Use the actual ABI-determined C calling convention for runtime

calls and declarations.

LLVM has a default CC determined by the target triple.  This is
not always the actual default CC for the ABI we've been asked to
target, and so we sometimes find ourselves annotating all user
functions with an explicit calling convention.  Since these
calling conventions usually agree for the simple set of argument
types passed to most runtime functions, using the LLVM-default CC
in principle has no effect.  However, the LLVM optimizer goes
into histrionics if it sees this kind of formal CC mismatch,
since it has no concept of CC compatibility.  Therefore, if this
module happens to define the "runtime" function, or got LTO'ed
with such a definition, we can miscompile;  so it's quite
important to get this right.

Defining runtime functions locally is quite common in embedded
applications.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@176286 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 33 insertions, 51 deletions

diff --git a/lib/CodeGen/CGException.cpp b/lib/CodeGen/CGException.cpp
index 8dced6327b..9794ca4731 100644
--- a/lib/CodeGen/CGException.cpp
+++ b/lib/CodeGen/CGException.cpp
@@ -364,8 +364,7 @@ namespace {
     llvm::Value *exn;
     FreeException(llvm::Value *exn) : exn(exn) {}
     void Emit(CodeGenFunction &CGF, Flags flags) {
-      CGF.Builder.CreateCall(getFreeExceptionFn(CGF.CGM), exn)
-        ->setDoesNotThrow();
+      CGF.EmitNounwindRuntimeCall(getFreeExceptionFn(CGF.CGM), exn);
     }
   };
 }
@@ -422,15 +421,8 @@ llvm::Value *CodeGenFunction::getSelectorFromSlot() {
 
 void CodeGenFunction::EmitCXXThrowExpr(const CXXThrowExpr *E) {
   if (!E->getSubExpr()) {
-    if (getInvokeDest()) {
-      Builder.CreateInvoke(getReThrowFn(CGM),
-                           getUnreachableBlock(),
-                           getInvokeDest())
-        ->setDoesNotReturn();
-    } else {
-      Builder.CreateCall(getReThrowFn(CGM))->setDoesNotReturn();
-      Builder.CreateUnreachable();
-    }
+    EmitNoreturnRuntimeCallOrInvoke(getReThrowFn(CGM),
+                                    ArrayRef<llvm::Value*>());
 
     // throw is an expression, and the expression emitters expect us
     // to leave ourselves at a valid insertion point.
@@ -458,10 +450,9 @@ void CodeGenFunction::EmitCXXThrowExpr(const CXXThrowExpr *E) {
 
   llvm::Constant *AllocExceptionFn = getAllocateExceptionFn(CGM);
   llvm::CallInst *ExceptionPtr =
-    Builder.CreateCall(AllocExceptionFn,
-                       llvm::ConstantInt::get(SizeTy, TypeSize),
-                       "exception");
-  ExceptionPtr->setDoesNotThrow();
+    EmitNounwindRuntimeCall(AllocExceptionFn,
+                            llvm::ConstantInt::get(SizeTy, TypeSize),
+                            "exception");
   
   EmitAnyExprToExn(*this, E->getSubExpr(), ExceptionPtr);
 
@@ -482,18 +473,8 @@ void CodeGenFunction::EmitCXXThrowExpr(const CXXThrowExpr *E) {
   }
   if (!Dtor) Dtor = llvm::Constant::getNullValue(Int8PtrTy);
 
-  if (getInvokeDest()) {
-    llvm::InvokeInst *ThrowCall =
-      Builder.CreateInvoke3(getThrowFn(CGM),
-                            getUnreachableBlock(), getInvokeDest(),
-                            ExceptionPtr, TypeInfo, Dtor);
-    ThrowCall->setDoesNotReturn();
-  } else {
-    llvm::CallInst *ThrowCall =
-      Builder.CreateCall3(getThrowFn(CGM), ExceptionPtr, TypeInfo, Dtor);
-    ThrowCall->setDoesNotReturn();
-    Builder.CreateUnreachable();
-  }
+  llvm::Value *args[] = { ExceptionPtr, TypeInfo, Dtor };
+  EmitNoreturnRuntimeCallOrInvoke(getThrowFn(CGM), args);
 
