gcc/tree-diagnostic.c - gcc - Git at Google

 /* 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, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008,
    2009, 2010 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
 <http://www.gnu.org/licenses/>.  */

 #include "config.h"
 #include "system.h"
 #include "coretypes.h"
 #include "tree.h"
 #include "diagnostic.h"
 #include "tree-diagnostic.h"
 #include "langhooks.h"
 #include "langhooks-def.h"
 #include "vec.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);
   lang_hooks.print_error_function (context, input_filename, diagnostic);
 }

 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.  */
 typedef struct
 {
   const struct line_map *map;
   source_location where;
 } loc_map_pair;

 DEF_VEC_O (loc_map_pair);
 DEF_VEC_ALLOC_O (loc_map_pair, heap);

 /* 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 expansion of macro 'OPERATE'
     test.c:5:3: note: expanded from here
     test.c:5:14: note: in expansion of macro 'SHIFTL'
     test.c:8:3: note: expanded from here
     test.c:8:3: note: in expansion of macro 'MULT2'
     test.c:13:3: note: expanded from here

    The part that goes from the third to the eighth 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.

    If FIRST_EXP_POINT_MAP is non-null, *FIRST_EXP_POINT_MAP is set to
    the map of the location in the source that first triggered the
    macro expansion.  This must be an ordinary map.  */

 static void
 maybe_unwind_expanded_macro_loc (diagnostic_context *context,
                                  diagnostic_info *diagnostic,
                                  source_location where,
                                  const struct line_map **first_exp_point_map)
 {
   const struct line_map *map;
   VEC(loc_map_pair,heap) *loc_vec = NULL;
   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 = map;

       VEC_safe_push (loc_map_pair, heap, loc_vec, &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));

   if (first_exp_point_map)
     *first_exp_point_map = 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.  */
   if (!LINEMAP_SYSP (map))
     FOR_EACH_VEC_ELT (loc_map_pair, loc_vec, ix, iter)
       {
         source_location resolved_def_loc = 0, resolved_exp_loc = 0;
         diagnostic_t saved_kind;
         const char *saved_prefix;
         source_location saved_location;

         /* 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.  */
         resolved_def_loc =
           linemap_resolve_location (line_table, iter->where,
                                     LRK_MACRO_DEFINITION_LOCATION, NULL);

         /* 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.  */
         resolved_exp_loc =
           linemap_resolve_location (line_table,
                                     MACRO_MAP_EXPANSION_POINT_LOCATION (iter->map),
                                     LRK_MACRO_DEFINITION_LOCATION, NULL);

         saved_kind = diagnostic->kind;
         saved_prefix = context->printer->prefix;
         saved_location = diagnostic->location;

         diagnostic->kind = DK_NOTE;
         diagnostic->location = resolved_def_loc;
         pp_base_set_prefix (context->printer,
                             diagnostic_build_prefix (context,
                                                      diagnostic));
         pp_newline (context->printer);
         pp_printf (context->printer, "in expansion of macro '%s'",
                    linemap_map_get_macro_name (iter->map));
         pp_destroy_prefix (context->printer);

         diagnostic->location = resolved_exp_loc;
         pp_base_set_prefix (context->printer,
                             diagnostic_build_prefix (context,
                                                      diagnostic));
         pp_newline (context->printer);
         pp_printf (context->printer, "expanded from here");
         pp_destroy_prefix (context->printer);

         diagnostic->kind = saved_kind;
         diagnostic->location = saved_location;
         context->printer->prefix = saved_prefix;
       }

   VEC_free (loc_map_pair, heap, loc_vec);
 }

 /*  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,
 				   NULL);
 }
	/* 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, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008,
	2009, 2010 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
	<http://www.gnu.org/licenses/>. */

	#include "config.h"
	#include "system.h"
	#include "coretypes.h"
	#include "tree.h"
	#include "diagnostic.h"
	#include "tree-diagnostic.h"
	#include "langhooks.h"
	#include "langhooks-def.h"
	#include "vec.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);
	lang_hooks.print_error_function (context, input_filename, diagnostic);
	}

	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. */
	typedef struct
	{
	const struct line_map *map;
	source_location where;
	} loc_map_pair;

	DEF_VEC_O (loc_map_pair);
	DEF_VEC_ALLOC_O (loc_map_pair, heap);

	/* 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 expansion of macro 'OPERATE'
	test.c:5:3: note: expanded from here
	test.c:5:14: note: in expansion of macro 'SHIFTL'
	test.c:8:3: note: expanded from here
	test.c:8:3: note: in expansion of macro 'MULT2'
	test.c:13:3: note: expanded from here

	The part that goes from the third to the eighth 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.

	If FIRST_EXP_POINT_MAP is non-null, *FIRST_EXP_POINT_MAP is set to
	the map of the location in the source that first triggered the
	macro expansion. This must be an ordinary map. */

	static void
	maybe_unwind_expanded_macro_loc (diagnostic_context *context,
	diagnostic_info *diagnostic,
	source_location where,
	const struct line_map **first_exp_point_map)
	{
	const struct line_map *map;
	VEC(loc_map_pair,heap) *loc_vec = NULL;
	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 = map;

	VEC_safe_push (loc_map_pair, heap, loc_vec, &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));

	if (first_exp_point_map)
	*first_exp_point_map = 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. */
	if (!LINEMAP_SYSP (map))
	FOR_EACH_VEC_ELT (loc_map_pair, loc_vec, ix, iter)
	{
	source_location resolved_def_loc = 0, resolved_exp_loc = 0;
	diagnostic_t saved_kind;
	const char *saved_prefix;
	source_location saved_location;

	/* 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. */
	resolved_def_loc =
	linemap_resolve_location (line_table, iter->where,
	LRK_MACRO_DEFINITION_LOCATION, NULL);

	/* 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. */
	resolved_exp_loc =
	linemap_resolve_location (line_table,
	MACRO_MAP_EXPANSION_POINT_LOCATION (iter->map),
	LRK_MACRO_DEFINITION_LOCATION, NULL);

	saved_kind = diagnostic->kind;
	saved_prefix = context->printer->prefix;
	saved_location = diagnostic->location;

	diagnostic->kind = DK_NOTE;
	diagnostic->location = resolved_def_loc;
	pp_base_set_prefix (context->printer,
	diagnostic_build_prefix (context,
	diagnostic));
	pp_newline (context->printer);
	pp_printf (context->printer, "in expansion of macro '%s'",
	linemap_map_get_macro_name (iter->map));
	pp_destroy_prefix (context->printer);

	diagnostic->location = resolved_exp_loc;
	pp_base_set_prefix (context->printer,
	diagnostic_build_prefix (context,
	diagnostic));
	pp_newline (context->printer);
	pp_printf (context->printer, "expanded from here");
	pp_destroy_prefix (context->printer);

	diagnostic->kind = saved_kind;
	diagnostic->location = saved_location;
	context->printer->prefix = saved_prefix;
	}

	VEC_free (loc_map_pair, heap, loc_vec);
	}

	/* 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,
	NULL);
	}