/* Language-independent diagnostic subroutines for the GNU Compiler Collection that are only for use in the compilers proper and not the driver or other programs. Copyright (C) 1999-2016 Free Software Foundation, Inc. This file is part of GCC. GCC is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3, or (at your option) any later version. GCC is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with GCC; see the file COPYING3. If not see . */ #include "config.h" #include "system.h" #include "coretypes.h" #include "tree.h" #include "diagnostic.h" #include "tree-pretty-print.h" #include "tree-diagnostic.h" #include "dumpfile.h" /* TDF_DIAGNOSTIC */ #include "langhooks.h" #include "intl.h" /* Prints out, if necessary, the name of the current function that caused an error. Called from all error and warning functions. */ void diagnostic_report_current_function (diagnostic_context *context, diagnostic_info *diagnostic) { diagnostic_report_current_module (context, diagnostic_location (diagnostic)); lang_hooks.print_error_function (context, LOCATION_FILE (input_location), diagnostic); } static void default_tree_diagnostic_starter (diagnostic_context *context, diagnostic_info *diagnostic) { diagnostic_report_current_function (context, diagnostic); pp_set_prefix (context->printer, diagnostic_build_prefix (context, diagnostic)); } /* This is a pair made of a location and the line map it originated from. It's used in the maybe_unwind_expanded_macro_loc function below. */ struct loc_map_pair { const line_map_macro *map; source_location where; }; /* Unwind the different macro expansions that lead to the token which location is WHERE and emit diagnostics showing the resulting unwound macro expansion trace. Let's look at an example to see how the trace looks like. Suppose we have this piece of code, artificially annotated with the line numbers to increase legibility: $ cat -n test.c 1 #define OPERATE(OPRD1, OPRT, OPRD2) \ 2 OPRD1 OPRT OPRD2; 3 4 #define SHIFTL(A,B) \ 5 OPERATE (A,<<,B) 6 7 #define MULT(A) \ 8 SHIFTL (A,1) 9 10 void 11 g () 12 { 13 MULT (1.0);// 1.0 << 1; <-- so this is an error. 14 } Here is the diagnostic that we want the compiler to generate: test.c: In function ‘g’: test.c:5:14: error: invalid operands to binary << (have ‘double’ and ‘int’) test.c:2:9: note: in definition of macro 'OPERATE' test.c:8:3: note: in expansion of macro 'SHIFTL' test.c:13:3: note: in expansion of macro 'MULT' The part that goes from the third to the fifth line of this diagnostic (the lines containing the 'note:' string) is called the unwound macro expansion trace. That's the part generated by this function. */ static void maybe_unwind_expanded_macro_loc (diagnostic_context *context, const diagnostic_info *diagnostic, source_location where) { const struct line_map *map; vec loc_vec = vNULL; unsigned ix; loc_map_pair loc, *iter; map = linemap_lookup (line_table, where); if (!linemap_macro_expansion_map_p (map)) return; /* Let's unwind the macros that got expanded and led to the token which location is WHERE. We are going to store these macros into LOC_VEC, so that we can later walk it at our convenience to display a somewhat meaningful trace of the macro expansion history to the user. Note that the first macro of the trace (which is OPERATE in the example above) is going to be stored at the beginning of LOC_VEC. */ do { loc.where = where; loc.map = linemap_check_macro (map); loc_vec.safe_push (loc); /* WHERE is the location of a token inside the expansion of a macro. MAP is the map holding the locations of that macro expansion. Let's get the location of the token inside the context that triggered the expansion of this macro. This is basically how we go "down" in the trace of macro expansions that led to WHERE. */ where = linemap_unwind_toward_expansion (line_table, where, &map); } while (linemap_macro_expansion_map_p (map)); /* Now map is set to the map of the location in the source that first triggered the macro expansion. This must be an ordinary map. */ const line_map_ordinary *ord_map = linemap_check_ordinary (map); /* Walk LOC_VEC and print the macro expansion trace, unless the first macro which expansion triggered this trace was expanded inside a system header. */ int saved_location_line = expand_location_to_spelling_point (diagnostic_location (diagnostic)).line; if (!LINEMAP_SYSP (ord_map)) FOR_EACH_VEC_ELT (loc_vec, ix, iter) { /* Sometimes, in the unwound macro expansion trace, we want to print a part of the context that shows where, in the definition of the relevant macro, is the token (we are looking at) used. That is the case in the introductory