mirror of
https://github.com/LadybirdBrowser/ladybird.git
synced 2024-11-11 01:06:01 +03:00
626 lines
19 KiB
C++
626 lines
19 KiB
C++
/*
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* Copyright (c) 2021, the SerenityOS developers.
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*
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* SPDX-License-Identifier: BSD-2-Clause
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*/
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#include <AK/Assertions.h>
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#include <AK/Format.h>
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#include <AK/GenericLexer.h>
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#include <AK/StdLibExtras.h>
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#include <ctype.h>
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#include <stdarg.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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enum class LengthModifier {
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None,
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Default,
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Char,
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Short,
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Long,
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LongLong,
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IntMax,
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Size,
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PtrDiff,
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LongDouble,
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};
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enum class ConversionSpecifier {
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Unspecified,
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Decimal,
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Integer,
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Octal,
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Unsigned,
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Hex,
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Floating,
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String,
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UseScanList,
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Character,
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Pointer,
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OutputNumberOfBytes,
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Invalid,
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};
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enum class ReadKind {
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Normal,
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Octal,
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Hex,
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Infer,
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};
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template<typename T, typename ApT, ReadKind kind = ReadKind::Normal>
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struct ReadElementConcrete {
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bool operator()(GenericLexer&, va_list)
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{
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return false;
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}
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};
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template<typename ApT, ReadKind kind>
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struct ReadElementConcrete<int, ApT, kind> {
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bool operator()(GenericLexer& lexer, va_list* ap)
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{
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lexer.ignore_while(isspace);
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auto* ptr = ap ? va_arg(*ap, ApT*) : nullptr;
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long value = 0;
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char* endptr = nullptr;
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auto nptr = lexer.remaining().characters_without_null_termination();
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if constexpr (kind == ReadKind::Normal)
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value = strtol(nptr, &endptr, 10);
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if constexpr (kind == ReadKind::Octal)
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value = strtol(nptr, &endptr, 8);
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if constexpr (kind == ReadKind::Hex)
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value = strtol(nptr, &endptr, 16);
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if constexpr (kind == ReadKind::Infer)
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value = strtol(nptr, &endptr, 0);
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if (!endptr)
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return false;
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if (endptr == nptr)
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return false;
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auto diff = endptr - nptr;
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VERIFY(diff > 0);
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lexer.ignore((size_t)diff);
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if (ptr)
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*ptr = value;
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return true;
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}
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};
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template<typename ApT, ReadKind kind>
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struct ReadElementConcrete<char, ApT, kind> {
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bool operator()(GenericLexer& lexer, va_list* ap)
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{
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static_assert(kind == ReadKind::Normal, "Can't read a non-normal character");
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auto* ptr = ap ? va_arg(*ap, ApT*) : nullptr;
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if (lexer.is_eof())
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return false;
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auto ch = lexer.consume();
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if (ptr)
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*ptr = ch;
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return true;
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}
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};
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template<typename ApT, ReadKind kind>
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struct ReadElementConcrete<unsigned, ApT, kind> {
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bool operator()(GenericLexer& lexer, va_list* ap)
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{
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lexer.ignore_while(isspace);
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auto* ptr = ap ? va_arg(*ap, ApT*) : nullptr;
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unsigned long value = 0;
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char* endptr = nullptr;
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auto nptr = lexer.remaining().characters_without_null_termination();
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if constexpr (kind == ReadKind::Normal)
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value = strtoul(nptr, &endptr, 10);
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if constexpr (kind == ReadKind::Octal)
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value = strtoul(nptr, &endptr, 8);
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if constexpr (kind == ReadKind::Hex)
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value = strtoul(nptr, &endptr, 16);
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if constexpr (kind == ReadKind::Infer)
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value = strtoul(nptr, &endptr, 0);
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if (!endptr)
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return false;
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if (endptr == nptr)
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return false;
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auto diff = endptr - nptr;
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VERIFY(diff > 0);
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lexer.ignore((size_t)diff);
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if (ptr)
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*ptr = value;
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return true;
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}
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};
