| 1 | /* Functions for deciding which macros are currently in scope. |
| 2 | Copyright (C) 2002-2017 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 | struct compunit_symtab *cust; |
| 44 | |
| 45 | if (sal.symtab == NULL) |
| 46 | return NULL; |
| 47 | cust = SYMTAB_COMPUNIT (sal.symtab); |
| 48 | if (COMPUNIT_MACRO_TABLE (cust) == NULL) |
| 49 | return NULL; |
| 50 | |
| 51 | ms = XNEW (struct macro_scope); |
| 52 | |
| 53 | main_file = macro_main (COMPUNIT_MACRO_TABLE (cust)); |
| 54 | inclusion = macro_lookup_inclusion (main_file, sal.symtab->filename); |
| 55 | |
| 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. |
| 70 | |
| 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. |
| 74 | |
| 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; |
| 79 | |
| 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 | } |
| 85 | |
| 86 | return ms; |
| 87 | } |
| 88 | |
| 89 | |
| 90 | struct macro_scope * |
| 91 | user_macro_scope (void) |
| 92 | { |
| 93 | struct macro_scope *ms; |
| 94 | |
| 95 | ms = XNEW (struct macro_scope); |
| 96 | ms->file = macro_main (macro_user_macros); |
| 97 | ms->line = -1; |
| 98 | return ms; |
| 99 | } |
| 100 | |
| 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; |
| 108 | |
| 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); |
| 113 | |
| 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. |
| 120 | |
| 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 (); |
| 130 | |
| 131 | sal.symtab = cursal.symtab; |
| 132 | sal.line = cursal.line; |
| 133 | } |
| 134 | |
| 135 | ms = sal_macro_scope (sal); |
| 136 | if (! ms) |
| 137 | ms = user_macro_scope (); |
| 138 | |
| 139 | return ms; |
| 140 | } |
| 141 | |
| 142 | |
| 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; |
| 151 | |
| 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 | } |
| 158 | |
| 159 | /* Provide a prototype to silence -Wmissing-prototypes. */ |
| 160 | extern initialize_file_ftype _initialize_macroscope; |
| 161 | |
| 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 | } |