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author | Yaron Keren <yaron.keren@gmail.com> | 2014-04-19 13:47:43 +0000 |
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committer | Yaron Keren <yaron.keren@gmail.com> | 2014-04-19 13:47:43 +0000 |
commit | 64b2297786f7fd6f5fa24cdd4db0298fbf211466 (patch) | |
tree | c5250834c0fd832fbdb7363822269f603cee844f /lib/Target/X86/X86TargetMachine.cpp | |
parent | 2fa9e6ca34a1f696904c0b8006c91d64679c2b51 (diff) | |
download | llvm-64b2297786f7fd6f5fa24cdd4db0298fbf211466.tar.gz llvm-64b2297786f7fd6f5fa24cdd4db0298fbf211466.tar.bz2 llvm-64b2297786f7fd6f5fa24cdd4db0298fbf211466.tar.xz |
Patch by Vadim Chugunov
Win64 stack unwinder gets confused when execution flow "falls through" after
a call to 'noreturn' function. This fixes the "missing epilogue" problem by
emitting a trap instruction for IR 'unreachable' on x86_x64-pc-windows.
A secondary use for it would be for anyone wanting to make double-sure that
'noreturn' functions, indeed, do not return.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206684 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Target/X86/X86TargetMachine.cpp')
-rw-r--r-- | lib/Target/X86/X86TargetMachine.cpp | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/lib/Target/X86/X86TargetMachine.cpp b/lib/Target/X86/X86TargetMachine.cpp index 6f09ccf0ce..cb5ab0dd50 100644 --- a/lib/Target/X86/X86TargetMachine.cpp +++ b/lib/Target/X86/X86TargetMachine.cpp @@ -108,6 +108,13 @@ X86TargetMachine::X86TargetMachine(const Target &T, StringRef TT, if (Options.FloatABIType == FloatABI::Default) this->Options.FloatABIType = FloatABI::Hard; + // Windows stack unwinder gets confused when execution flow "falls through" + // after a call to 'noreturn' function. + // To prevent that, we emit a trap for 'unreachable' IR instructions. + // (which on X86, happens to be the 'ud2' instruction) + if (Subtarget.isTargetWin64()) + this->Options.TrapUnreachable = true; + initAsmInfo(); } |