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carbon-lang/toolchain/lexer/test_helpers.h
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Jon Meow 20728dbd3a CARBON_ header guards (#1261)
This modifies scripts/check_header_guards.py to add the CARBON_ prefix; everything else is pre-commit.
2022-05-12 17:25:43 -07:00

57 lines
2.0 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_LEXER_TEST_HELPERS_H_
#define CARBON_TOOLCHAIN_LEXER_TEST_HELPERS_H_
#include <gmock/gmock.h>
#include <array>
#include <string>
#include "common/check.h"
#include "common/string_helpers.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/Support/FormatVariadic.h"
#include "toolchain/diagnostics/diagnostic_emitter.h"
namespace Carbon::Testing {
// A diagnostic translator for tests that lex a single token. Produces
// locations such as "`12.5`:1:3" to refer to the third character in the token.
class SingleTokenDiagnosticTranslator
: public DiagnosticLocationTranslator<const char*> {
public:
// Form a translator for a given token. The string provided here must refer
// to the same character array that we are going to lex.
explicit SingleTokenDiagnosticTranslator(llvm::StringRef token)
: token_(token) {}
auto GetLocation(const char* pos) -> DiagnosticLocation override {
CARBON_CHECK(StringRefContainsPointer(token_, pos))
<< "invalid diagnostic location";
llvm::StringRef prefix = token_.take_front(pos - token_.begin());
auto [before_last_newline, this_line] = prefix.rsplit('\n');
if (before_last_newline.size() == prefix.size()) {
// On first line.
return {.line_number = 1,
.column_number = static_cast<int32_t>(pos - token_.begin() + 1)};
} else {
// On second or subsequent lines. Note that the line number here is 2
// more than the number of newlines because `rsplit` removed one newline
// and `line_number` is 1-based.
return {.line_number =
static_cast<int32_t>(before_last_newline.count('\n') + 2),
.column_number = static_cast<int32_t>(this_line.size() + 1)};
}
}
private:
llvm::StringRef token_;
};
} // namespace Carbon::Testing
#endif // CARBON_TOOLCHAIN_LEXER_TEST_HELPERS_H_