58207d6fe1
D13550 added the diagnostic to address/work around a crash. The rule was refined by D19836 (test/ELF/tls-archive.s) to exclude Lazy symbols. https://bugs.llvm.org/show_bug.cgi?id=45598 reported another case where the current logic has a false positive: Bitcode does not record undefined module-level inline assembly symbols (`IRSymtab.cpp:Builder::addSymbol`). Such an undefined symbol does not have the FB_tls bit and lld will not consider it STT_TLS. When the symbol is later replaced by a STT_TLS Defined, lld will error "TLS attribute mismatch". This patch fixes this false positive by allowing a STT_NOTYPE undefined symbol to be replaced by a STT_TLS. Considered alternative: Moving the diagnostics to scanRelocs() can improve the diagnostics (PR36049) but that requires a fair amount of refactoring. We will need more RelExpr members. It requires more thoughts whether it is worthwhile. See `test/ELF/tls-mismatch.s` for behavior differences. We will fail to diagnose a likely runtime bug (STT_NOTYPE non-TLS relocation referencing a TLS definition). This is probably acceptable because compiler generated code sets symbol types properly. Reviewed By: grimar, psmith Differential Revision: https://reviews.llvm.org/D78438
LLVM Linker (lld)
This directory and its subdirectories contain source code for the LLVM Linker, a modular cross platform linker which is built as part of the LLVM compiler infrastructure project.
lld is open source software. You may freely distribute it under the terms of the license agreement found in LICENSE.txt.
Benchmarking
In order to make sure various developers can evaluate patches over the same tests, we create a collection of self contained programs.
It is hosted at https://s3-us-west-2.amazonaws.com/linker-tests/lld-speed-test.tar.xz
The current sha256 is 10eec685463d5a8bbf08d77f4ca96282161d396c65bd97dc99dbde644a31610f.