| //===--- CompileCommands.cpp ----------------------------------------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "CompileCommands.h" |
| #include "Logger.h" |
| #include "clang/Frontend/CompilerInvocation.h" |
| #include "clang/Tooling/ArgumentsAdjusters.h" |
| #include "llvm/Support/FileSystem.h" |
| #include "llvm/Support/FileUtilities.h" |
| #include "llvm/Support/MemoryBuffer.h" |
| #include "llvm/Support/Path.h" |
| #include "llvm/Support/Program.h" |
| |
| namespace clang { |
| namespace clangd { |
| namespace { |
| |
| // Query apple's `xcrun` launcher, which is the source of truth for "how should" |
| // clang be invoked on this system. |
| llvm::Optional<std::string> queryXcrun(llvm::ArrayRef<llvm::StringRef> Argv) { |
| auto Xcrun = llvm::sys::findProgramByName("xcrun"); |
| if (!Xcrun) { |
| log("Couldn't find xcrun. Hopefully you have a non-apple toolchain..."); |
| return llvm::None; |
| } |
| llvm::SmallString<64> OutFile; |
| llvm::sys::fs::createTemporaryFile("clangd-xcrun", "", OutFile); |
| llvm::FileRemover OutRemover(OutFile); |
| llvm::Optional<llvm::StringRef> Redirects[3] = { |
| /*stdin=*/{""}, /*stdout=*/{OutFile}, /*stderr=*/{""}}; |
| vlog("Invoking {0} to find clang installation", *Xcrun); |
| int Ret = llvm::sys::ExecuteAndWait(*Xcrun, Argv, |
| /*Env=*/llvm::None, Redirects, |
| /*SecondsToWait=*/10); |
| if (Ret != 0) { |
| log("xcrun exists but failed with code {0}. " |
| "If you have a non-apple toolchain, this is OK. " |
| "Otherwise, try xcode-select --install.", |
| Ret); |
| return llvm::None; |
| } |
| |
| auto Buf = llvm::MemoryBuffer::getFile(OutFile); |
| if (!Buf) { |
| log("Can't read xcrun output: {0}", Buf.getError().message()); |
| return llvm::None; |
| } |
| StringRef Path = Buf->get()->getBuffer().trim(); |
| if (Path.empty()) { |
| log("xcrun produced no output"); |
| return llvm::None; |
| } |
| return Path.str(); |
| } |
| |
| // Resolve symlinks if possible. |
| std::string resolve(std::string Path) { |
| llvm::SmallString<128> Resolved; |
| if (llvm::sys::fs::real_path(Path, Resolved)) { |
| log("Failed to resolve possible symlink {0}", Path); |
| return Path; |
| } |
| return std::string(Resolved.str()); |
| } |
| |
| // Get a plausible full `clang` path. |
| // This is used in the fallback compile command, or when the CDB returns a |
| // generic driver with no path. |
| std::string detectClangPath() { |
| // The driver and/or cc1 sometimes depend on the binary name to compute |
| // useful things like the standard library location. |
| // We need to emulate what clang on this system is likely to see. |
| // cc1 in particular looks at the "real path" of the running process, and |
| // so if /usr/bin/clang is a symlink, it sees the resolved path. |
| // clangd doesn't have that luxury, so we resolve symlinks ourselves. |
| |
| // On Mac, `which clang` is /usr/bin/clang. It runs `xcrun clang`, which knows |
| // where the real clang is kept. We need to do the same thing, |
| // because cc1 (not the driver!) will find libc++ relative to argv[0]. |
| #ifdef __APPLE__ |
| if (auto MacClang = queryXcrun({"xcrun", "--find", "clang"})) |
| return resolve(std::move(*MacClang)); |
| #endif |
| // On other platforms, just look for compilers on the PATH. |
| for (const char *Name : {"clang", "gcc", "cc"}) |
| if (auto PathCC = llvm::sys::findProgramByName(Name)) |
| return resolve(std::move(*PathCC)); |
| // Fallback: a nonexistent 'clang' binary next to clangd. |
