| 1 | /* Scheme interface to lazy strings. |
| 2 | |
| 3 | Copyright (C) 2010-2015 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 | /* See README file in this directory for implementation notes, coding |
| 21 | conventions, et.al. */ |
| 22 | |
| 23 | #include "defs.h" |
| 24 | #include "charset.h" |
| 25 | #include "value.h" |
| 26 | #include "valprint.h" |
| 27 | #include "language.h" |
| 28 | #include "guile-internal.h" |
| 29 | |
| 30 | /* The <gdb:lazy-string> smob. */ |
| 31 | |
| 32 | typedef struct |
| 33 | { |
| 34 | /* This always appears first. */ |
| 35 | gdb_smob base; |
| 36 | |
| 37 | /* Holds the address of the lazy string. */ |
| 38 | CORE_ADDR address; |
| 39 | |
| 40 | /* Holds the encoding that will be applied to the string when the string |
| 41 | is printed by GDB. If the encoding is set to NULL then GDB will select |
| 42 | the most appropriate encoding when the sting is printed. |
| 43 | Space for this is malloc'd and will be freed when the object is |
| 44 | freed. */ |
| 45 | char *encoding; |
| 46 | |
| 47 | /* Holds the length of the string in characters. If the length is -1, |
| 48 | then the string will be fetched and encoded up to the first null of |
| 49 | appropriate width. */ |
| 50 | int length; |
| 51 | |
| 52 | /* This attribute holds the type that is represented by the lazy |
| 53 | string's type. */ |
| 54 | struct type *type; |
| 55 | } lazy_string_smob; |
| 56 | |
| 57 | static const char lazy_string_smob_name[] = "gdb:lazy-string"; |
| 58 | |
| 59 | /* The tag Guile knows the lazy string smob by. */ |
| 60 | static scm_t_bits lazy_string_smob_tag; |
| 61 | \f |
| 62 | /* Administrivia for lazy string smobs. */ |
| 63 | |
| 64 | /* The smob "free" function for <gdb:lazy-string>. */ |
| 65 | |
| 66 | static size_t |
| 67 | lsscm_free_lazy_string_smob (SCM self) |
| 68 | { |
| 69 | lazy_string_smob *v_smob = (lazy_string_smob *) SCM_SMOB_DATA (self); |
| 70 | |
| 71 | xfree (v_smob->encoding); |
| 72 | |
| 73 | return 0; |
| 74 | } |
| 75 | |
| 76 | /* The smob "print" function for <gdb:lazy-string>. */ |
| 77 | |
| 78 | static int |
| 79 | lsscm_print_lazy_string_smob (SCM self, SCM port, scm_print_state *pstate) |
| 80 | { |
| 81 | lazy_string_smob *ls_smob = (lazy_string_smob *) SCM_SMOB_DATA (self); |
| 82 | |
| 83 | gdbscm_printf (port, "#<%s", lazy_string_smob_name); |
| 84 | gdbscm_printf (port, " @%s", hex_string (ls_smob->address)); |
| 85 | if (ls_smob->length >= 0) |
| 86 | gdbscm_printf (port, " length %d", ls_smob->length); |
| 87 | if (ls_smob->encoding != NULL) |
| 88 | gdbscm_printf (port, " encoding %s", ls_smob->encoding); |
| 89 | scm_puts (">", port); |
| 90 | |
| 91 | scm_remember_upto_here_1 (self); |
| 92 | |
| 93 | /* Non-zero means success. */ |
| 94 | return 1; |
| 95 | } |
| 96 | |
| 97 | /* Low level routine to create a <gdb:lazy-string> object. |
| 98 | The caller must verify !(address == 0 && length != 0). */ |
| 99 | |
| 100 | static SCM |
| 101 | lsscm_make_lazy_string_smob (CORE_ADDR address, int length, |
| 102 | const char *encoding, struct type *type) |
| 103 | { |
