diff options
Diffstat (limited to 'clang/lib/CodeGen/CGException.cpp')
-rw-r--r-- | clang/lib/CodeGen/CGException.cpp | 110 |
1 files changed, 54 insertions, 56 deletions
diff --git a/clang/lib/CodeGen/CGException.cpp b/clang/lib/CodeGen/CGException.cpp index ce57d02bcd3..1a4a5f988a5 100644 --- a/clang/lib/CodeGen/CGException.cpp +++ b/clang/lib/CodeGen/CGException.cpp @@ -1298,14 +1298,16 @@ namespace { /// Enters a finally block for an implementation using zero-cost /// exceptions. This is mostly general, but hard-codes some /// language/ABI-specific behavior in the catch-all sections. -CodeGenFunction::FinallyInfo -CodeGenFunction::EnterFinallyBlock(const Stmt *Body, - llvm::Constant *BeginCatchFn, - llvm::Constant *EndCatchFn, - llvm::Constant *RethrowFn) { - assert((BeginCatchFn != 0) == (EndCatchFn != 0) && +void CodeGenFunction::FinallyInfo::enter(CodeGenFunction &CGF, + const Stmt *body, + llvm::Constant *beginCatchFn, + llvm::Constant *endCatchFn, + llvm::Constant *rethrowFn) { + assert((beginCatchFn != 0) == (endCatchFn != 0) && "begin/end catch functions not paired"); - assert(RethrowFn && "rethrow function is required"); + assert(rethrowFn && "rethrow function is required"); + + BeginCatchFn = beginCatchFn; // The rethrow function has one of the following two types: // void (*)() @@ -1313,13 +1315,12 @@ CodeGenFunction::EnterFinallyBlock(const Stmt *Body, // In the latter case we need to pass it the exception object. // But we can't use the exception slot because the @finally might // have a landing pad (which would overwrite the exception slot). - const llvm::FunctionType *RethrowFnTy = + const llvm::FunctionType *rethrowFnTy = cast<llvm::FunctionType>( - cast<llvm::PointerType>(RethrowFn->getType()) - ->getElementType()); - llvm::Value *SavedExnVar = 0; - if (RethrowFnTy->getNumParams()) - SavedExnVar = CreateTempAlloca(Builder.getInt8PtrTy(), "finally.exn"); + cast<llvm::PointerType>(rethrowFn->getType())->getElementType()); + SavedExnVar = 0; + if (rethrowFnTy->getNumParams()) + SavedExnVar = CGF.CreateTempAlloca(CGF.Int8PtrTy, "finally.exn"); // A finally block is a statement which must be executed on any edge // out of a given scope. Unlike a cleanup, the finally block may @@ -1333,67 +1334,64 @@ CodeGenFunction::EnterFinallyBlock(const Stmt *Body, // The finally block itself is generated in the context of a cleanup // which conditionally leaves the catch-all. - FinallyInfo Info; - // Jump destination for performing the finally block on an exception // edge. We'll never actually reach this block, so unreachable is // fine. - JumpDest RethrowDest = getJumpDestInCurrentScope(getUnreachableBlock()); + RethrowDest = CGF.getJumpDestInCurrentScope(CGF.getUnreachableBlock()); // Whether the finally block is being executed for EH purposes. - llvm::AllocaInst *ForEHVar = CreateTempAlloca(Builder.getInt1Ty(), - "finally.for-eh"); - InitTempAlloca(ForEHVar, llvm::ConstantInt::getFalse(getLLVMContext())); + ForEHVar = CGF.CreateTempAlloca(CGF.Builder.getInt1Ty(), "finally.for-eh"); + CGF.Builder.CreateStore(CGF.Builder.getFalse(), ForEHVar); // Enter a normal cleanup which will perform the @finally block. - EHStack.pushCleanup<PerformFinally>(NormalCleanup, Body, - ForEHVar, EndCatchFn, - RethrowFn, SavedExnVar); + CGF.EHStack.pushCleanup<PerformFinally>(NormalCleanup, body, + ForEHVar, endCatchFn, + rethrowFn, SavedExnVar); // Enter a catch-all scope. - llvm::BasicBlock *CatchAllBB = createBasicBlock("finally.catchall"); - CGBuilderTy::InsertPoint SavedIP = Builder.saveIP(); - Builder.SetInsertPoint(CatchAllBB); - - // If there's a begin-catch function, call it. - if (BeginCatchFn) { - Builder.CreateCall(BeginCatchFn, Builder.CreateLoad(getExceptionSlot())) - ->setDoesNotThrow(); - } + llvm::BasicBlock *catchBB = CGF.createBasicBlock("finally.catchall"); + EHCatchScope *catchScope = CGF.EHStack.pushCatch(1); + catchScope->setCatchAllHandler(0, catchBB); +} - // If we need to remember the exception pointer to rethrow later, do so. - if (SavedExnVar) { - llvm::Value *SavedExn = Builder.CreateLoad(getExceptionSlot()); - Builder.CreateStore(SavedExn, SavedExnVar); - } +void CodeGenFunction::FinallyInfo::exit(CodeGenFunction &CGF) { + // Leave the finally catch-all. + EHCatchScope &catchScope = cast<EHCatchScope>(*CGF.EHStack.begin()); + llvm::BasicBlock *catchBB = catchScope.getHandler(0).Block; + CGF.EHStack.popCatch(); - // Tell the finally block that we're in EH. - Builder.CreateStore(llvm::ConstantInt::getTrue(getLLVMContext()), ForEHVar); + // If there are any references to the catch-all block, emit it. + if (catchBB->use_empty()) { + delete catchBB; + } else { + CGBuilderTy::InsertPoint savedIP = CGF.Builder.saveAndClearIP(); + CGF.EmitBlock(catchBB); - // Thread a jump through the finally cleanup. - EmitBranchThroughCleanup(RethrowDest); + llvm::Value *exn = 0; - Builder.restoreIP(SavedIP); + // If there's a begin-catch function, call it. + if (BeginCatchFn) { + exn = CGF.Builder.CreateLoad(CGF.getExceptionSlot()); + CGF.Builder.CreateCall(BeginCatchFn, exn)->setDoesNotThrow(); + } - EHCatchScope *CatchScope = EHStack.pushCatch(1); - CatchScope->setCatchAllHandler(0, CatchAllBB); + // If we need to remember the exception pointer to rethrow later, do so. + if (SavedExnVar) { + if (!exn) exn = CGF.Builder.CreateLoad(CGF.getExceptionSlot()); + CGF.Builder.CreateStore(exn, SavedExnVar); + } - return Info; -} + // Tell the cleanups in the finally block that we're do this for EH. + CGF.Builder.CreateStore(CGF.Builder.getTrue(), ForEHVar); -void CodeGenFunction::ExitFinallyBlock(FinallyInfo &Info) { - // Leave the finally catch-all. - EHCatchScope &Catch = cast<EHCatchScope>(*EHStack.begin()); - llvm::BasicBlock *CatchAllBB = Catch.getHandler(0).Block; - EHStack.popCatch(); + // Thread a jump through the finally cleanup. + CGF.EmitBranchThroughCleanup(RethrowDest); - // And leave the normal cleanup. - PopCleanupBlock(); - - CGBuilderTy::InsertPoint SavedIP = Builder.saveAndClearIP(); - EmitBlock(CatchAllBB, true); + CGF.Builder.restoreIP(savedIP); + } - Builder.restoreIP(SavedIP); + // Finally, leave the @finally cleanup. + CGF.PopCleanupBlock(); } llvm::BasicBlock *CodeGenFunction::getTerminateLandingPad() { |