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

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//===--- 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 included by the user.
#include "GlobalCompilationDatabase.h"
#include "support/Logger.h"
#include "support/Path.h"
#include "support/Trace.h"
#include "clang/Basic/Diagnostic.h"
#include "clang/Basic/TargetInfo.h"
#include "clang/Basic/TargetOptions.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 <map>
#include <string>
#include <vector>
namespace clang {
namespace clangd {
namespace {
struct DriverInfo {
std::vector<std::string> SystemIncludes;
std::string Target;
};
bool isValidTarget(llvm::StringRef Triple) {
std::shared_ptr<TargetOptions> TargetOpts(new TargetOptions);
TargetOpts->Triple = Triple.str();
DiagnosticsEngine Diags(new DiagnosticIDs, new DiagnosticOptions,
new IgnoringDiagConsumer);
IntrusiveRefCntPtr<TargetInfo> Target =
TargetInfo::CreateTargetInfo(Diags, TargetOpts);
return bool(Target);
}
llvm::Optional<DriverInfo> parseDriverOutput(llvm::StringRef Output) {
DriverInfo Info;
const char SIS[] = "#include <...> search starts here:";
const char SIE[] = "End of search list.";
const char TS[] = "Target: ";
llvm::SmallVector<llvm::StringRef> Lines;
Output.split(Lines, '\n', /*MaxSplit=*/-1, /*KeepEmpty=*/false);
enum {
Initial, // Initial state: searching for target or includes list.
IncludesExtracting, // Includes extracting.
Done // Includes and target extraction done.
} State = Initial;
bool SeenIncludes = false;
bool SeenTarget = false;
for (auto *It = Lines.begin(); State != Done && It != Lines.end(); ++It) {
auto Line = *It;
switch (State) {
case Initial:
if (!SeenIncludes && Line.trim() == SIS) {
SeenIncludes = true;
State = IncludesExtracting;
} else if (!SeenTarget && Line.trim().startswith(TS)) {
SeenTarget = true;
llvm::StringRef TargetLine = Line.trim();
TargetLine.consume_front(TS);
// Only detect targets that clang understands
if (!isValidTarget(TargetLine)) {
elog("System include extraction: invalid target \"{0}\", ignoring",
TargetLine);
} else {
Info.Target = TargetLine.str();
vlog("System include extraction: target extracted: \"{0}\"",
TargetLine);
}
}
break;
case IncludesExtracting:
if (Line.trim() == SIE) {
State = SeenTarget ? Done : Initial;
} else {
Info.SystemIncludes.push_back(Line.trim().str());
vlog("System include extraction: adding {0}", Line);
}
break;
default:
llvm_unreachable("Impossible state of the driver output parser");
break;
}
}
if (!SeenIncludes) {
elog("System include extraction: start marker not found: {0}", Output);
return llvm::None;
}
if (State == IncludesExtracting) {
elog("System include extraction: end marker missing: {0}", Output);
return llvm::None;
}
return std::move(Info);
}
llvm::Optional<DriverInfo>
extractSystemIncludesAndTarget(llvm::SmallString<128> Driver,
llvm::StringRef Lang,
llvm::ArrayRef<std::string> CommandLine,
const llvm::Regex &QueryDriverRegex) {
trace::Span Tracer("Extract system includes and target");
if (!llvm::sys::path::is_absolute(Driver)) {
assert(llvm::none_of(
Driver, [](char C) { return llvm::sys::path::is_separator(C); }));
auto DriverProgram = llvm::sys::findProgramByName(Driver);
if (DriverProgram) {
vlog("System include extraction: driver {0} expanded to {1}", Driver,
*DriverProgram);
Driver = *DriverProgram;
} else {
elog("System include extraction: driver {0} not found in PATH", Driver);
return llvm::None;
}
}
SPAN_ATTACH(Tracer, "driver", Driver);
SPAN_ATTACH(Tracer, "lang", Lang);
if (!QueryDriverRegex.match(Driver)) {
vlog("System include extraction: not allowed driver {0}", Driver);
return llvm::None;
}
if (!llvm::sys::fs::exists(Driver)) {
elog("System include extraction: {0} does not exist.", Driver);
return llvm::None;
}
if (!llvm::sys::fs::can_execute(Driver)) {
elog("System include extraction: {0} is not executable.", Driver);
return llvm::None;
}
llvm::SmallString<128> StdErrPath;
if (auto EC = llvm::sys::fs::createTemporaryFile("system-includes", "clangd",
StdErrPath)) {
elog("System include extraction: failed to create temporary file with "
"error {0}",
EC.message());
return llvm::None;
}
auto CleanUp = llvm::make_scope_exit(
