Index: include/llvm/CodeGen/Passes.h =================================================================== --- include/llvm/CodeGen/Passes.h +++ include/llvm/CodeGen/Passes.h @@ -329,13 +329,17 @@ /// createWinEHPass - Prepares personality functions used by MSVC on Windows, /// in addition to the Itanium LSDA based personalities. - FunctionPass *createWinEHPass(); + FunctionPass *createWinEHPass(bool DemoteCatchSwitchPHIOnly = false); /// createSjLjEHPreparePass - This pass adapts exception handling code to use /// the GCC-style builtin setjmp/longjmp (sjlj) to handling EH control flow. /// FunctionPass *createSjLjEHPreparePass(); + /// createWasmEHPass - This pass adapts exception handling code to use + /// WebAssembly's exception handling scheme. + FunctionPass *createWasmEHPass(); + /// LocalStackSlotAllocation - This pass assigns local frame indices to stack /// slots relative to one another and allocates base registers to access them /// when it is estimated by the target to be out of range of normal frame Index: include/llvm/IR/IntrinsicsWebAssembly.td =================================================================== --- include/llvm/IR/IntrinsicsWebAssembly.td +++ include/llvm/IR/IntrinsicsWebAssembly.td @@ -45,4 +45,17 @@ def int_wasm_get_exception : Intrinsic<[llvm_ptr_ty], [], [IntrHasSideEffects]>; def int_wasm_get_ehselector : Intrinsic<[llvm_i32_ty], [], [IntrHasSideEffects]>; + +// wasm.catch returns the pointer to the exception object caught by wasm 'catch' +// instruction. +def int_wasm_catch : Intrinsic<[llvm_ptr_ty], [llvm_i32_ty], + [IntrHasSideEffects]>; + +// WebAssembly EH must maintain the landingpads in the order assigned to them +// by WasmEHPrepare pass to generate landingpad table in EHStreamer. This is +// used in order to give them the indices in WasmEHPrepare. +def int_wasm_landingpad_index: Intrinsic<[], [llvm_i32_ty], [IntrNoMem]>; + +// Returns LSDA address of the current function. +def int_wasm_lsda : Intrinsic<[llvm_ptr_ty], [], [IntrNoMem]>; } Index: include/llvm/InitializePasses.h =================================================================== --- include/llvm/InitializePasses.h +++ include/llvm/InitializePasses.h @@ -388,6 +388,7 @@ void initializeVerifierLegacyPassPass(PassRegistry&); void initializeVirtRegMapPass(PassRegistry&); void initializeVirtRegRewriterPass(PassRegistry&); +void initializeWasmEHPreparePass(PassRegistry&); void initializeWholeProgramDevirtPass(PassRegistry&); void initializeWinEHPreparePass(PassRegistry&); void initializeWriteBitcodePassPass(PassRegistry&); Index: lib/CodeGen/CMakeLists.txt =================================================================== --- lib/CodeGen/CMakeLists.txt +++ lib/CodeGen/CMakeLists.txt @@ -158,6 +158,7 @@ UnreachableBlockElim.cpp ValueTypes.cpp VirtRegMap.cpp + WasmEHPrepare.cpp WinEHPrepare.cpp XRayInstrumentation.cpp Index: lib/CodeGen/CodeGen.cpp =================================================================== --- lib/CodeGen/CodeGen.cpp +++ lib/CodeGen/CodeGen.cpp @@ -102,6 +102,7 @@ initializeUnreachableMachineBlockElimPass(Registry); initializeVirtRegMapPass(Registry); initializeVirtRegRewriterPass(Registry); + initializeWasmEHPreparePass(Registry); initializeWinEHPreparePass(Registry); initializeXRayInstrumentationPass(Registry); initializeMIRCanonicalizerPass(Registry); Index: lib/CodeGen/TargetPassConfig.cpp =================================================================== --- lib/CodeGen/TargetPassConfig.cpp +++ lib/CodeGen/TargetPassConfig.cpp @@ -656,7 +656,12 @@ addPass(createDwarfEHPass()); break; case ExceptionHandling::Wasm: - // TODO to prevent warning + // Wasm EH uses Windows EH instructions, but it does not need to demote PHIs + // on catchpads and cleanuppads because it does not outline them into + // funclets. Catchswitch blocks are not lowered in SelectionDAG, so we + // should remove PHIs