Files
carbon-lang/toolchain/source/source_buffer.cpp
T
Jon Ross-PerkinsandRichard Smith a93e621488 Add vfs support to toolchain. (#2888)
This adds vfs support to the toolchain, allowing Driver to take in-memory inputs in tests. As a consequence, I'm simplifying SourceBuffer: rather than allowing tests to pass in their own memory buffer, I'm using InMemoryFileSystem to push for greater consistency with production code. This does hit a quirk where I need to be careful about null terminator handling because fuzzer imports don't always have one, but that's probably more robust anyways.

Co-authored-by: Richard Smith <richard@metafoo.co.uk>
2023-06-12 13:19:57 -07:00

43 lines
1.3 KiB
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// 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/source/source_buffer.h"
#include <limits>
#include "llvm/Support/Error.h"
#include "llvm/Support/FormatVariadic.h"
namespace Carbon {
auto SourceBuffer::CreateFromFile(llvm::vfs::FileSystem& fs,
llvm::StringRef filename)
-> ErrorOr<SourceBuffer> {
llvm::ErrorOr<std::unique_ptr<llvm::vfs::File>> file =
fs.openFileForRead(filename);
if (file.getError()) {
return Error(file.getError().message());
}
llvm::ErrorOr<llvm::vfs::Status> status = (*file)->status();
if (status.getError()) {
return Error(status.getError().message());
}
auto size = status->getSize();
if (size >= std::numeric_limits<int32_t>::max()) {
return Error(
llvm::formatv("`{0}` is over the 2GiB input limit.", filename));
}
llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> buffer =
(*file)->getBuffer(filename, size, /*RequiresNullTerminator=*/false);
if (buffer.getError()) {
return Error(buffer.getError().message());
}
return SourceBuffer(filename.str(), std::move(buffer.get()));
}
} // namespace Carbon