1 /* Functions for deciding which macros are currently in scope. 2 Copyright (C) 2002-2023 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 gdb::unique_xmalloc_ptr<struct macro_scope> 39 sal_macro_scope (struct symtab_and_line sal) 40 { 41 struct macro_source_file *main_file, *inclusion; 42 struct compunit_symtab *cust; 43 44 if (sal.symtab == NULL) 45 return NULL; 46 47 cust = sal.symtab->compunit (); 48 if (cust->macro_table () == NULL) 49 return NULL; 50 51 gdb::unique_xmalloc_ptr<struct macro_scope> ms (XNEW (struct macro_scope)); 52 53 main_file = macro_main (cust->macro_table ()); 54 inclusion = macro_lookup_inclusion (main_file, sal.symtab->filename_for_id); 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 (_("symtab found for `%s', but that file\n" 81 "is not covered in the compilation unit's macro information"), 82 symtab_to_filename_for_display (sal.symtab)); 83 } 84 85 return ms; 86 } 87 88 89 gdb::unique_xmalloc_ptr<struct macro_scope> 90 user_macro_scope (void) 91 { 92 gdb::unique_xmalloc_ptr<struct macro_scope> ms (XNEW (struct macro_scope)); 93 ms->file = macro_main (macro_user_macros); 94 ms->line = -1; 95 return ms; 96 } 97 98 gdb::unique_xmalloc_ptr<struct macro_scope> 99 default_macro_scope (void) 100 { 101 struct symtab_and_line sal; 102 gdb::unique_xmalloc_ptr<struct macro_scope> ms; 103 frame_info_ptr frame; 104 CORE_ADDR pc; 105 106 /* If there's a selected frame, use its PC. */ 107 frame = deprecated_safe_get_selected_frame (); 108 if (frame && get_frame_pc_if_available (frame, &pc)) 109 sal = find_pc_line (pc, 0); 110 111 /* Fall back to the current listing position. */ 112 else 113 { 114 /* Don't call select_source_symtab here. That can raise an 115 error if symbols aren't loaded, but GDB calls the expression 116 evaluator in all sorts of contexts. 117 118 For example, commands like `set width' call the expression 119 evaluator to evaluate their numeric arguments. If the 120 current language is C, then that may call this function to 121 choose a scope for macro expansion. If you don't have any 122 symbol files loaded, then get_current_or_default would raise an 123 error. But `set width' shouldn't raise an error just because 124 it can't decide which scope to macro-expand its argument in. */ 125 struct symtab_and_line cursal 126 = get_current_source_symtab_and_line (); 127 128 sal.symtab = cursal.symtab; 129 sal.line = cursal.line; 130 } 131 132 ms = sal_macro_scope (sal); 133 if (! ms) 134 ms = user_macro_scope (); 135 136 return ms; 137 } 138 139 140 /* Look up the definition of the macro named NAME in scope at the source 141 location given by BATON, which must be a pointer to a `struct 142 macro_scope' structure. */ 143 struct macro_definition * 144 standard_macro_lookup (const char *name, const macro_scope &ms) 145 { 146 /* Give user-defined macros priority over all others. */ 147 macro_definition *result 148 = macro_lookup_definition (macro_main (macro_user_macros), -1, name); 149 150 if (result == nullptr) 151 result = macro_lookup_definition (ms.file, ms.line, name); 152 153 return result; 154 } 155 156 void _initialize_macroscope (); 157 void 158 _initialize_macroscope () 159 { 160 macro_user_macros = new_macro_table (NULL, NULL, NULL); 161 macro_set_main (macro_user_macros, "<user-defined>"); 162 macro_allow_redefinitions (macro_user_macros); 163 } 164