gdb/macrocmd.c

   1 /* C preprocessor macro expansion commands for GDB.
   2    Copyright 2002 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 2 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, write to the Free Software
  19    Foundation, Inc., 59 Temple Place - Suite 330,
  20    Boston, MA 02111-1307, USA.  */
  21
  22
  23 #include "defs.h"
  24 #include "macrotab.h"
  25 #include "macroexp.h"
  26 #include "macroscope.h"
  27 #include "command.h"
  28 #include "gdbcmd.h"
  29
  30 \f
  31 /* The `macro' prefix command.  */
  32
  33 static struct cmd_list_element *macrolist;
  34
  35 static void
  36 macro_command (char *arg, int from_tty)
  37 {
  38   printf_unfiltered
  39     ("\"macro\" must be followed by the name of a macro command.\n");
  40   help_list (macrolist, "macro ", -1, gdb_stdout);
  41 }
  42
  43
  44 \f
  45 /* Macro expansion commands.  */
  46
  47
  48 static void
  49 macro_expand_command (char *exp, int from_tty)
  50 {
  51   struct macro_scope *ms = NULL;
  52   char *expanded = NULL;
  53   struct cleanup *cleanup_chain = make_cleanup (free_current_contents, &ms);
  54   make_cleanup (free_current_contents, &expanded);
  55
  56   /* You know, when the user doesn't specify any expression, it would be
  57      really cool if this defaulted to the last expression evaluated.
  58      Then it would be easy to ask, "Hey, what did I just evaluate?"  But
  59      at the moment, the `print' commands don't save the last expression
  60      evaluated, just its value.  */
  61   if (! exp || ! *exp)
  62     error ("You must follow the `macro expand' command with the"
  63            " expression you\n"
  64            "want to expand.");
  65
  66   ms = default_macro_scope ();
  67   if (ms)
  68     {
  69       expanded = macro_expand (exp, standard_macro_lookup, ms);
  70       fputs_filtered ("expands to: ", gdb_stdout);
  71       fputs_filtered (expanded, gdb_stdout);
  72       fputs_filtered ("\n", gdb_stdout);
  73     }
  74   else
  75     fputs_filtered ("GDB has no preprocessor macro information for "
  76                     "that code.\n",
  77                     gdb_stdout);
  78
  79   do_cleanups (cleanup_chain);
  80   return;
  81 }
  82
  83
  84 static void
  85 macro_expand_once_command (char *exp, int from_tty)
  86 {
  87   struct macro_scope *ms = NULL;
  88   char *expanded = NULL;
  89   struct cleanup *cleanup_chain = make_cleanup (free_current_contents, &ms);
  90   make_cleanup (free_current_contents, &expanded);
  91
  92   /* You know, when the user doesn't specify any expression, it would be
  93      really cool if this defaulted to the last expression evaluated.
  94      And it should set the once-expanded text as the new `last
  95      expression'.  That way, you could just hit return over and over and
  96      see the expression expanded one level at a time.  */
  97   if (! exp || ! *exp)
  98     error ("You must follow the `macro expand-once' command with"
  99            " the expression\n"
 100            "you want to expand.");
 101
 102   ms = default_macro_scope ();
 103   if (ms)
 104     {
 105       expanded = macro_expand_once (exp, standard_macro_lookup, ms);
 106       fputs_filtered ("expands to: ", gdb_stdout);
 107       fputs_filtered (expanded, gdb_stdout);
 108       fputs_filtered ("\n", gdb_stdout);
 109     }
 110   else
 111     fputs_filtered ("GDB has no preprocessor macro information for "
 112                     "that code.\n",
 113                     gdb_stdout);
 114
 115   do_cleanups (cleanup_chain);
 116   return;
 117 }
 118
 119
 120 static void
 121 show_pp_source_pos (struct ui_file *stream,
 122                     struct macro_source_file *file,
 123                     int line)
 124 {
 125   fprintf_filtered (stream, "%s:%d\n", file->filename, line);
 126
 127   while (file->included_by)
 128     {
 129       fprintf_filtered (gdb_stdout, "  included at %s:%d\n",
 130                         file->included_by->filename,
 131                         file->included_at_line);
 132       file = file->included_by;
 133     }
 134 }
 135
 136
 137 static void
 138 info_macro_command (char *name, int from_tty)
 139 {
 140   struct macro_scope *ms = NULL;
 141   struct cleanup *cleanup_chain = make_cleanup (free_current_contents, &ms);
 142   struct macro_definition *d;
 143
 144   if (! name || ! *name)
 145     error ("You must follow the `info macro' command with the name"
 146            " of the macro\n"
 147            "whose definition you want to see.");
 148
 149   ms = default_macro_scope ();
 150   if (! ms)
 151     error ("GDB has no preprocessor macro information for that code.");
 152
 153   d = macro_lookup_definition (ms->file, ms->line, name);
 154   if (d)
 155     {
 156       int line;
