clang  10.0.0git
WebAssembly.cpp
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1 //===--- WebAssembly.cpp - WebAssembly ToolChain Implementation -*- 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 #include "WebAssembly.h"
10 #include "CommonArgs.h"
11 #include "clang/Basic/Version.h"
12 #include "clang/Config/config.h"
14 #include "clang/Driver/Driver.h"
16 #include "clang/Driver/Options.h"
17 #include "llvm/Support/FileSystem.h"
18 #include "llvm/Support/Path.h"
19 #include "llvm/Option/ArgList.h"
20 
21 using namespace clang::driver;
22 using namespace clang::driver::tools;
23 using namespace clang::driver::toolchains;
24 using namespace clang;
25 using namespace llvm::opt;
26 
27 /// Following the conventions in https://wiki.debian.org/Multiarch/Tuples,
28 /// we remove the vendor field to form the multiarch triple.
29 static std::string getMultiarchTriple(const Driver &D,
30  const llvm::Triple &TargetTriple,
31  StringRef SysRoot) {
32  return (TargetTriple.getArchName() + "-" +
33  TargetTriple.getOSAndEnvironmentName()).str();
34 }
35 
36 std::string wasm::Linker::getLinkerPath(const ArgList &Args) const {
37  const ToolChain &ToolChain = getToolChain();
38  if (const Arg* A = Args.getLastArg(options::OPT_fuse_ld_EQ)) {
39  StringRef UseLinker = A->getValue();
40  if (!UseLinker.empty()) {
41  if (llvm::sys::path::is_absolute(UseLinker) &&
42  llvm::sys::fs::can_execute(UseLinker))
43  return UseLinker;
44 
45  // Accept 'lld', and 'ld' as aliases for the default linker
46  if (UseLinker != "lld" && UseLinker != "ld")
47  ToolChain.getDriver().Diag(diag::err_drv_invalid_linker_name)
48  << A->getAsString(Args);
49  }
50  }
51 
52  return ToolChain.GetProgramPath(ToolChain.getDefaultLinker());
53 }
54 
56  const InputInfo &Output,
57  const InputInfoList &Inputs,
58  const ArgList &Args,
59  const char *LinkingOutput) const {
60 
61  const ToolChain &ToolChain = getToolChain();
62  const char *Linker = Args.MakeArgString(getLinkerPath(Args));
63  ArgStringList CmdArgs;
64 
65  if (Args.hasArg(options::OPT_s))
66  CmdArgs.push_back("--strip-all");
67 
68  Args.AddAllArgs(CmdArgs, options::OPT_L);
69  Args.AddAllArgs(CmdArgs, options::OPT_u);
70  ToolChain.AddFilePathLibArgs(Args, CmdArgs);
71 
72  if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nostartfiles))
73  CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath("crt1.o")));
74 
75  AddLinkerInputs(ToolChain, Inputs, Args, CmdArgs, JA);
76 
77  if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nodefaultlibs)) {
78  if (ToolChain.ShouldLinkCXXStdlib(Args))
79  ToolChain.AddCXXStdlibLibArgs(Args, CmdArgs);
80 
81  if (Args.hasArg(options::OPT_pthread)) {
82  CmdArgs.push_back("-lpthread");
83  CmdArgs.push_back("--shared-memory");
84  }
85 
86  CmdArgs.push_back("-lc");
87  AddRunTimeLibs(ToolChain, ToolChain.getDriver(), CmdArgs, Args);
88  }
89 
90  CmdArgs.push_back("-o");
91  CmdArgs.push_back(Output.getFilename());
92 
93  C.addCommand(std::make_unique<Command>(JA, *this, Linker, CmdArgs, Inputs));
94 
95  // When optimizing, if wasm-opt is available, run it.
96  if (Arg *A = Args.getLastArg(options::OPT_O_Group)) {
97  auto WasmOptPath = getToolChain().GetProgramPath("wasm-opt");
98  if (WasmOptPath != "wasm-opt") {
99  StringRef OOpt = "s";
100  if (A->getOption().matches(options::OPT_O4) ||
101  A->getOption().matches(options::OPT_Ofast))
102  OOpt = "4";
103  else if (A->getOption().matches(options::OPT_O0))
104  OOpt = "0";
105  else if (A->getOption().matches(options::OPT_O))
106  OOpt = A->getValue();
107 
108  if (OOpt != "0") {
109  const char *WasmOpt = Args.MakeArgString(WasmOptPath);
110  ArgStringList CmdArgs;
111  CmdArgs.push_back(Output.getFilename());
112  CmdArgs.push_back(Args.MakeArgString(llvm::Twine("-O") + OOpt));
113  CmdArgs.push_back("-o");
114  CmdArgs.push_back(Output.getFilename());
115  C.addCommand(std::make_unique<Command>(JA, *this, WasmOpt, CmdArgs, Inputs));
116  }
117  }
118  }
119 }
120 
121 /// Given a base library directory, append path components to form the
122 /// LTO directory.
