From: Reid Kleckner <rnk@google.com>
Date: Mon, 20 Mar 2017 17:45:59 +0000 (+0000)
Subject: [WinEH] Adjust decision to emit SEH moves for leaf functions
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=3993050daa60a8d5265c64800157c64585495fcc;p=llvm

[WinEH] Adjust decision to emit SEH moves for leaf functions

Move the check for "MF->hasWinCFI()" up into the calculation of the
shouldEmitMoves boolean, rather than putting it in the early returning
if. This ensures that endFunction doesn't try to emit .seh_* directives
for leaf functions.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@298276 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/CodeGen/AsmPrinter/WinException.cpp b/lib/CodeGen/AsmPrinter/WinException.cpp
index 9d7c96a1b8e..704f0ac2f19 100644
--- a/lib/CodeGen/AsmPrinter/WinException.cpp
+++ b/lib/CodeGen/AsmPrinter/WinException.cpp
@@ -68,7 +68,7 @@ void WinException::beginFunction(const MachineFunction *MF) {
 
   const Function *F = MF->getFunction();
 
-  shouldEmitMoves = Asm->needsSEHMoves();
+  shouldEmitMoves = Asm->needsSEHMoves() && MF->hasWinCFI();
 
   const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
   unsigned PerEncoding = TLOF.getPersonalityEncoding();
@@ -94,7 +94,7 @@ void WinException::beginFunction(const MachineFunction *MF) {
 
   // If we're not using CFI, we don't want the CFI or the personality, but we
   // might want EH tables if we had EH pads.
-  if (!Asm->MAI->usesWindowsCFI() || (!MF->hasWinCFI() && !PerFn)) {
+  if (!Asm->MAI->usesWindowsCFI()) {
     if (Per == EHPersonality::MSVC_X86SEH && !hasEHFunclets) {
       // If this is 32-bit SEH and we don't have any funclets (really invokes),
       // make sure we emit the parent offset label. Some unreferenced filter
diff --git a/test/CodeGen/X86/win64_eh_leaf2.ll b/test/CodeGen/X86/win64_eh_leaf2.ll
new file mode 100644
index 00000000000..a840d948518
--- /dev/null
+++ b/test/CodeGen/X86/win64_eh_leaf2.ll
@@ -0,0 +1,22 @@
+; RUN: llc < %s -O1 -mtriple=x86_64-pc-win32 | FileCheck %s
+
+; Neither of these functions need .seh_ directives. We used to crash.
+
+target datalayout = "e-m:w-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-pc-windows-msvc"
+
+declare i32 @__CxxFrameHandler3(...)
+
+define void @f1() uwtable nounwind personality i32 (...)* @__CxxFrameHandler3 {
+  ret void
+}
+
+; CHECK-LABEL: f1:
+; CHECK-NOT: .seh_
+
+define void @f2() uwtable {
+  ret void
+}
+
+; CHECK-LABEL: f2:
+; CHECK-NOT: .seh_