[LLVMbugs] [Bug 24009] New: Need to disable most libc library builtin optimizations when SEH is present

[bugzilla-daemon at llvm.org]

https://llvm.org/bugs/show_bug.cgi?id=24009

            Bug ID: 24009
           Summary: Need to disable most libc library builtin
                    optimizations when SEH is present
           Product: clang
           Version: unspecified
          Hardware: PC
                OS: Windows NT
            Status: NEW
          Severity: normal
          Priority: P
         Component: LLVM Codegen
          Assignee: unassignedclangbugs at nondot.org
          Reporter: rnk at google.com
                CC: david.majnemer at gmail.com, llvmbugs at cs.uiuc.edu
    Classification: Unclassified

This program crashes instead of exiting zero:

#include <string.h>
bool try_memcpy(void *d, void *s, size_t n) {
  __try {
    memcpy(d, s, n);
  } __except (1) {
    return false;
  }
  return true;
}
int main() {
  return try_memcpy(nullptr, nullptr, 42);
}

This is because we codegen memcpy to llvm.memcpy instead of emitting the
libcall. We don't support invoking most intrinsics, so for now we should
probably behave as if -fno-builtin was set in functions that use SEH.

-- 
You are receiving this mail because:
You are on the CC list for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-bugs/attachments/20150701/a38bc730/attachment.html>