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Jon Ross-PerkinsandGeoff Romer
4c4c4a4d2c
This adds a RawStringOstream. Versus TestRawOstream, which is
consolidated over to RawStringOstream, it uses a string for storage
instead of a vector, mainly to support move-to-string semantics. Versus
llvm::raw_string_ostream, it owns the string and supports pwrite (which
is needed for driver and its fd_ostream compatibility requirement).
This converts most uses of llvm::raw_string_ostream, leaving behind a
few in InstNamer that explicitly cannot own the string, such as:
```
llvm::raw_string_ostream(name)
<< "_" << tree.tokens().GetColumnNumber(token);
```
I have this as its own library so that it can use CHECK.
Yes this doesn't save much code, but it's code we repeatedly write.
---------
Co-authored-by: Geoff Romer <gromer@google.com>
65 lines
1.8 KiB
C++
65 lines
1.8 KiB
C++
// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
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// Exceptions. See /LICENSE for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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#ifndef CARBON_COMMON_RAW_STRING_OSTREAM_H_
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#define CARBON_COMMON_RAW_STRING_OSTREAM_H_
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#include "common/check.h"
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#include "common/ostream.h"
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namespace Carbon {
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// Implements streaming output with an underlying string. The string must always
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// be taken prior to destruction.
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//
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// Versus `llvm::raw_string_ostream`:
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// - Owns the underlying string.
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// - Supports `pwrite` for compatibility with more stream uses in tests.
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class RawStringOstream : public llvm::raw_pwrite_stream {
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public:
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explicit RawStringOstream() : llvm::raw_pwrite_stream(/*Unbuffered=*/true) {}
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~RawStringOstream() override {
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CARBON_CHECK(str_.empty(), "Expected to be emptied by TakeStr, have: {0}",
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str_);
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}
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// Returns the streamed contents, clearing the stream back to empty.
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auto TakeStr() -> std::string {
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std::string result = std::move(str_);
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clear();
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return result;
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}
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// Clears the buffer, which can be helpful when destructing without
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// necessarily calling `TakeStr()`.
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auto clear() -> void { str_.clear(); }
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auto empty() -> bool { return str_.empty(); }
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auto size() -> size_t { return str_.size(); }
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private:
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auto current_pos() const -> uint64_t override { return str_.size(); }
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auto pwrite_impl(const char* ptr, size_t size, uint64_t offset)
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-> void override {
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str_.replace(offset, size, ptr, size);
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}
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auto write_impl(const char* ptr, size_t size) -> void override {
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str_.append(ptr, size);
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}
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void reserveExtraSpace(uint64_t extra_size) override {
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str_.reserve(str_.size() + extra_size);
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}
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// The actual buffer.
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std::string str_;
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};
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} // namespace Carbon
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#endif // CARBON_COMMON_RAW_STRING_OSTREAM_H_
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