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template<typename ApT, ReadKind kind>
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struct ReadElementConcrete<long long, ApT, kind> {
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bool operator()(GenericLexer& lexer, va_list* ap)
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{
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lexer.ignore_while(isspace);
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auto* ptr = ap ? va_arg(*ap, ApT*) : nullptr;
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long long value = 0;
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char* endptr = nullptr;
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auto nptr = lexer.remaining().characters_without_null_termination();
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if constexpr (kind == ReadKind::Normal)
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value = strtoll(nptr, &endptr, 10);
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if constexpr (kind == ReadKind::Octal)
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value = strtoll(nptr, &endptr, 8);
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if constexpr (kind == ReadKind::Hex)
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value = strtoll(nptr, &endptr, 16);
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if constexpr (kind == ReadKind::Infer)
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value = strtoll(nptr, &endptr, 0);
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if (!endptr)
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return false;
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if (endptr == nptr)
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return false;
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auto diff = endptr - nptr;
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VERIFY(diff > 0);
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lexer.ignore((size_t)diff);
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if (ptr)
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*ptr = value;
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return true;
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}
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};
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template<typename ApT, ReadKind kind>
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struct ReadElementConcrete<unsigned long long, ApT, kind> {
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bool operator()(GenericLexer& lexer, va_list* ap)
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{
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lexer.ignore_while(isspace);
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auto* ptr = ap ? va_arg(*ap, ApT*) : nullptr;
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unsigned long long value = 0;
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char* endptr = nullptr;
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auto nptr = lexer.remaining().characters_without_null_termination();
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if constexpr (kind == ReadKind::Normal)
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value = strtoull(nptr, &endptr, 10);
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if constexpr (kind == ReadKind::Octal)
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value = strtoull(nptr, &endptr, 8);
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if constexpr (kind == ReadKind::Hex)
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value = strtoull(nptr, &endptr, 16);
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if constexpr (kind == ReadKind::Infer)
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value = strtoull(nptr, &endptr, 0);
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if (!endptr)
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return false;
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if (endptr == nptr)
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return false;
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auto diff = endptr - nptr;
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VERIFY(diff > 0);
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lexer.ignore((size_t)diff);
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if (ptr)
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*ptr = value;
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return true;
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}
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};
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template<typename ApT, ReadKind kind>
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struct ReadElementConcrete<float, ApT, kind> {
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bool operator()(GenericLexer& lexer, va_list* ap)
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{
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lexer.ignore_while(isspace);
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auto* ptr = ap ? va_arg(*ap, ApT*) : nullptr;
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double value = 0;
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char* endptr = nullptr;
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auto nptr = lexer.remaining().characters_without_null_termination();
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if constexpr (kind == ReadKind::Normal)
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value = strtod(nptr, &endptr);
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else
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return false;
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if (!endptr)
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return false;
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if (endptr == nptr)
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return false;
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auto diff = endptr - nptr;
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VERIFY(diff > 0);
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lexer.ignore((size_t)diff);
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if (ptr)
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*ptr = value;
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return true;
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}
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};
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template<typename T, ReadKind kind>
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struct ReadElement {
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bool operator()(LengthModifier length_modifier, GenericLexer& input_lexer, va_list* ap)
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{
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switch (length_modifier) {
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default:
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case LengthModifier::None:
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VERIFY_NOT_REACHED();
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case LengthModifier::Default:
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return ReadElementConcrete<T, T, kind> {}(input_lexer, ap);
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case LengthModifier::Char:
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return ReadElementConcrete<T, char, kind> {}(input_lexer, ap);
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case LengthModifier::Short:
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return ReadElementConcrete<T, short, kind> {}(input_lexer, ap);
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case LengthModifier::Long:
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if constexpr (IsSame<T, int>)
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return ReadElementConcrete<T, long, kind> {}(input_lexer, ap);
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if constexpr (IsSame<T, unsigned>)
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return ReadElementConcrete<T, unsigned, kind> {}(input_lexer, ap);
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if constexpr (IsSame<T, float>)
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return ReadElementConcrete<int, double, kind> {}(input_lexer, ap);
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return false;
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case LengthModifier::LongLong:
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if constexpr (IsSame<T, int>)
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return ReadElementConcrete<long long, long long, kind> {}(input_lexer, ap);
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if constexpr (IsSame<T, unsigned>)
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return ReadElementConcrete<unsigned long long, unsigned long long, kind> {}(input_lexer, ap);
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if constexpr (IsSame<T, float>)
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return ReadElementConcrete<long long, double, kind> {}(input_lexer, ap);
