diff --git a/clang/test/CodeGen/WebAssembly/wasm-eh.ll b/clang/test/CodeGen/WebAssembly/wasm-eh.ll new file mode 100644 --- /dev/null +++ b/clang/test/CodeGen/WebAssembly/wasm-eh.ll @@ -0,0 +1,38 @@ +; REQUIRES: webassembly-registered-target +; RUN: %clang %s -target wasm32-unknown-unknown -fwasm-exceptions -c -S -o - | FileCheck %s + +; This tests whether clang driver can take -fwasm-exceptions and compile bitcode +; files using Wasm EH. + +; CHECK-LABEL: test +; CHECK: try +; CHECK: call foo +; CHECK: catch __cpp_exception +; CHECK: end +define void @test() personality i8* bitcast (i32 (...)* @__gxx_wasm_personality_v0 to i8*) { +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(token %1) + %3 = call i32 @llvm.wasm.get.ehselector(token %1) + %4 = call i8* @__cxa_begin_catch(i8* %2) #2 [ "funclet"(token %1) ] + call void @__cxa_end_catch() [ "funclet"(token %1) ] + catchret from %1 to label %try.cont + +try.cont: ; preds = %entry, %catch.start + ret void +} + +declare void @foo() +declare i32 @__gxx_wasm_personality_v0(...) +declare i8* @llvm.wasm.get.exception(token) +declare i32 @llvm.wasm.get.ehselector(token) +declare i8* @__cxa_begin_catch(i8*) +declare void @__cxa_end_catch() + diff --git a/llvm/lib/Target/WebAssembly/MCTargetDesc/WebAssemblyMCAsmInfo.cpp b/llvm/lib/Target/WebAssembly/MCTargetDesc/WebAssemblyMCAsmInfo.cpp --- a/llvm/lib/Target/WebAssembly/MCTargetDesc/WebAssemblyMCAsmInfo.cpp +++ b/llvm/lib/Target/WebAssembly/MCTargetDesc/WebAssemblyMCAsmInfo.cpp @@ -13,7 +13,9 @@ //===----------------------------------------------------------------------===// #include "WebAssemblyMCAsmInfo.h" +#include "Utils/WebAssemblyUtilities.h" #include "llvm/ADT/Triple.h" +#include "llvm/Support/CommandLine.h" using namespace llvm; @@ -44,5 +46,13 @@ SupportsDebugInformation = true; + // When compilation is done on a cpp file by clang, the exception model info + // is stored in LangOptions, which is later used to set the info in + // TargetOptions and then MCAsmInfo in LLVMTargetMachine::initAsmInfo(). But + // this process does not happen when compiling bitcode directly with clang, so + // we make sure this info is set correctly. + if (WebAssembly::WasmEnableEH || WebAssembly::WasmEnableSjLj) + ExceptionsType = ExceptionHandling::Wasm; + // TODO: UseIntegratedAssembler? } diff --git a/llvm/lib/Target/WebAssembly/Utils/WebAssemblyUtilities.h b/llvm/lib/Target/WebAssembly/Utils/WebAssemblyUtilities.h --- a/llvm/lib/Target/WebAssembly/Utils/WebAssemblyUtilities.h +++ b/llvm/lib/Target/WebAssembly/Utils/WebAssemblyUtilities.h @@ -16,6 +16,7 @@ #define LLVM_LIB_TARGET_WEBASSEMBLY_UTILS_WEBASSEMBLYUTILITIES_H #include "llvm/IR/DerivedTypes.h" +#include "llvm/Support/CommandLine.h" namespace llvm { @@ -70,6 +71,12 @@ bool isChild(const MachineInstr &MI, const WebAssemblyFunctionInfo &MFI); bool mayThrow(const MachineInstr &MI); +// Exception handling / setjmp-longjmp handling command-line options +extern cl::opt WasmEnableEmEH; // asm.js-style EH +extern cl::opt WasmEnableEmSjLj; // asm.js-style SjLJ +extern cl::opt WasmEnableEH; // EH using Wasm EH instructions +extern cl::opt WasmEnableSjLj; // SjLj using Wasm EH instructions + // Exception-related function names extern const char *const ClangCallTerminateFn; extern const char *const CxaBeginCatchFn; diff --git a/llvm/lib/Target/WebAssembly/Utils/WebAssemblyUtilities.cpp b/llvm/lib/Target/WebAssembly/Utils/WebAssemblyUtilities.cpp --- a/llvm/lib/Target/WebAssembly/Utils/WebAssemblyUtilities.cpp +++ b/llvm/lib/Target/WebAssembly/Utils/WebAssemblyUtilities.cpp @@ -18,6 +18,31 @@ #include "llvm/MC/MCContext.h" using namespace llvm; +// Exception handling & setjmp-longjmp handling related options. These are +// defined here to be shared between