| 1 | /* Miscellaneous routines making it easier to use GMP within GDB's framework. |
| 2 | |
| 3 | Copyright (C) 2019-2021 Free Software Foundation, Inc. |
| 4 | |
| 5 | This file is part of GDB. |
| 6 | |
| 7 | This program is free software; you can redistribute it and/or modify |
| 8 | it under the terms of the GNU General Public License as published by |
| 9 | the Free Software Foundation; either version 3 of the License, or |
| 10 | (at your option) any later version. |
| 11 | |
| 12 | This program is distributed in the hope that it will be useful, |
| 13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | GNU General Public License for more details. |
| 16 | |
| 17 | You should have received a copy of the GNU General Public License |
| 18 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| 19 | |
| 20 | #ifndef GMP_UTILS_H |
| 21 | #define GMP_UTILS_H |
| 22 | |
| 23 | #include "defs.h" |
| 24 | |
| 25 | /* Include <stdio.h> and <stdarg.h> ahead of <gmp.h>, so as to get |
| 26 | access to GMP's various formatting functions. */ |
| 27 | #include <stdio.h> |
| 28 | #include <stdarg.h> |
| 29 | #include <gmp.h> |
| 30 | #include "gdbsupport/traits.h" |
| 31 | |
| 32 | /* Same as gmp_asprintf, but returning an std::string. */ |
| 33 | |
| 34 | std::string gmp_string_printf (const char *fmt, ...); |
| 35 | |
| 36 | /* A class to make it easier to use GMP's mpz_t values within GDB. */ |
| 37 | |
| 38 | struct gdb_mpz |
| 39 | { |
| 40 | mpz_t val; |
| 41 | |
| 42 | /* Constructors. */ |
| 43 | gdb_mpz () { mpz_init (val); } |
| 44 | |
| 45 | explicit gdb_mpz (const mpz_t &from_val) |
| 46 | { |
| 47 | mpz_init (val); |
| 48 | mpz_set (val, from_val); |
| 49 | } |
| 50 | |
| 51 | gdb_mpz (const gdb_mpz &from) |
| 52 | { |
| 53 | mpz_init (val); |
| 54 | mpz_set (val, from.val); |
| 55 | } |
| 56 | |
| 57 | /* Initialize using the given integral value. |
| 58 | |
| 59 | The main advantage of this method is that it handles both signed |
| 60 | and unsigned types, with no size restriction. */ |
| 61 | template<typename T, typename = gdb::Requires<std::is_integral<T>>> |
| 62 | explicit gdb_mpz (T src) |
| 63 | { |
| 64 | mpz_init (val); |
| 65 | set (src); |
| 66 | } |
| 67 | |
| 68 | explicit gdb_mpz (gdb_mpz &&from) |
| 69 | { |
| 70 | mpz_init (val); |
| 71 | mpz_swap (val, from.val); |
| 72 | } |
| 73 | |
| 74 | |
| 75 | gdb_mpz &operator= (const gdb_mpz &from) |
| 76 | { |
| 77 | mpz_set (val, from.val); |
| 78 | return *this; |
| 79 | } |
| 80 | |
| 81 | gdb_mpz &operator= (gdb_mpz &&other) |
| 82 | { |
| 83 | mpz_swap (val, other.val); |
| 84 | return *this; |
| 85 | } |
| 86 | |
| 87 | template<typename T, typename = gdb::Requires<std::is_integral<T>>> |
| 88 | gdb_mpz &operator= (T src) |
| 89 | { |
| 90 | set (src); |
| 91 | return *this; |
| 92 | } |
| 93 | |
| 94 | /* Convert VAL to an integer of the given type. |
| 95 | |
| 96 | The return type can signed or unsigned, with no size restriction. */ |
| 97 | template<typename T> T as_integer () const; |
| 98 | |
| 99 | /* Set VAL by importing the number stored in the byte array (BUF), |
| 100 | using the given BYTE_ORDER. The size of the data to read is |
| 101 | the byte array's size. |
| 102 | |
| 103 | UNSIGNED_P indicates whether the number has an unsigned type. */ |
