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 } 169