llvm-project/clang/lib/Format/NumericLiteralInfo.cpp

66 lines
1.9 KiB
C++

//===--- NumericLiteralInfo.cpp ---------------------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
///
/// \file
/// This file implements the functionality of getting information about a
/// numeric literal string, including 0-based positions of the base letter, the
/// decimal/hexadecimal point, the exponent letter, and the suffix, or npos if
/// absent.
///
//===----------------------------------------------------------------------===//
#include "NumericLiteralInfo.h"
#include "llvm/ADT/StringExtras.h"
namespace clang {
namespace format {
using namespace llvm;
NumericLiteralInfo::NumericLiteralInfo(StringRef Text, char Separator) {
if (Text.size() < 2)
return;
bool IsHex = false;
if (Text[0] == '0') {
switch (Text[1]) {
case 'x':
case 'X':
IsHex = true;
[[fallthrough]];
case 'b':
case 'B':
case 'o': // JavaScript octal.
case 'O':
BaseLetterPos = 1; // e.g. 0xF
break;
}
}
DotPos = Text.find('.', BaseLetterPos + 1); // e.g. 0x.1 or .1
// e.g. 1.e2 or 0xFp2
const auto Pos = DotPos != StringRef::npos ? DotPos + 1 : BaseLetterPos + 2;
ExponentLetterPos =
// Trim C++ user-defined suffix as in `1_Pa`.
(Separator == '\'' ? Text.take_front(Text.find('_')) : Text)
.find_insensitive(IsHex ? 'p' : 'e', Pos);
const bool HasExponent = ExponentLetterPos != StringRef::npos;
SuffixPos = Text.find_if_not(
[&](char C) {
return (HasExponent || !IsHex ? isDigit : isHexDigit)(C) ||
C == Separator;
},
HasExponent ? ExponentLetterPos + 2 : Pos); // e.g. 1e-2f
}
} // namespace format
} // namespace clang