1 /* Functions for deciding which macros are currently in scope. 2 Copyright (C) 2002, 2007, 2008, 2009, 2010 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 #include "defs.h" 21 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" 29 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; 36 37 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 44 if (! sal.symtab 45 || ! sal.symtab->macro_table) 46 return 0; 47 48 ms = (struct macro_scope *) xmalloc (sizeof (*ms)); 49 50 main_file = macro_main (sal.symtab->macro_table); 51 inclusion = macro_lookup_inclusion (main_file, sal.symtab->filename); 52 53 if (inclusion) 54 { 55 ms->file = inclusion; 56 ms->line = sal.line; 57 } 58 else 59 { 60 /* There are, unfortunately, cases where a compilation unit can 61 have a symtab for a source file that doesn't appear in the 62 macro table. For example, at the moment, Dwarf doesn't have 63 any way in the .debug_macinfo section to describe the effect 64 of #line directives, so if you debug a YACC parser you'll get 65 a macro table which only mentions the .c files generated by 66 YACC, but symtabs that mention the .y files consumed by YACC. 67 68 In the long run, we should extend the Dwarf macro info 69 representation to handle #line directives, and get GCC to 70 emit it. 71 72 For the time being, though, we'll just treat these as 73 occurring at the end of the main source file. */ 74 ms->file = main_file; 75 ms->line = -1; 76 77 complaint (&symfile_complaints, 78 _("symtab found for `%s', but that file\n" 79 "is not covered in the compilation unit's macro information"), 80 sal.symtab->filename); 81 } 82 83 return ms; 84 } 85 86 87 struct macro_scope * 88 user_macro_scope (void) 89 { 90 struct macro_scope *ms; 91 92 ms = XNEW (struct macro_scope); 93 ms->file = macro_main (macro_user_macros); 94 ms->line = -1; 95 return ms; 96 } 97 98 struct macro_scope * 99 default_macro_scope (void) 100 { 101 struct symtab_and_line sal; 102 struct macro_scope *ms; 103 struct frame_info *frame; 104 105 /* If there's a selected frame, use its PC. */ 106 frame = deprecated_safe_get_selected_frame (); 107 if (frame) 108 sal = find_pc_line (get_frame_pc (frame), 0); 109 110 /* Fall back to the current listing position. */ 111 else 112 { 113 /* Don't call select_source_symtab here. That can raise an 114 error if symbols aren't loaded, but GDB calls the expression 115 evaluator in all sorts of contexts. 116 117 For example, commands like `set width' call the expression 118 evaluator to evaluate their numeric arguments. If the 119 current language is C, then that may call this function to 120 choose a scope for macro expansion. If you don't have any 121 symbol files loaded, then get_current_or_default would raise an 122 error. But `set width' shouldn't raise an error just because 123 it can't decide which scope to macro-expand its argument in. */ 124 struct symtab_and_line cursal = 125 get_current_source_symtab_and_line (); 126 127 sal.symtab = cursal.symtab; 128 sal.line = cursal.line; 129 } 130 131 ms = sal_macro_scope (sal); 132 if (! ms) 133 ms = user_macro_scope (); 134 135 return ms; 136 } 137 138 139 /* Look up the definition of the macro named NAME in scope at the source 140 location given by BATON, which must be a pointer to a `struct 141 macro_scope' structure. */ 142 struct macro_definition * 143 standard_macro_lookup (const char *name, void *baton) 144 { 145 struct macro_scope *ms = (struct macro_scope *) baton; 146 struct macro_definition *result; 147 148 /* Give user-defined macros priority over all others. */ 149 result = macro_lookup_definition (macro_main (macro_user_macros), -1, name); 150 if (! result) 151 result = macro_lookup_definition (ms->file, ms->line, name); 152 return result; 153 } 154 155 /* Provide a prototype to silence -Wmissing-prototypes. */ 156 extern initialize_file_ftype _initialize_macroscope; 157 158 void 159 _initialize_macroscope (void) 160 { 161 macro_user_macros = new_macro_table (0, 0); 162 macro_set_main (macro_user_macros, "<user-defined>"); 163 macro_allow_redefinitions (macro_user_macros); 164 } 165