there. + addPass(createWinEHPass(/*DemoteCatchSwitchPHIOnly=*/false)); + addPass(createWasmEHPass()); break; case ExceptionHandling::None: addPass(createLowerInvokePass()); Index: lib/CodeGen/WasmEHPrepare.cpp =================================================================== --- /dev/null +++ lib/CodeGen/WasmEHPrepare.cpp @@ -0,0 +1,325 @@ +//===-- WasmEHPrepare - Prepare excepton handling for WebAssembly --------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This transformation is designed for use by code generators which use +// WebAssembly exception handling scheme. +// +// WebAssembly exception handling uses Windows exception IR for the middle level +// representation. This pass does the following transformation for every +// catchpad block: +// (In C-style pseudocode) +// +// - Before: +// catchpad ... +// exn = wasm.get.exception(); +// selector = wasm.get.selector(); +// ... +// +// - After: +// catchpad ... +// exn = wasm.catch(0); // 0 is a tag for C++ +// wasm.landingpad.index(index); +// // Only add below in case it's not a single catch (...) +// __wasm_lpad_context.lpad_index = index; +// __wasm_lpad_context.lsda = wasm.lsda(); +// _Unwind_CallPersonality(exn); +// int selector = __wasm.landingpad_context.selector; +// ... +// +// Also, does the following for a cleanuppad block with a call to +// __clang_call_terminate(): +// - Before: +// cleanuppad ... +// exn = wasm.get.exception(); +// __clang_call_terminate(exn); +// +// - After: +// cleanuppad ... +// exn = wasm.catch(0); // 0 is a tag for C++ +// __clang_call_terminate(exn); +// +// +// * Background: WebAssembly EH instructions +// WebAssembly's try and catch instructions are structured as follows: +// try +// instruction* +// catch (C++ tag) +// instruction* +// ... +// catch_all +// instruction* +// try_end +// +// A catch instruction in WebAssembly does not correspond to a C++ catch clause. +// In WebAssembly, there is a single catch instruction for all C++ exceptions. +// There can be more catch instructions for exceptions in other languages, but +// they are not generated for now. catch_all catches all exceptions including +// foreign exceptions (e.g. JavaScript). We turn catchpads into catch (C++ tag) +// and cleanuppads into catch_all, with one exception: cleanuppad with a call to +// __clang_call_terminate should be both in catch (C++ tag) and catch_all. +// +// +// * Background: Direct personality function call +// In WebAssembly EH, the VM is responsible for unwinding the stack once an +// exception is thrown. After the stack is unwound, the control flow is +// transfered to WebAssembly 'catch' instruction, which returns a caught +// exception object. +// +// Unwinding the stack is not done by libunwind but the VM, so the personality +// function in libcxxabi cannot be called from libunwind during the unwinding +// process. So after a catch instruction, we insert a call to a wrapper function +// in libunwind that in turn calls the real personality function. +// +// In Itanium EH, if the personality function decides there is no matching catch +// clause in a call frame and no cleanup action to perform, the unwinder doesn't +// stop there and continues unwinding. But in Wasm EH, the unwinder stops at +// every call frame with a catch intruction, after which the personality +// function is called from the compiler-generated user code here. +// +// In libunwind, we have this struct that serves as a communincation channel +// between the compiler-generated user code and the personality function in +// libcxxabi. +// +// struct _Unwind_LandingPadContext { +// uintptr_t lpad_index; +// uintptr_t lsda; +// uintptr_t selector; +// }; +// struct _Unwind_LandingPadContext __wasm_lpad_context = ...; +// +// And this wrapper in libunwind calls the personality function. +// +// _Unwind_Reason_Code _Unwind_CallPersonality(void *exception_ptr) { +// struct _Unwind_Exception *exception_obj = +// (struct _Unwind_Exception *)exception_ptr; +// _Unwind_Reason_Code ret = __gxx_personality_v0( +// 1, _UA_CLEANUP_PHASE, exception_obj->exception_class, exception_obj, +// (struct _Unwind_Context *)__wasm_lpad_context); +// return ret; +// } +// +// We pass a landing pad index, and the address of LSDA for the current function +// to the wrapper function _Unwind_CallPersonality in libunwind, and we retrieve +// the selector after it returns. +// +//===----------------------------------------------------------------------===// + +#include "llvm/ADT/SetVector.h" +#include "llvm/ADT/Statistic.h" +#include "llvm/ADT/Triple.h" +#include "llvm/CodeGen/Passes.h" +#include "llvm/CodeGen/TargetLowering.h" +#include "llvm/CodeGen/TargetSubtargetInfo.h" +#include "llvm/IR/Dominators.h" +#include "llvm/IR/IRBuilder.h" +#include "llvm/IR/Intrinsics.h" +#include "llvm/Pass.h" +#include "llvm/Transforms/Utils/BasicBlockUtils.h" + +using namespace llvm; + +#define DEBUG_TYPE "wasmehprepare" + +namespace { +class WasmEHPrepare : public FunctionPass { + Type *LPadContextTy = nullptr; // type of 'struct _Unwind_LandingPadContext' + GlobalVariable *LPadContextGV = nullptr; // __wasm_lpad_context + + // Field addresses of struct _Unwind_LandingPadContext + Value *LPadIndexField = nullptr; // lpad_index field + Value *LSDAField = nullptr; // lsda field + Value *SelectorField = nullptr; // selector + + Function *CatchF = nullptr; // wasm.catch.extract() intrinsic + Function *LPadIndexF = nullptr; // wasm.landingpad.index() intrinsic + Function *LSDAF = nullptr; // wasm.lsda() intrinsic + Function *GetExnF = nullptr; // wasm.get.exception() intrinsic + Function *GetSelectorF = nullptr; // wasm.get.ehselector() intrinsic + Function *CallPersonalityF = nullptr; // _Unwind_CallPersonality() wrapper + Function *ClangCallTermF = nullptr; // __clang_call_terminate() function + + void prepareEHPad(BasicBlock *BB, unsigned Index); + void prepareTerminateCleanupPad(BasicBlock *BB); + +public: + static char ID; // Pass identification, replacement for typeid + + WasmEHPrepare() : FunctionPass(ID) {} + + bool doInitialization(Module &M) override; + bool runOnFunction(Function &F) override; + + StringRef getPassName() const override { + return "WebAssembly Exception handling preparation"; + } +}; +} // end anonymous namespace + +char WasmEHPrepare::ID = 0; +INITIALIZE_PASS(WasmEHPrepare, DEBUG_TYPE, "Prepare WebAssembly exceptions", + false, false); + +FunctionPass *llvm::createWasmEHPass() { return new WasmEHPrepare(); } + +bool WasmEHPrepare::doInitialization(Module &M) { + IRBuilder<> IRB(M.getContext()); + LPadContextTy = StructType::get(IRB.getInt32Ty(), // lpad_index + IRB.getInt8PtrTy(), // lsda + IRB.getInt32Ty() // selector + ); + + // __wasm_lpad_context global variable + LPadContextGV = cast( + M.getOrInsertGlobal("__wasm_lpad_context", LPadContextTy)); + LPadIndexField = IRB.CreateConstGEP2_32(LPadContextTy, LPadContextGV, 0, 0, + "lpad_index_gep"); + LSDAField = + IRB.CreateConstGEP2_32(LPadContextTy, LPadContextGV, 0, 1, "lsda_gep"); + SelectorField = IRB.CreateConstGEP2_32(LPadContextTy, LPadContextGV, 0, 2, + "selector_gep"); + + // wasm.catch() intinsic, which will be lowered to wasm 'catch' instruction. + CatchF = Intrinsic::getDeclaration(&M, Intrinsic::wasm_catch); + // wasm.landingpad.index() intrinsic, which is to specify landingpad index + LPadIndexF = Intrinsic::getDeclaration(&M, Intrinsic::wasm_landingpad_index); + // wasm.lsda() intrinsic. Returns the address of LSDA table for the current + // function. + LSDAF = Intrinsic::getDeclaration(&M, Intrinsic::wasm_lsda); + // wasm.get.exception() and wasm.get.ehselector() intrinsics. Calls to these + // are generated in clang. + GetExnF = Intrinsic::getDeclaration(&M, Intrinsic::wasm_get_exception); + GetSelectorF = Intrinsic::getDeclaration(&M, Intrinsic::wasm_get_ehselector); + + // _Unwind_CallPersonality() wrapper function, which calls