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return false;
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case LengthModifier::IntMax:
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return ReadElementConcrete<T, intmax_t, kind> {}(input_lexer, ap);
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case LengthModifier::Size:
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return ReadElementConcrete<T, size_t, kind> {}(input_lexer, ap);
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case LengthModifier::PtrDiff:
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return ReadElementConcrete<T, ptrdiff_t, kind> {}(input_lexer, ap);
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case LengthModifier::LongDouble:
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return ReadElementConcrete<T, long double, kind> {}(input_lexer, ap);
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}
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}
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};
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template<>
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struct ReadElement<char*, ReadKind::Normal> {
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ReadElement(StringView scan_set = {}, bool invert = false)
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: scan_set(scan_set.is_null() ? " \t\n\f\r" : scan_set)
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, invert(scan_set.is_null() ? true : invert)
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, was_null(scan_set.is_null())
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{
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}
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bool operator()(LengthModifier length_modifier, GenericLexer& input_lexer, va_list* ap)
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{
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// FIXME: Implement wide strings and such.
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if (length_modifier != LengthModifier::Default)
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return false;
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if (was_null)
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input_lexer.ignore_while(isspace);
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auto* ptr = ap ? va_arg(*ap, char*) : nullptr;
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auto str = input_lexer.consume_while([this](auto c) { return this->matches(c); });
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if (str.is_empty())
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return false;
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memcpy(ptr, str.characters_without_null_termination(), str.length());
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ptr[str.length()] = 0;
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return true;
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}
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private:
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bool matches(char c) const
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{
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return invert ^ scan_set.contains(c);
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}
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const StringView scan_set;
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bool invert { false };
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bool was_null { false };
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};
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template<>
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struct ReadElement<void*, ReadKind::Normal> {
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bool operator()(LengthModifier length_modifier, GenericLexer& input_lexer, va_list* ap)
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{
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if (length_modifier != LengthModifier::Default)
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return false;
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input_lexer.ignore_while(isspace);
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auto* ptr = ap ? va_arg(*ap, void**) : nullptr;
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auto str = input_lexer.consume_while([this](auto c) { return this->should_consume(c); });
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if (count != 8) {
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fail:;
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for (size_t i = 0; i < count; ++i)
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input_lexer.retreat();
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return false;
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}
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char buf[9] { 0 };
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memcpy(buf, str.characters_without_null_termination(), 8);
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buf[8] = 0;
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char* endptr = nullptr;
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auto value = strtoull(buf, &endptr, 16);
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if (endptr != &buf[8])
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goto fail;
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memcpy(ptr, &value, sizeof(value));
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return true;
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}
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private:
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bool should_consume(char c)
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{
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if (count == 8)
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return false;
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if (!isxdigit(c))
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return false;
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++count;
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return true;
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}
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size_t count { 0 };
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};
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extern "C" int vsscanf(const char* input, const char* format, va_list ap)
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{
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GenericLexer format_lexer { format };
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GenericLexer input_lexer { input };
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int elements_matched = 0;
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va_list copy;
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__builtin_va_copy(copy, ap);
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while (!format_lexer.is_eof()) {
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format_lexer.ignore_while(isspace);
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if (!format_lexer.next_is('%')) {
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read_one_literal:;
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input_lexer.ignore_while(isspace);
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if (format_lexer.is_eof())
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break;
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auto next_char = format_lexer.consume();
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if (!input_lexer.consume_specific(next_char))
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return elements_matched;
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continue;
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}
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if (format_lexer.next_is("%%")) {
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format_lexer.ignore();
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goto read_one_literal;
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}
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format_lexer.ignore(); // '%'
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bool suppress_assignment = false;
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if (format_lexer.next_is('*')) {
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suppress_assignment = true;
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format_lexer.ignore();
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}
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// Parse width specification
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[[maybe_unused]] int width_specifier = 0;
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if (format_lexer.next_is(isdigit)) {
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auto width_digits = format_lexer.consume_while([](char c) { return isdigit(c); });
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width_specifier = width_digits.to_int().value();
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// FIXME: Actually use width specifier
