llvm-project/clang-tools-extra/clangd/CompileCommands.h

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//===--- CompileCommands.h - Manipulation of compile flags -------*- 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
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANGD_COMPILECOMMANDS_H
#define LLVM_CLANG_TOOLS_EXTRA_CLANGD_COMPILECOMMANDS_H
#include "support/Threading.h"
#include "clang/Tooling/ArgumentsAdjusters.h"
#include "clang/Tooling/CompilationDatabase.h"
#include "llvm/ADT/StringMap.h"
#include <deque>
#include <string>
#include <vector>
namespace clang {
namespace clangd {
// CommandMangler transforms compile commands from some external source
// for use in clangd. This means:
// - running the frontend only, stripping args regarding output files etc
// - forcing the use of clangd's builtin headers rather than clang's
// - resolving argv0 as cc1 expects
// - injecting -isysroot flags on mac as the system clang does
struct CommandMangler {
// Absolute path to clang.
llvm::Optional<std::string> ClangPath;
// Directory containing builtin headers.
llvm::Optional<std::string> ResourceDir;
// Root for searching for standard library (passed to -isysroot).
llvm::Optional<std::string> Sysroot;
// A command-mangler that doesn't know anything about the system.
// This is hermetic for unit-tests, but won't work well in production.
static CommandMangler forTests();
// Probe the system and build a command-mangler that knows the toolchain.
// - try to find clang on $PATH, otherwise fake a path near clangd
// - find the resource directory installed near clangd
// - on mac, find clang and isysroot by querying the `xcrun` launcher
static CommandMangler detect();
void adjust(std::vector<std::string> &Cmd) const;
explicit operator clang::tooling::ArgumentsAdjuster() &&;
private:
CommandMangler() = default;
Memoize<llvm::StringMap<std::string>> ResolvedDrivers;
Memoize<llvm::StringMap<std::string>> ResolvedDriversNoFollow;
};
// Removes args from a command-line in a semantically-aware way.
//
// Internally this builds a large (0.5MB) table of clang options on first use.
// Both strip() and process() are fairly cheap after that.
//
// FIXME: this reimplements much of OptTable, it might be nice to expose more.
// The table-building strategy may not make sense outside clangd.
class ArgStripper {
public:
ArgStripper() = default;
ArgStripper(ArgStripper &&) = default;
ArgStripper(const ArgStripper &) = delete;
ArgStripper &operator=(ArgStripper &&) = default;
ArgStripper &operator=(const ArgStripper &) = delete;
// Adds the arg to the set which should be removed.
//
// Recognized clang flags are stripped semantically. When "-I" is stripped:
// - so is its value (either as -Ifoo or -I foo)
// - aliases like --include-directory=foo are also stripped
// - CL-style /Ifoo will be removed if the args indicate MS-compatible mode
// Compile args not recognized as flags are removed literally, except:
// - strip("ABC*") will remove any arg with an ABC prefix.
//
// In either case, the -Xclang prefix will be dropped if present.
void strip(llvm::StringRef Arg);
// Remove the targets from a compile command, in-place.
void process(std::vector<std::string> &Args) const;
private:
// Deletion rules, to be checked for each arg.
struct Rule {
llvm::StringRef Text; // Rule applies only if arg begins with Text.
unsigned char Modes = 0; // Rule applies only in specified driver modes.
uint16_t Priority = 0; // Lower is better.
uint16_t ExactArgs = 0; // Num args consumed when Arg == Text.
uint16_t PrefixArgs = 0; // Num args consumed when Arg starts with Text.
};
static llvm::ArrayRef<Rule> rulesFor(llvm::StringRef Arg);
const Rule *matchingRule(llvm::StringRef Arg, unsigned Mode,
unsigned &ArgCount) const;
llvm::SmallVector<Rule, 4> Rules;
std::deque<std::string> Storage; // Store strings not found in option table.
};
} // namespace clangd
} // namespace clang
#endif