the personality + CallPersonalityF = cast(M.getOrInsertFunction( + "_Unwind_CallPersonality", IRB.getInt32Ty(), IRB.getInt8PtrTy())); + + // __clang_call_terminate() function, which is inserted by clang in case a + // cleanup throws + ClangCallTermF = M.getFunction("__clang_call_terminate"); + + return false; +} + +bool WasmEHPrepare::runOnFunction(Function &F) { + SmallVector CatchPads; + SmallVector CleanupPads; + for (BasicBlock &BB : F) { + if (!BB.isEHPad()) + continue; + if (isa(BB.getFirstNonPHI())) + CatchPads.push_back(&BB); + else if (isa(BB.getFirstNonPHI())) + CleanupPads.push_back(&BB); + } + + if (CatchPads.empty() && CleanupPads.empty()) + return false; + assert(F.hasPersonalityFn() && "Personality function not found"); + + unsigned Index = 0; + for (auto *BB : CatchPads) { + auto *CPI = cast(BB->getFirstNonPHI()); + // In case of a single catch (...), we don't need to emit LSDA + if (CPI->getNumArgOperands() == 1 && + cast(CPI->getArgOperand(0))->isNullValue()) + prepareEHPad(BB, -1); + else + prepareEHPad(BB, Index++); + } + + if (!ClangCallTermF) + return !CatchPads.empty(); + + // Cleanuppads will turn into catch_all later, but cleanuppads with a call to + // __clang_call_terminate() is a special case. __clang_call_terminate() takes + // an exception object, so we have to duplicate call in both 'catch ' + // and 'catch_all' clauses. Here we only insert a call to catch; the + // duplication will be done later. In catch_all, the exception object will be + // set to null. + for (auto *BB : CleanupPads) + for (auto &I : *BB) + if (auto *CI = dyn_cast(&I)) + if (CI->getCalledValue() == ClangCallTermF) + prepareEHPad(BB, -1); + + return true; +} + +void WasmEHPrepare::prepareEHPad(BasicBlock *BB, unsigned Index) { + assert(BB->isEHPad() && "BB is not an EHPad!"); + IRBuilder<> IRB(BB->getContext()); + + IRB.SetInsertPoint(&*BB->getFirstInsertionPt()); + // The argument to wasm.catch() is the tag for C++ exceptions, which we set to + // 0 for this module. + // Pseudocode: void *exn = wasm.catch(0); + Instruction *Exn = IRB.CreateCall(CatchF, IRB.getInt32(0), "exn"); + // Replace the return value of wasm.get.exception() with the return value from + // wasm.catch(). + Instruction *GetExnCI = nullptr, *GetSelectorCI = nullptr; + for (auto &I : *BB) + if (auto *CI = dyn_cast(&I)) { + if (CI->getCalledValue() == GetExnF) + GetExnCI = CI; + if (CI->getCalledValue() == GetSelectorF) + GetSelectorCI = CI; + } + assert(GetExnCI && "wasm.get.exception() call does not exist"); + GetExnCI->replaceAllUsesWith(Exn); + GetExnCI->eraseFromParent(); + + // In case it is a catchpad with single catch (...) or a cleanuppad, we don't + // need to call personality function because we don't need a selector. + auto *FPI = cast(BB->getFirstNonPHI()); + if (FPI->getNumArgOperands() == 0 || + (FPI->getNumArgOperands() == 1 && + cast(FPI->getArgOperand(0))->isNullValue())) { + if (GetSelectorCI) { + assert(GetSelectorCI->use_empty() && + "wasm.get.ehselector() still has uses!"); + GetSelectorCI->eraseFromParent(); + } + return; + } + IRB.SetInsertPoint(Exn->getNextNode()); + + // This is to create a map of in + // SelectionDAGISel, which is to be used in EHStreamer to emit LSDA tables. + // Pseudocode: wasm.landingpad.index(Index); + IRB.CreateCall(LPadIndexF, IRB.getInt32(Index)); + + // Pseudocode: __wasm_lpad_context.lpad_index = index; + IRB.CreateStore(IRB.getInt32(Index), LPadIndexField); + + // Store LSDA address only if this catchpad belongs to a top-level + // catchswitch. If there is another catchpad that dominates this pad, we don't + // need to store LSDA address again, because they are the same throughout the + // function and have been already stored before. + // TODO Can we not store LSDA address in user function but make libcxxabi + // compute it? + auto *CPI = cast(FPI); + if (isa(CPI->getCatchSwitch()->getParentPad())) + // Pseudocode: __wasm_lpad_context.lsda = wasm.lsda(); + IRB.CreateStore(IRB.CreateCall(LSDAF), LSDAField); + + // Pseudocode: _Unwind_CallPersonality(exn); + CallInst *PersCI = + IRB.CreateCall(CallPersonalityF, Exn, OperandBundleDef("funclet", CPI)); + PersCI->setDoesNotThrow(); + + // Pseudocode: int selector = __wasm.landingpad_context.selector; + Instruction *Selector = IRB.CreateLoad(SelectorField, "selector"); + + // Replace the return value from wasm.get.ehselector() with the selector value + // loaded from __wasm_lpad_context.selector. + assert(GetSelectorCI && "wasm.get.ehselector() call does not exist"); + GetSelectorCI->replaceAllUsesWith(Selector); + GetSelectorCI->eraseFromParent(); +} Index: lib/CodeGen/WinEHPrepare.cpp =================================================================== --- lib/CodeGen/WinEHPrepare.cpp +++ lib/CodeGen/WinEHPrepare.cpp @@ -49,12 +49,17 @@ cl::desc("Do not remove implausible terminators or other similar cleanups"), cl::init(false)); +static cl::opt DemoteCatchSwitchPHIOnlyOpt( + "demote-catchswitch-only", cl::Hidden, + cl::desc("Demote catchswitch BBs only (for wasm EH)"), cl::init(false)); + namespace { class WinEHPrepare : public FunctionPass { public: static char ID; // Pass identification, replacement for typeid. - WinEHPrepare() : FunctionPass(ID) {} + WinEHPrepare(bool DemoteCatchSwitchPHIOnly = false) + : FunctionPass(ID), DemoteCatchSwitchPHIOnly(DemoteCatchSwitchPHIOnly) {} bool runOnFunction(Function &Fn) override; @@ -77,12 +82,14 @@ bool prepareExplicitEH(Function &F); void colorFunclets(Function &F); - void demotePHIsOnFunclets(Function &F); + void demotePHIsOnFunclets(Function &F, bool DemoteCatchSwitchPHIOnly); void cloneCommonBlocks(Function &F); void removeImplausibleInstructions(Function &F); void cleanupPreparedFunclets(Function &F); void verifyPreparedFunclets(Function &F); + bool DemoteCatchSwitchPHIOnly; + // All fields are reset by runOnFunction. EHPersonality Personality = EHPersonality::Unknown; @@ -97,7 +104,9 @@ INITIALIZE_PASS(WinEHPrepare, DEBUG_TYPE, "Prepare Windows exceptions", false, false) -FunctionPass *llvm::createWinEHPass() { return new WinEHPrepare(); } +FunctionPass *llvm::createWinEHPass(bool DemoteCatchSwitchPHIOnly) { + return new WinEHPrepare(DemoteCatchSwitchPHIOnly); +} bool WinEHPrepare::runOnFunction(Function &Fn) { if (!Fn.hasPersonalityFn()) @@ -677,13 +686,17 @@ } } -void WinEHPrepare::demotePHIsOnFunclets(Function &F) { +void WinEHPrepare::demotePHIsOnFunclets(Function &F, + bool DemoteCatchSwitchPHIOnly) { // Strip PHI nodes off of EH pads. SmallVector PHINodes; for (Function::iterator FI = F.begin(), FE = F.end(); FI != FE;) { BasicBlock *BB = &*FI++; if (!BB->isEHPad()) continue; + if (DemoteCatchSwitchPHIOnly && !isa(BB->getFirstNonPHI())) + continue; + for (BasicBlock::iterator BI = BB->begin(), BE = BB->end(); BI != BE;) { Instruction *I = &*BI++; auto *PN = dyn_cast(I); @@ -1031,7 +1044,8 @@ cloneCommonBlocks(F); if (!DisableDemotion) - demotePHIsOnFunclets(F); + demotePHIsOnFunclets(F, DemoteCatchSwitchPHIOnly || + DemoteCatchSwitchPHIOnlyOpt); if (!DisableCleanups) { DEBUG(verifyFunction(F)); Index: test/CodeGen/WebAssembly/wasmehprepare.ll =================================================================== --- /dev/null +++ test/CodeGen/WebAssembly/wasmehprepare.ll @@ -0,0 +1,317 @@ +; RUN: opt < %s -winehprepare -demote-catchswitch-only -wasmehprepare -S | FileCheck %s + +target datalayout = "e-m:e-p:32:32-i64:64-n32:64-S128" +target triple = "wasm32-unknown-unknown" + +; CHECK: @__wasm_lpad_context = external global { i32, i8*, i32 } + +@_ZTIi = external constant i8* +%struct.Cleanup = type { i8 } + +; A single 'catch (int)' clause. +; A wasm.catch() call, wasm.lsda() call, and personality call to generate a +; selector should all be genereated after the catchpad. +define void @test0() personality i8* bitcast (i32 (...)