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carbon-lang/toolchain/source/source_buffer.h
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Jon Ross-Perkins 1974e44fd9 Rename factory functions from 'Create' to 'Make' (#3706)
Similar to #3705, we actually have a mix of `Make` and `Create` in
factory functions too, so this PR is normalizing on `Make`. It's
intended to be consistent with the naming choice for Carbon factory
functions.

Note, MakeSyntheticBlock is the only one I feel a little weird about
because llvm's own APIs use Create, and this is essentially wrapping
LLVM calls. But the flipside is it also feels like a vague line to draw,
when we also differ from LLVM coding style in other ways.
2024-02-14 18:26:56 +00:00

85 lines
3.1 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
#ifndef CARBON_TOOLCHAIN_SOURCE_SOURCE_BUFFER_H_
#define CARBON_TOOLCHAIN_SOURCE_SOURCE_BUFFER_H_
#include <memory>
#include <string>
#include "llvm/ADT/StringRef.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/VirtualFileSystem.h"
#include "toolchain/diagnostics/diagnostic_emitter.h"
namespace Carbon {
// A buffer of Carbon source code.
//
// This class holds a buffer of Carbon source code as text and makes it
// available for use in the rest of the Carbon compiler. It owns the memory for
// the underlying source code text and ensures it lives as long as the buffer
// objects.
//
// Every buffer of source code text is notionally loaded from a Carbon source
// file, even if provided directly when constructing the buffer. The name that
// should be used for that Carbon source file is also retained and made
// available.
//
// Because the underlying memory for the source code text may have been read
// from a file, and we may want to use facilities like `mmap` to simply map that
// file into memory, the buffer itself is not copyable to avoid needing to
// define copy semantics for a mapped file. We can relax this restriction with
// some implementation complexity in the future if needed.
class SourceBuffer {
public:
// Opens and reads the contents of stdin. Returns a SourceBuffer on success.
// Prints an error and returns nullopt on failure.
static auto MakeFromStdin(DiagnosticConsumer& consumer)
-> std::optional<SourceBuffer>;
// Opens the requested file. Returns a SourceBuffer on success. Prints an
// error and returns nullopt on failure.
static auto MakeFromFile(llvm::vfs::FileSystem& fs, llvm::StringRef filename,
DiagnosticConsumer& consumer)
-> std::optional<SourceBuffer>;
// Use one of the factory functions above to create a source buffer.
SourceBuffer() = delete;
auto filename() const -> llvm::StringRef { return filename_; }
auto text() const -> llvm::StringRef { return text_->getBuffer(); }
[[nodiscard]] auto is_regular_file() const -> bool {
return is_regular_file_;
}
private:
// Creates a `SourceBuffer` from the given `llvm::MemoryBuffer`. Prints an
// error and returns nullopt on failure.
static auto MakeFromMemoryBuffer(
llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> buffer,
llvm::StringRef filename, bool is_regular_file,
DiagnosticConsumer& consumer) -> std::optional<SourceBuffer>;
explicit SourceBuffer(std::string filename,
std::unique_ptr<llvm::MemoryBuffer> text,
bool is_regular_file)
: filename_(std::move(filename)),
text_(std::move(text)),
is_regular_file_(is_regular_file) {}
std::string filename_;
std::unique_ptr<llvm::MemoryBuffer> text_;
// Whether this buffer is a regular file, rather than stdin or a named pipe or
// similar.
bool is_regular_file_;
};
} // namespace Carbon
#endif // CARBON_TOOLCHAIN_SOURCE_SOURCE_BUFFER_H_