libc/src/stdio/scanf_core/converter_utils.h

   1 //===-- Format specifier converter for scanf -------------------*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #ifndef LLVM_LIBC_SRC_STDIO_SCANF_CORE_CONVERTER_UTILS_H
  10 #define LLVM_LIBC_SRC_STDIO_SCANF_CORE_CONVERTER_UTILS_H
  11
  12 #include "src/__support/common.h"
  13 #include "src/__support/ctype_utils.h"
  14 #include "src/__support/str_to_float.h"
  15 #include "src/stdio/scanf_core/core_structs.h"
  16 #include "src/stdio/scanf_core/reader.h"
  17
  18 #include <stddef.h>
  19
  20 namespace LIBC_NAMESPACE {
  21 namespace scanf_core {
  22
  23 LIBC_INLINE constexpr char to_lower(char a) { return a | 32; }
  24
  25 LIBC_INLINE constexpr int b36_char_to_int(char input) {
  26   if (internal::isdigit(input))
  27     return input - '0';
  28   if (internal::isalpha(input))
  29     return to_lower(input) + 10 - 'a';
  30   return 0;
  31 }
  32
  33 LIBC_INLINE void write_int_with_length(uintmax_t output_val,
  34                                        const FormatSection &to_conv) {
  35   if ((to_conv.flags & NO_WRITE) != 0) {
  36     return;
  37   }
  38   void *output_ptr = to_conv.output_ptr;
  39   // The %p conversion uses this function, and is always void*.
  40   if (to_conv.conv_name == 'p') {
  41     *reinterpret_cast<void **>(output_ptr) =
  42         reinterpret_cast<void *>(output_val);
  43     return;
  44   }
  45   LengthModifier lm = to_conv.length_modifier;
  46   switch (lm) {
  47   case (LengthModifier::hh):
  48     *reinterpret_cast<unsigned char *>(output_ptr) =
  49         static_cast<unsigned char>(output_val);
  50     break;
  51   case (LengthModifier::h):
  52     *reinterpret_cast<unsigned short *>(output_ptr) =
  53         static_cast<unsigned short>(output_val);
  54     break;
  55   case (LengthModifier::NONE):
  56     *reinterpret_cast<unsigned int *>(output_ptr) =
  57         static_cast<unsigned int>(output_val);
  58     break;
  59   case (LengthModifier::l):
  60     *reinterpret_cast<unsigned long *>(output_ptr) =
  61         static_cast<unsigned long>(output_val);
  62     break;
  63   case (LengthModifier::ll):
  64   case (LengthModifier::L):
  65     *reinterpret_cast<unsigned long long *>(output_ptr) =
  66         static_cast<unsigned long long>(output_val);
  67     break;
  68   case (LengthModifier::j):
  69     *reinterpret_cast<uintmax_t *>(output_ptr) =
  70         static_cast<uintmax_t>(output_val);
  71     break;
  72   case (LengthModifier::z):
  73     *reinterpret_cast<size_t *>(output_ptr) = static_cast<size_t>(output_val);
  74     break;
  75   case (LengthModifier::t):
  76     *reinterpret_cast<ptrdiff_t *>(output_ptr) =
  77         static_cast<ptrdiff_t>(output_val);
  78     break;
  79   }
  80 }
  81
  82 LIBC_INLINE void write_float_with_length(char *str,
  83                                          const FormatSection &to_conv) {
  84   if ((to_conv.flags & NO_WRITE) != 0) {
  85     return;
  86   }
  87
  88   void *output_ptr = to_conv.output_ptr;
  89
  90   LengthModifier lm = to_conv.length_modifier;
  91   switch (lm) {
  92   case (LengthModifier::l): {
  93     auto value = internal::strtofloatingpoint<double>(str);
  94     *reinterpret_cast<double *>(output_ptr) = value;
  95     break;
  96   }
  97   case (LengthModifier::L): {
  98     auto value = internal::strtofloatingpoint<long double>(str);
  99     *reinterpret_cast<long double *>(output_ptr) = value;
 100     break;
 101   }
 102   default: {
 103     auto value = internal::strtofloatingpoint<float>(str);
 104     *reinterpret_cast<float *>(output_ptr) = value;
 105     break;
 106   }
 107   }
 108 }
 109
 110 } // namespace scanf_core
 111 } // namespace LIBC_NAMESPACE
 112
 113 #endif // LLVM_LIBC_SRC_STDIO_SCANF_CORE_CONVERTER_UTILS_H