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}
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bool invert_scanlist = false;
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StringView scanlist;
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LengthModifier length_modifier { LengthModifier::None };
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ConversionSpecifier conversion_specifier { ConversionSpecifier::Unspecified };
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reread_lookahead:;
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auto format_lookahead = format_lexer.peek();
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if (length_modifier == LengthModifier::None) {
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switch (format_lookahead) {
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case 'h':
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if (format_lexer.peek(1) == 'h') {
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format_lexer.consume(2);
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length_modifier = LengthModifier::Char;
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} else {
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format_lexer.consume(1);
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length_modifier = LengthModifier::Short;
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}
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break;
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case 'l':
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if (format_lexer.peek(1) == 'l') {
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format_lexer.consume(2);
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length_modifier = LengthModifier::LongLong;
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} else {
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format_lexer.consume(1);
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length_modifier = LengthModifier::Long;
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}
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break;
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case 'j':
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format_lexer.consume();
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length_modifier = LengthModifier::IntMax;
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break;
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case 'z':
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format_lexer.consume();
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length_modifier = LengthModifier::Size;
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break;
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case 't':
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format_lexer.consume();
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length_modifier = LengthModifier::PtrDiff;
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break;
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case 'L':
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format_lexer.consume();
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length_modifier = LengthModifier::LongDouble;
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break;
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default:
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length_modifier = LengthModifier::Default;
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break;
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}
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goto reread_lookahead;
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}
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if (conversion_specifier == ConversionSpecifier::Unspecified) {
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switch (format_lookahead) {
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case 'd':
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format_lexer.consume();
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conversion_specifier = ConversionSpecifier::Decimal;
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break;
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case 'i':
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format_lexer.consume();
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conversion_specifier = ConversionSpecifier::Integer;
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break;
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case 'o':
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format_lexer.consume();
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conversion_specifier = ConversionSpecifier::Octal;
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break;
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case 'u':
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format_lexer.consume();
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conversion_specifier = ConversionSpecifier::Unsigned;
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break;
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case 'x':
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format_lexer.consume();
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conversion_specifier = ConversionSpecifier::Hex;
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break;
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case 'a':
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case 'e':
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case 'f':
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case 'g':
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format_lexer.consume();
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conversion_specifier = ConversionSpecifier::Floating;
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break;
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case 's':
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format_lexer.consume();
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conversion_specifier = ConversionSpecifier::String;
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break;
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case '[':
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format_lexer.consume();
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scanlist = format_lexer.consume_until(']');
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if (scanlist.starts_with('^')) {
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scanlist = scanlist.substring_view(1);
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invert_scanlist = true;
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}
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conversion_specifier = ConversionSpecifier::UseScanList;
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break;
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case 'c':
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format_lexer.consume();
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conversion_specifier = ConversionSpecifier::Character;
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break;
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case 'p':
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format_lexer.consume();
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conversion_specifier = ConversionSpecifier::Pointer;
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break;
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case 'n':
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format_lexer.consume();
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conversion_specifier = ConversionSpecifier::OutputNumberOfBytes;
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break;
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case 'C':
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format_lexer.consume();
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length_modifier = LengthModifier::Long;
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conversion_specifier = ConversionSpecifier::Character;
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break;
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case 'S':
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format_lexer.consume();
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length_modifier = LengthModifier::Long;
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conversion_specifier = ConversionSpecifier::String;
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break;
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default:
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format_lexer.consume();
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conversion_specifier = ConversionSpecifier::Invalid;
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break;
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}
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}
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auto* ap_or_null = !suppress_assignment ? (va_list*)© : nullptr;
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// Now try to read.