* @__gxx_wasm_personality_v0 to i8*) { +; CHECK-LABEL: @test0() +entry: + invoke void @foo() + to label %try.cont unwind label %catch.dispatch + +catch.dispatch: ; preds = %entry + %0 = catchswitch within none [label %catch.start] unwind to caller + +catch.start: ; preds = %catch.dispatch + %1 = catchpad within %0 [i8* bitcast (i8** @_ZTIi to i8*)] + %2 = call i8* @llvm.wasm.get.exception() + %3 = call i32 @llvm.wasm.get.ehselector() + %4 = call i32 @llvm.eh.typeid.for(i8* bitcast (i8** @_ZTIi to i8*)) + %matches = icmp eq i32 %3, %4 + br i1 %matches, label %catch, label %rethrow +; CHECK: catch.start: +; CHECK-NEXT: %[[CATCHPAD:.*]] = catchpad +; CHECK-NEXT: %[[EXN:.*]] = call i8* @llvm.wasm.catch(i32 0) +; CHECK-NEXT: call void @llvm.wasm.landingpad.index(i32 0) +; CHECK-NEXT: store i32 0, i32* getelementptr inbounds ({ i32, i8*, i32 }, { i32, i8*, i32 }* @__wasm_lpad_context, i32 0, i32 0) +; CHECK-NEXT: %[[LSDA:.*]] = call i8* @llvm.wasm.lsda() +; CHECK-NEXT: store i8* %[[LSDA]], i8** getelementptr inbounds ({ i32, i8*, i32 }, { i32, i8*, i32 }* @__wasm_lpad_context, i32 0, i32 1) +; CHECK-NEXT: call i32 @_Unwind_CallPersonality(i8* %[[EXN]]) {{.*}} [ "funclet"(token %[[CATCHPAD]]) ] +; CHECK-NEXT: %[[SELECTOR:.*]] = load i32, i32* getelementptr inbounds ({ i32, i8*, i32 }, { i32, i8*, i32 }* @__wasm_lpad_context, i32 0, i32 2) +; CHECK: icmp eq i32 %[[SELECTOR]] + +catch: ; preds = %catch.start + %5 = call i8* @__cxa_begin_catch(i8* %2) [ "funclet"(token %1) ] + call void @__cxa_end_catch() [ "funclet"(token %1) ] + catchret from %1 to label %try.cont +; CHECK: catch: +; CHECK-NEXT: call i8* @__cxa_begin_catch(i8* %[[EXN]]) + +rethrow: ; preds = %catch.start + call void @__cxa_rethrow() [ "funclet"(token %1) ] + unreachable + +try.cont: ; preds = %entry, %catch + ret void +} + +; Two try-catches, one of them is with a single 'catch (...)' clause. +; For the catchpad with a single 'catch (...)', only a wasm.catch() call should +; be generated after the catchpad; wasm.landingpad.index() and personality call +; should NOT be generated. For the other catchpad, the argument of +; wasm.landingpad.index() should be not 1 but 0. +define void @test1() personality i8* bitcast (i32 (...)* @__gxx_wasm_personality_v0 to i8*) { +; CHECK-LABEL: @test1() +entry: + invoke void @foo() + to label %try.cont unwind label %catch.dispatch + +catch.dispatch: ; preds = %entry + %0 = catchswitch within none [label %catch.start] unwind to caller + +catch.start: ; preds = %catch.dispatch + %1 = catchpad within %0 [i8* null] + %2 = call i8* @llvm.wasm.get.exception() + %3 = call i32 @llvm.wasm.get.ehselector() + %4 = call i8* @__cxa_begin_catch(i8* %2) [ "funclet"(token %1) ] + call void @__cxa_end_catch() [ "funclet"(token %1) ] + catchret from %1 to label %try.cont +; CHECK: catch.start: +; CHECK-NEXT: catchpad within %0 [i8* null] +; CHECK-NEXT: call i8* @llvm.wasm.catch(i32 0) +; CHECK-NOT: call void @llvm.wasm.landingpad.index +; CHECK-NOT: store {{.*}} @__wasm_lpad_context +; CHECK-NOT: call i8* @llvm.wasm.lsda() +; CHECK-NOT: call i32 @_Unwind_CallPersonality +; CHECK-NOT: load {{.*}} @__wasm_lpad_context + +try.cont: ; preds = %entry, %catch.start + invoke void @foo() + to label %try.cont7 unwind label %catch.dispatch2 + +catch.dispatch2: ; preds = %try.cont + %5 = catchswitch within none [label %catch.start3] unwind to caller + +catch.start3: ; preds = %catch.dispatch2 + %6 = catchpad within %5 [i8* bitcast (i8** @_ZTIi to i8*)] + %7 = call i8* @llvm.wasm.get.exception() + %8 = call i32 @llvm.wasm.get.ehselector() + %9 = call i32 @llvm.eh.typeid.for(i8* bitcast (i8** @_ZTIi to i8*)) + %matches = icmp eq i32 %8, %9 + br i1 %matches, label %catch4, label %rethrow +; CHECK: catch.start3: +; CHECK: call void @llvm.wasm.landingpad.index(i32 0) + +catch4: ; preds = %catch.start3 + %10 = call i8* @__cxa_begin_catch(i8* %7) [ "funclet"(token %6) ] + call void @__cxa_end_catch() [ "funclet"(token %6) ] + catchret from %6 to label %try.cont7 + +rethrow: ; preds = %catch.start3 + call void @__cxa_rethrow() [ "funclet"(token %6) ] + unreachable + +try.cont7: ; preds = %try.cont, %catch4 + ret void +} + +; A nested try-catch within a catch. Within the nested catchpad, wasm.lsda() +; call should NOT be generated. +define void @test2() personality i8* bitcast (i32 (...)