From b4eeb6bca5f9037af0c319036e558ba08f18ee3d Mon Sep 17 00:00:00 2001
From: Reid Kleckner <reid@kleckner.net>
Date: Fri, 10 Jul 2015 00:08:49 +0000
Subject: [PATCH] [WinEH] Make sure LSDA tables are 4 byte aligned

Apparently this is important, otherwise _except_handler3 assumes that
the registration node is corrupted and ignores it.

Also fix a bug in WinEHPrepare where we would insert code after a
terminator instruction.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@241877 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/AsmPrinter/WinException.cpp              | 2 ++
 lib/Target/X86/X86WinEHState.cpp                     | 6 ++++--
 test/CodeGen/WinEH/cppeh-prepared-catch-reordered.ll | 1 +
 test/CodeGen/WinEH/cppeh-prepared-catch.ll           | 1 +
 test/CodeGen/WinEH/cppeh-prepared-cleanups.ll        | 2 ++
 test/CodeGen/X86/seh-catch-all-win32.ll              | 1 +
 test/CodeGen/X86/win32-eh.ll                         | 1 +
 7 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/lib/CodeGen/AsmPrinter/WinException.cpp b/lib/CodeGen/AsmPrinter/WinException.cpp
index 0294a2b7c4b..55f97e6214b 100644
--- a/lib/CodeGen/AsmPrinter/WinException.cpp
+++ b/lib/CodeGen/AsmPrinter/WinException.cpp
@@ -350,6 +350,7 @@ void WinException::emitCXXFrameHandler3Table(const MachineFunction *MF) {
   // EHFlags & 1 -> Synchronous exceptions only, no async exceptions.
   // EHFlags & 2 -> ???
   // EHFlags & 4 -> The function is noexcept(true), unwinding can't continue.
+  OS.EmitValueToAlignment(4);
   OS.EmitLabel(FuncInfoXData);
   OS.EmitIntValue(0x19930522, 4);                      // MagicNumber
   OS.EmitIntValue(FuncInfo.UnwindMap.size(), 4);       // MaxState
@@ -578,6 +579,7 @@ void WinException::emitExceptHandlerTable(const MachineFunction *MF) {
 
   // Emit the __ehtable label that we use for llvm.x86.seh.lsda.
   MCSymbol *LSDALabel = Asm->OutContext.getOrCreateLSDASymbol(FLinkageName);
+  OS.EmitValueToAlignment(4);
   OS.EmitLabel(LSDALabel);
 
   const Function *Per = MMI->getPersonality();
diff --git a/lib/Target/X86/X86WinEHState.cpp b/lib/Target/X86/X86WinEHState.cpp
index 3a8bcaa4bb7..1bbcf704255 100644
--- a/lib/Target/X86/X86WinEHState.cpp
+++ b/lib/Target/X86/X86WinEHState.cpp
@@ -440,8 +440,10 @@ int WinEHStatePass::escapeRegNode(Function &F) {
 
   // Replace the call (if it exists) with new one. Otherwise, insert at the end
   // of the entry block.
-  IRBuilder<> Builder(&F.getEntryBlock(),
-                      EscapeCall ? EscapeCall : F.getEntryBlock().end());
+  Instruction *InsertPt = EscapeCall;
+  if (!EscapeCall)
+    InsertPt = F.getEntryBlock().getTerminator();
+  IRBuilder<> Builder(&F.getEntryBlock(), InsertPt);
   Builder.CreateCall(FrameEscape, Args);
   if (EscapeCall)
     EscapeCall->eraseFromParent();
diff --git a/test/CodeGen/WinEH/cppeh-prepared-catch-reordered.ll b/test/CodeGen/WinEH/cppeh-prepared-catch-reordered.ll
index 9a790174922..2d31a1d5cf4 100644
--- a/test/CodeGen/WinEH/cppeh-prepared-catch-reordered.ll
+++ b/test/CodeGen/WinEH/cppeh-prepared-catch-reordered.ll
@@ -114,6 +114,7 @@ stub:                                             ; preds = %entry
 ; CHECK:        .seh_handlerdata
 ; CHECK:        .long   ($cppxdata$main)@IMGREL
 