| static int Dummy; |
| std::string ClangdExecutable = |
| llvm::sys::fs::getMainExecutable("clangd", (void *)&Dummy); |
| SmallString<128> ClangPath; |
| ClangPath = llvm::sys::path::parent_path(ClangdExecutable); |
| llvm::sys::path::append(ClangPath, "clang"); |
| return std::string(ClangPath.str()); |
| } |
| |
| // On mac, /usr/bin/clang sets SDKROOT and then invokes the real clang. |
| // The effect of this is to set -isysroot correctly. We do the same. |
| const llvm::Optional<std::string> detectSysroot() { |
| #ifndef __APPLE__ |
| return llvm::None; |
| #endif |
| |
| // SDKROOT overridden in environment, respect it. Driver will set isysroot. |
| if (::getenv("SDKROOT")) |
| return llvm::None; |
| return queryXcrun({"xcrun", "--show-sdk-path"}); |
| return llvm::None; |
| } |
| |
| std::string detectStandardResourceDir() { |
| static int Dummy; // Just an address in this process. |
| return CompilerInvocation::GetResourcesPath("clangd", (void *)&Dummy); |
| } |
| |
| } // namespace |
| |
| CommandMangler CommandMangler::detect() { |
| CommandMangler Result; |
| Result.ClangPath = detectClangPath(); |
| Result.ResourceDir = detectStandardResourceDir(); |
| Result.Sysroot = detectSysroot(); |
| return Result; |
| } |
| |
| CommandMangler CommandMangler::forTests() { |
| return CommandMangler(); |
| } |
| |
| void CommandMangler::adjust(std::vector<std::string> &Cmd) const { |
| // Check whether the flag exists, either as -flag or -flag=* |
| auto Has = [&](llvm::StringRef Flag) { |
| for (llvm::StringRef Arg : Cmd) { |
| if (Arg.consume_front(Flag) && (Arg.empty() || Arg[0] == '=')) |
| return true; |
| } |
| return false; |
| }; |
| |
| // clangd should not write files to disk, including dependency files |
| // requested on the command line. |
| Cmd = tooling::getClangStripDependencyFileAdjuster()(Cmd, ""); |
| // Strip plugin related command line arguments. Clangd does |
| // not support plugins currently. Therefore it breaks if |
| // compiler tries to load plugins. |
| Cmd = tooling::getStripPluginsAdjuster()(Cmd, ""); |
| Cmd = tooling::getClangSyntaxOnlyAdjuster()(Cmd, ""); |
| |
| if (ResourceDir && !Has("-resource-dir")) |
| Cmd.push_back(("-resource-dir=" + *ResourceDir)); |
| |
| // Don't set `-isysroot` if it is already set or if `--sysroot` is set. |
| // `--sysroot` is a superset of the `-isysroot` argument. |
| if (Sysroot && !Has("-isysroot") && !Has("--sysroot")) { |
| Cmd.push_back("-isysroot"); |
| Cmd.push_back(*Sysroot); |
| } |
| |
| // If the driver is a generic name like "g++" with no path, add a clang path. |
| // This makes it easier for us to find the standard libraries on mac. |
| if (ClangPath && llvm::sys::path::is_absolute(*ClangPath) && !Cmd.empty()) { |
| std::string &Driver = Cmd.front(); |
| if (Driver == "clang" || Driver == "clang++" || Driver == "gcc" || |
| Driver == "g++" || Driver == "cc" || Driver == "c++") { |
| llvm::SmallString<128> QualifiedDriver = |
| llvm::sys::path::parent_path(*ClangPath); |
| llvm::sys::path::append(QualifiedDriver, Driver); |
| Driver = std::string(QualifiedDriver.str()); |
| } |
| } |
| } |
| |
| CommandMangler::operator clang::tooling::ArgumentsAdjuster() { |
| return [Mangler{*this}](const std::vector<std::string> &Args, |
| llvm::StringRef File) { |
| auto Result = Args; |
| Mangler.adjust(Result); |
| return Result; |
| }; |
| } |
| |
| } // namespace clangd |
| } // namespace clang |