[&StdErrPath]() { llvm::sys::fs::remove(StdErrPath); });
llvm::Optional<llvm::StringRef> Redirects[] = {
{""}, {""}, llvm::StringRef(StdErrPath)};
llvm::SmallVector<llvm::StringRef> Args = {Driver, "-E", "-x",
Lang, "-", "-v"};
// These flags will be preserved
const llvm::StringRef FlagsToPreserve[] = {
"-nostdinc", "--no-standard-includes", "-nostdinc++", "-nobuiltininc"};
// Preserves these flags and their values, either as separate args or with an
// equalsbetween them
const llvm::StringRef ArgsToPreserve[] = {"--sysroot", "-isysroot"};
for (size_t I = 0, E = CommandLine.size(); I < E; ++I) {
llvm::StringRef Arg = CommandLine[I];
if (llvm::any_of(FlagsToPreserve,
[&Arg](llvm::StringRef S) { return S == Arg; })) {
Args.push_back(Arg);
} else {
const auto *Found =
llvm::find_if(ArgsToPreserve, [&Arg](llvm::StringRef S) {
return Arg.startswith(S);
});
if (Found == std::end(ArgsToPreserve))
continue;
Arg = Arg.drop_front(Found->size());
if (Arg.empty() && I + 1 < E) {
Args.push_back(CommandLine[I]);
Args.push_back(CommandLine[++I]);
} else if (Arg.startswith("=")) {
Args.push_back(CommandLine[I]);
}
}
}
if (int RC = llvm::sys::ExecuteAndWait(Driver, Args, /*Env=*/llvm::None,
Redirects)) {
elog("System include extraction: driver execution failed with return code: "
"{0}. Args: [{1}]",
llvm::to_string(RC), printArgv(Args));
return llvm::None;
}
auto BufOrError = llvm::MemoryBuffer::getFile(StdErrPath);
if (!BufOrError) {
elog("System include extraction: failed to read {0} with error {1}",
StdErrPath, BufOrError.getError().message());
return llvm::None;
}
llvm::Optional<DriverInfo> Info =
parseDriverOutput(BufOrError->get()->getBuffer());
if (!Info)
return llvm::None;
log("System includes extractor: successfully executed {0}\n\tgot includes: "
"\"{1}\"\n\tgot target: \"{2}\"",
Driver, llvm::join(Info->SystemIncludes, ", "), Info->Target);
return Info;
}
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;
}
tooling::CompileCommand &setTarget(tooling::CompileCommand &Cmd,
const std::string &Target) {
if (!Target.empty()) {
// We do not want to override existing target with extracted one.
for (llvm::StringRef Arg : Cmd.CommandLine) {
if (Arg == "-target" || Arg.startswith("--target="))
return Cmd;
}
Cmd.CommandLine.push_back("--target=" + Target);
}
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 DelegatingCDB {
public:
QueryDriverDatabase(llvm::ArrayRef<std::string> QueryDriverGlobs,
std::unique_ptr<GlobalCompilationDatabase> Base)
: DelegatingCDB(std::move(Base)),
QueryDriverRegex(convertGlobsToRegex(QueryDriverGlobs)) {}
llvm::Optional<tooling::CompileCommand>
getCompileCommand(PathRef File) const override {
auto Cmd = DelegatingCDB::getCompileCommand(File);
if (!Cmd || Cmd->CommandLine.empty())
return Cmd;
llvm::StringRef Lang;
for (size_t I = 0, E = Cmd->CommandLine.size(); I < E; ++I) {
llvm::StringRef Arg = Cmd->CommandLine[I];
if (Arg == "-x" && I + 1 < E)
Lang = Cmd->CommandLine[I + 1];
else if (Arg.startswith("-x"))
Lang = Arg.drop_front(2).trim();
}
if (Lang.empty()) {
llvm::StringRef Ext = llvm::sys::path::extension(File).trim('.');
auto Type = driver::types::lookupTypeForExtension(Ext);
if (Type == driver::types::TY_INVALID) {
elog("System include extraction: invalid file type for {0}", Ext);
return {};
}
Lang = driver::types::getTypeName(Type);
}
llvm::SmallString<128> Driver(Cmd->CommandLine.front());
if (llvm::any_of(Driver,
[](char C) { return llvm::sys::path::is_separator(C); }))
// Driver is a not a single executable name but instead a path (either
// relative or absolute).
llvm::sys::fs::make_absolute(Cmd->Directory, Driver);
if (auto Info =
QueriedDrivers.get(/*Key=*/(Driver + ":" + Lang).str(), [&] {
return extractSystemIncludesAndTarget(
Driver, Lang, Cmd->CommandLine, QueryDriverRegex);
})) {
setTarget(addSystemIncludes(*Cmd, Info->SystemIncludes), Info->Target);
}
return Cmd;
}
private:
// Caches includes extracted from a driver. Key is driver:lang.
Memoize<llvm::StringMap<llvm::Optional<DriverInfo>>> QueriedDrivers;
llvm::Regex QueryDriverRegex;
};
} // 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 std::make_unique<QueryDriverDatabase>(QueryDriverGlobs,
std::move(Base));
}
} // namespace clangd
} // namespace clang