diff --git a/llvm/docs/GoldPlugin.html b/llvm/docs/GoldPlugin.html index 77a417f5710d..66e099bad0a0 100644 --- a/llvm/docs/GoldPlugin.html +++ b/llvm/docs/GoldPlugin.html @@ -27,7 +27,7 @@
Building with link time optimization requires cooperation from the system linker. LTO support on Linux systems requires that you use the gold linker which supports -LTO via plugins. This is the same system used by the upcoming +LTO via plugins. This is the same mechanism used by the GCC LTO project.
The LLVM gold plugin implements the @@ -41,10 +41,15 @@ The same plugin can also be used by other tools such as ar and
You need to build gold with plugin support and build the LLVMgold -plugin.
+You need to have gold with plugin support and build the LLVMgold +plugin. Check whether you have gold running /usr/bin/ld -v. It will +report “GNU gold” or else “GNU ld” if not. If you have +gold, check for plugin support by running /usr/bin/ld -plugin. If it +complains “missing argument” then you have plugin support. If not, +such as an “unknown option” error then you will either need to +build gold or install a version with plugin support.
mkdir binutils cd binutils @@ -56,9 +61,11 @@ cd build ../src/configure --enable-gold --enable-plugins make all-gold- That should leave you with binutils/build/gold/ld-new which supports the --plugin option. - + That should leave you with binutils/build/gold/ld-new which supports the -plugin option. It also built would have +binutils/build/binutils/ar and nm-new which support plugins +but don't have a visible -plugin option, instead relying on the gold plugin +being present in ../lib/bfd-plugins relative to where the binaries are +placed.
You can produce bitcode files from llvm-gcc using @@ -83,6 +90,11 @@ make all-gold passes the -plugin option to ld. It will not look for an alternate linker, which is why you need gold to be the installed system linker in your path.
+If you want ar and nm to work seamlessly as well, install + libLLVMgold.so to /usr/lib/bfd-plugins. If you built your + own gold, be sure to install the ar and nm-new you built to + /usr/bin. +
gold, ar and nm all support plugins now, so everything should be - in place for an easy to use LTO build of autotooled projects:
+Once your system ld, ar and nm all support LLVM + bitcode, everything is in place for an easy to use LTO build of autotooled + projects: