llvm-project/clang-tools-extra/clangd/QueryDriverDatabase.cpp

266 lines
9.0 KiB
C++

//===--- QueryDriverDatabase.cpp ---------------------------------*- C++-*-===//
//
// 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
//
//===----------------------------------------------------------------------===//
// Some compiler drivers have implicit search mechanism for system headers.
// This compilation database implementation tries to extract that information by
// executing the driver in verbose mode. gcc-compatible drivers print something
// like:
// ....
// ....
// #include <...> search starts here:
// /usr/lib/gcc/x86_64-linux-gnu/7/include
// /usr/local/include
// /usr/lib/gcc/x86_64-linux-gnu/7/include-fixed
// /usr/include/x86_64-linux-gnu
// /usr/include
// End of search list.
// ....
// ....
// This component parses that output and adds each path to command line args
// provided by Base, after prepending them with -isystem. Therefore current
// implementation would not work with a driver that is not gcc-compatible.
//
// First argument of the command line received from underlying compilation
// database is used as compiler driver path. Due to this arbitrary binary
// execution, this mechanism is not used by default and only executes binaries
// in the paths that are explicitly whitelisted by the user.
#include "GlobalCompilationDatabase.h"
#include "Logger.h"
#include "Path.h"
#include "Trace.h"
#include "clang/Driver/Types.h"
#include "clang/Tooling/CompilationDatabase.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/ScopeExit.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/iterator_range.h"
#include "llvm/Support/FileSystem.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/Path.h"
#include "llvm/Support/Program.h"
#include "llvm/Support/Regex.h"
#include "llvm/Support/ScopedPrinter.h"
#include <algorithm>
#include <string>
#include <vector>
namespace clang {
namespace clangd {
namespace {
std::vector<std::string> parseDriverOutput(llvm::StringRef Output) {
std::vector<std::string> SystemIncludes;
constexpr char const *SIS = "#include <...> search starts here:";
constexpr char const *SIE = "End of search list.";
llvm::SmallVector<llvm::StringRef, 8> Lines;
Output.split(Lines, '\n', /*MaxSplit=*/-1, /*KeepEmpty=*/false);
auto StartIt = std::find(Lines.begin(), Lines.end(), SIS);
if (StartIt == Lines.end()) {
elog("System include extraction: start marker not found: {0}", Output);
return {};
}
++StartIt;
const auto EndIt = std::find(StartIt, Lines.end(), SIE);
if (EndIt == Lines.end()) {
elog("System include extraction: end marker missing: {0}", Output);
return {};
}
for (llvm::StringRef Line : llvm::make_range(StartIt, EndIt)) {
SystemIncludes.push_back(Line.str());
vlog("System include extraction: adding {0}", Line);
}
return SystemIncludes;
}
std::vector<std::string> extractSystemIncludes(PathRef Driver,
llvm::StringRef Ext,
llvm::Regex &QueryDriverRegex) {
trace::Span Tracer("Extract system includes");
SPAN_ATTACH(Tracer, "driver", Driver);
SPAN_ATTACH(Tracer, "ext", Ext);
if (!QueryDriverRegex.match(Driver)) {
vlog("System include extraction: not whitelisted driver {0}", Driver);
return {};
}
if (!llvm::sys::fs::exists(Driver)) {
elog("System include extraction: {0} does not exist.", Driver);
return {};
}
if (!llvm::sys::fs::can_execute(Driver)) {
elog("System include extraction: {0} is not executable.", Driver);
return {};
}
llvm::SmallString<128> OutputPath;
auto EC = llvm::sys::fs::createTemporaryFile("system-includes", "clangd",
OutputPath);
if (EC) {
elog("System include extraction: failed to create temporary file with "
"error {0}",
EC.message());
return {};
}
auto CleanUp = llvm::make_scope_exit(
[&OutputPath]() { llvm::sys::fs::remove(OutputPath); });
llvm::Optional<llvm::StringRef> Redirects[] = {
{""}, llvm::StringRef(OutputPath), {""}};
auto Type = driver::types::lookupTypeForExtension(Ext);
if (Type == driver::types::TY_INVALID) {
elog("System include extraction: invalid file type for {0}", Ext);
return {};
}
// Should we also preserve flags like "-sysroot", "-nostdinc" ?
