1 /* Functions for deciding which macros are currently in scope. 2 Copyright (C) 2002, 2007, 2008, 2009, 2010, 2011 3 Free Software Foundation, Inc. 4 Contributed by Red Hat, Inc. 5 6 This file is part of GDB. 7 8 This program is free software; you can redistribute it and/or modify 9 it under the terms of the GNU General Public License as published by 10 the Free Software Foundation; either version 3 of the License, or 11 (at your option) any later version. 12 13 This program is distributed in the hope that it will be useful, 14 but WITHOUT ANY WARRANTY; without even the implied warranty of 15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 GNU General Public License for more details. 17 18 You should have received a copy of the GNU General Public License 19 along with this program. If not, see <http://www.gnu.org/licenses/>. */ 20 21 #include "defs.h" 22 23 #include "macroscope.h" 24 #include "symtab.h" 25 #include "source.h" 26 #include "target.h" 27 #include "frame.h" 28 #include "inferior.h" 29 #include "complaints.h" 30 31 /* A table of user-defined macros. Unlike the macro tables used for 32 symtabs, this one uses xmalloc for all its allocation, not an 33 obstack, and it doesn't bcache anything; it just xmallocs things. So 34 it's perfectly possible to remove things from this, or redefine 35 things. */ 36 struct macro_table *macro_user_macros; 37 38 39 struct macro_scope * 40 sal_macro_scope (struct symtab_and_line sal) 41 { 42 struct macro_source_file *main_file, *inclusion; 43 struct macro_scope *ms; 44 45 if (! sal.symtab 46 || ! sal.symtab->macro_table) 47 return 0; 48 49 ms = (struct macro_scope *) xmalloc (sizeof (*ms)); 50 51 main_file = macro_main (sal.symtab->macro_table); 52 inclusion = macro_lookup_inclusion (main_file, sal.symtab->filename); 53 54 if (inclusion) 55 { 56 ms->file = inclusion; 57 ms->line = sal.line; 58 } 59 else 60 { 61 /* There are, unfortunately, cases where a compilation unit can 62 have a symtab for a source file that doesn't appear in the 63 macro table. For example, at the moment, Dwarf doesn't have 64 any way in the .debug_macinfo section to describe the effect 65 of #line directives, so if you debug a YACC parser you'll get 66 a macro table which only mentions the .c files generated by 67 YACC, but symtabs that mention the .y files consumed by YACC. 68 69 In the long run, we should extend the Dwarf macro info 70 representation to handle #line directives, and get GCC to 71 emit it. 72 73 For the time being, though, we'll just treat these as 74 occurring at the end of the main source file. */ 75 ms->file = main_file; 76 ms->line = -1; 77 78 complaint (&symfile_complaints, 79 _("symtab found for `%s', but that file\n" 80 "is not covered in the compilation unit's macro information"), 81 sal.symtab->filename); 82 } 83 84 return ms; 85 } 86 87 88 struct macro_scope * 89 user_macro_scope (void) 90 { 91 struct macro_scope *ms; 92 93 ms = XNEW (struct macro_scope); 94 ms->file = macro_main (macro_user_macros); 95 ms->line = -1; 96 return ms; 97 } 98 99 struct macro_scope * 100 default_macro_scope (void) 101 { 102 struct symtab_and_line sal; 103 struct macro_scope *ms; 104 struct frame_info *frame; 105 CORE_ADDR pc; 106 107 /* If there's a selected frame, use its PC. */ 108 frame = deprecated_safe_get_selected_frame (); 109 if (frame && get_frame_pc_if_available (frame, &pc)) 110 sal = find_pc_line (pc, 0); 111 112 /* Fall back to the current listing position. */ 113 else 114 { 115 /* Don't call select_source_symtab here. That can raise an 116 error if symbols aren't loaded, but GDB calls the expression 117 evaluator in all sorts of contexts. 118 119 For example, commands like `set width' call the expression 120 evaluator to evaluate their numeric arguments. If the 121 current language is C, then that may call this function to 122 choose a scope for macro expansion. If you don't have any 123 symbol files loaded, then get_current_or_default would raise an 124 error. But `set width' shouldn't raise an error just because 125 it can't decide which scope to macro-expand its argument in. */ 126 struct symtab_and_line cursal = 127 get_current_source_symtab_and_line (); 128 129 sal.symtab = cursal.symtab; 130 sal.line = cursal.line; 131 } 132 133 ms = sal_macro_scope (sal); 134 if (! ms) 135 ms = user_macro_scope (); 136 137 return ms; 138 } 139 140 141 /* Look up the definition of the macro named NAME in scope at the source 142 location given by BATON, which must be a pointer to a `struct 143 macro_scope' structure. */ 144 struct macro_definition * 145 standard_macro_lookup (const char *name, void *baton) 146 { 147 struct macro_scope *ms = (struct macro_scope *) baton; 148 struct macro_definition *result; 149 150 /* Give user-defined macros priority over all others. */ 151 result = macro_lookup_definition (macro_main (macro_user_macros), -1, name); 152 if (! result) 153 result = macro_lookup_definition (ms->file, ms->line, name); 154 return result; 155 } 156 157 /* Provide a prototype to silence -Wmissing-prototypes. */ 158 extern initialize_file_ftype _initialize_macroscope; 159 160 void 161 _initialize_macroscope (void) 162 { 163 macro_user_macros = new_macro_table (0, 0); 164 macro_set_main (macro_user_macros, "<user-defined>"); 165 macro_allow_redefinitions (macro_user_macros); 166 } 167