* @__gxx_wasm_personality_v0 to i8*) { +; CHECK-LABEL: @test2() +entry: + invoke void @foo() + to label %try.cont9 unwind label %catch.dispatch + +catch.dispatch: ; preds = %entry + %0 = catchswitch within none [label %catch.start] unwind to caller + +catch.start: ; preds = %catch.dispatch + %1 = catchpad within %0 [i8* bitcast (i8** @_ZTIi to i8*)] + %2 = call i8* @llvm.wasm.get.exception() + %3 = call i32 @llvm.wasm.get.ehselector() + %4 = call i32 @llvm.eh.typeid.for(i8* bitcast (i8** @_ZTIi to i8*)) + %matches = icmp eq i32 %3, %4 + br i1 %matches, label %catch, label %rethrow +; CHECK: catch.start: +; CHECK: call i8* @llvm.wasm.lsda() + +catch: ; preds = %catch.start + %5 = call i8* @__cxa_begin_catch(i8* %2) [ "funclet"(token %1) ] + invoke void @foo() [ "funclet"(token %1) ] + to label %try.cont unwind label %catch.dispatch2 + +catch.dispatch2: ; preds = %catch + %6 = catchswitch within %1 [label %catch.start3] unwind label %ehcleanup + +catch.start3: ; preds = %catch.dispatch2 + %7 = catchpad within %6 [i8* bitcast (i8** @_ZTIi to i8*)] + %8 = call i8* @llvm.wasm.get.exception() + %9 = call i32 @llvm.wasm.get.ehselector() + %10 = call i32 @llvm.eh.typeid.for(i8* bitcast (i8** @_ZTIi to i8*)) + %matches4 = icmp eq i32 %9, %10 + br i1 %matches4, label %catch6, label %rethrow5 +; CHECK: catch.start3: +; CHECK-NOT: call i8* @llvm.wasm.lsda() + +catch6: ; preds = %catch.start3 + %11 = call i8* @__cxa_begin_catch(i8* %8) [ "funclet"(token %7) ] + call void @__cxa_end_catch() [ "funclet"(token %7) ] + catchret from %7 to label %try.cont + +rethrow5: ; preds = %catch.start3 + invoke void @__cxa_rethrow() [ "funclet"(token %7) ] + to label %unreachable unwind label %ehcleanup + +try.cont: ; preds = %catch, %catch6 + call void @__cxa_end_catch() [ "funclet"(token %1) ] + catchret from %1 to label %try.cont9 + +rethrow: ; preds = %catch.start + call void @__cxa_rethrow() [ "funclet"(token %1) ] + unreachable + +try.cont9: ; preds = %entry, %try.cont + ret void + +ehcleanup: ; preds = %rethrow5, %catch.dispatch2 + %12 = cleanuppad within %1 [] + call void @__cxa_end_catch() [ "funclet"(token %12) ] + cleanupret from %12 unwind to caller +; CHECK: ehcleanup: +; CHECK-NEXT: cleanuppad +; CHECK-NOT: call i8* @llvm.wasm.catch(i32 0) +; CHECK-NOT: call void @llvm.wasm.landingpad.index +; CHECK-NOT: store {{.*}} @__wasm_lpad_context +; CHECK-NOT: call i8* @llvm.wasm.lsda() +; CHECK-NOT: call i32 @_Unwind_CallPersonality +; CHECK-NOT: load {{.*}} @__wasm_lpad_context + +unreachable: ; preds = %rethrow5 + unreachable +} + +; A cleanuppad with a call to __clang_call_terminate(). +; A call to wasm.catch() should be generated after the cleanuppad. +define hidden void @test3() personality i8* bitcast (i32 (...)* @__gxx_wasm_personality_v0 to i8*) { +; CHECK-LABEL: @test3 +entry: + invoke void @foo() + to label %try.cont unwind label %catch.dispatch + +catch.dispatch: ; preds = %entry + %0 = catchswitch within none [label %catch.start] unwind to caller + +catch.start: ; preds = %catch.dispatch + %1 = catchpad within %0 [i8* null] + %2 = call i8* @llvm.wasm.get.exception() + %3 = call i32 @llvm.wasm.get.ehselector() + %4 = call i8* @__cxa_begin_catch(i8* %2) [ "funclet"(token %1) ] + invoke void @foo() [ "funclet"(token %1) ] + to label %invoke.cont1 unwind label %ehcleanup + +invoke.cont1: ; preds = %catch.start + call void @__cxa_end_catch() [ "funclet"(token %1) ] + catchret from %1 to label %try.cont + +try.cont: ; preds = %entry, %invoke.cont1 + ret void + +ehcleanup: ; preds = %catch.start + %5 = cleanuppad within %1 [] + invoke void @__cxa_end_catch() [ "funclet"(token %5) ] + to label %invoke.cont2 unwind label %terminate + +invoke.cont2: ; preds = %ehcleanup + cleanupret from %5 unwind to caller + +terminate: ; preds = %ehcleanup + %6 = cleanuppad within %5 [] + %7 = call i8* @llvm.wasm.get.exception() + call void @__clang_call_terminate(i8* %7) [ "funclet"(token %6) ] + unreachable +; CHECK: terminate: +; CHECK-NEXT: cleanuppad +; CHECK-NEXT: %[[EXN:.