Bill Wendling dc86704114 Consider this function: ...

void foo() { __builtin_unreachable(); }

It will output the following on Darwin X86:

_func1:
Leh_func_begin0:
        pushq %rbp
Ltmp0:
        movq %rsp, %rbp
Ltmp1:
Leh_func_end0:

This prolog adds a new Call Frame Information (CFI) row to the FDE with an
address that is not within the address range of the code it describes -- part is
equal to the end of the function -- and therefore results in an invalid EH
frame. If we emit a nop in this situation, then the CFI row is now within the
address range.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@108568 91177308-0d34-0410-b5e6-96231b3b80d8

2010-07-16 22:51:10 +00:00

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