123 static std::string AppendLTOLibDir(const std::string &Dir) {
124  // The version allows the path to be keyed to the specific version of
125  // LLVM in used, as the bitcode format is not stable.
126  return Dir + "/llvm-lto/" LLVM_VERSION_STRING;
127 }
128 
129 WebAssembly::WebAssembly(const Driver &D, const llvm::Triple &Triple,
130  const llvm::opt::ArgList &Args)
131  : ToolChain(D, Triple, Args) {
132 
133  assert(Triple.isArch32Bit() != Triple.isArch64Bit());
134 
135  getProgramPaths().push_back(getDriver().getInstalledDir());
136 
137  auto SysRoot = getDriver().SysRoot;
138  if (getTriple().getOS() == llvm::Triple::UnknownOS) {
139  // Theoretically an "unknown" OS should mean no standard libraries, however
140  // it could also mean that a custom set of libraries is in use, so just add
141  // /lib to the search path. Disable multiarch in this case, to discourage
142  // paths containing "unknown" from acquiring meanings.
143  getFilePaths().push_back(SysRoot + "/lib");
144  } else {
145  const std::string MultiarchTriple =
146  getMultiarchTriple(getDriver(), Triple, SysRoot);
147  if (D.isUsingLTO()) {
148  // For LTO, enable use of lto-enabled sysroot libraries too, if available.
149  // Note that the directory is keyed to the LLVM revision, as LLVM's
150  // bitcode format is not stable.
151  auto Dir = AppendLTOLibDir(SysRoot + "/lib/" + MultiarchTriple);
152  getFilePaths().push_back(Dir);
153  }
154  getFilePaths().push_back(SysRoot + "/lib/" + MultiarchTriple);
155  }
156 }
157 
158 bool WebAssembly::IsMathErrnoDefault() const { return false; }
159 
160 bool WebAssembly::IsObjCNonFragileABIDefault() const { return true; }
161 
162 bool WebAssembly::UseObjCMixedDispatch() const { return true; }
163 
164 bool WebAssembly::isPICDefault() const { return false; }
165 
166 bool WebAssembly::isPIEDefault() const { return false; }
167 
168 bool WebAssembly::isPICDefaultForced() const { return false; }
169 
170 bool WebAssembly::IsIntegratedAssemblerDefault() const { return true; }
171 
172 bool WebAssembly::hasBlocksRuntime() const { return false; }
173 
174 // TODO: Support profiling.
175 bool WebAssembly::SupportsProfiling() const { return false; }
176 
177 bool WebAssembly::HasNativeLLVMSupport() const { return true; }
178 
179 void WebAssembly::addClangTargetOptions(const ArgList &DriverArgs,
180  ArgStringList &CC1Args,
181  Action::OffloadKind) const {
182  if (!DriverArgs.hasFlag(clang::driver::options::OPT_fuse_init_array,
183  options::OPT_fno_use_init_array, true))
184  CC1Args.push_back("-fno-use-init-array");
185 
186  // '-pthread' implies atomics, bulk-memory, mutable-globals, and sign-ext
187  if (DriverArgs.hasFlag(options::OPT_pthread, options::OPT_no_pthread,
188  false)) {
189  if (DriverArgs.hasFlag(options::OPT_mno_atomics, options::OPT_matomics,
190  false))
191  getDriver().Diag(diag::err_drv_argument_not_allowed_with)
192  << "-pthread"
193  << "-mno-atomics";
194  if (DriverArgs.hasFlag(options::OPT_mno_bulk_memory,
195  options::OPT_mbulk_memory, false))
196  getDriver().Diag(diag::err_drv_argument_not_allowed_with)
197  << "-pthread"
198  << "-mno-bulk-memory";
199  if (DriverArgs.hasFlag(options::OPT_mno_mutable_globals,
200  options::OPT_mmutable_globals, false))
201  getDriver().Diag(diag::err_drv_argument_not_allowed_with)
202  << "-pthread"
203  << "-mno-mutable-globals";
204  if (DriverArgs.hasFlag(options::OPT_mno_sign_ext, options::OPT_msign_ext,
205  false))
206  getDriver().Diag(diag::err_drv_argument_not_allowed_with)
207  << "-pthread"
208  << "-mno-sign-ext";
209  CC1Args.push_back("-target-feature");
210  CC1Args.push_back("+atomics");
211  CC1Args.push_back("-target-feature");
212  CC1Args.push_back("+bulk-memory");
213  CC1Args.push_back("-target-feature");
214  CC1Args.push_back("+mutable-globals");
215  CC1Args.push_back("-target-feature");
216  CC1Args.push_back("+sign-ext");
217  }
218 
219  if (DriverArgs.getLastArg(options::OPT_fwasm_exceptions)) {
220  // '-fwasm-exceptions' is not compatible with '-mno-exception-handling'
221  if (DriverArgs.hasFlag(options::OPT_mno_exception_handing,
222  options::OPT_mexception_handing, false))
223  getDriver().Diag(diag::err_drv_argument_not_allowed_with)
224  << "-fwasm-exceptions"
225  << "-mno-exception-handling";
226  // '-fwasm-exceptions' is not compatible with '-mno-reference-types'
227  if (DriverArgs.hasFlag(options::OPT_mno_reference_types,
228  options::OPT_mexception_handing, false))
229  getDriver().Diag(diag::err_drv_argument_not_allowed_with)
230  << "-fwasm-exceptions"
231  << "-mno-reference-types";
232  // '-fwasm-exceptions' is not compatible with
233  // '-mllvm -enable-emscripten-cxx-exceptions'
234  for (const Arg *A : DriverArgs.filtered(options::OPT_mllvm)) {
235  if (StringRef(A->getValue(0)) == "-enable-emscripten-cxx-exceptions")
236  getDriver().Diag(diag::err_drv_argument_not_allowed_with)
237  << "-fwasm-exceptions"
238  << "-mllvm -enable-emscripten-cxx-exceptions";
239  }
240  // '-fwasm-exceptions' implies exception-handling and reference-types
241  CC1Args.push_back("-target-feature");
242  CC1Args.push_back("+exception-handling");
243  CC1Args.push_back("-target-feature");
244  CC1Args.push_back("+reference-types");
245  }
246 }
247 
248 ToolChain::RuntimeLibType WebAssembly::GetDefaultRuntimeLibType() const {
250 }
251 
253 WebAssembly::GetCXXStdlibType(const ArgList &Args) const {
254  if (Arg *A = Args.getLastArg(options::OPT_stdlib_EQ)) {
255  StringRef Value = A->getValue();
256  if (Value != "libc++")
257  getDriver().Diag(diag::err_drv_invalid_stdlib_name)
258  << A->getAsString(Args);
259  }
260  return ToolChain::CST_Libcxx;
261 }
262 
263 void WebAssembly::AddClangSystemIncludeArgs(const ArgList &DriverArgs,
264  ArgStringList &CC1Args) const {
265  if (DriverArgs.hasArg(clang::driver::options::OPT_nostdinc))
266  return;
267 
268  const Driver &D = getDriver();
269 
270  if (!DriverArgs.hasArg(options::OPT_nobuiltininc)) {
272  llvm::sys::path::append(P, "include");
273  addSystemInclude(DriverArgs, CC1Args, P);
274  }
275 
276  if (DriverArgs.hasArg(options::OPT_nostdlibinc))
277  return;
278 
279  // Check for configure-time C include directories.
280  StringRef CIncludeDirs(C_INCLUDE_DIRS);
281  if (CIncludeDirs != "") {
283  CIncludeDirs.split(dirs, ":");
284  for (StringRef dir : dirs) {
285  StringRef Prefix =
286  llvm::sys::path::is_absolute(dir) ? StringRef(D.SysRoot) : "";
287  addExternCSystemInclude(DriverArgs, CC1Args, Prefix + dir);
288  }
289  return;
290  }
291 
292  if (getTriple().getOS() != llvm::Triple::UnknownOS) {
293  const std::string MultiarchTriple =
294  getMultiarchTriple(D, getTriple(), D.SysRoot);
295  addSystemInclude(DriverArgs, CC1Args, D.SysRoot + "/include/" + MultiarchTriple);
296  }
297  addSystemInclude(DriverArgs, CC1Args, D.SysRoot + "/include");
298 }
299 
300 void WebAssembly::AddClangCXXStdlibIncludeArgs(const ArgList &DriverArgs,
301  ArgStringList &CC1Args) const {
302  if (!DriverArgs.hasArg(options::OPT_nostdlibinc) &&
303  !DriverArgs.hasArg(options::OPT_nostdincxx)) {
304  if (getTriple().getOS() != llvm::Triple::UnknownOS) {
305  const std::string MultiarchTriple =
306  getMultiarchTriple(getDriver(), getTriple(), getDriver().SysRoot);
307  addSystemInclude(DriverArgs, CC1Args,
308  getDriver().SysRoot + "/include/" + MultiarchTriple +
309  "/c++/v1");
310  }
311  addSystemInclude(DriverArgs, CC1Args,
312  getDriver().SysRoot + "/include/c++/v1");
313  }
314 }
315 
316 void WebAssembly::AddCXXStdlibLibArgs(const llvm::opt::ArgList &Args,
317  llvm::opt::ArgStringList &CmdArgs) const {
318 
319  switch (GetCXXStdlibType(Args)) {
321  CmdArgs.push_back("-lc++");
322  CmdArgs.push_back("-lc++abi");
323  break;
325  llvm_unreachable("invalid stdlib name");
326  }
327 }
328 
329 SanitizerMask WebAssembly::getSupportedSanitizers() const {
331  if (getTriple().isOSEmscripten()) {
332  Res |= SanitizerKind::Vptr | SanitizerKind::Leak | SanitizerKind::Address;
333  }
334  return Res;
335 }
336 
337 Tool *WebAssembly::buildLinker() const {
338  return new tools::wasm::Linker(*this);
339 }
virtual const char * getDefaultLinker() const
GetDefaultLinker - Get the default linker to use.