*]] = call i8* @llvm.wasm.catch(i32 0) +; CHECK-NEXT: call void @__clang_call_terminate(i8* %[[EXN]]) +} + +; PHI demotion test. Only the phi before catchswitch should be demoted; the phi +; before cleanuppad should NOT. +define void @test5() personality i8* bitcast (i32 (...)* @__gxx_wasm_personality_v0 to i8*) { +; CHECK-LABEL: @test5 +entry: + %c = alloca %struct.Cleanup, align 1 + invoke void @foo() + to label %invoke.cont unwind label %ehcleanup + +invoke.cont: ; preds = %entry + invoke void @foo() + to label %invoke.cont1 unwind label %ehcleanup + +invoke.cont1: ; preds = %invoke.cont + %call = call %struct.Cleanup* @_ZN7CleanupD1Ev(%struct.Cleanup* %c) + br label %try.cont + +ehcleanup: ; preds = %invoke.cont, %entry + %num.0 = phi i32 [ 2, %invoke.cont ], [ 1, %entry ] + %0 = cleanuppad within none [] + %call2 = call %struct.Cleanup* @_ZN7CleanupD1Ev(%struct.Cleanup* %c) [ "funclet"(token %0) ] + cleanupret from %0 unwind label %catch.dispatch +; CHECK: ehcleanup: +; CHECK-NEXT: = phi + +catch.dispatch: ; preds = %ehcleanup + %1 = catchswitch within none [label %catch.start] unwind to caller + +catch.start: ; preds = %catch.dispatch + %2 = catchpad within %1 [i8* null] + %3 = call i8* @llvm.wasm.get.exception() + %4 = call i32 @llvm.wasm.get.ehselector() + %5 = call i8* @__cxa_begin_catch(i8* %3) [ "funclet"(token %2) ] + call void @func(i32 %num.0) [ "funclet"(token %2) ] + call void @__cxa_end_catch() [ "funclet"(token %2) ] + catchret from %2 to label %try.cont + +try.cont: ; preds = %catch.start, %invoke.cont1 + invoke void @foo() + to label %invoke.cont3 unwind label %catch.dispatch5 + +invoke.cont3: ; preds = %try.cont + invoke void @foo() + to label %try.cont10 unwind label %catch.dispatch5 + +catch.dispatch5: ; preds = %invoke.cont3, %try.cont + %num.1 = phi i32 [ 2, %invoke.cont3 ], [ 1, %try.cont ] + %6 = catchswitch within none [label %catch.start6] unwind to caller +; CHECK: catch.dispatch5: +; CHECK-NOT: = phi + +catch.start6: ; preds = %catch.dispatch5 + %7 = catchpad within %6 [i8* null] + %8 = call i8* @llvm.wasm.get.exception() + %9 = call i32 @llvm.wasm.get.ehselector() + %10 = call i8* @__cxa_begin_catch(i8* %8) [ "funclet"(token %7) ] + call void @func(i32 %num.1) [ "funclet"(token %7) ] + call void @__cxa_end_catch() [ "funclet"(token %7) ] + catchret from %7 to label %try.cont10 + +try.cont10: ; preds = %invoke.cont3, %catch.start6 + ret void +} + +declare void @foo() +declare void @func(i32) +declare %struct.Cleanup* @_ZN7CleanupD1Ev(%struct.Cleanup* returned) +declare i32 @__gxx_wasm_personality_v0(...) +declare i8* @llvm.wasm.get.exception() +declare i32 @llvm.wasm.get.ehselector() +declare i32 @llvm.eh.typeid.for(i8*) +declare i8* @__cxa_begin_catch(i8*) +declare void @__cxa_end_catch() +declare void @__cxa_rethrow() +declare void @__clang_call_terminate(i8*) + +; CHECK-DAG: declare i8* @llvm.wasm.catch(i32) +; CHECK-DAG: declare void @llvm.wasm.landingpad.index(i32) +; CHECK-DAG: declare i8* @llvm.wasm.lsda() +; CHECK-DAG: declare i32 @_Unwind_CallPersonality(i8*) + Index: tools/opt/opt.cpp =================================================================== --- tools/opt/opt.cpp +++ tools/opt/opt.cpp @@ -411,6 +411,7 @@ initializePostInlineEntryExitInstrumenterPass(Registry); initializeUnreachableBlockElimLegacyPassPass(Registry); initializeExpandReductionsPass(Registry); + initializeWasmEHPreparePass(Registry); initializeWriteBitcodePassPass(Registry); #ifdef LINK_POLLY_INTO_TOOLS