const llvm::StringRef Args[] = {"-E", "-x", driver::types::getTypeName(Type),
"-", "-v"};
int RC =
llvm::sys::ExecuteAndWait(Driver, Args, /*Env=*/llvm::None, Redirects);
if (RC) {
elog("System include extraction: driver execution failed with return code: "
"{0}",
llvm::to_string(RC));
return {};
}
auto BufOrError = llvm::MemoryBuffer::getFile(OutputPath);
if (!BufOrError) {
elog("System include extraction: failed to read {0} with error {1}",
OutputPath, BufOrError.getError().message());
return {};
}
auto Includes = parseDriverOutput(BufOrError->get()->getBuffer());
log("System include extractor: succesfully executed {0}, got includes: "
"\"{1}\"",
Driver, llvm::join(Includes, ", "));
return Includes;
}
tooling::CompileCommand &
addSystemIncludes(tooling::CompileCommand &Cmd,
llvm::ArrayRef<std::string> SystemIncludes) {
for (llvm::StringRef Include : SystemIncludes) {
// FIXME(kadircet): This doesn't work when we have "--driver-mode=cl"
Cmd.CommandLine.push_back("-isystem");
Cmd.CommandLine.push_back(Include.str());
}
return Cmd;
}
/// Converts a glob containing only ** or * into a regex.
std::string convertGlobToRegex(llvm::StringRef Glob) {
std::string RegText;
llvm::raw_string_ostream RegStream(RegText);
RegStream << '^';
for (size_t I = 0, E = Glob.size(); I < E; ++I) {
if (Glob[I] == '*') {
if (I + 1 < E && Glob[I + 1] == '*') {
// Double star, accept any sequence.
RegStream << ".*";
// Also skip the second star.
++I;
} else {
// Single star, accept any sequence without a slash.
RegStream << "[^/]*";
}
} else {
RegStream << llvm::Regex::escape(Glob.substr(I, 1));
}
}
RegStream << '$';
RegStream.flush();
return RegText;
}
/// Converts a glob containing only ** or * into a regex.
llvm::Regex convertGlobsToRegex(llvm::ArrayRef<std::string> Globs) {
assert(!Globs.empty() && "Globs cannot be empty!");
std::vector<std::string> RegTexts;
RegTexts.reserve(Globs.size());
for (llvm::StringRef Glob : Globs)
RegTexts.push_back(convertGlobToRegex(Glob));
llvm::Regex Reg(llvm::join(RegTexts, "|"));
assert(Reg.isValid(RegTexts.front()) &&
"Created an invalid regex from globs");
return Reg;
}
/// Extracts system includes from a trusted driver by parsing the output of
/// include search path and appends them to the commands coming from underlying
/// compilation database.
class QueryDriverDatabase : public GlobalCompilationDatabase {
public:
QueryDriverDatabase(llvm::ArrayRef<std::string> QueryDriverGlobs,
std::unique_ptr<GlobalCompilationDatabase> Base)
: QueryDriverRegex(convertGlobsToRegex(QueryDriverGlobs)),
Base(std::move(Base)) {
assert(this->Base);
BaseChanged =
this->Base->watch([this](const std::vector<std::string> &Changes) {
OnCommandChanged.broadcast(Changes);
});
}
llvm::Optional<tooling::CompileCommand>
getCompileCommand(PathRef File, ProjectInfo *PI = nullptr) const override {
auto Cmd = Base->getCompileCommand(File, PI);
if (!Cmd || Cmd->CommandLine.empty())
return Cmd;
llvm::SmallString<128> Driver(Cmd->CommandLine.front());
llvm::sys::fs::make_absolute(Cmd->Directory, Driver);
llvm::ArrayRef<std::string> SystemIncludes;
{
std::lock_guard<std::mutex> Lock(Mu);
llvm::StringRef Ext = llvm::sys::path::extension(File).trim('.');
auto It = DriverToIncludesCache.try_emplace({Driver, Ext});
if (It.second)
It.first->second = extractSystemIncludes(Driver, Ext, QueryDriverRegex);
SystemIncludes = It.first->second;
}
return addSystemIncludes(*Cmd, SystemIncludes);
}
private:
mutable std::mutex Mu;
// Caches includes extracted from a driver.
mutable llvm::DenseMap<std::pair<StringRef, StringRef>,
std::vector<std::string>>
DriverToIncludesCache;
mutable llvm::Regex QueryDriverRegex;
std::unique_ptr<GlobalCompilationDatabase> Base;
CommandChanged::Subscription BaseChanged;
};
} // namespace
std::unique_ptr<GlobalCompilationDatabase>
getQueryDriverDatabase(llvm::ArrayRef<std::string> QueryDriverGlobs,
std::unique_ptr<GlobalCompilationDatabase> Base) {
assert(Base && "Null base to SystemIncludeExtractor");
if (QueryDriverGlobs.empty())
return Base;
return llvm::make_unique<QueryDriverDatabase>(QueryDriverGlobs,
std::move(Base));
}
} // namespace clangd
} // namespace clang