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switch (conversion_specifier) {
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case ConversionSpecifier::Invalid:
|
|
case ConversionSpecifier::Unspecified:
|
|
default:
|
|
// "undefined behavior", let's be nice and crash.
|
|
dbgln("Invalid conversion specifier {} in scanf!", (int)conversion_specifier);
|
|
VERIFY_NOT_REACHED();
|
|
case ConversionSpecifier::Decimal:
|
|
if (!ReadElement<int, ReadKind::Normal> {}(length_modifier, input_lexer, ap_or_null))
|
|
format_lexer.consume_all();
|
|
else
|
|
++elements_matched;
|
|
break;
|
|
case ConversionSpecifier::Integer:
|
|
if (!ReadElement<int, ReadKind::Infer> {}(length_modifier, input_lexer, ap_or_null))
|
|
format_lexer.consume_all();
|
|
else
|
|
++elements_matched;
|
|
break;
|
|
case ConversionSpecifier::Octal:
|
|
if (!ReadElement<unsigned, ReadKind::Octal> {}(length_modifier, input_lexer, ap_or_null))
|
|
format_lexer.consume_all();
|
|
else
|
|
++elements_matched;
|
|
break;
|
|
case ConversionSpecifier::Unsigned:
|
|
if (!ReadElement<unsigned, ReadKind::Normal> {}(length_modifier, input_lexer, ap_or_null))
|
|
format_lexer.consume_all();
|
|
else
|
|
++elements_matched;
|
|
break;
|
|
case ConversionSpecifier::Hex:
|
|
if (!ReadElement<unsigned, ReadKind::Hex> {}(length_modifier, input_lexer, ap_or_null))
|
|
format_lexer.consume_all();
|
|
else
|
|
++elements_matched;
|
|
break;
|
|
case ConversionSpecifier::Floating:
|
|
if (!ReadElement<float, ReadKind::Normal> {}(length_modifier, input_lexer, ap_or_null))
|
|
format_lexer.consume_all();
|
|
else
|
|
++elements_matched;
|
|
break;
|
|
case ConversionSpecifier::String:
|
|
if (!ReadElement<char*, ReadKind::Normal> {}(length_modifier, input_lexer, ap_or_null))
|
|
format_lexer.consume_all();
|
|
else
|
|
++elements_matched;
|
|
break;
|
|
case ConversionSpecifier::UseScanList:
|
|
if (!ReadElement<char*, ReadKind::Normal> { scanlist, invert_scanlist }(length_modifier, input_lexer, ap_or_null))
|
|
format_lexer.consume_all();
|
|
else
|
|
++elements_matched;
|
|
break;
|
|
case ConversionSpecifier::Character:
|
|
if (!ReadElement<char, ReadKind::Normal> {}(length_modifier, input_lexer, ap_or_null))
|
|
format_lexer.consume_all();
|
|
else
|
|
++elements_matched;
|
|
break;
|
|
case ConversionSpecifier::Pointer:
|
|
if (!ReadElement<void*, ReadKind::Normal> {}(length_modifier, input_lexer, ap_or_null))
|
|
format_lexer.consume_all();
|
|
else
|
|
++elements_matched;
|
|
break;
|
|
case ConversionSpecifier::OutputNumberOfBytes: {
|
|
if (!suppress_assignment) {
|
|
auto* ptr = va_arg(ap, int*);
|
|
*ptr = input_lexer.tell();
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
va_end(copy);
|
|
|
|
return elements_matched;
|
|
}
|