xref: /aosp_15_r20/external/llvm-libc/src/stdio/scanf_core/converter_utils.h (revision 71db0c75aadcf003ffe3238005f61d7618a3fead)
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/ctype_utils.h"
13 #include "src/__support/macros/config.h"
14 #include "src/__support/str_to_float.h"
15 #include "src/stdio/scanf_core/core_structs.h"
16 
17 #include <stddef.h>
18 
19 namespace LIBC_NAMESPACE_DECL {
20 namespace scanf_core {
21 
to_lower(char a)22 LIBC_INLINE constexpr char to_lower(char a) { return a | 32; }
23 
b36_char_to_int(char input)24 LIBC_INLINE constexpr int b36_char_to_int(char input) {
25   if (internal::isdigit(input))
26     return input - '0';
27   if (internal::isalpha(input))
28     return to_lower(input) + 10 - 'a';
29   return 0;
30 }
31 
write_int_with_length(uintmax_t output_val,const FormatSection & to_conv)32 LIBC_INLINE void write_int_with_length(uintmax_t output_val,
33                                        const FormatSection &to_conv) {
34   if ((to_conv.flags & NO_WRITE) != 0) {
35     return;
36   }
37   void *output_ptr = to_conv.output_ptr;
38   // The %p conversion uses this function, and is always void*.
39   if (to_conv.conv_name == 'p') {
40     *reinterpret_cast<void **>(output_ptr) =
41         reinterpret_cast<void *>(output_val);
42     return;
43   }
44   LengthModifier lm = to_conv.length_modifier;
45   switch (lm) {
46   case (LengthModifier::hh):
47     *reinterpret_cast<unsigned char *>(output_ptr) =
48         static_cast<unsigned char>(output_val);
49     break;
50   case (LengthModifier::h):
51     *reinterpret_cast<unsigned short *>(output_ptr) =
52         static_cast<unsigned short>(output_val);
53     break;
54   case (LengthModifier::NONE):
55     *reinterpret_cast<unsigned int *>(output_ptr) =
56         static_cast<unsigned int>(output_val);
57     break;
58   case (LengthModifier::l):
59     *reinterpret_cast<unsigned long *>(output_ptr) =
60         static_cast<unsigned long>(output_val);
61     break;
62   case (LengthModifier::ll):
63   case (LengthModifier::L):
64     *reinterpret_cast<unsigned long long *>(output_ptr) =
65         static_cast<unsigned long long>(output_val);
66     break;
67   case (LengthModifier::j):
68     *reinterpret_cast<uintmax_t *>(output_ptr) =
69         static_cast<uintmax_t>(output_val);
70     break;
71   case (LengthModifier::z):
72     *reinterpret_cast<size_t *>(output_ptr) = static_cast<size_t>(output_val);
73     break;
74   case (LengthModifier::t):
75     *reinterpret_cast<ptrdiff_t *>(output_ptr) =
76         static_cast<ptrdiff_t>(output_val);
77     break;
78   }
79 }
80 
write_float_with_length(char * str,const FormatSection & to_conv)81 LIBC_INLINE void write_float_with_length(char *str,
82                                          const FormatSection &to_conv) {
83   if ((to_conv.flags & NO_WRITE) != 0) {
84     return;
85   }
86 
87   void *output_ptr = to_conv.output_ptr;
88 
89   LengthModifier lm = to_conv.length_modifier;
90   switch (lm) {
91   case (LengthModifier::l): {
92     auto value = internal::strtofloatingpoint<double>(str);
93     *reinterpret_cast<double *>(output_ptr) = value;
94     break;
95   }
96   case (LengthModifier::L): {
97     auto value = internal::strtofloatingpoint<long double>(str);
98     *reinterpret_cast<long double *>(output_ptr) = value;
99     break;
100   }
101   default: {
102     auto value = internal::strtofloatingpoint<float>(str);
103     *reinterpret_cast<float *>(output_ptr) = value;
104     break;
105   }
106   }
107 }
108 
109 } // namespace scanf_core
110 } // namespace LIBC_NAMESPACE_DECL
111 
112 #endif // LLVM_LIBC_SRC_STDIO_SCANF_CORE_CONVERTER_UTILS_H
113