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view ir/irlandingpad.cpp @ 1351:8d501abecd24
Initial (but disabled) fix for ticket #294 , the actual part that fixes the bug is in a #if 0 block as I'm afraid it will cause regressions. I'm most likely not going to be around tonight, and maybe not tomorrow as well, so I'm pushing it in case someone wants to run some serious testing/investigate the problem noted in llvmhelpers.cpp : realignOffset .
author | Tomas Lindquist Olsen <tomas.l.olsen gmail com> |
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date | Thu, 14 May 2009 17:20:17 +0200 |
parents | 15e9762bb620 |
children | 3f5ea912149d |
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#include "gen/llvm.h" #include "gen/tollvm.h" #include "gen/irstate.h" #include "gen/runtime.h" #include "gen/logger.h" #include "gen/classes.h" #include "gen/llvmhelpers.h" #include "ir/irlandingpad.h" IRLandingPadInfo::IRLandingPadInfo(Catch* catchstmt, llvm::BasicBlock* end) : finallyBody(NULL) { target = llvm::BasicBlock::Create("catch", gIR->topfunc(), end); gIR->scope() = IRScope(target,end); // assign storage to catch var if(catchstmt->var) { // use the same storage for all exceptions that are not accessed in // nested functions #if DMDV2 if(!catchstmt->var->nestedrefs.dim) { #else if(!catchstmt->var->nestedref) { #endif assert(!catchstmt->var->ir.irLocal); catchstmt->var->ir.irLocal = new IrLocal(catchstmt->var); LLValue* catch_var = gIR->func()->landingPad.getExceptionStorage(); catchstmt->var->ir.irLocal->value = gIR->ir->CreateBitCast(catch_var, getPtrToType(DtoType(catchstmt->var->type))); } // this will alloca if we haven't already and take care of nested refs DtoDeclarationExp(catchstmt->var); // the exception will only be stored in catch_var. copy it over if necessary if(catchstmt->var->ir.irLocal->value != gIR->func()->landingPad.getExceptionStorage()) { LLValue* exc = gIR->ir->CreateBitCast(DtoLoad(gIR->func()->landingPad.getExceptionStorage()), DtoType(catchstmt->var->type)); DtoStore(exc, catchstmt->var->ir.irLocal->value); } } // emit handler, if there is one // handler is zero for instance for 'catch { debug foo(); }' if(catchstmt->handler) catchstmt->handler->toIR(gIR); if (!gIR->scopereturned()) gIR->ir->CreateBr(end); assert(catchstmt->type); catchType = catchstmt->type->toBasetype()->isClassHandle(); assert(catchType); catchType->codegen(Type::sir); } IRLandingPadInfo::IRLandingPadInfo(Statement* finallystmt) : target(NULL), finallyBody(finallystmt), catchType(NULL) { } void IRLandingPad::addCatch(Catch* catchstmt, llvm::BasicBlock* end) { unpushed_infos.push_front(IRLandingPadInfo(catchstmt, end)); } void IRLandingPad::addFinally(Statement* finallystmt) { unpushed_infos.push_front(IRLandingPadInfo(finallystmt)); } void IRLandingPad::push(llvm::BasicBlock* inBB) { // store infos such that matches are right to left nInfos.push(infos.size()); infos.insert(infos.end(), unpushed_infos.begin(), unpushed_infos.end()); unpushed_infos.clear(); constructLandingPad(inBB); // store as invoke target padBBs.push(inBB); } void IRLandingPad::pop() { padBBs.pop(); size_t n = nInfos.top(); infos.resize(n); nInfos.pop(); } llvm::BasicBlock* IRLandingPad::get() { if(padBBs.size() == 0) return NULL; else return padBBs.top(); } void IRLandingPad::constructLandingPad(llvm::BasicBlock* inBB) { // save and rewrite scope IRScope savedscope = gIR->scope(); gIR->scope() = IRScope(inBB,savedscope.end); // eh_ptr = llvm.eh.exception(); llvm::Function* eh_exception_fn = GET_INTRINSIC_DECL(eh_exception); LLValue* eh_ptr = gIR->ir->CreateCall(eh_exception_fn); // build selector arguments LLSmallVector<LLValue*, 6> selectorargs; // put in classinfos in the right order bool hasFinally = false; std::deque<IRLandingPadInfo>::iterator it = infos.begin(), end = infos.end(); for(; it != end; ++it) { if(it->finallyBody) hasFinally = true; else { if(catchToInt.find(it->catchType) == catchToInt.end()) { int newval = 1 + catchToInt.size(); catchToInt[it->catchType] = newval; } assert(it->catchType); assert(it->catchType->ir.irStruct); selectorargs.insert(selectorargs.begin(), it->catchType->ir.irStruct->getClassInfoSymbol()); } } // if there's a finally, the eh table has to have a 0 action if(hasFinally) selectorargs.push_back(llvm::ConstantInt::get(LLType::Int32Ty, 0)); // personality fn llvm::Function* personality_fn = LLVM_D_GetRuntimeFunction(gIR->module, "_d_eh_personality"); LLValue* personality_fn_arg = gIR->ir->CreateBitCast(personality_fn, getPtrToType(LLType::Int8Ty)); selectorargs.insert(selectorargs.begin(), personality_fn_arg); // eh storage target selectorargs.insert(selectorargs.begin(), eh_ptr); // if there is a catch and some catch allocated storage, store exception object if(catchToInt.size() && catch_var) { const LLType* objectTy = DtoType(ClassDeclaration::object->type); gIR->ir->CreateStore(gIR->ir->CreateBitCast(eh_ptr, objectTy), catch_var); } // eh_sel = llvm.eh.selector(eh_ptr, cast(byte*)&_d_eh_personality, <selectorargs>); llvm::Function* eh_selector_fn; if (global.params.is64bit) eh_selector_fn = GET_INTRINSIC_DECL(eh_selector_i64); else eh_selector_fn = GET_INTRINSIC_DECL(eh_selector_i32); LLValue* eh_sel = gIR->ir->CreateCall(eh_selector_fn, selectorargs.begin(), selectorargs.end()); // emit finallys and switches that branch to catches until there are no more catches // then simply branch to the finally chain llvm::SwitchInst* switchinst = NULL; std::deque<IRLandingPadInfo>::reverse_iterator rit, rend = infos.rend(); for(rit = infos.rbegin(); rit != rend; ++rit) { // if it's a finally, emit its code if(rit->finallyBody) { if(switchinst) switchinst = NULL; // since this may be emitted multiple times // give the labels a new scope gIR->func()->pushUniqueLabelScope("finally"); rit->finallyBody->toIR(gIR); gIR->func()->popLabelScope(); } // otherwise it's a catch and we'll add a switch case else { if(!switchinst) { switchinst = gIR->ir->CreateSwitch(eh_sel, llvm::BasicBlock::Create("switchdefault", gIR->topfunc(), gIR->scopeend()), infos.size()); gIR->scope() = IRScope(switchinst->getDefaultDest(), gIR->scopeend()); } // dubious comment // catches matched first get the largest switchval, so do size - unique int llvm::ConstantInt* switchval = llvm::ConstantInt::get(DtoSize_t(), catchToInt[rit->catchType]); // and make sure we don't add the same switchval twice, may happen with nested trys if(!switchinst->findCaseValue(switchval)) switchinst->addCase(switchval, rit->target); } } // no catch matched and all finallys executed - resume unwind llvm::Function* unwind_resume_fn = LLVM_D_GetRuntimeFunction(gIR->module, "_d_eh_resume_unwind"); gIR->ir->CreateCall(unwind_resume_fn, eh_ptr); gIR->ir->CreateUnreachable(); gIR->scope() = savedscope; } LLValue* IRLandingPad::getExceptionStorage() { if(!catch_var) { Logger::println("Making new catch var"); catch_var = DtoAlloca(ClassDeclaration::object->type, "catchvar"); } return catch_var; }