gdb/macrocmd.c

   1 /* C preprocessor macro expansion commands for GDB.
   2    Copyright (C) 2002, 2007, 2008 Free Software Foundation, Inc.
   3    Contributed by Red Hat, 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
  21 #include "defs.h"
  22 #include "macrotab.h"
  23 #include "macroexp.h"
  24 #include "macroscope.h"
  25 #include "command.h"
  26 #include "gdbcmd.h"
  27 #include "gdb_string.h"
  28
  29 \f
  30 /* The `macro' prefix command.  */
  31
  32 static struct cmd_list_element *macrolist;
  33
  34 static void
  35 macro_command (char *arg, int from_tty)
  36 {
  37   printf_unfiltered
  38     ("\"macro\" must be followed by the name of a macro command.\n");
  39   help_list (macrolist, "macro ", -1, gdb_stdout);
  40 }
  41
  42
  43 \f
  44 /* Macro expansion commands.  */
  45
  46
  47 static void
  48 macro_expand_command (char *exp, int from_tty)
  49 {
  50   struct macro_scope *ms = NULL;
  51   char *expanded = NULL;
  52   struct cleanup *cleanup_chain = make_cleanup (free_current_contents, &ms);
  53   make_cleanup (free_current_contents, &expanded);
  54
  55   /* You know, when the user doesn't specify any expression, it would be
  56      really cool if this defaulted to the last expression evaluated.
  57      Then it would be easy to ask, "Hey, what did I just evaluate?"  But
  58      at the moment, the `print' commands don't save the last expression
  59      evaluated, just its value.  */
  60   if (! exp || ! *exp)
  61     error (_("You must follow the `macro expand' command with the"
  62            " expression you\n"
  63            "want to expand."));
  64
  65   ms = default_macro_scope ();
  66   if (ms)
  67     {
  68       expanded = macro_expand (exp, standard_macro_lookup, ms);
  69       fputs_filtered ("expands to: ", gdb_stdout);
  70       fputs_filtered (expanded, gdb_stdout);
  71       fputs_filtered ("\n", gdb_stdout);
  72     }
  73   else
  74     fputs_filtered ("GDB has no preprocessor macro information for "
  75                     "that code.\n",
  76                     gdb_stdout);
  77
  78   do_cleanups (cleanup_chain);
  79   return;
  80 }
  81
  82
  83 static void
  84 macro_expand_once_command (char *exp, int from_tty)
  85 {
  86   struct macro_scope *ms = NULL;
  87   char *expanded = NULL;
  88   struct cleanup *cleanup_chain = make_cleanup (free_current_contents, &ms);
  89   make_cleanup (free_current_contents, &expanded);
  90
  91   /* You know, when the user doesn't specify any expression, it would be
  92      really cool if this defaulted to the last expression evaluated.
  93      And it should set the once-expanded text as the new `last
  94      expression'.  That way, you could just hit return over and over and
  95      see the expression expanded one level at a time.  */
  96   if (! exp || ! *exp)
  97     error (_("You must follow the `macro expand-once' command with"
  98            " the expression\n"
  99            "you want to expand."));
 100
 101   ms = default_macro_scope ();
 102   if (ms)
 103     {
 104       expanded = macro_expand_once (exp, standard_macro_lookup, ms);
 105       fputs_filtered ("expands to: ", gdb_stdout);
 106       fputs_filtered (expanded, gdb_stdout);
 107       fputs_filtered ("\n", gdb_stdout);
 108     }
 109   else
 110     fputs_filtered ("GDB has no preprocessor macro information for "
 111                     "that code.\n",
 112                     gdb_stdout);
 113
 114   do_cleanups (cleanup_chain);
 115   return;
 116 }
 117
 118
 119 static void
 120 show_pp_source_pos (struct ui_file *stream,
 121                     struct macro_source_file *file,
 122                     int line)
 123 {
 124   fprintf_filtered (stream, "%s:%d\n", file->filename, line);
 125
 126   while (file->included_by)
 127     {
 128       fprintf_filtered (gdb_stdout, "  included at %s:%d\n",
 129                         file->included_by->filename,
 130                         file->included_at_line);
 131       file = file->included_by;
 132     }
 133 }
 134
 135
 136 static void
 137 info_macro_command (char *name, int from_tty)
 138 {
 139   struct macro_scope *ms = NULL;
 140   struct cleanup *cleanup_chain = make_cleanup (free_current_contents, &ms);
 141   struct macro_definition *d;
 142
 143   if (! name || ! *name)
 144     error (_("You must follow the `info macro' command with the name"
 145            " of the macro\n"
 146            "whose definition you want to see."));