+; CHECK: .align 4
 ; CHECK-NEXT: $cppxdata$main:
 ; CHECK-NEXT:         .long   429065506
 ; CHECK-NEXT:         .long   2
diff --git a/test/CodeGen/WinEH/cppeh-prepared-catch.ll b/test/CodeGen/WinEH/cppeh-prepared-catch.ll
index f97c9ee0fed..255709ceb4e 100644
--- a/test/CodeGen/WinEH/cppeh-prepared-catch.ll
+++ b/test/CodeGen/WinEH/cppeh-prepared-catch.ll
@@ -121,6 +121,7 @@ try.cont8:                                        ; preds = %lpad2, %try.cont
 ; CHECK-NOT: jmpq *
 ; CHECK:             .seh_handlerdata
 ; CHECK-NEXT:        .long   ("$cppxdata$?f@@YAXXZ")@IMGREL
+; CHECK-NEXT: .align 4
 ; CHECK-NEXT:"$cppxdata$?f@@YAXXZ":
 ; CHECK-NEXT:        .long   429065506
 ; CHECK-NEXT:        .long   4
diff --git a/test/CodeGen/WinEH/cppeh-prepared-cleanups.ll b/test/CodeGen/WinEH/cppeh-prepared-cleanups.ll
index fe91ffd28a0..b5cfd65030a 100644
--- a/test/CodeGen/WinEH/cppeh-prepared-cleanups.ll
+++ b/test/CodeGen/WinEH/cppeh-prepared-cleanups.ll
@@ -30,6 +30,7 @@ $_TI1H = comdat any
 ; CHECK-LABEL: "?test1@@YAXXZ":
 ; CHECK:             .seh_handlerdata
 ; CHECK-NEXT:        .long   ("$cppxdata$?test1@@YAXXZ")@IMGREL
+; CHECK-NEXT: .align 4
 ; CHECK-NEXT:"$cppxdata$?test1@@YAXXZ":
 ; CHECK-NEXT:        .long   429065506
 ; CHECK-NEXT:        .long   1
@@ -92,6 +93,7 @@ entry:
 ; CHECK-LABEL: "?test2@@YAX_N@Z":
 ; CHECK:             .seh_handlerdata
 ; CHECK-NEXT:        .long   ("$cppxdata$?test2@@YAX_N@Z")@IMGREL
+; CHECK-NEXT: .align 4
 ; CHECK-NEXT:"$cppxdata$?test2@@YAX_N@Z":
 ; CHECK-NEXT:        .long   429065506
 ; CHECK-NEXT:        .long   2
diff --git a/test/CodeGen/X86/seh-catch-all-win32.ll b/test/CodeGen/X86/seh-catch-all-win32.ll
index 39906f8fecc..a4ea8ab78c7 100644
--- a/test/CodeGen/X86/seh-catch-all-win32.ll
+++ b/test/CodeGen/X86/seh-catch-all-win32.ll
@@ -90,6 +90,7 @@ entry:
 
 ; CHECK: .section .xdata,"dr"
 ; CHECK: Lmain$parent_frame_offset = Lmain$frame_escape_1
+; CHECK: .align 4
 ; CHECK: L__ehtable$main
 ; CHECK-NEXT: .long -1
 ; CHECK-NEXT: .long _filt$main
diff --git a/test/CodeGen/X86/win32-eh.ll b/test/CodeGen/X86/win32-eh.ll
index 199afd07f79..3ee4723ce5f 100644
--- a/test/CodeGen/X86/win32-eh.ll
+++ b/test/CodeGen/X86/win32-eh.ll
@@ -132,6 +132,7 @@ catchall:
 ; CHECK: retl
 
 ; CHECK: .section .xdata,"dr"
+; CHECK: .align 4
 ; CHECK-LABEL: L__ehtable$use_CxxFrameHandler3:
 ; CHECK-NEXT:  .long   429065506
 ; CHECK-NEXT:  .long   2