| 104 | lazy_string_smob *ls_smob = (lazy_string_smob *) |
| 105 | scm_gc_malloc (sizeof (lazy_string_smob), lazy_string_smob_name); |
| 106 | SCM ls_scm; |
| 107 | |
| 108 | /* Caller must verify this. */ |
| 109 | gdb_assert (!(address == 0 && length != 0)); |
| 110 | gdb_assert (type != NULL); |
| 111 | |
| 112 | ls_smob->address = address; |
| 113 | /* Coerce all values < 0 to -1. */ |
| 114 | ls_smob->length = length < 0 ? -1 : length; |
| 115 | if (encoding == NULL || strcmp (encoding, "") == 0) |
| 116 | ls_smob->encoding = NULL; |
| 117 | else |
| 118 | ls_smob->encoding = xstrdup (encoding); |
| 119 | ls_smob->type = type; |
| 120 | |
| 121 | ls_scm = scm_new_smob (lazy_string_smob_tag, (scm_t_bits) ls_smob); |
| 122 | gdbscm_init_gsmob (&ls_smob->base); |
| 123 | |
| 124 | return ls_scm; |
| 125 | } |
| 126 | |
| 127 | /* Return non-zero if SCM is a <gdb:lazy-string> object. */ |
| 128 | |
| 129 | int |
| 130 | lsscm_is_lazy_string (SCM scm) |
| 131 | { |
| 132 | return SCM_SMOB_PREDICATE (lazy_string_smob_tag, scm); |
| 133 | } |
| 134 | |
| 135 | /* (lazy-string? object) -> boolean */ |
| 136 | |
| 137 | static SCM |
| 138 | gdbscm_lazy_string_p (SCM scm) |
| 139 | { |
| 140 | return scm_from_bool (lsscm_is_lazy_string (scm)); |
| 141 | } |
| 142 | |
| 143 | /* Main entry point to create a <gdb:lazy-string> object. |
| 144 | If there's an error a <gdb:exception> object is returned. */ |
| 145 | |
| 146 | SCM |
| 147 | lsscm_make_lazy_string (CORE_ADDR address, int length, |
| 148 | const char *encoding, struct type *type) |
| 149 | { |
| 150 | if (address == 0 && length != 0) |
| 151 | { |
| 152 | return gdbscm_make_out_of_range_error |
| 153 | (NULL, 0, scm_from_int (length), |
| 154 | _("cannot create a lazy string with address 0x0" |
| 155 | " and a non-zero length")); |
| 156 | } |
| 157 | |
| 158 | if (type == NULL) |
| 159 | { |
| 160 | return gdbscm_make_out_of_range_error |
| 161 | (NULL, 0, scm_from_int (0), _("a lazy string's type cannot be NULL")); |
| 162 | } |
| 163 | |
| 164 | return lsscm_make_lazy_string_smob (address, length, encoding, type); |
| 165 | } |
| 166 | |
| 167 | /* Returns the <gdb:lazy-string> smob in SELF. |
| 168 | Throws an exception if SELF is not a <gdb:lazy-string> object. */ |
| 169 | |
| 170 | static SCM |
| 171 | lsscm_get_lazy_string_arg_unsafe (SCM self, int arg_pos, const char *func_name) |
| 172 | { |
| 173 | SCM_ASSERT_TYPE (lsscm_is_lazy_string (self), self, arg_pos, func_name, |
| 174 | lazy_string_smob_name); |
| 175 | |
| 176 | return self; |
| 177 | } |
| 178 | \f |
| 179 | /* Lazy string methods. */ |
| 180 | |
| 181 | /* (lazy-string-address <gdb:lazy-string>) -> address */ |
| 182 | |
| 183 | static SCM |
| 184 | gdbscm_lazy_string_address (SCM self) |
| 185 | { |
| 186 | SCM ls_scm = lsscm_get_lazy_string_arg_unsafe (self, SCM_ARG1, FUNC_NAME); |
| 187 | lazy_string_smob *ls_smob = (lazy_string_smob *) SCM_SMOB_DATA (ls_scm); |
| 188 | |
| 189 | return gdbscm_scm_from_ulongest (ls_smob->address); |
| 190 | } |
| 191 | |
| 192 | /* (lazy-string-length <gdb:lazy-string>) -> integer */ |
| 193 | |
