From 9a837be2b947946e6918bd81016e5f6d78af5f1c Mon Sep 17 00:00:00 2001
From: David Chisnall <csdavec@swan.ac.uk>
Date: Wed, 7 Nov 2012 16:50:40 +0000
Subject: [PATCH] Fix the Objective-C exception rethrow from cleanups (GNU
 runtimes).  Note that a bug in the inliner still causes the wrong thing to
 happen at -O2 and above (PR14116).

llvm-svn: 167534
---
 clang/lib/CodeGen/CGException.cpp       | 8 ++++----
 clang/lib/CodeGen/CGObjCGNU.cpp         | 6 ++++--
 clang/lib/CodeGen/CodeGenFunction.h     | 2 +-
 clang/test/CodeGenObjC/gnu-exceptions.m | 2 +-
 4 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/clang/lib/CodeGen/CGException.cpp b/clang/lib/CodeGen/CGException.cpp
index ba9c2967cd3d..369711a8a628 100644
--- a/clang/lib/CodeGen/CGException.cpp
+++ b/clang/lib/CodeGen/CGException.cpp
@@ -534,7 +534,7 @@ static void emitFilterDispatchBlock(CodeGenFunction &CGF,
     llvm::Value *zero = CGF.Builder.getInt32(0);
     llvm::Value *failsFilter =
       CGF.Builder.CreateICmpSLT(selector, zero, "ehspec.fails");
-    CGF.Builder.CreateCondBr(failsFilter, unexpectedBB, CGF.getEHResumeBlock());
+    CGF.Builder.CreateCondBr(failsFilter, unexpectedBB, CGF.getEHResumeBlock(false));
 
     CGF.EmitBlock(unexpectedBB);
   }
@@ -614,7 +614,7 @@ CodeGenFunction::getEHDispatchBlock(EHScopeStack::stable_iterator si) {
   // The dispatch block for the end of the scope chain is a block that
   // just resumes unwinding.
   if (si == EHStack.stable_end())
-    return getEHResumeBlock();
+    return getEHResumeBlock(true);
 
   // Otherwise, we should look at the actual scope.
   EHScope &scope = *EHStack.find(si);
@@ -1546,7 +1546,7 @@ llvm::BasicBlock *CodeGenFunction::getTerminateHandler() {
   return TerminateHandler;
 }
 
-llvm::BasicBlock *CodeGenFunction::getEHResumeBlock() {
+llvm::BasicBlock *CodeGenFunction::getEHResumeBlock(bool isCleanup) {
   if (EHResumeBlock) return EHResumeBlock;
 
   CGBuilderTy::InsertPoint SavedIP = Builder.saveIP();
@@ -1560,7 +1560,7 @@ llvm::BasicBlock *CodeGenFunction::getEHResumeBlock() {
   // This can always be a call because we necessarily didn't find
   // anything on the EH stack which needs our help.
   const char *RethrowName = Personality.CatchallRethrowFn;
-  if (RethrowName != 0) {
+  if (RethrowName != 0 && !isCleanup) {
     Builder.CreateCall(getCatchallRethrowFn(*this, RethrowName),
                        getExceptionFromSlot())
       ->setDoesNotReturn();
diff --git a/clang/lib/CodeGen/CGObjCGNU.cpp b/clang/lib/CodeGen/CGObjCGNU.cpp
index 99abf0545ba4..5acc199b524d 100644
--- a/clang/lib/CodeGen/CGObjCGNU.cpp
+++ b/clang/lib/CodeGen/CGObjCGNU.cpp
@@ -2547,7 +2547,7 @@ void CGObjCGNU::EmitTryStmt(CodeGenFunction &CGF,
   // Unlike the Apple non-fragile runtimes, which also uses
   // unwind-based zero cost exceptions, the GNU Objective C runtime's
   // EH support isn't a veneer over C++ EH.  Instead, exception
-  // objects are created by __objc_exception_throw and destroyed by
+  // objects are created by objc_exception_throw and destroyed by
   // the personality function; this avoids the need for bracketing
   // catch handlers with calls to __blah_begin_catch/__blah_end_catch
   // (or even _Unwind_DeleteException), but probably doesn't
@@ -2572,7 +2572,9 @@ void CGObjCGNU::EmitThrowStmt(CodeGenFunction &CGF,
     ExceptionAsObject = CGF.ObjCEHValueStack.back();
   }
   ExceptionAsObject = CGF.Builder.CreateBitCast(ExceptionAsObject, IdTy);
-  CGF.EmitCallOrInvoke(ExceptionThrowFn, ExceptionAsObject);
+  llvm::CallSite Throw =
+      CGF.EmitCallOrInvoke(ExceptionThrowFn, ExceptionAsObject);
+  Throw.setDoesNotReturn();
   CGF.Builder.CreateUnreachable();
   CGF.Builder.ClearInsertionPoint();
 }
diff --git a/clang/lib/CodeGen/CodeGenFunction.h b/clang/lib/CodeGen/CodeGenFunction.h
index fadc391328ff..f2ab226ab530 100644
--- a/clang/lib/CodeGen/CodeGenFunction.h
+++ b/clang/lib/CodeGen/CodeGenFunction.h
@@ -908,7 +908,7 @@ public:
   /// themselves).
   void popCatchScope();
 
-  llvm::BasicBlock *getEHResumeBlock();
+  llvm::BasicBlock *getEHResumeBlock(bool isCleanup);
   llvm::BasicBlock *getEHDispatchBlock(EHScopeStack::stable_iterator scope);
 
   /// An object to manage conditionally-evaluated expressions.
diff --git a/clang/test/CodeGenObjC/gnu-exceptions.m b/clang/test/CodeGenObjC/gnu-exceptions.m
index 141747ec8d3d..b7d0adbc6d64 100644
--- a/clang/test/CodeGenObjC/gnu-exceptions.m
+++ b/clang/test/CodeGenObjC/gnu-exceptions.m
@@ -20,7 +20,7 @@ void test0() {
 
     // CHECK: call void @log(i32 0)
 
-    // CHECK: call void @objc_exception_throw
+    // CHECK: resume
 
     log(0);
   }