Definition: ToolChain.h:373
std::string getLinkerPath(const llvm::opt::ArgList &Args) const
Definition: WebAssembly.cpp:36
StringRef P
bool isUsingLTO() const
Returns true if we are performing any kind of LTO.
Definition: Driver.h:554
void AddRunTimeLibs(const ToolChain &TC, const Driver &D, llvm::opt::ArgStringList &CmdArgs, const llvm::opt::ArgList &Args)
DiagnosticBuilder Diag(unsigned DiagID) const
Definition: Driver.h:109
const char * getFilename() const
Definition: InputInfo.h:83
InputInfo - Wrapper for information about an input source.
Definition: InputInfo.h:22
std::string GetFilePath(const char *Name) const
Definition: ToolChain.cpp:512
Driver - Encapsulate logic for constructing compilation processes from a set of gcc-driver-like comma...
Definition: Driver.h:59
Defines version macros and version-related utility functions for Clang.
void addCommand(std::unique_ptr< Command > C)
Definition: Compilation.h:205
void AddFilePathLibArgs(const llvm::opt::ArgList &Args, llvm::opt::ArgStringList &CmdArgs) const
AddFilePathLibArgs - Add each thing in getFilePaths() as a "-L" option.
Definition: ToolChain.cpp:906
const Driver & getDriver() const
Definition: ToolChain.h:199
static std::string getMultiarchTriple(const Driver &D, const llvm::Triple &TargetTriple, StringRef SysRoot)
Following the conventions in https://wiki.debian.org/Multiarch/Tuples, we remove the vendor field to ...
Definition: WebAssembly.cpp:29
bool ShouldLinkCXXStdlib(const llvm::opt::ArgList &Args) const
Returns if the C++ standard library should be linked in.
Definition: ToolChain.cpp:883
Dataflow Directional Tag Classes.
void AddLinkerInputs(const ToolChain &TC, const InputInfoList &Inputs, const llvm::opt::ArgList &Args, llvm::opt::ArgStringList &CmdArgs, const JobAction &JA)
void ConstructJob(Compilation &C, const JobAction &JA, const InputInfo &Output, const InputInfoList &Inputs, const llvm::opt::ArgList &TCArgs, const char *LinkingOutput) const override
ConstructJob - Construct jobs to perform the action JA, writing to Output and with Inputs...
Definition: WebAssembly.cpp:55
std::string SysRoot
sysroot, if present
Definition: Driver.h:148
Tool - Information on a specific compilation tool.
Definition: Tool.h:33
Compilation - A set of tasks to perform for a single driver invocation.
Definition: Compilation.h:45
virtual SanitizerMask getSupportedSanitizers() const
Return sanitizers which are available in this toolchain.
Definition: ToolChain.cpp:942
std::string GetProgramPath(const char *Name) const
Definition: ToolChain.cpp:516
static std::string AppendLTOLibDir(const std::string &Dir)
Given a base library directory, append path components to form the LTO directory. ...
virtual void AddCXXStdlibLibArgs(const llvm::opt::ArgList &Args, llvm::opt::ArgStringList &CmdArgs) const
AddCXXStdlibLibArgs - Add the system specific linker arguments to use for the given C++ standard libr...
Definition: ToolChain.cpp:889
ToolChain - Access to tools for a single platform.
Definition: ToolChain.h:88
std::string ResourceDir
The path to the compiler resource directory.
Definition: Driver.h:132