| 194 | static SCM |
| 195 | gdbscm_lazy_string_length (SCM self) |
| 196 | { |
| 197 | SCM ls_scm = lsscm_get_lazy_string_arg_unsafe (self, SCM_ARG1, FUNC_NAME); |
| 198 | lazy_string_smob *ls_smob = (lazy_string_smob *) SCM_SMOB_DATA (ls_scm); |
| 199 | |
| 200 | return scm_from_int (ls_smob->length); |
| 201 | } |
| 202 | |
| 203 | /* (lazy-string-encoding <gdb:lazy-string>) -> string */ |
| 204 | |
| 205 | static SCM |
| 206 | gdbscm_lazy_string_encoding (SCM self) |
| 207 | { |
| 208 | SCM ls_scm = lsscm_get_lazy_string_arg_unsafe (self, SCM_ARG1, FUNC_NAME); |
| 209 | lazy_string_smob *ls_smob = (lazy_string_smob *) SCM_SMOB_DATA (ls_scm); |
| 210 | |
| 211 | /* An encoding can be set to NULL by the user, so check first. |
| 212 | If NULL return #f. */ |
| 213 | if (ls_smob != NULL) |
| 214 | return gdbscm_scm_from_c_string (ls_smob->encoding); |
| 215 | return SCM_BOOL_F; |
| 216 | } |
| 217 | |
| 218 | /* (lazy-string-type <gdb:lazy-string>) -> <gdb:type> */ |
| 219 | |
| 220 | static SCM |
| 221 | gdbscm_lazy_string_type (SCM self) |
| 222 | { |
| 223 | SCM ls_scm = lsscm_get_lazy_string_arg_unsafe (self, SCM_ARG1, FUNC_NAME); |
| 224 | lazy_string_smob *ls_smob = (lazy_string_smob *) SCM_SMOB_DATA (ls_scm); |
| 225 | |
| 226 | return tyscm_scm_from_type (ls_smob->type); |
| 227 | } |
| 228 | |
| 229 | /* (lazy-string->value <gdb:lazy-string>) -> <gdb:value> */ |
| 230 | |
| 231 | static SCM |
| 232 | gdbscm_lazy_string_to_value (SCM self) |
| 233 | { |
| 234 | SCM ls_scm = lsscm_get_lazy_string_arg_unsafe (self, SCM_ARG1, FUNC_NAME); |
| 235 | lazy_string_smob *ls_smob = (lazy_string_smob *) SCM_SMOB_DATA (ls_scm); |
| 236 | struct value *value = NULL; |
| 237 | |
| 238 | if (ls_smob->address == 0) |
| 239 | { |
| 240 | gdbscm_throw (gdbscm_make_out_of_range_error (FUNC_NAME, SCM_ARG1, self, |
| 241 | _("cannot create a value from NULL"))); |
| 242 | } |
| 243 | |
| 244 | TRY |
| 245 | { |
| 246 | value = value_at_lazy (ls_smob->type, ls_smob->address); |
| 247 | } |
| 248 | CATCH (except, RETURN_MASK_ALL) |
| 249 | { |
| 250 | GDBSCM_HANDLE_GDB_EXCEPTION (except); |
| 251 | } |
| 252 | END_CATCH |
| 253 | |
| 254 | return vlscm_scm_from_value (value); |
| 255 | } |
| 256 | |
| 257 | /* A "safe" version of gdbscm_lazy_string_to_value for use by |
| 258 | vlscm_convert_typed_value_from_scheme. |
| 259 | The result, upon success, is the value of <gdb:lazy-string> STRING. |
| 260 | ARG_POS is the argument position of STRING in the original Scheme |
| 261 | function call, used in exception text. |
| 262 | If there's an error, NULL is returned and a <gdb:exception> object |
| 263 | is stored in *except_scmp. |
| 264 | |
| 265 | Note: The result is still "lazy". The caller must call value_fetch_lazy |
| 266 | to actually fetch the value. */ |
| 267 | |
| 268 | struct value * |
| 269 | lsscm_safe_lazy_string_to_value (SCM string, int arg_pos, |
| 270 | const char *func_name, SCM *except_scmp) |
| 271 | { |
| 272 | lazy_string_smob *ls_smob; |
| 273 | struct value *value = NULL; |
| 274 | |
| 275 | gdb_assert (lsscm_is_lazy_string (string)); |
| 276 | |
