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1 //===-- Core Structures 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_CORE_STRUCTS_H
10 #define LLVM_LIBC_SRC_STDIO_SCANF_CORE_CORE_STRUCTS_H
11 
12 #include "src/__support/CPP/bitset.h"
13 #include "src/__support/CPP/string_view.h"
14 
15 #include <inttypes.h>
16 #include <stddef.h>
17 
18 namespace LIBC_NAMESPACE {
19 namespace scanf_core {
20 
21 // These length modifiers match the length modifiers in the format string, which
22 // is why they are formatted differently from the rest of the file.
23 enum class LengthModifier { hh, h, l, ll, j, z, t, L, NONE };
24 
25 enum FormatFlags : uint8_t {
26   NONE = 0x00,
27   NO_WRITE = 0x01, // *
28   ALLOCATE = 0x02, // m
29 };
30 
31 struct FormatSection {
32   bool has_conv;
33 
34   cpp::string_view raw_string;
35 
36   // Format Specifier Values
37   FormatFlags flags = FormatFlags::NONE;
38   LengthModifier length_modifier = LengthModifier::NONE;
39   int max_width = -1;
40 
41   // output_ptr is nullptr if and only if the NO_WRITE flag is set.
42   void *output_ptr = nullptr;
43 
44   char conv_name;
45 
46   cpp::bitset<256> scan_set;
47 
48   LIBC_INLINE bool operator==(const FormatSection &other) {
49     if (has_conv != other.has_conv)
50       return false;
51 
52     if (raw_string != other.raw_string)
53       return false;
54 
55     if (has_conv) {
56       if (!((static_cast<uint8_t>(flags) ==
57              static_cast<uint8_t>(other.flags)) &&
58             (max_width == other.max_width) &&
59             (length_modifier == other.length_modifier) &&
60             (conv_name == other.conv_name)))
61         return false;
62 
63       // If the pointers are used, then they should be equal. If the NO_WRITE
64       // flag is set or the conversion is %, then the pointers are not used.
65       // If the pointers are used and they are not equal, return false.
66 
67       if (!(((flags & FormatFlags::NO_WRITE) != 0) || (conv_name == '%') ||
68             (output_ptr == other.output_ptr)))
69         return false;
70 
71       if (conv_name == '[')
72         return scan_set == other.scan_set;
73     }
74     return true;
75   }
76 };
77 
78 enum ErrorCodes : int {
79   // This is the value to be returned by conversions when no error has occurred.
80   READ_OK = 0,
81   // These are the scanf return values for when an error has occurred. They are
82   // all negative, and should be distinct.
83   FILE_READ_ERROR = -1,
84   FILE_STATUS_ERROR = -2,
85   MATCHING_FAILURE = -3,
86   ALLOCATION_FAILURE = -4,
87 };
88 } // namespace scanf_core
89 } // namespace LIBC_NAMESPACE
90 
91 #endif // LLVM_LIBC_SRC_STDIO_SCANF_CORE_CORE_STRUCTS_H
92