[os_log] Mark os_log_helper `nounwind`
Allow the optimizer to remove unnecessary EH cleanups surrounding calls
to os_log_helper, to save some code size.
As a follow-up, it might be worthwhile to add a BasicNoexcept exception
spec to os_log_helper, and to then teach CGCall to emit direct calls for
callees which can't throw. This could save some compile-time.
Differential Revision: https://reviews.llvm.org/D60108
llvm-svn: 357501
diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp
index 72a336b..97789218 100644
--- a/clang/lib/CodeGen/CGBuiltin.cpp
+++ b/clang/lib/CodeGen/CGBuiltin.cpp
@@ -1138,6 +1138,7 @@
Fn->setVisibility(llvm::GlobalValue::HiddenVisibility);
CGM.SetLLVMFunctionAttributes(GlobalDecl(), FI, Fn);
CGM.SetLLVMFunctionAttributesForDefinition(nullptr, Fn);
+ Fn->setDoesNotThrow();
// Attach 'noinline' at -Oz.
if (CGM.getCodeGenOpts().OptimizeSize == 2)