9a9546e30c
This commit introduces support for running clang-repl and executing C++ code interactively inside a Javascript engine using WebAssembly when built with Emscripten. This is achieved by producing WASM "shared libraries" that can be loaded by the Emscripten runtime using dlopen() More discussion is available in https://reviews.llvm.org/D158140 Co-authored-by: Anubhab Ghosh <anubhabghosh.me@gmail.com>
115 lines
4.1 KiB
C++
115 lines
4.1 KiB
C++
//===----------------- Wasm.cpp - Wasm Interpreter --------------*- C++ -*-===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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//
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// This file implements interpreter support for code execution in WebAssembly.
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//
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//===----------------------------------------------------------------------===//
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#include "Wasm.h"
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#include "IncrementalExecutor.h"
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#include <llvm/IR/LegacyPassManager.h>
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#include <llvm/IR/Module.h>
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#include <llvm/MC/TargetRegistry.h>
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#include <llvm/Target/TargetMachine.h>
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#include <clang/Interpreter/Interpreter.h>
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#include <string>
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namespace lld {
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namespace wasm {
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bool link(llvm::ArrayRef<const char *> args, llvm::raw_ostream &stdoutOS,
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llvm::raw_ostream &stderrOS, bool exitEarly, bool disableOutput);
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} // namespace wasm
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} // namespace lld
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#include <dlfcn.h>
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namespace clang {
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WasmIncrementalExecutor::WasmIncrementalExecutor(
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llvm::orc::ThreadSafeContext &TSC)
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: IncrementalExecutor(TSC) {}
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llvm::Error WasmIncrementalExecutor::addModule(PartialTranslationUnit &PTU) {
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std::string ErrorString;
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const llvm::Target *Target = llvm::TargetRegistry::lookupTarget(
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PTU.TheModule->getTargetTriple(), ErrorString);
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if (!Target) {
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return llvm::make_error<llvm::StringError>("Failed to create Wasm Target: ",
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llvm::inconvertibleErrorCode());
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}
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llvm::TargetOptions TO = llvm::TargetOptions();
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llvm::TargetMachine *TargetMachine = Target->createTargetMachine(
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PTU.TheModule->getTargetTriple(), "", "", TO, llvm::Reloc::Model::PIC_);
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PTU.TheModule->setDataLayout(TargetMachine->createDataLayout());
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std::string OutputFileName = PTU.TheModule->getName().str() + ".wasm";
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std::error_code Error;
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llvm::raw_fd_ostream OutputFile(llvm::StringRef(OutputFileName), Error);
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llvm::legacy::PassManager PM;
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if (TargetMachine->addPassesToEmitFile(PM, OutputFile, nullptr,
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llvm::CodeGenFileType::ObjectFile)) {
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return llvm::make_error<llvm::StringError>(
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"Wasm backend cannot produce object.", llvm::inconvertibleErrorCode());
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}
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if (!PM.run(*PTU.TheModule)) {
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return llvm::make_error<llvm::StringError>("Failed to emit Wasm object.",
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llvm::inconvertibleErrorCode());
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}
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OutputFile.close();
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std::vector<const char *> LinkerArgs = {"wasm-ld",
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"-pie",
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"--import-memory",
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"--no-entry",
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"--export-all",
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"--experimental-pic",
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"--no-export-dynamic",
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"--stack-first",
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OutputFileName.c_str(),
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"-o",
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OutputFileName.c_str()};
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int Result =
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lld::wasm::link(LinkerArgs, llvm::outs(), llvm::errs(), false, false);
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if (!Result)
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return llvm::make_error<llvm::StringError>(
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"Failed to link incremental module", llvm::inconvertibleErrorCode());
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void *LoadedLibModule =
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dlopen(OutputFileName.c_str(), RTLD_NOW | RTLD_GLOBAL);
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if (LoadedLibModule == nullptr) {
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llvm::errs() << dlerror() << '\n';
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return llvm::make_error<llvm::StringError>(
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"Failed to load incremental module", llvm::inconvertibleErrorCode());
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}
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return llvm::Error::success();
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}
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llvm::Error WasmIncrementalExecutor::removeModule(PartialTranslationUnit &PTU) {
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return llvm::make_error<llvm::StringError>("Not implemented yet",
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llvm::inconvertibleErrorCode());
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}
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llvm::Error WasmIncrementalExecutor::runCtors() const {
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// This seems to be automatically done when using dlopen()
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return llvm::Error::success();
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}
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WasmIncrementalExecutor::~WasmIncrementalExecutor() = default;
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} // namespace clang
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