gdb/macroscope.c - gdb

Global variables defined

Functions defined

Source code

  1. /* Functions for deciding which macros are currently in scope.
  2.    Copyright (C) 2002-2015 Free Software Foundation, Inc.
  3.    Contributed by Red Hat, Inc.

  5.    This file is part of GDB.

  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.

  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.

  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/>.  */

  20. #include "defs.h"

  22. #include "macroscope.h"
  23. #include "symtab.h"
  24. #include "source.h"
  25. #include "target.h"
  26. #include "frame.h"
  27. #include "inferior.h"
  28. #include "complaints.h"

  30. /* A table of user-defined macros.  Unlike the macro tables used for
  31.    symtabs, this one uses xmalloc for all its allocation, not an
  32.    obstack, and it doesn't bcache anything; it just xmallocs things.  So
  33.    it's perfectly possible to remove things from this, or redefine
  34.    things.  */
  35. ‌struct macro_table *macro_user_macros;


  38. struct macro_scope *
  39. ‌sal_macro_scope (struct symtab_and_line sal)
  40. {
  41.   struct macro_source_file *main_file, *inclusion;
  42.   struct macro_scope *ms;
  43.   struct compunit_symtab *cust;

  45.   if (sal.symtab == NULL)
  46.     return NULL;
  47.   cust = SYMTAB_COMPUNIT (sal.symtab);
  48.   if (COMPUNIT_MACRO_TABLE (cust) == NULL)
  49.     return NULL;

  51.   ms = (struct macro_scope *) xmalloc (sizeof (*ms));

  53.   main_file = macro_main (COMPUNIT_MACRO_TABLE (cust));
  54.   inclusion = macro_lookup_inclusion (main_file, sal.symtab->filename);

  56.   if (inclusion)
  57.     {
  58.       ms->file = inclusion;
  59.       ms->line = sal.line;
  60.     }
  61.   else
  62.     {
  63.       /* There are, unfortunately, cases where a compilation unit can
  64.          have a symtab for a source file that doesn't appear in the
  65.          macro table.  For example, at the moment, Dwarf doesn't have
  66.          any way in the .debug_macinfo section to describe the effect
  67.          of #line directives, so if you debug a YACC parser you'll get
  68.          a macro table which only mentions the .c files generated by
  69.          YACC, but symtabs that mention the .y files consumed by YACC.

  71.          In the long run, we should extend the Dwarf macro info
  72.          representation to handle #line directives, and get GCC to
  73.          emit it.

  75.          For the time being, though, we'll just treat these as
  76.          occurring at the end of the main source file.  */
  77.       ms->file = main_file;
  78.       ms->line = -1;

  80.       complaint (&symfile_complaints,
  81.                  _("symtab found for `%s', but that file\n"
  82.                  "is not covered in the compilation unit's macro information"),
  83.                  symtab_to_filename_for_display (sal.symtab));
  84.     }

  86.   return ms;
  87. }


  90. struct macro_scope *
  91. ‌user_macro_scope (void)
  92. {
  93.   struct macro_scope *ms;

  95.   ms = XNEW (struct macro_scope);
  96.   ms->file = macro_main (macro_user_macros);
  97.   ms->line = -1;
  98.   return ms;
  99. }

  101. struct macro_scope *
  102. ‌default_macro_scope (void)
  103. {
  104.   struct symtab_and_line sal;
  105.   struct macro_scope *ms;
  106.   struct frame_info *frame;
  107.   CORE_ADDR pc;

  109.   /* If there's a selected frame, use its PC.  */
  110.   frame = deprecated_safe_get_selected_frame ();
  111.   if (frame && get_frame_pc_if_available (frame, &pc))
  112.     sal = find_pc_line (pc, 0);

  114.   /* Fall back to the current listing position.  */
  115.   else
  116.     {
  117.       /* Don't call select_source_symtab here.  That can raise an
  118.          error if symbols aren't loaded, but GDB calls the expression
  119.          evaluator in all sorts of contexts.

  121.          For example, commands like `set width' call the expression
  122.          evaluator to evaluate their numeric arguments.  If the
  123.          current language is C, then that may call this function to
  124.          choose a scope for macro expansion.  If you don't have any
  125.          symbol files loaded, then get_current_or_default would raise an
  126.          error.  But `set width' shouldn't raise an error just because
  127.          it can't decide which scope to macro-expand its argument in.  */
  128.       struct symtab_and_line cursal =
  129.                               get_current_source_symtab_and_line ();

  131.       sal.symtab = cursal.symtab;
  132.       sal.line = cursal.line;
  133.     }

  135.   ms = sal_macro_scope (sal);
  136.   if (! ms)
  137.     ms = user_macro_scope ();

  139.   return ms;
  140. }


  143. /* Look up the definition of the macro named NAME in scope at the source
  144.    location given by BATON, which must be a pointer to a `struct
  145.    macro_scope' structure.  */
  146. struct macro_definition *
  147. ‌standard_macro_lookup (const char *name, void *baton)
  148. {
  149.   struct macro_scope *ms = (struct macro_scope *) baton;
  150.   struct macro_definition *result;

  152.   /* Give user-defined macros priority over all others.  */
  153.   result = macro_lookup_definition (macro_main (macro_user_macros), -1, name);
  154.   if (! result)
  155.     result = macro_lookup_definition (ms->file, ms->line, name);
  156.   return result;
  157. }

  159. /* Provide a prototype to silence -Wmissing-prototypes.  */
  160. extern initialize_file_ftype _initialize_macroscope;

  162. void
  163. ‌_initialize_macroscope (void)
  164. {
  165.   macro_user_macros = new_macro_table (NULL, NULL, NULL);
  166.   macro_set_main (macro_user_macros, "<user-defined>");
  167.   macro_allow_redefinitions (macro_user_macros);
  168. }