comment of this function, where we print: test.c:2:9: note: in definition of macro 'OPERATE'. We print that "macro definition context" because the diagnostic line (emitted by the call to pp_ouput_formatted_text in diagnostic_report_diagnostic): test.c:5:14: error: invalid operands to binary << (have ‘double’ and ‘int’) does not point into the definition of the macro where the token '<<' (that is an argument to the function-like macro OPERATE) is used. So we must "display" the line of that macro definition context to the user somehow. A contrario, when the first interesting diagnostic line points into the definition of the macro, we don't need to display any line for that macro definition in the trace anymore, otherwise it'd be redundant. */ /* Okay, now here is what we want. For each token resulting from macro expansion we want to show: 1/ where in the definition of the macro the token comes from; 2/ where the macro got expanded. */ /* Resolve the location iter->where into the locus 1/ of the comment above. */ source_location resolved_def_loc = linemap_resolve_location (line_table, iter->where, LRK_MACRO_DEFINITION_LOCATION, NULL); /* Don't print trace for locations that are reserved or from within a system header. */ const line_map_ordinary *m = NULL; source_location l = linemap_resolve_location (line_table, resolved_def_loc, LRK_SPELLING_LOCATION, &m); if (l < RESERVED_LOCATION_COUNT || LINEMAP_SYSP (m)) continue; /* We need to print the context of the macro definition only when the locus of the first displayed diagnostic (displayed before this trace) was inside the definition of the macro. */ int resolved_def_loc_line = SOURCE_LINE (m, l); if (ix == 0 && saved_location_line != resolved_def_loc_line) { diagnostic_append_note (context, resolved_def_loc, "in definition of macro %qs", linemap_map_get_macro_name (iter->map)); /* At this step, as we've printed the context of the macro definition, we don't want to print the context of its expansion, otherwise, it'd be redundant. */ continue; } /* Resolve the location of the expansion point of the macro which expansion gave the token represented by def_loc. This is the locus 2/ of the earlier comment. */ source_location resolved_exp_loc = linemap_resolve_location (line_table, MACRO_MAP_EXPANSION_POINT_LOCATION (iter->map), LRK_MACRO_DEFINITION_LOCATION, NULL); diagnostic_append_note (context, resolved_exp_loc, "in expansion of macro %qs", linemap_map_get_macro_name (iter->map)); } loc_vec.release (); } /* This is a diagnostic finalizer implementation that is aware of virtual locations produced by libcpp. It has to be called by the diagnostic finalizer of front ends that uses libcpp and wish to get diagnostics involving tokens resulting from macro expansion. For a given location, if said location belongs to a token resulting from a macro expansion, this starter prints the context of the token. E.g, for multiply nested macro expansion, it unwinds the nested macro expansions and prints them in a manner that is similar to what is done for function call stacks, or template instantiation contexts. */ void virt_loc_aware_diagnostic_finalizer (diagnostic_context *context, diagnostic_info *diagnostic) { maybe_unwind_expanded_macro_loc (context, diagnostic, diagnostic_location (diagnostic)); } /* Default tree printer. Handles declarations only. */ static bool default_tree_printer (pretty_printer *pp, text_info *text, const char *spec, int precision, bool wide, bool set_locus, bool hash) { tree t; /* FUTURE: %+x should set the locus. */ if (precision != 0 || wide || hash) return false; switch (*spec) { case 'E': t = va_arg (*text->args_ptr, tree); if (TREE_CODE (t) == IDENTIFIER_NODE) { pp_identifier (pp, IDENTIFIER_POINTER (t)); return true; } break; case 'D': t = va_arg (*text->args_ptr, tree); if (TREE_CODE (t) == VAR_DECL && DECL_HAS_DEBUG_EXPR_P (t)) t = DECL_DEBUG_EXPR (t); break; case 'F': case 'T': t = va_arg (*text->args_ptr, tree); break; case 'K': percent_K_format (text); return true; default: return false; } if (set_locus) text->set_location (0, DECL_SOURCE_LOCATION (t), true); if (DECL_P (t)) { const char *n = DECL_NAME (t) ? identifier_to_locale (lang_hooks.decl_printable_name (t, 2)) : _(""); pp_string (pp, n); } else dump_generic_node (pp, t, 0, TDF_DIAGNOSTIC, 0); return true; } /* Sets CONTEXT to use language independent diagnostics. */ void tree_diagnostics_defaults (diagnostic_context *context) { diagnostic_starter (context) = default_tree_diagnostic_starter; diagnostic_finalizer (context) = default_diagnostic_finalizer; diagnostic_format_decoder (context) = default_tree_printer; }