| 104 | void read (gdb::array_view<const gdb_byte> buf, enum bfd_endian byte_order, |
| 105 | bool unsigned_p); |
| 106 | |
| 107 | /* Write VAL into BUF as a number whose byte size is the size of BUF, |
| 108 | using the given BYTE_ORDER. |
| 109 | |
| 110 | UNSIGNED_P indicates whether the number has an unsigned type. */ |
| 111 | void write (gdb::array_view<gdb_byte> buf, enum bfd_endian byte_order, |
| 112 | bool unsigned_p) const; |
| 113 | |
| 114 | /* Return a string containing VAL. */ |
| 115 | std::string str () const { return gmp_string_printf ("%Zd", val); } |
| 116 | |
| 117 | /* The destructor. */ |
| 118 | ~gdb_mpz () { mpz_clear (val); } |
| 119 | |
| 120 | private: |
| 121 | |
| 122 | /* Helper template for constructor and operator=. */ |
| 123 | template<typename T> void set (T src); |
| 124 | |
| 125 | /* Low-level function to export VAL into BUF as a number whose byte size |
| 126 | is the size of BUF. |
| 127 | |
| 128 | If UNSIGNED_P is true, then export VAL into BUF as an unsigned value. |
| 129 | Otherwise, export it as a signed value. |
| 130 | |
| 131 | The API is inspired from GMP's mpz_export, hence the naming and types |
| 132 | of the following parameter: |
| 133 | - ENDIAN should be: |
| 134 | . 1 for most significant byte first; or |
| 135 | . -1 for least significant byte first; or |
| 136 | . 0 for native endianness. |
| 137 | |
| 138 | An error is raised if BUF is not large enough to contain the value |
| 139 | being exported. */ |
| 140 | void safe_export (gdb::array_view<gdb_byte> buf, |
| 141 | int endian, bool unsigned_p) const; |
| 142 | }; |
| 143 | |
| 144 | /* A class to make it easier to use GMP's mpq_t values within GDB. */ |
| 145 | |
| 146 | struct gdb_mpq |
| 147 | { |
| 148 | mpq_t val; |
| 149 | |
| 150 | /* Constructors. */ |
| 151 | gdb_mpq () { mpq_init (val); } |
| 152 | |
| 153 | explicit gdb_mpq (const mpq_t &from_val) |
| 154 | { |
| 155 | mpq_init (val); |
| 156 | mpq_set (val, from_val); |
| 157 | } |
| 158 | |
| 159 | gdb_mpq (const gdb_mpq &from) |
| 160 | { |
| 161 | mpq_init (val); |
| 162 | mpq_set (val, from.val); |
| 163 | } |
| 164 | |
| 165 | explicit gdb_mpq (gdb_mpq &&from) |
| 166 | { |
| 167 | mpq_init (val); |
| 168 | mpq_swap (val, from.val); |
| 169 | } |
| 170 | |
| 171 | /* Copy assignment operator. */ |
| 172 | gdb_mpq &operator= (const gdb_mpq &from) |
| 173 | { |
| 174 | mpq_set (val, from.val); |
| 175 | return *this; |
| 176 | } |
| 177 | |
| 178 | gdb_mpq &operator= (gdb_mpq &&from) |
| 179 | { |
| 180 | mpq_swap (val, from.val); |
| 181 | return *this; |
| 182 | } |
| 183 | |
| 184 | /* Return a string representing VAL as "<numerator> / <denominator>". */ |
| 185 | std::string str () const { return gmp_string_printf ("%Qd", val); } |
| 186 | |
| 187 | /* Return VAL rounded to the nearest integer. */ |
| 188 | gdb_mpz get_rounded () const; |
| 189 | |
| 190 | /* Set VAL from the contents of the given byte array (BUF), which |
| 191 | contains the unscaled value of a fixed point type object. |
| 192 | The byte size of the data is the size of BUF. |
| 193 | |
| 194 | BYTE_ORDER provides the byte_order to use when reading the data. |
| 195 | |
| 196 | UNSIGNED_P indicates whether the number has an unsigned type. |
| 197 | SCALING_FACTOR is the scaling factor to apply after having |