WebAssembly and its subdirectories. + +// Emscripten's asm.js-style exception handling +cl::opt WebAssembly::WasmEnableEmEH( + "enable-emscripten-cxx-exceptions", + cl::desc("WebAssembly Emscripten-style exception handling"), + cl::init(false)); +// Emscripten's asm.js-style setjmp/longjmp handling +cl::opt WebAssembly::WasmEnableEmSjLj( + "enable-emscripten-sjlj", + cl::desc("WebAssembly Emscripten-style setjmp/longjmp handling"), + cl::init(false)); +// Exception handling using wasm EH instructions +cl::opt + WebAssembly::WasmEnableEH("wasm-enable-eh", + cl::desc("WebAssembly exception handling"), + cl::init(false)); +// setjmp/longjmp handling using wasm EH instrutions +cl::opt + WebAssembly::WasmEnableSjLj("wasm-enable-sjlj", + cl::desc("WebAssembly setjmp/longjmp handling"), + cl::init(false)); + +// Function names in libc++abi and libunwind const char *const WebAssembly::CxaBeginCatchFn = "__cxa_begin_catch"; const char *const WebAssembly::CxaRethrowFn = "__cxa_rethrow"; const char *const WebAssembly::StdTerminateFn = "_ZSt9terminatev"; diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyAsmPrinter.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyAsmPrinter.cpp --- a/llvm/lib/Target/WebAssembly/WebAssemblyAsmPrinter.cpp +++ b/llvm/lib/Target/WebAssembly/WebAssemblyAsmPrinter.cpp @@ -51,8 +51,6 @@ #define DEBUG_TYPE "asm-printer" extern cl::opt WasmKeepRegisters; -extern cl::opt WasmEnableEmEH; -extern cl::opt WasmEnableEmSjLj; //===----------------------------------------------------------------------===// // Helpers. @@ -322,8 +320,9 @@ // will discard it later if it turns out not to be necessary. auto Signature = signatureFromMVTs(Results, Params); bool InvokeDetected = false; - auto *Sym = getMCSymbolForFunction(&F, WasmEnableEmEH || WasmEnableEmSjLj, - Signature.get(), InvokeDetected); + auto *Sym = getMCSymbolForFunction( + &F, WebAssembly::WasmEnableEmEH || WebAssembly::WasmEnableEmSjLj, + Signature.get(), InvokeDetected); // Multiple functions can be mapped to the same invoke symbol. For // example, two IR functions '__invoke_void_i8*' and '__invoke_void_i32' diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyLowerEmscriptenEHSjLj.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyLowerEmscriptenEHSjLj.cpp --- a/llvm/lib/Target/WebAssembly/WebAssemblyLowerEmscriptenEHSjLj.cpp +++ b/llvm/lib/Target/WebAssembly/WebAssemblyLowerEmscriptenEHSjLj.cpp @@ -267,6 +267,7 @@ /// ///===----------------------------------------------------------------------===// +#include "Utils/WebAssemblyUtilities.h" #include "WebAssembly.h" #include "WebAssemblyTargetMachine.h" #include "llvm/ADT/StringExtras.h" @@ -285,13 +286,6 @@ #define DEBUG_TYPE "wasm-lower-em-ehsjlj" -// Emscripten's asm.js-style exception handling -extern cl::opt WasmEnableEmEH; -// Emscripten's asm.js-style setjmp/longjmp handling -extern cl::opt WasmEnableEmSjLj; -// Wasm setjmp/longjmp handling using wasm EH instructions -extern cl::opt WasmEnableSjLj; - static cl::list EHAllowlist("emscripten-cxx-exceptions-allowed", cl::desc("The list of function names in which Emscripten-style " @@ -370,8 +364,9 @@ static char ID; WebAssemblyLowerEmscriptenEHSjLj() - : ModulePass(ID), EnableEmEH(WasmEnableEmEH), - EnableEmSjLj(WasmEnableEmSjLj), EnableWasmSjLj(WasmEnableSjLj) { + : ModulePass(ID), EnableEmEH(WebAssembly::WasmEnableEmEH), + EnableEmSjLj(WebAssembly::WasmEnableEmSjLj), + EnableWasmSjLj(WebAssembly::WasmEnableSjLj) { assert(!(EnableEmSjLj && EnableWasmSjLj) && "Two SjLj modes cannot be turned on at the same time"); assert(!(EnableEmEH && EnableWasmSjLj) && diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyMCInstLower.