gcc/gcc-rich-location.c

   1 /* Implementation of gcc_rich_location class
   2    Copyright (C) 2014-2020 Free Software Foundation, Inc.
   3
   4 This file is part of GCC.
   5
   6 GCC is free software; you can redistribute it and/or modify it under
   7 the terms of the GNU General Public License as published by the Free
   8 Software Foundation; either version 3, or (at your option) any later
   9 version.
  10
  11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14 for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GCC; see the file COPYING3.  If not see
  18 <http://www.gnu.org/licenses/>.  */
  19
  20 #include "config.h"
  21 #include "system.h"
  22 #include "coretypes.h"
  23 #include "tm.h"
  24 #include "rtl.h"
  25 #include "hash-set.h"
  26 #include "vec.h"
  27 #include "input.h"
  28 #include "alias.h"
  29 #include "symtab.h"
  30 #include "inchash.h"
  31 #include "tree-core.h"
  32 #include "tree.h"
  33 #include "diagnostic-core.h"
  34 #include "gcc-rich-location.h"
  35 #include "print-tree.h"
  36 #include "pretty-print.h"
  37 #include "intl.h"
  38 #include "cpplib.h"
  39 #include "diagnostic.h"
  40
  41 /* Add a range to the rich_location, covering expression EXPR,
  42    using LABEL if non-NULL. */
  43
  44 void
  45 gcc_rich_location::add_expr (tree expr, range_label *label)
  46 {
  47   gcc_assert (expr);
  48
  49   if (CAN_HAVE_RANGE_P (expr))
  50     add_range (EXPR_LOCATION (expr), SHOW_RANGE_WITHOUT_CARET, label);
  51 }
  52
  53 /* If T is an expression, add a range for it to the rich_location,
  54    using LABEL if non-NULL. */
  55
  56 void
  57 gcc_rich_location::maybe_add_expr (tree t, range_label *label)
  58 {
  59   if (EXPR_P (t))
  60     add_expr (t, label);
  61 }
  62
  63 /* Add a fixit hint suggesting replacing the range at MISSPELLED_TOKEN_LOC
  64    with the identifier HINT_ID.  */
  65
  66 void
  67 gcc_rich_location::add_fixit_misspelled_id (location_t misspelled_token_loc,
  68                                             tree hint_id)
  69 {
  70   gcc_assert (TREE_CODE (hint_id) == IDENTIFIER_NODE);
  71
  72   add_fixit_replace (misspelled_token_loc, IDENTIFIER_POINTER (hint_id));
  73 }
  74
  75 /* Return true if there is nothing on LOC's line before LOC.  */
  76
  77 static bool
  78 blank_line_before_p (location_t loc)
  79 {
  80   expanded_location exploc = expand_location (loc);
  81   char_span line = location_get_source_line (exploc.file, exploc.line);
  82   if (!line)
  83     return false;
  84   if (line.length () < (size_t)exploc.column)
  85     return false;
  86   /* Columns are 1-based.  */
  87   for (int column = 1; column < exploc.column; ++column)
  88     if (!ISSPACE (line[column - 1]))
  89       return false;
  90   return true;
  91 }
  92
  93 /* Subroutine of gcc_rich_location::add_fixit_insert_formatted.
  94    Return true if we should add the content on its own line,
  95    false otherwise.
  96    If true is returned then *OUT_START_OF_LINE is written to.  */
  97
  98 static bool
  99 use_new_line (location_t insertion_point, location_t indent,
 100               location_t *out_start_of_line)
 101 {
 102   if (indent == UNKNOWN_LOCATION)
 103     return false;
 104   const line_map *indent_map = linemap_lookup (line_table, indent);
 105   if (linemap_macro_expansion_map_p (indent_map))
 106     return false;
 107
 108   if (!blank_line_before_p (insertion_point))
 109     return false;
 110
 111   /* Locate the start of the line containing INSERTION_POINT.  */
 112   const line_map *insertion_point_map
 113     = linemap_lookup (line_table, insertion_point);
 114   if (linemap_macro_expansion_map_p (insertion_point_map))
 115     return false;
 116   const line_map_ordinary *ordmap
 117     = linemap_check_ordinary (insertion_point_map);
 118   expanded_location exploc_insertion_point = expand_location (insertion_point);
 119   location_t start_of_line
 120     = linemap_position_for_line_and_column (line_table, ordmap,
 121                                             exploc_insertion_point.line, 1);
 122   *out_start_of_line = start_of_line;
 123   return true;
 124 }
 125
 126 /* Add a fix-it hint suggesting the insertion of CONTENT before
 127    INSERTION_POINT.
 128
 129    Attempt to handle formatting: if INSERTION_POINT is the first thing on
 130    its line, and INDENT is sufficiently sane, then add CONTENT on its own
 131    line, using the indentation of INDENT.