 147
 148   ms = default_macro_scope ();
 149   if (! ms)
 150     error (_("GDB has no preprocessor macro information for that code."));
 151
 152   d = macro_lookup_definition (ms->file, ms->line, name);
 153   if (d)
 154     {
 155       int line;
 156       struct macro_source_file *file
 157         = macro_definition_location (ms->file, ms->line, name, &line);
 158
 159       fprintf_filtered (gdb_stdout, "Defined at ");
 160       show_pp_source_pos (gdb_stdout, file, line);
 161       fprintf_filtered (gdb_stdout, "#define %s", name);
 162       if (d->kind == macro_function_like)
 163         {
 164           int i;
 165
 166           fputs_filtered ("(", gdb_stdout);
 167           for (i = 0; i < d->argc; i++)
 168             {
 169               fputs_filtered (d->argv[i], gdb_stdout);
 170               if (i + 1 < d->argc)
 171                 fputs_filtered (", ", gdb_stdout);
 172             }
 173           fputs_filtered (")", gdb_stdout);
 174         }
 175       fprintf_filtered (gdb_stdout, " %s\n", d->replacement);
 176     }
 177   else
 178     {
 179       fprintf_filtered (gdb_stdout,
 180                         "The symbol `%s' has no definition as a C/C++"
 181                         " preprocessor macro\n"
 182                         "at ", name);
 183       show_pp_source_pos (gdb_stdout, ms->file, ms->line);
 184     }
 185
 186   do_cleanups (cleanup_chain);
 187 }
 188
 189
 190 \f
 191 /* User-defined macros.  */
 192
 193 static void
 194 skip_ws (char **expp)
 195 {
 196   while (macro_is_whitespace (**expp))
 197     ++*expp;
 198 }
 199
 200 static char *
 201 extract_identifier (char **expp)
 202 {
 203   char *result;
 204   char *p = *expp;
 205   unsigned int len;
 206   if (! *p || ! macro_is_identifier_nondigit (*p))
 207     return NULL;
 208   for (++p;
 209        *p && (macro_is_identifier_nondigit (*p) || macro_is_digit (*p));
 210        ++p)
 211     ;
 212   len = p - *expp;
 213   result = (char *) xmalloc (len + 1);
 214   memcpy (result, *expp, len);
 215   result[len] = '\0';
 216   *expp += len;
 217   return result;
 218 }
 219
 220 /* Helper function to clean up a temporarily-constructed macro object.
 221    This assumes that the contents were all allocated with xmalloc.  */
 222 static void
 223 free_macro_definition_ptr (void *ptr)
 224 {
 225   int i;
 226   struct macro_definition *loc = (struct macro_definition *) ptr;
 227   for (i = 0; i < loc->argc; ++i)
 228     xfree ((char *) loc->argv[i]);
 229   xfree ((char *) loc->argv);
 230   /* Note that the 'replacement' field is not allocated.  */
 231 }
 232
 233 static void
 234 macro_define_command (char *exp, int from_tty)
 235 {
 236   struct macro_definition new_macro;
 237   char *name = NULL;
 238   struct cleanup *cleanup_chain = make_cleanup (free_macro_definition_ptr,
 239                                                 &new_macro);
 240   make_cleanup (free_current_contents, &name);
 241
 242   memset (&new_macro, 0, sizeof (struct macro_definition));
 243
 244   skip_ws (&exp);
 245   name = extract_identifier (&exp);
 246   if (! name)
 247     error (_("Invalid macro name."));
 248   if (*exp == '(')
 249     {
 250       /* Function-like macro.  */
 251       int alloced = 5;
 252       char **argv = (char **) xmalloc (alloced * sizeof (char *));
 253
 254       new_macro.kind = macro_function_like;
 255       new_macro.argc = 0;
 256       new_macro.argv = (const char * const *) argv;
 257
 258       /* Skip the '(' and whitespace.  */
 259       ++exp;
 260       skip_ws (&exp);
 261
 262       while (*exp != ')')
 263         {
 264           int i;
 265
 266           if (new_macro.argc == alloced)
 267             {
 268               alloced *= 2;
 269               argv = (char **) xrealloc (argv, alloced * sizeof (char *));
 270               /* Must update new_macro as well... */
 271               new_macro.argv = (const char * const *) argv;
 272             }
 273           argv[new_macro.argc] = extract_identifier (&exp);
 274           if (! argv[new_macro.argc])
 275             error (_("Macro is missing an argument."));
 276           ++new_macro.argc;
 277
 278           for (i = new_macro.argc - 2; i >= 0; --i)
 279             {
 280               if (! strcmp (argv[i], argv[new_macro.argc - 1]))
 281                 error (_("Two macro arguments with identical names."));
 282             }
 283
 284           skip_ws (&exp);
