[PATCH] D32064: [asan] Disable ASan global-GC depending on the target and compiler flags

[Reid Kleckner via Phabricator via cfe-commits]

rnk added a comment.

In https://reviews.llvm.org/D32064#726861, @pcc wrote:

> I think it would be better to move this logic to the driver and have it pass in an `-mllvm` flag. The sanitizer passes should really be taking no arguments in the constructor like the other passes, so I don't want us to add another argument here.


That seems like the opposite of the direction we've been moving, though. cl::opt flags can't appear twice, and this means one process can't do two asan compilations in two LLVMContexts in parallel with different settings.



================
Comment at: lib/Driver/SanitizerArgs.cpp:636
+  case llvm::Triple::COFF:
+    return DataSections;
+  case llvm::Triple::ELF:
----------------
We can return true for COFF here. By adding a comdat during asan instrumentation, we effectively implement -fdata-sections ourselves. If the user really wanted -fno-data-sections for some reason, they're out of luck right now.


Repository:
  rL LLVM

https://reviews.llvm.org/D32064