libc/src/stdio/scanf_core/converter.cpp

   1 //===-- Format specifier converter implmentation 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 #include "src/stdio/scanf_core/converter.h"
  10
  11 #include "src/__support/ctype_utils.h"
  12 #include "src/stdio/scanf_core/core_structs.h"
  13 #include "src/stdio/scanf_core/reader.h"
  14
  15 #ifndef LIBC_COPT_SCANF_DISABLE_FLOAT
  16 #include "src/stdio/scanf_core/float_converter.h"
  17 #endif // LIBC_COPT_SCANF_DISABLE_FLOAT
  18 #include "src/stdio/scanf_core/current_pos_converter.h"
  19 #include "src/stdio/scanf_core/int_converter.h"
  20 #include "src/stdio/scanf_core/ptr_converter.h"
  21 #include "src/stdio/scanf_core/string_converter.h"
  22
  23 #include <stddef.h>
  24
  25 namespace LIBC_NAMESPACE {
  26 namespace scanf_core {
  27
  28 int convert(Reader *reader, const FormatSection &to_conv) {
  29   int ret_val = 0;
  30   switch (to_conv.conv_name) {
  31   case '%':
  32     return raw_match(reader, "%");
  33   case 's':
  34     ret_val = raw_match(reader, " ");
  35     if (ret_val != READ_OK)
  36       return ret_val;
  37     return convert_string(reader, to_conv);
  38   case 'c':
  39   case '[':
  40     return convert_string(reader, to_conv);
  41   case 'd':
  42   case 'i':
  43   case 'u':
  44   case 'o':
  45   case 'x':
  46   case 'X':
  47     ret_val = raw_match(reader, " ");
  48     if (ret_val != READ_OK)
  49       return ret_val;
  50     return convert_int(reader, to_conv);
  51 #ifndef LIBC_COPT_SCANF_DISABLE_FLOAT
  52   case 'f':
  53   case 'F':
  54   case 'e':
  55   case 'E':
  56   case 'a':
  57   case 'A':
  58   case 'g':
  59   case 'G':
  60     ret_val = raw_match(reader, " ");
  61     if (ret_val != READ_OK)
  62       return ret_val;
  63     return convert_float(reader, to_conv);
  64 #endif // LIBC_COPT_SCANF_DISABLE_FLOAT
  65   case 'n':
  66     return convert_current_pos(reader, to_conv);
  67   case 'p':
  68     ret_val = raw_match(reader, " ");
  69     if (ret_val != READ_OK)
  70       return ret_val;
  71     return convert_pointer(reader, to_conv);
  72   default:
  73     return raw_match(reader, to_conv.raw_string);
  74   }
  75   return -1;
  76 }
  77
  78 // raw_string is assumed to have a positive size.
  79 int raw_match(Reader *reader, cpp::string_view raw_string) {
  80   char cur_char = reader->getc();
  81   int ret_val = READ_OK;
  82   for (size_t i = 0; i < raw_string.size(); ++i) {
  83     // Any space character matches any number of space characters.
  84     if (internal::isspace(raw_string[i])) {
  85       while (internal::isspace(cur_char)) {
  86         cur_char = reader->getc();
  87       }
  88     } else {
  89       if (raw_string[i] == cur_char) {
  90         cur_char = reader->getc();
  91       } else {
  92         ret_val = MATCHING_FAILURE;
  93         break;
  94       }
  95     }
  96   }
  97   reader->ungetc(cur_char);
  98   return ret_val;
  99 }
 100
 101 } // namespace scanf_core
 102 } // namespace LIBC_NAMESPACE