This patch allows the Swift compiler to emit calls to `__tsan_external_write` before starting any modifying access, which will cause TSan to detect races on arrays, dictionaries and other classes defined in non-instrumented modules. Races on collections from the Swift standard library and user-defined structs and a frequent cause of subtle bugs and it's important that TSan detects those on top of existing LLVM IR instrumentation, which already detects races in direct memory accesses.
Differential Revision: https://reviews.llvm.org/D31630
llvm-svn: 302050
To make the TSan external API work with Swift and other use cases, we need to track "tags" for individual memory accesses. Since there is no space to store this information in shadow cells, let's use the thread traces for that. This patch stores the tag as an extra frame in the stack traces (by calling FuncEntry and FuncExit with the address of a registered tag), this extra frame is then stripped before printing the backtrace to stderr.
Differential Revision: https://reviews.llvm.org/D32382
llvm-svn: 301777
On Darwin, the setting ignore_noninstrumented_modules is used to suppress false positives in code that users don't have control of. The recently added "external" API (which can be used to detect races on objects provided by system libraries, but the race is actually user's fault) ignores this flag and it can report issues in non-instrumented modules. This patch fixes that.
Differential Revision: https://reviews.llvm.org/D31553
llvm-svn: 301000
This patch allows a non-instrumented library to call into TSan runtime, and tell us about "readonly" and "modifying" accesses to an arbitrary "object" and provide the caller and tag (type of object). This allows TSan to detect violations of API threading contracts where "read-only" methods can be called simulatenously from multiple threads, while modifying methods must be exclusive.
Differential Revision: https://reviews.llvm.org/D28836
llvm-svn: 293885
Kuba Mracek