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyMCInstLower.cpp --- a/llvm/lib/Target/WebAssembly/WebAssemblyMCInstLower.cpp +++ b/llvm/lib/Target/WebAssembly/WebAssemblyMCInstLower.cpp @@ -40,9 +40,6 @@ " instruction output for test purposes only."), cl::init(false)); -extern cl::opt WasmEnableEmEH; -extern cl::opt WasmEnableEmSjLj; - static void removeRegisterOperands(const MachineInstr *MI, MCInst &OutMI); MCSymbol * @@ -112,7 +109,8 @@ bool InvokeDetected = false; auto *WasmSym = Printer.getMCSymbolForFunction( - F, WasmEnableEmEH || WasmEnableEmSjLj, Signature.get(), InvokeDetected); + F, WebAssembly::WasmEnableEmEH || WebAssembly::WasmEnableEmSjLj, + Signature.get(), InvokeDetected); WasmSym->setSignature(Signature.get()); Printer.addSignature(std::move(Signature)); WasmSym->setType(wasm::WASM_SYMBOL_TYPE_FUNCTION); diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyTargetMachine.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyTargetMachine.cpp --- a/llvm/lib/Target/WebAssembly/WebAssemblyTargetMachine.cpp +++ b/llvm/lib/Target/WebAssembly/WebAssemblyTargetMachine.cpp @@ -14,6 +14,7 @@ #include "WebAssemblyTargetMachine.h" #include "MCTargetDesc/WebAssemblyMCTargetDesc.h" #include "TargetInfo/WebAssemblyTargetInfo.h" +#include "Utils/WebAssemblyUtilities.h" #include "WebAssembly.h" #include "WebAssemblyMachineFunctionInfo.h" #include "WebAssemblyTargetObjectFile.h" @@ -24,6 +25,7 @@ #include "llvm/CodeGen/RegAllocRegistry.h" #include "llvm/CodeGen/TargetPassConfig.h" #include "llvm/IR/Function.h" +#include "llvm/MC/MCAsmInfo.h" #include "llvm/MC/TargetRegistry.h" #include "llvm/Target/TargetOptions.h" #include "llvm/Transforms/Scalar.h" @@ -33,28 +35,6 @@ #define DEBUG_TYPE "wasm" -// Emscripten's asm.js-style exception handling -cl::opt - WasmEnableEmEH("enable-emscripten-cxx-exceptions", - cl::desc("WebAssembly Emscripten-style exception handling"), - cl::init(false)); - -// Emscripten's asm.js-style setjmp/longjmp handling -cl::opt WasmEnableEmSjLj( - "enable-emscripten-sjlj", - cl::desc("WebAssembly Emscripten-style setjmp/longjmp handling"), - cl::init(false)); - -// Exception handling using wasm EH instructions -cl::opt WasmEnableEH("wasm-enable-eh", - cl::desc("WebAssembly exception handling"), - cl::init(false)); - -// setjmp/longjmp handling using wasm EH instrutions -cl::opt WasmEnableSjLj("wasm-enable-sjlj", - cl::desc("WebAssembly setjmp/longjmp handling"), - cl::init(false)); - // A command-line option to keep implicit locals // for the purpose of testing with lit/llc ONLY. // This produces output which is not valid WebAssembly, and is not supported @@ -368,7 +348,23 @@ return nullptr; // No reg alloc } -static void basicCheckForEHAndSjLj(const TargetMachine *TM) { +using WebAssembly::WasmEnableEH; +using WebAssembly::WasmEnableEmEH; +using WebAssembly::WasmEnableEmSjLj; +using WebAssembly::WasmEnableSjLj; + +static void basicCheckForEHAndSjLj(TargetMachine *TM) { + // Before checking, we make sure TargetOptions.ExceptionModel is the same as + // MCAsmInfo.ExceptionsType. Normally these have to be the same, because clang + // stores the exception model info in LangOptions, which is later transferred + // to TargetOptions and MCAsmInfo. But when clang compiles bitcode directly, + // clang's LangOptions is not used and thus the exception model info is not + // correctly transferred to TargetOptions and MCAsmInfo, so we make sure we + // have the correct exception model in in WebAssemblyMCAsmInfo constructor. + // But in this case TargetOptions is still not updated, so we make sure they + // are the same. + TM->Options.ExceptionModel = TM->getMCAsmInfo()->getExceptionHandlingType(); + // Basic Correctness checking related to -exception-model if (TM->Options.ExceptionModel != ExceptionHandling::None && TM->Options.ExceptionModel != ExceptionHandling::Wasm)