clang/lib/Interpreter/Wasm.cpp

   1 //===----------------- Wasm.cpp - Wasm Interpreter --------------*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This file implements interpreter support for code execution in WebAssembly.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "Wasm.h"
  14 #include "IncrementalExecutor.h"
  15
  16 #include <llvm/IR/LegacyPassManager.h>
  17 #include <llvm/IR/Module.h>
  18 #include <llvm/MC/TargetRegistry.h>
  19 #include <llvm/Target/TargetMachine.h>
  20
  21 #include <clang/Interpreter/Interpreter.h>
  22
  23 #include <string>
  24
  25 namespace lld {
  26 namespace wasm {
  27 bool link(llvm::ArrayRef<const char *> args, llvm::raw_ostream &stdoutOS,
  28           llvm::raw_ostream &stderrOS, bool exitEarly, bool disableOutput);
  29 } // namespace wasm
  30 } // namespace lld
  31
  32 #include <dlfcn.h>
  33
  34 namespace clang {
  35
  36 WasmIncrementalExecutor::WasmIncrementalExecutor(
  37     llvm::orc::ThreadSafeContext &TSC)
  38     : IncrementalExecutor(TSC) {}
  39
  40 llvm::Error WasmIncrementalExecutor::addModule(PartialTranslationUnit &PTU) {
  41   std::string ErrorString;
  42
  43   const llvm::Target *Target = llvm::TargetRegistry::lookupTarget(
  44       PTU.TheModule->getTargetTriple(), ErrorString);
  45   if (!Target) {
  46     return llvm::make_error<llvm::StringError>("Failed to create Wasm Target: ",
  47                                                llvm::inconvertibleErrorCode());
  48   }
  49
  50   llvm::TargetOptions TO = llvm::TargetOptions();
  51   llvm::TargetMachine *TargetMachine = Target->createTargetMachine(
  52       PTU.TheModule->getTargetTriple(), "", "", TO, llvm::Reloc::Model::PIC_);
  53   PTU.TheModule->setDataLayout(TargetMachine->createDataLayout());
  54   std::string OutputFileName = PTU.TheModule->getName().str() + ".wasm";
  55
  56   std::error_code Error;
  57   llvm::raw_fd_ostream OutputFile(llvm::StringRef(OutputFileName), Error);
  58
  59   llvm::legacy::PassManager PM;
  60   if (TargetMachine->addPassesToEmitFile(PM, OutputFile, nullptr,
  61                                          llvm::CodeGenFileType::ObjectFile)) {
  62     return llvm::make_error<llvm::StringError>(
  63         "Wasm backend cannot produce object.", llvm::inconvertibleErrorCode());
  64   }
  65
  66   if (!PM.run(*PTU.TheModule)) {
  67
  68     return llvm::make_error<llvm::StringError>("Failed to emit Wasm object.",
  69                                                llvm::inconvertibleErrorCode());
  70   }
  71
  72   OutputFile.close();
  73
  74   std::vector<const char *> LinkerArgs = {"wasm-ld",
  75                                           "-shared",
  76                                           "--import-memory",
  77                                           "--no-entry",
  78                                           "--export-all",
  79                                           "--experimental-pic",
  80                                           "--stack-first",
  81                                           "--allow-undefined",
  82                                           OutputFileName.c_str(),
  83                                           "-o",
  84                                           OutputFileName.c_str()};
  85   int Result =
  86       lld::wasm::link(LinkerArgs, llvm::outs(), llvm::errs(), false, false);
  87   if (!Result)
  88     return llvm::make_error<llvm::StringError>(
  89         "Failed to link incremental module", llvm::inconvertibleErrorCode());
  90
  91   void *LoadedLibModule =
  92       dlopen(OutputFileName.c_str(), RTLD_NOW | RTLD_GLOBAL);
  93   if (LoadedLibModule == nullptr) {
  94     llvm::errs() << dlerror() << '\n';
  95     return llvm::make_error<llvm::StringError>(
  96         "Failed to load incremental module", llvm::inconvertibleErrorCode());
  97   }
  98
  99   return llvm::Error::success();
 100 }
 101
 102 llvm::Error WasmIncrementalExecutor::removeModule(PartialTranslationUnit &PTU) {
 103   return llvm::make_error<llvm::StringError>("Not implemented yet",
 104                                              llvm::inconvertibleErrorCode());
 105 }
 106
 107 llvm::Error WasmIncrementalExecutor::runCtors() const {
 108   // This seems to be automatically done when using dlopen()
 109   return llvm::Error::success();
 110 }
 111
 112 llvm::Error WasmIncrementalExecutor::cleanUp() const {
 113   // Can't call cleanUp through IncrementalExecutor as it
 114   // tries to deinitialize JIT which hasn't been initialized
 115   return llvm::Error::success();
 116 }
 117
 118 WasmIncrementalExecutor::~WasmIncrementalExecutor() = default;
 119
 120 } // namespace clang