2 Commits

Author	SHA1	Message	Date
Fangrui Song	f347541fbc	[ELF] resolveUndefined: ignore undefined symbols in SharedFile for Undefined and SharedSymbol ... If %t1.o has a weak reference on foo, and %t2.so has a non-weak reference on foo: `ld.lld %t1.o %t2.so -o %t` We incorrectly set the binding of the undefined foo to STB_GLOBAL. Fix this by ignoring undefined symbols in a SharedFile for Undefined and SharedSymbol. This fixes the binding of pthread_once when the program links against both librt.so and libpthread.so ``` a.o: STB_WEAK reference to pthread_once librt.so: STB_GLOBAL reference to pthread_once # should be ignored libstdc++.so: STB_WEAK reference to pthread_once # should be ignored libgcc_s.so.1: STB_WEAK reference to pthread_once # should be ignored ``` The STB_GLOBAL pthread_once issue (not fixed by D63974) can cause a link error when the result DSO is used to link another DSO with -z defs if -lpthread is not specified. (libstdc++.so.6 not having a dependency on libpthread.so is a really nasty hack...) We happened to create a weak undef before D63974 because libgcc_s.so.1 was linked the last and it changed the binding again to weak. Reviewed By: ruiu Differential Revision: https://reviews.llvm.org/D64136 llvm-svn: 365129	2019-07-04 10:38:04 +00:00
George Rimar	65eceee701	[LLD][ELF] - Add a test case for code in Archive::fetch(). NFCI. ... This covers the following piece with a test. https://github.com/llvm-mirror/lld/blob/master/ELF/InputFiles.cpp#L830 Thanks to Peter Collingbourne for providing the reproducer sample! llvm-svn: 339114	2018-08-07 08:41:37 +00:00