GCC Middle and Back End API Reference
tree-diagnostic.c File Reference
#include "langhooks.h"
Include dependency graph for tree-diagnostic.c:

Data Structures

struct  loc_map_pair


void diagnostic_report_current_function (diagnostic_context *context, diagnostic_info *diagnostic)
static void default_tree_diagnostic_starter (diagnostic_context *context, diagnostic_info *diagnostic)
static void maybe_unwind_expanded_macro_loc (diagnostic_context *context, const diagnostic_info *diagnostic, source_location where)
void virt_loc_aware_diagnostic_finalizer (diagnostic_context *context, diagnostic_info *diagnostic)
static bool default_tree_printer (pretty_printer *pp, text_info *text, const char *spec, int precision, bool wide, bool set_locus, bool hash)
void tree_diagnostics_defaults ()

Function Documentation

static void default_tree_diagnostic_starter ( diagnostic_context context,
diagnostic_info diagnostic 
static bool default_tree_printer ( pretty_printer pp,
text_info text,
const char *  spec,
int  precision,
bool  wide,
bool  set_locus,
bool  hash 
   Default tree printer.   Handles declarations only.  
     FUTURE: %+x should set the locus.  
void diagnostic_report_current_function ( diagnostic_context context,
diagnostic_info diagnostic 

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) 1999-2013 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/.

   Prints out, if necessary, the name of the current function
   that caused an error.  Called from all error and warning functions.  

References diagnostic_report_current_module(), diagnostic_info::location, and lang_hooks::print_error_function.

Referenced by default_tree_diagnostic_starter().

static void maybe_unwind_expanded_macro_loc ( diagnostic_context context,
const diagnostic_info diagnostic,
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

    $ cat -n test.c
      1    #define OPERATE(OPRD1, OPRT, OPRD2) \
      2      OPRD1 OPRT OPRD2;
      4    #define SHIFTL(A,B) \
      5      OPERATE (A,<<,B)
      7    #define MULT(A) \
      8      SHIFTL (A,1)
     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
     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.  
         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.  
     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.  
     Walk LOC_VEC and print the macro expansion trace, unless the
     first macro which expansion triggered this trace was expanded
     inside a system header.  
           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.  
           Don't print trace for locations that are reserved or from
           within a system header.  
           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
               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.  
           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.  
void tree_diagnostics_defaults ( )
   Sets CONTEXT to use language independent diagnostics.  
void virt_loc_aware_diagnostic_finalizer ( diagnostic_context context,
diagnostic_info diagnostic 
    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.  

References text_info::args_ptr, and gdbhooks::IDENTIFIER_NODE.