 157       struct macro_source_file *file
 158         = macro_definition_location (ms->file, ms->line, name, &line);
 159
 160       fprintf_filtered (gdb_stdout, "Defined at ");
 161       show_pp_source_pos (gdb_stdout, file, line);
 162       fprintf_filtered (gdb_stdout, "#define %s", name);
 163       if (d->kind == macro_function_like)
 164         {
 165           int i;
 166
 167           fputs_filtered ("(", gdb_stdout);
 168           for (i = 0; i < d->argc; i++)
 169             {
 170               fputs_filtered (d->argv[i], gdb_stdout);
 171               if (i + 1 < d->argc)
 172                 fputs_filtered (", ", gdb_stdout);
 173             }
 174           fputs_filtered (")", gdb_stdout);
 175         }
 176       fprintf_filtered (gdb_stdout, " %s\n", d->replacement);
 177     }
 178   else
 179     {
 180       fprintf_filtered (gdb_stdout,
 181                         "The symbol `%s' has no definition as a C/C++"
 182                         " preprocessor macro\n"
 183                         "at ", name);
 184       show_pp_source_pos (gdb_stdout, ms->file, ms->line);
 185     }
 186
 187   do_cleanups (cleanup_chain);
 188 }
 189
 190
 191 \f
 192 /* User-defined macros.  */
 193
 194 /* A table of user-defined macros.  Unlike the macro tables used for
 195    symtabs, this one uses xmalloc for all its allocation, not an
 196    obstack, and it doesn't bcache anything; it just xmallocs things.  So
 197    it's perfectly possible to remove things from this, or redefine
 198    things.  */
 199 static struct macro_table *user_macros;
 200
 201 static void
 202 macro_define_command (char *exp, int from_tty)
 203 {
 204   error ("Command not implemented yet.");
 205 }
 206
 207
 208 static void
 209 macro_undef_command (char *exp, int from_tty)
 210 {
 211   error ("Command not implemented yet.");
 212 }
 213
 214
 215 static void
 216 macro_list_command (char *exp, int from_tty)
 217 {
 218   error ("Command not implemented yet.");
 219 }
 220
 221
 222 \f
 223 /* Initializing the `macrocmd' module.  */
 224
 225 extern initialize_file_ftype _initialize_macrocmd; /* -Wmissing-prototypes */
 226
 227 void
 228 _initialize_macrocmd (void)
 229 {
 230   struct cmd_list_element *c;
 231
 232   /* We introduce a new command prefix, `macro', under which we'll put
 233      the various commands for working with preprocessor macros.  */
 234   add_prefix_cmd
 235     ("macro", class_info, macro_command,
 236      "Prefix for commands dealing with C preprocessor macros.",
 237      &macrolist, "macro ", 0, &cmdlist);
 238
 239   add_cmd
 240     ("expand", no_class, macro_expand_command,
 241      "Fully expand any C/C++ preprocessor macro invocations in EXPRESSION.\n"
 242      "Show the expanded expression.",
 243      &macrolist);
 244   add_alias_cmd ("exp", "expand", no_class, 1, &macrolist);
 245   add_cmd
 246     ("expand-once", no_class, macro_expand_once_command,
 247      "Expand C/C++ preprocessor macro invocations appearing directly in"
 248      " EXPRESSION.\n"
 249      "Show the expanded expression.\n"
 250      "\n"
 251      "This command differs from `macro expand' in that it only expands macro\n"
 252      "invocations that appear directly in EXPRESSION; if expanding a macro\n"
 253      "introduces further macro invocations, those are left unexpanded.\n"
 254      "\n"
 255      "`macro expand-once' helps you see how a particular macro expands,\n"
 256      "whereas `macro expand' shows you how all the macros involved in an\n"
 257      "expression work together to yield a pre-processed expression.",
 258      &macrolist);
 259   add_alias_cmd ("exp1", "expand-once", no_class, 1, &macrolist);
 260
 261   add_cmd
 262     ("macro", no_class, info_macro_command,
 263      "Show the definition of MACRO, and its source location.",
 264      &infolist);
 265
 266   add_cmd
 267     ("define", no_class, macro_define_command,
 268      "Define a new C/C++ preprocessor macro.\n"
 269      "The GDB command `macro define DEFINITION' is equivalent to placing a\n"
 270      "preprocessor directive of the form `#define DEFINITION' such that the\n"
 271      "definition is visible in all the inferior's source files.\n"
 272      "For example:\n"
 273      "  (gdb) macro define PI (3.1415926)\n"
 274      "  (gdb) macro define MIN(x,y) ((x) < (y) ? (x) : (y))",
 275      &macrolist);
 276
 277   add_cmd
 278     ("undef", no_class, macro_undef_command,
 279      "Remove the definition of the C/C++ preprocessor macro with the"
 280      " given name.",
 281      &macrolist);
 282
 283   add_cmd
 284     ("list", no_class, macro_list_command,
 285      "List all the macros defined using the `macro define' command.",
 286      &macrolist);
 287
 288   user_macros = new_macro_table (0, 0);
 289 }