   // throw is an expression, and the expression emitters expect us
   // to leave ourselves at a valid insertion point.
@@ -563,7 +544,7 @@ static void emitFilterDispatchBlock(CodeGenFunction &CGF,
   // according to the last landing pad the exception was thrown
   // into.  Seriously.
   llvm::Value *exn = CGF.getExceptionFromSlot();
-  CGF.Builder.CreateCall(getUnexpectedFn(CGF.CGM), exn)
+  CGF.EmitRuntimeCall(getUnexpectedFn(CGF.CGM), exn)
     ->setDoesNotReturn();
   CGF.Builder.CreateUnreachable();
 }
@@ -925,11 +906,11 @@ namespace {
 
     void Emit(CodeGenFunction &CGF, Flags flags) {
       if (!MightThrow) {
-        CGF.Builder.CreateCall(getEndCatchFn(CGF.CGM))->setDoesNotThrow();
+        CGF.EmitNounwindRuntimeCall(getEndCatchFn(CGF.CGM));
         return;
       }
 
-      CGF.EmitCallOrInvoke(getEndCatchFn(CGF.CGM));
+      CGF.EmitRuntimeCallOrInvoke(getEndCatchFn(CGF.CGM));
     }
   };
 }
@@ -941,12 +922,12 @@ namespace {
 static llvm::Value *CallBeginCatch(CodeGenFunction &CGF,
                                    llvm::Value *Exn,
                                    bool EndMightThrow) {
-  llvm::CallInst *Call = CGF.Builder.CreateCall(getBeginCatchFn(CGF.CGM), Exn);
-  Call->setDoesNotThrow();
+  llvm::CallInst *call =
+    CGF.EmitNounwindRuntimeCall(getBeginCatchFn(CGF.CGM), Exn);
 
   CGF.EHStack.pushCleanup<CallEndCatch>(NormalAndEHCleanup, EndMightThrow);
 
-  return Call;
+  return call;
 }
 
 /// A "special initializer" callback for initializing a catch
@@ -1086,8 +1067,7 @@ static void InitCatchParam(CodeGenFunction &CGF,
   // We have to call __cxa_get_exception_ptr to get the adjusted
   // pointer before copying.
   llvm::CallInst *rawAdjustedExn =
-    CGF.Builder.CreateCall(getGetExceptionPtrFn(CGF.CGM), Exn);
-  rawAdjustedExn->setDoesNotThrow();
+    CGF.EmitNounwindRuntimeCall(getGetExceptionPtrFn(CGF.CGM), Exn);
 
   // Cast that to the appropriate type.
   llvm::Value *adjustedExn = CGF.Builder.CreateBitCast(rawAdjustedExn, PtrTy);
@@ -1310,7 +1290,7 @@ void CodeGenFunction::ExitCXXTryStmt(const CXXTryStmt &S, bool IsFnTryBlock) {
     // constructor function-try-block's catch handler (p14), so this
     // really only applies to destructors.
     if (doImplicitRethrow && HaveInsertPoint()) {
-      EmitCallOrInvoke(getReThrowFn(CGM));
+      EmitRuntimeCallOrInvoke(getReThrowFn(CGM));
       Builder.CreateUnreachable();
       Builder.ClearInsertionPoint();
     }
@@ -1342,7 +1322,7 @@ namespace {
         CGF.Builder.CreateLoad(ForEHVar, "finally.endcatch");
       CGF.Builder.CreateCondBr(ShouldEndCatch, EndCatchBB, CleanupContBB);
       CGF.EmitBlock(EndCatchBB);
-      CGF.EmitCallOrInvoke(EndCatchFn); // catch-all, so might throw
+      CGF.EmitRuntimeCallOrInvoke(EndCatchFn); // catch-all, so might throw
       CGF.EmitBlock(CleanupContBB);
     }
   };
@@ -1387,9 +1367,10 @@ namespace {
 
         CGF.EmitBlock(RethrowBB);
         if (SavedExnVar) {
-          CGF.EmitCallOrInvoke(RethrowFn, CGF.Builder.CreateLoad(SavedExnVar));
+          CGF.EmitRuntimeCallOrInvoke(RethrowFn,
+                                      CGF.Builder.CreateLoad(SavedExnVar));
         } else {
-          CGF.EmitCallOrInvoke(RethrowFn);
+          CGF.EmitRuntimeCallOrInvoke(RethrowFn);
         }
         CGF.Builder.CreateUnreachable();
 
@@ -1494,7 +1475,7 @@ void CodeGenFunction::FinallyInfo::exit(CodeGenFunction &CGF) {
     // If there's a begin-catch function, call it.
     if (BeginCatchFn) {
       exn = CGF.getExceptionFromSlot();
-      CGF.Builder.CreateCall(BeginCatchFn, exn)->setDoesNotThrow();
+      CGF.EmitNounwindRuntimeCall(BeginCatchFn, exn);
     }
 
