[compiler-rt] Fix interception of multiple defined symbols.

Authored by etienneb on Sep 28 2016, 11:04 AM.


[compiler-rt] Fix interception of multiple defined symbols.

The MSVC compiler is generating multiple instance of the exception handler
when compiling on win64 with /MD.

see: https://msdn.microsoft.com/en-us/library/2kzt1wy3.aspx

Two tests were failing when running:

ninja check-asan-dynamic.

The tests were failing because only the first occurence of the function was patched.
The function __C_specific_handler is defined in ntdll and vcruntime140.

After this patch, there is still two remaining tests failing.

Testing: 0 .. 10.. 20.. 30.. 40.. 50.. 60.. 70.. 80.. 90..
Testing Time: 87.81s
Failing Tests (2):
    AddressSanitizer-x86_64-windows-dynamic :: TestCases/Windows/dll_intercept_memchr.cc
    AddressSanitizer-x86_64-windows-dynamic :: TestCases/Windows/dll_intercept_memcpy_indirect.cc

  Expected Passes    : 342
  Passes With Retry  : 2
  Expected Failures  : 16
  Unsupported Tests  : 152
  Unexpected Failures: 2

Reviewers: rnk, vitalybuka

Subscribers: vitalybuka, llvm-commits, chrisha, dberris

Differential Revision: https://reviews.llvm.org/D24983

llvm-svn: 282614