 285           if (*exp == ',')
 286             {
 287               ++exp;
 288               skip_ws (&exp);
 289             }
 290           else if (*exp != ')')
 291             error (_("',' or ')' expected at end of macro arguments."));
 292         }
 293       /* Skip the closing paren.  */
 294       ++exp;
 295
 296       macro_define_function (macro_main (macro_user_macros), -1, name,
 297                              new_macro.argc, (const char **) new_macro.argv,
 298                              exp);
 299     }
 300   else
 301     macro_define_object (macro_main (macro_user_macros), -1, name, exp);
 302
 303   do_cleanups (cleanup_chain);
 304 }
 305
 306
 307 static void
 308 macro_undef_command (char *exp, int from_tty)
 309 {
 310   char *name;
 311   skip_ws (&exp);
 312   name = extract_identifier (&exp);
 313   if (! name)
 314     error (_("Invalid macro name."));
 315   macro_undef (macro_main (macro_user_macros), -1, name);
 316   xfree (name);
 317 }
 318
 319
 320 static void
 321 print_one_macro (const char *name, const struct macro_definition *macro)
 322 {
 323   fprintf_filtered (gdb_stdout, "macro define %s", name);
 324   if (macro->kind == macro_function_like)
 325     {
 326       int i;
 327       fprintf_filtered (gdb_stdout, "(");
 328       for (i = 0; i < macro->argc; ++i)
 329         fprintf_filtered (gdb_stdout, "%s%s", (i > 0) ? ", " : "",
 330                           macro->argv[i]);
 331       fprintf_filtered (gdb_stdout, ")");
 332     }
 333   /* Note that we don't need a leading space here -- "macro define"
 334      provided it.  */
 335   fprintf_filtered (gdb_stdout, "%s\n", macro->replacement);
 336 }
 337
 338
 339 static void
 340 macro_list_command (char *exp, int from_tty)
 341 {
 342   macro_for_each (macro_user_macros, print_one_macro);
 343 }
 344
 345
 346 \f
 347 /* Initializing the `macrocmd' module.  */
 348
 349 extern initialize_file_ftype _initialize_macrocmd; /* -Wmissing-prototypes */
 350
 351 void
 352 _initialize_macrocmd (void)
 353 {
 354   struct cmd_list_element *c;
 355
 356   /* We introduce a new command prefix, `macro', under which we'll put
 357      the various commands for working with preprocessor macros.  */
 358   add_prefix_cmd ("macro", class_info, macro_command,
 359                   _("Prefix for commands dealing with C preprocessor macros."),
 360                   &macrolist, "macro ", 0, &cmdlist);
 361
 362   add_cmd ("expand", no_class, macro_expand_command, _("\
 363 Fully expand any C/C++ preprocessor macro invocations in EXPRESSION.\n\
 364 Show the expanded expression."),
 365            &macrolist);
 366   add_alias_cmd ("exp", "expand", no_class, 1, &macrolist);
 367   add_cmd ("expand-once", no_class, macro_expand_once_command, _("\
 368 Expand C/C++ preprocessor macro invocations appearing directly in EXPRESSION.\n\
 369 Show the expanded expression.\n\
 370 \n\
 371 This command differs from `macro expand' in that it only expands macro\n\
 372 invocations that appear directly in EXPRESSION; if expanding a macro\n\
 373 introduces further macro invocations, those are left unexpanded.\n\
 374 \n\
 375 `macro expand-once' helps you see how a particular macro expands,\n\
 376 whereas `macro expand' shows you how all the macros involved in an\n\
 377 expression work together to yield a pre-processed expression."),
 378            &macrolist);
 379   add_alias_cmd ("exp1", "expand-once", no_class, 1, &macrolist);
 380
 381   add_cmd ("macro", no_class, info_macro_command,
 382            _("Show the definition of MACRO, and its source location."),
 383            &infolist);
 384
 385   add_cmd ("define", no_class, macro_define_command, _("\
 386 Define a new C/C++ preprocessor macro.\n\
 387 The GDB command `macro define DEFINITION' is equivalent to placing a\n\
 388 preprocessor directive of the form `#define DEFINITION' such that the\n\
 389 definition is visible in all the inferior's source files.\n\
 390 For example:\n\
 391   (gdb) macro define PI (3.1415926)\n\
 392   (gdb) macro define MIN(x,y) ((x) < (y) ? (x) : (y))"),
 393            &macrolist);
 394
 395   add_cmd ("undef", no_class, macro_undef_command, _("\
 396 Remove the definition of the C/C++ preprocessor macro with the given name."),
 397            &macrolist);
 398
 399   add_cmd ("list", no_class, macro_list_command,
 400            _("List all the macros defined using the `macro define' command."),
 401            &macrolist);
 402 }