     // If we need to remember the exception pointer to rethrow later, do so.
@@ -1561,12 +1542,15 @@ static llvm::Constant *getClangCallTerminateFn(CodeGenModule &CGM) {
     llvm::Value *exn = &*fn->arg_begin();
 
     // Call __cxa_begin_catch(exn).
-    builder.CreateCall(getBeginCatchFn(CGM), exn)->setDoesNotThrow();
+    llvm::CallInst *catchCall = builder.CreateCall(getBeginCatchFn(CGM), exn);
+    catchCall->setDoesNotThrow();
+    catchCall->setCallingConv(CGM.getRuntimeCC());
 
     // Call std::terminate().
     llvm::CallInst *termCall = builder.CreateCall(getTerminateFn(CGM));
     termCall->setDoesNotThrow();
     termCall->setDoesNotReturn();
+    termCall->setCallingConv(CGM.getRuntimeCC());
 
     // std::terminate cannot return.
     builder.CreateUnreachable();
@@ -1596,12 +1580,11 @@ llvm::BasicBlock *CodeGenFunction::getTerminateLandingPad() {
   if (useClangCallTerminate(CGM)) {
     // Extract out the exception pointer.
     llvm::Value *exn = Builder.CreateExtractValue(LPadInst, 0);
-    terminateCall = Builder.CreateCall(getClangCallTerminateFn(CGM), exn);
+    terminateCall = EmitNounwindRuntimeCall(getClangCallTerminateFn(CGM), exn);
   } else {
-    terminateCall = Builder.CreateCall(getTerminateFn(CGM));
+    terminateCall = EmitNounwindRuntimeCall(getTerminateFn(CGM));
   }
   terminateCall->setDoesNotReturn();
-  terminateCall->setDoesNotThrow();
   Builder.CreateUnreachable();
 
   // Restore the saved insertion state.
@@ -1620,9 +1603,8 @@ llvm::BasicBlock *CodeGenFunction::getTerminateHandler() {
   // end of the function by FinishFunction.
   TerminateHandler = createBasicBlock("terminate.handler");
   Builder.SetInsertPoint(TerminateHandler);
-  llvm::CallInst *TerminateCall = Builder.CreateCall(getTerminateFn(CGM));
+  llvm::CallInst *TerminateCall = EmitNounwindRuntimeCall(getTerminateFn(CGM));
   TerminateCall->setDoesNotReturn();
-  TerminateCall->setDoesNotThrow();
   Builder.CreateUnreachable();
 
   // Restore the saved insertion state.
@@ -1646,8 +1628,8 @@ llvm::BasicBlock *CodeGenFunction::getEHResumeBlock(bool isCleanup) {
   // anything on the EH stack which needs our help.
   const char *RethrowName = Personality.CatchallRethrowFn;
   if (RethrowName != 0 && !isCleanup) {
-    Builder.CreateCall(getCatchallRethrowFn(CGM, RethrowName),
-                       getExceptionFromSlot())
+    EmitRuntimeCall(getCatchallRethrowFn(CGM, RethrowName),
+                      getExceptionFromSlot())
       ->setDoesNotReturn();
   } else {
     switch (CleanupHackLevel) {
@@ -1655,8 +1637,8 @@ llvm::BasicBlock *CodeGenFunction::getEHResumeBlock(bool isCleanup) {
       // In mandatory-catchall mode, we need to use
       // _Unwind_Resume_or_Rethrow, or whatever the personality's
       // equivalent is.
-      Builder.CreateCall(getUnwindResumeOrRethrowFn(),
-                         getExceptionFromSlot())
+      EmitRuntimeCall(getUnwindResumeOrRethrowFn(),
+                        getExceptionFromSlot())
         ->setDoesNotReturn();
       break;
     case CHL_MandatoryCleanup: {
@@ -1680,7 +1662,7 @@ llvm::BasicBlock *CodeGenFunction::getEHResumeBlock(bool isCleanup) {
       // In an idealized mode where we don't have to worry about the
       // optimizer combining landing pads, we should just use
       // _Unwind_Resume (or the personality's equivalent).
-      Builder.CreateCall(getUnwindResumeFn(), getExceptionFromSlot())
+      EmitRuntimeCall(getUnwindResumeFn(), getExceptionFromSlot())
         ->setDoesNotReturn();
       break;
     }