1 /* Functions for deciding which macros are currently in scope. 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 #include "defs.h" 23 24 #include "macroscope.h" 25 #include "symtab.h" 26 #include "source.h" 27 #include "target.h" 28 #include "frame.h" 29 #include "inferior.h" 30 #include "complaints.h" 31 32 33 struct macro_scope * 34 sal_macro_scope (struct symtab_and_line sal) 35 { 36 struct macro_source_file *main, *inclusion; 37 struct macro_scope *ms; 38 39 if (! sal.symtab 40 || ! sal.symtab->macro_table) 41 return 0; 42 43 ms = (struct macro_scope *) xmalloc (sizeof (*ms)); 44 45 main = macro_main (sal.symtab->macro_table); 46 inclusion = macro_lookup_inclusion (main, sal.symtab->filename); 47 48 if (inclusion) 49 { 50 ms->file = inclusion; 51 ms->line = sal.line; 52 } 53 else 54 { 55 /* There are, unfortunately, cases where a compilation unit can 56 have a symtab for a source file that doesn't appear in the 57 macro table. For example, at the moment, Dwarf doesn't have 58 any way in the .debug_macinfo section to describe the effect 59 of #line directives, so if you debug a YACC parser you'll get 60 a macro table which only mentions the .c files generated by 61 YACC, but symtabs that mention the .y files consumed by YACC. 62 63 In the long run, we should extend the Dwarf macro info 64 representation to handle #line directives, and get GCC to 65 emit it. 66 67 For the time being, though, we'll just treat these as 68 occurring at the end of the main source file. */ 69 ms->file = main; 70 ms->line = -1; 71 72 complaint (&symfile_complaints, 73 "symtab found for `%s', but that file\n" 74 "is not covered in the compilation unit's macro information", 75 sal.symtab->filename); 76 } 77 78 return ms; 79 } 80 81 82 struct macro_scope * 83 default_macro_scope (void) 84 { 85 struct symtab_and_line sal; 86 struct macro_source_file *main; 87 struct macro_scope *ms; 88 89 /* If there's a selected frame, use its PC. */ 90 if (deprecated_selected_frame) 91 sal = find_pc_line (get_frame_pc (deprecated_selected_frame), 0); 92 93 /* If the target has any registers at all, then use its PC. Why we 94 would have registers but no stack, I'm not sure. */ 95 else if (target_has_registers) 96 sal = find_pc_line (read_pc (), 0); 97 98 /* If all else fails, fall back to the current listing position. */ 99 else 100 { 101 /* Don't call select_source_symtab here. That can raise an 102 error if symbols aren't loaded, but GDB calls the expression 103 evaluator in all sorts of contexts. 104 105 For example, commands like `set width' call the expression 106 evaluator to evaluate their numeric arguments. If the 107 current language is C, then that may call this function to 108 choose a scope for macro expansion. If you don't have any 109 symbol files loaded, then get_current_or_default would raise an 110 error. But `set width' shouldn't raise an error just because 111 it can't decide which scope to macro-expand its argument in. */ 112 struct symtab_and_line cursal = 113 get_current_source_symtab_and_line (); 114 115 sal.symtab = cursal.symtab; 116 sal.line = cursal.line; 117 } 118 119 return sal_macro_scope (sal); 120 } 121 122 123 /* Look up the definition of the macro named NAME in scope at the source 124 location given by BATON, which must be a pointer to a `struct 125 macro_scope' structure. */ 126 struct macro_definition * 127 standard_macro_lookup (const char *name, void *baton) 128 { 129 struct macro_scope *ms = (struct macro_scope *) baton; 130 131 return macro_lookup_definition (ms->file, ms->line, name); 132 } 133