| 277 | ls_smob = (lazy_string_smob *) SCM_SMOB_DATA (string); |
| 278 | *except_scmp = SCM_BOOL_F; |
| 279 | |
| 280 | if (ls_smob->address == 0) |
| 281 | { |
| 282 | *except_scmp |
| 283 | = gdbscm_make_out_of_range_error (FUNC_NAME, SCM_ARG1, string, |
| 284 | _("cannot create a value from NULL")); |
| 285 | return NULL; |
| 286 | } |
| 287 | |
| 288 | TRY |
| 289 | { |
| 290 | value = value_at_lazy (ls_smob->type, ls_smob->address); |
| 291 | } |
| 292 | CATCH (except, RETURN_MASK_ALL) |
| 293 | { |
| 294 | *except_scmp = gdbscm_scm_from_gdb_exception (except); |
| 295 | return NULL; |
| 296 | } |
| 297 | END_CATCH |
| 298 | |
| 299 | return value; |
| 300 | } |
| 301 | |
| 302 | /* Print a lazy string to STREAM using val_print_string. |
| 303 | STRING must be a <gdb:lazy-string> object. */ |
| 304 | |
| 305 | void |
| 306 | lsscm_val_print_lazy_string (SCM string, struct ui_file *stream, |
| 307 | const struct value_print_options *options) |
| 308 | { |
| 309 | lazy_string_smob *ls_smob; |
| 310 | |
| 311 | gdb_assert (lsscm_is_lazy_string (string)); |
| 312 | |
| 313 | ls_smob = (lazy_string_smob *) SCM_SMOB_DATA (string); |
| 314 | |
| 315 | val_print_string (ls_smob->type, ls_smob->encoding, |
| 316 | ls_smob->address, ls_smob->length, |
| 317 | stream, options); |
| 318 | } |
| 319 | \f |
| 320 | /* Initialize the Scheme lazy-strings code. */ |
| 321 | |
| 322 | static const scheme_function lazy_string_functions[] = |
| 323 | { |
| 324 | { "lazy-string?", 1, 0, 0, as_a_scm_t_subr (gdbscm_lazy_string_p), |
| 325 | "\ |
| 326 | Return #t if the object is a <gdb:lazy-string> object." }, |
| 327 | |
| 328 | { "lazy-string-address", 1, 0, 0, |
| 329 | as_a_scm_t_subr (gdbscm_lazy_string_address), |
| 330 | "\ |
| 331 | Return the address of the lazy-string." }, |
| 332 | |
| 333 | { "lazy-string-length", 1, 0, 0, as_a_scm_t_subr (gdbscm_lazy_string_length), |
| 334 | "\ |
| 335 | Return the length of the lazy-string.\n\ |
| 336 | If the length is -1 then the length is determined by the first null\n\ |
| 337 | of appropriate width." }, |
| 338 | |
| 339 | { "lazy-string-encoding", 1, 0, 0, |
| 340 | as_a_scm_t_subr (gdbscm_lazy_string_encoding), |
| 341 | "\ |
| 342 | Return the encoding of the lazy-string." }, |
| 343 | |
| 344 | { "lazy-string-type", 1, 0, 0, as_a_scm_t_subr (gdbscm_lazy_string_type), |
| 345 | "\ |
| 346 | Return the <gdb:type> of the lazy-string." }, |
| 347 | |
| 348 | { "lazy-string->value", 1, 0, 0, |
| 349 | as_a_scm_t_subr (gdbscm_lazy_string_to_value), |
| 350 | "\ |
| 351 | Return the <gdb:value> representation of the lazy-string." }, |
| 352 | |
| 353 | END_FUNCTIONS |
| 354 | }; |
| 355 | |
| 356 | void |
| 357 | gdbscm_initialize_lazy_strings (void) |
| 358 | { |
| 359 | lazy_string_smob_tag = gdbscm_make_smob_type (lazy_string_smob_name, |
| 360 | sizeof (lazy_string_smob)); |
| 361 | scm_set_smob_free (lazy_string_smob_tag, lsscm_free_lazy_string_smob); |
| 362 | scm_set_smob_print (lazy_string_smob_tag, lsscm_print_lazy_string_smob); |
| 363 | |
| 364 | gdbscm_define_functions (lazy_string_functions, 1); |
| 365 | } |