Files
carbon-lang/toolchain/base/clang_invocation.cpp
T
Richard SmithandChandler Carruth 553dd6e531 Build the clang::CompilerInvocation in the driver. (#5784)
Add driver flags to specify clang driver arguments.

---------

Co-authored-by: Chandler Carruth <chandlerc@gmail.com>
2025-07-18 16:30:47 +00:00

114 lines
4.2 KiB
C++

// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
// Exceptions. See /LICENSE for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
#include "toolchain/base/clang_invocation.h"
#include "clang/Frontend/CompilerInstance.h"
#include "clang/Frontend/Utils.h"
namespace Carbon {
// The fake file name to use for the synthesized includes file.
static constexpr const char IncludesFileName[] = "<carbon Cpp imports>";
namespace {
// Used to convert diagnostics from the Clang driver to Carbon diagnostics.
class ClangDriverDiagnosticConsumer : public clang::DiagnosticConsumer {
public:
// Creates an instance with the location that triggers calling Clang.
// `context` must not be null.
explicit ClangDriverDiagnosticConsumer(Diagnostics::NoLocEmitter* emitter)
: emitter_(emitter) {}
// Generates a Carbon warning for each Clang warning and a Carbon error for
// each Clang error or fatal.
auto HandleDiagnostic(clang::DiagnosticsEngine::Level diag_level,
const clang::Diagnostic& info) -> void override {
DiagnosticConsumer::HandleDiagnostic(diag_level, info);
llvm::SmallString<256> message;
info.FormatDiagnostic(message);
switch (diag_level) {
case clang::DiagnosticsEngine::Ignored:
case clang::DiagnosticsEngine::Note:
case clang::DiagnosticsEngine::Remark: {
// TODO: Emit notes and remarks.
break;
}
case clang::DiagnosticsEngine::Warning:
case clang::DiagnosticsEngine::Error:
case clang::DiagnosticsEngine::Fatal: {
CARBON_DIAGNOSTIC(CppInteropDriverWarning, Warning, "{0}", std::string);
CARBON_DIAGNOSTIC(CppInteropDriverError, Error, "{0}", std::string);
emitter_->Emit(diag_level == clang::DiagnosticsEngine::Warning
? CppInteropDriverWarning
: CppInteropDriverError,
message.str().str());
break;
}
}
}
private:
// Diagnostic emitter. Note that driver diagnostics don't have meaningful
// locations attached.
Diagnostics::NoLocEmitter* emitter_;
};
} // namespace
static auto BuildClangInvocationImpl(
Diagnostics::NoLocEmitter& emitter,
llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem> fs,
llvm::ArrayRef<std::string> clang_path_and_args)
-> std::unique_ptr<clang::CompilerInvocation> {
ClangDriverDiagnosticConsumer diagnostics_consumer(&emitter);
// The clang driver inconveniently wants an array of `const char*`, so convert
// the arguments.
llvm::SmallVector<const char*> driver_args(llvm::map_range(
clang_path_and_args, [](const std::string& str) { return str.c_str(); }));
// Add our include file name as the input file, and force it to be interpreted
// as C++.
driver_args.push_back("-x");
driver_args.push_back("c++");
driver_args.push_back(IncludesFileName);
// Build a diagnostics engine. Note that we don't have any diagnostic options
// yet; they're produced by running the driver.
clang::DiagnosticOptions driver_diag_opts;
llvm::IntrusiveRefCntPtr<clang::DiagnosticsEngine> driver_diags(
clang::CompilerInstance::createDiagnostics(*fs, driver_diag_opts,
&diagnostics_consumer,
/*ShouldOwnClient=*/false));
// Ask the driver to process the arguments and build a corresponding clang
// frontend invocation.
return clang::createInvocation(driver_args,
{.Diags = driver_diags, .VFS = fs});
}
auto BuildClangInvocation(Diagnostics::Consumer& consumer,
llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem> fs,
llvm::ArrayRef<std::string> clang_path_and_args)
-> std::unique_ptr<clang::CompilerInvocation> {
Diagnostics::ErrorTrackingConsumer error_tracker(consumer);
Diagnostics::NoLocEmitter emitter(&error_tracker);
// Forward to the implementation to avoid exposing `import_cpp` outside check.
auto invocation = BuildClangInvocationImpl(emitter, fs, clang_path_and_args);
// If Clang produced an error, throw away its invocation.
if (error_tracker.seen_error()) {
return nullptr;
}
return invocation;
}
} // namespace Carbon