts/lib/lib
-lLTO
^^^^^^
-O3 -Wl,-R -Wl,'$ORIGIN'
-L.../native_client/pnacl/build/llvm/Release+Asserts/lib
-L.../native_client/pnacl/build/llvm/Release+Asserts/lib
-pedantic -Wno-long-long -Wall -W -Wno-unused-parameter -Wwrite-strings -shared
-o .../native_client/pnacl/build/llvm/Release+Asserts/lib/LLVMgold.so
.../native_client/pnacl/build/llvm/tools/gold/Release+Asserts/gold-plugin.o
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-lLLVMSupport
-Wl,--version-script,.../native_client/pnacl/build/llvm/tools/gold/Release+Asser
ts/gold.exports.map
-lpthread -ldl -lm

Since the -lLTO preceeds gold-plugin.o it seems legit for the linker to ignore
this dependency.
Which on precise, unlike lucid, it does.

Adding -lLTO to the very end of the link-line fixed the problem

BUG= http://code.google.com/p/nativeclient/issues/detail?id=2872
TEST= manual

REVIEW= http://codereview.chromium.org/10693178/

0 files changed, 0 insertions, 0 deletions