| 198 | read the unscaled value from our buffer. */ |
| 199 | void read_fixed_point (gdb::array_view<const gdb_byte> buf, |
| 200 | enum bfd_endian byte_order, bool unsigned_p, |
| 201 | const gdb_mpq &scaling_factor); |
| 202 | |
| 203 | /* Write VAL into BUF as fixed point value following the given BYTE_ORDER. |
| 204 | The size of BUF is used as the length to write the value into. |
| 205 | |
| 206 | UNSIGNED_P indicates whether the number has an unsigned type. |
| 207 | SCALING_FACTOR is the scaling factor to apply before writing |
| 208 | the unscaled value to our buffer. */ |
| 209 | void write_fixed_point (gdb::array_view<gdb_byte> buf, |
| 210 | enum bfd_endian byte_order, bool unsigned_p, |
| 211 | const gdb_mpq &scaling_factor) const; |
| 212 | |
| 213 | /* The destructor. */ |
| 214 | ~gdb_mpq () { mpq_clear (val); } |
| 215 | }; |
| 216 | |
| 217 | /* A class to make it easier to use GMP's mpf_t values within GDB. |
| 218 | |
| 219 | Should MPFR become a required dependency, we should probably |
| 220 | drop this class in favor of using MPFR. */ |
| 221 | |
| 222 | struct gdb_mpf |
| 223 | { |
| 224 | mpf_t val; |
| 225 | |
| 226 | /* Constructors. */ |
| 227 | gdb_mpf () { mpf_init (val); } |
| 228 | |
| 229 | DISABLE_COPY_AND_ASSIGN (gdb_mpf); |
| 230 | |
| 231 | /* Set VAL from the contents of the given buffer (BUF), which |
| 232 | contains the unscaled value of a fixed point type object |
| 233 | with the given size (LEN) and byte order (BYTE_ORDER). |
| 234 | |
| 235 | UNSIGNED_P indicates whether the number has an unsigned type. |
| 236 | SCALING_FACTOR is the scaling factor to apply after having |
| 237 | read the unscaled value from our buffer. */ |
| 238 | void read_fixed_point (gdb::array_view<const gdb_byte> buf, |
| 239 | enum bfd_endian byte_order, bool unsigned_p, |
| 240 | const gdb_mpq &scaling_factor) |
| 241 | { |
| 242 | gdb_mpq tmp_q; |
| 243 | |
| 244 | tmp_q.read_fixed_point (buf, byte_order, unsigned_p, scaling_factor); |
| 245 | mpf_set_q (val, tmp_q.val); |
| 246 | } |
| 247 | |
| 248 | /* The destructor. */ |
| 249 | ~gdb_mpf () { mpf_clear (val); } |
| 250 | }; |
| 251 | |
| 252 | /* See declaration above. */ |
| 253 | |
| 254 | template<typename T> |
| 255 | void |
| 256 | gdb_mpz::set (T src) |
| 257 | { |
| 258 | mpz_import (val, 1 /* count */, -1 /* order */, |
| 259 | sizeof (T) /* size */, 0 /* endian (0 = native) */, |
| 260 | 0 /* nails */, &src /* op */); |
| 261 | if (std::is_signed<T>::value && src < 0) |
| 262 | { |
| 263 | /* mpz_import does not handle the sign, so our value was imported |
| 264 | as an unsigned. Adjust that imported value so as to make it |
| 265 | the correct negative value. */ |
| 266 | gdb_mpz neg_offset; |
| 267 | |
| 268 | mpz_ui_pow_ui (neg_offset.val, 2, sizeof (T) * HOST_CHAR_BIT); |
| 269 | mpz_sub (val, val, neg_offset.val); |
| 270 | } |
| 271 | } |
| 272 | |
| 273 | /* See declaration above. */ |
| 274 | |
| 275 | template<typename T> |
| 276 | T |
| 277 | gdb_mpz::as_integer () const |
| 278 | { |
| 279 | T result; |
| 280 | |
| 281 | this->safe_export ({(gdb_byte *) &result, sizeof (result)}, |
| 282 | 0 /* endian (0 = native) */, |
| 283 | !std::is_signed<T>::value /* unsigned_p */); |
| 284 | |
| 285 | return result; |
| 286 | } |
| 287 | |
| 288 | #endif |