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| 1 | //===-- String type specifier converters 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_STRING_CONVERTER_H |
| 10 | #define LLVM_LIBC_SRC_STDIO_SCANF_CORE_STRING_CONVERTER_H |
| 11 | |
| 12 | #include "src/__support/CPP/limits.h" |
| 13 | #include "src/__support/ctype_utils.h" |
| 14 | #include "src/__support/macros/config.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_DECL { |
| 21 | namespace scanf_core { |
| 22 | |
| 23 | template <typename T> |
| 24 | int convert_string(Reader<T> *reader, const FormatSection &to_conv) { |
| 25 | // %s "Matches a sequence of non-white-space characters" |
| 26 | |
| 27 | // %c "Matches a sequence of characters of exactly the number specified by the |
| 28 | // field width (1 if no field width is present in the directive)" |
| 29 | |
| 30 | // %[ "Matches a nonempty sequence of characters from a set of expected |
| 31 | // characters (the scanset)." |
| 32 | size_t max_width = 0; |
| 33 | if (to_conv.max_width > 0) { |
| 34 | max_width = to_conv.max_width; |
| 35 | } else { |
| 36 | if (to_conv.conv_name == 'c') { |
| 37 | max_width = 1; |
| 38 | } else { |
| 39 | max_width = cpp::numeric_limits<size_t>::max(); |
| 40 | } |
| 41 | } |
| 42 | |
| 43 | char *output = reinterpret_cast<char *>(to_conv.output_ptr); |
| 44 | |
| 45 | char cur_char = reader->getc(); |
| 46 | size_t i = 0; |
| 47 | for (; i < max_width && cur_char != '\0'; ++i) { |
| 48 | // If this is %s and we've hit a space, or if this is %[] and we've found |
| 49 | // something not in the scanset. |
| 50 | if ((to_conv.conv_name == 's' && internal::isspace(cur_char)) || |
| 51 | (to_conv.conv_name == '[' && !to_conv.scan_set.test(cur_char))) { |
| 52 | break; |
| 53 | } |
| 54 | // if the NO_WRITE flag is not set, write to the output. |
| 55 | if ((to_conv.flags & NO_WRITE) == 0) |
| 56 | output[i] = cur_char; |
| 57 | cur_char = reader->getc(); |
| 58 | } |
| 59 | |
| 60 | // We always read one more character than will be used, so we have to put the |
| 61 | // last one back. |
| 62 | reader->ungetc(cur_char); |
| 63 | |
| 64 | // If this is %s or %[] |
| 65 | if (to_conv.conv_name != 'c' && (to_conv.flags & NO_WRITE) == 0) { |
| 66 | // Always null terminate the string. This may cause a write to the |
| 67 | // (max_width + 1) byte, which is correct. The max width describes the max |
| 68 | // number of characters read from the input string, and doesn't necessarily |
| 69 | // correspond to the output. |
| 70 | output[i] = '\0'; |
| 71 | } |
| 72 | |
| 73 | if (i == 0) |
| 74 | return MATCHING_FAILURE; |
| 75 | return READ_OK; |
| 76 | } |
| 77 | |
| 78 | } // namespace scanf_core |
| 79 | } // namespace LIBC_NAMESPACE_DECL |
| 80 | |
| 81 | #endif // LLVM_LIBC_SRC_STDIO_SCANF_CORE_STRING_CONVERTER_H |
| 82 |
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