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
25namespace lld {
26enum Flavor {
27 Invalid,
28 Gnu, // -flavor gnu
29 MinGW, // -flavor gnu MinGW
30 WinLink, // -flavor link
31 Darwin, // -flavor darwin
32 Wasm, // -flavor wasm
33};
34
35using Driver = bool (*)(llvm::ArrayRef<const char *>, llvm::raw_ostream &,
36 llvm::raw_ostream &, bool, bool);
37
38struct DriverDef {
39 Flavor f;
40 Driver d;
41};
42
43struct Result {
44 int retCode;
45 bool canRunAgain;
46};
47
48Result lldMain(llvm::ArrayRef<const char *> args, llvm::raw_ostream &stdoutOS,
49 llvm::raw_ostream &stderrOS, llvm::ArrayRef<DriverDef> drivers);
50
51namespace wasm {
52bool link(llvm::ArrayRef<const char *> args, llvm::raw_ostream &stdoutOS,
53 llvm::raw_ostream &stderrOS, bool exitEarly, bool disableOutput);
54} // namespace wasm
55} // namespace lld
56
57#include <dlfcn.h>
58
59namespace clang {
60
61WasmIncrementalExecutor::WasmIncrementalExecutor(
62 llvm::orc::ThreadSafeContext &TSC)
63 : IncrementalExecutor(TSC) {}
64
65llvm::Error WasmIncrementalExecutor::addModule(PartialTranslationUnit &PTU) {
66 std::string ErrorString;
67
68 const llvm::Target *Target = llvm::TargetRegistry::lookupTarget(
69 TheTriple: PTU.TheModule->getTargetTriple(), Error&: ErrorString);
70 if (!Target) {
71 return llvm::make_error<llvm::StringError>(Args: "Failed to create Wasm Target: ",
72 Args: llvm::inconvertibleErrorCode());
73 }
74
75 llvm::TargetOptions TO = llvm::TargetOptions();
76 llvm::TargetMachine *TargetMachine = Target->createTargetMachine(
77 TT: PTU.TheModule->getTargetTriple(), CPU: "", Features: "", Options: TO, RM: llvm::Reloc::Model::PIC_);
78 PTU.TheModule->setDataLayout(TargetMachine->createDataLayout());
79 std::string ObjectFileName = PTU.TheModule->getName().str() + ".o";
80 std::string BinaryFileName = PTU.TheModule->getName().str() + ".wasm";
81
82 std::error_code Error;
83 llvm::raw_fd_ostream ObjectFileOutput(llvm::StringRef(ObjectFileName), Error);
84
85 llvm::legacy::PassManager PM;
86 if (TargetMachine->addPassesToEmitFile(PM, ObjectFileOutput, nullptr,
87 llvm::CodeGenFileType::ObjectFile)) {
88 return llvm::make_error<llvm::StringError>(
89 Args: "Wasm backend cannot produce object.", Args: llvm::inconvertibleErrorCode());
90 }
91
92 if (!PM.run(M&: *PTU.TheModule)) {
93
94 return llvm::make_error<llvm::StringError>(Args: "Failed to emit Wasm object.",
95 Args: llvm::inconvertibleErrorCode());
96 }
97
98 ObjectFileOutput.close();
99
100 std::vector<const char *> LinkerArgs = {"wasm-ld",
101 "-shared",
102 "--import-memory",
103 "--experimental-pic",
104 "--stack-first",
105 "--allow-undefined",
106 ObjectFileName.c_str(),
107 "-o",
108 BinaryFileName.c_str()};
109
110 const lld::DriverDef WasmDriver = {.f: lld::Flavor::Wasm, .d: &lld::wasm::link};
111 std::vector<lld::DriverDef> WasmDriverArgs;
112 WasmDriverArgs.push_back(x: WasmDriver);
113 lld::Result Result =
114 lld::lldMain(args: LinkerArgs, stdoutOS&: llvm::outs(), stderrOS&: llvm::errs(), drivers: WasmDriverArgs);
115
116 if (Result.retCode)
117 return llvm::make_error<llvm::StringError>(
118 Args: "Failed to link incremental module", Args: llvm::inconvertibleErrorCode());
119
120 void *LoadedLibModule =
121 dlopen(file: BinaryFileName.c_str(), RTLD_NOW | RTLD_GLOBAL);
122 if (LoadedLibModule == nullptr) {
123 llvm::errs() << dlerror() << '\n';
124 return llvm::make_error<llvm::StringError>(
125 Args: "Failed to load incremental module", Args: llvm::inconvertibleErrorCode());
126 }
127
128 return llvm::Error::success();
129}
130
131llvm::Error WasmIncrementalExecutor::removeModule(PartialTranslationUnit &PTU) {
132 return llvm::make_error<llvm::StringError>(Args: "Not implemented yet",
133 Args: llvm::inconvertibleErrorCode());
134}
135
136llvm::Error WasmIncrementalExecutor::runCtors() const {
137 // This seems to be automatically done when using dlopen()
138 return llvm::Error::success();
139}
140
141llvm::Error WasmIncrementalExecutor::cleanUp() {
142 // Can't call cleanUp through IncrementalExecutor as it
143 // tries to deinitialize JIT which hasn't been initialized
144 return llvm::Error::success();
145}
146
147llvm::Expected<llvm::orc::ExecutorAddr>
148WasmIncrementalExecutor::getSymbolAddress(llvm::StringRef Name,
149 SymbolNameKind NameKind) const {
150 void *Sym = dlsym(RTLD_DEFAULT, name: Name.str().c_str());
151 if (!Sym) {
152 return llvm::make_error<llvm::StringError>(Args: "dlsym failed for symbol: " +
153 Name.str(),
154 Args: llvm::inconvertibleErrorCode());
155 }
156
157 return llvm::orc::ExecutorAddr::fromPtr(Ptr: Sym);
158}
159
160WasmIncrementalExecutor::~WasmIncrementalExecutor() = default;
161
162} // namespace clang
163

source code of clang/lib/Interpreter/Wasm.cpp