 132    Otherwise, add CONTENT directly before INSERTION_POINT.
 133
 134    For example, adding "CONTENT;" with the closing brace as the insertion
 135    point and "INDENT;" as the indentation point:
 136
 137    if ()
 138      {
 139        INDENT;
 140      }
 141
 142   would lead to:
 143
 144    if ()
 145      {
 146        INDENT;
 147        CONTENT;
 148      }
 149
 150   but adding it to:
 151
 152     if () {INDENT;}
 153
 154   would lead to:
 155
 156     if () {INDENT;CONTENT;}
 157 */
 158
 159 void
 160 gcc_rich_location::add_fixit_insert_formatted (const char *content,
 161                                                location_t insertion_point,
 162                                                location_t indent)
 163 {
 164   location_t start_of_line;
 165   if (use_new_line (insertion_point, indent, &start_of_line))
 166     {
 167       /* Add CONTENT on its own line, using the indentation of INDENT.  */
 168
 169       /* Generate an insertion string, indenting by the amount INDENT
 170          was indented.  */
 171       int indent_column = LOCATION_COLUMN (get_start (indent));
 172       pretty_printer tmp_pp;
 173       pretty_printer *pp = &tmp_pp;
 174       /* Columns are 1-based.  */
 175       for (int column = 1; column < indent_column; ++column)
 176         pp_space (pp);
 177       pp_string (pp, content);
 178       pp_newline (pp);
 179
 180       add_fixit_insert_before (start_of_line, pp_formatted_text (pp));
 181     }
 182   else
 183     add_fixit_insert_before (insertion_point, content);
 184 }
 185
 186 /* Implementation of range_label::get_text for
 187    maybe_range_label_for_tree_type_mismatch.
 188
 189    If both expressions are non-NULL, then generate text describing
 190    the first expression's type (using the other expression's type
 191    for comparison, analogous to %H and %I in the C++ frontend, but
 192    on expressions rather than types).  */
 193
 194 label_text
 195 maybe_range_label_for_tree_type_mismatch::get_text (unsigned range_idx) const
 196 {
 197   if (m_expr == NULL_TREE
 198       || !EXPR_P (m_expr))
 199     return label_text::borrow (NULL);
 200   tree expr_type = TREE_TYPE (m_expr);
 201
 202   tree other_type = NULL_TREE;
 203   if (m_other_expr && EXPR_P (m_other_expr))
 204     other_type = TREE_TYPE (m_other_expr);
 205
 206   range_label_for_type_mismatch inner (expr_type, other_type);
 207   return inner.get_text (range_idx);
 208 }
 209
 210 /* binary_op_rich_location's ctor.
 211
 212    If use_operator_loc_p (LOC, ARG0, ARG1), then attempt to make a 3-location
 213    rich_location of the form:
 214
 215      arg_0 op arg_1
 216      ~~~~~ ^~ ~~~~~
 217        |        |
 218        |        arg1 type
 219        arg0 type
 220
 221    labelling the types of the arguments if SHOW_TYPES is true.
 222
 223    Otherwise, make a 1-location rich_location using the compound
 224    location within LOC:
 225
 226      arg_0 op arg_1
 227      ~~~~~~^~~~~~~~
 228
 229    for which we can't label the types.  */
 230
 231 binary_op_rich_location::binary_op_rich_location (const op_location_t &loc,
 232                                                   tree arg0, tree arg1,
 233                                                   bool show_types)
 234 : gcc_rich_location (loc.m_combined_loc),
 235   m_label_for_arg0 (arg0, arg1),
 236   m_label_for_arg1 (arg1, arg0)
 237 {
 238   /* Default (above) to using the combined loc.
 239      Potentially override it here: if we have location information for the
 240      operator and for both arguments, then split them all out.
 241      Alternatively, override it if we don't have the combined location.  */
 242   if (use_operator_loc_p (loc, arg0, arg1))
 243     {
 244       set_range (0, loc.m_operator_loc, SHOW_RANGE_WITH_CARET);
 245       maybe_add_expr (arg0, show_types ? &m_label_for_arg0 : NULL);
 246       maybe_add_expr (arg1, show_types ? &m_label_for_arg1 : NULL);
 247     }
 248 }
 249
 250 /* Determine if binary_op_rich_location's ctor should attempt to make
 251    a 3-location rich_location (the location of the operator and of
 252    the 2 arguments), or fall back to a 1-location rich_location showing
 253    just the combined location of the operation as a whole.  */
 254
 255 bool
 256 binary_op_rich_location::use_operator_loc_p (const op_location_t &loc,
 257                                              tree arg0, tree arg1)
 258 {
 259   /* If we don't have a combined location, then use the operator location,
 260      and try to add ranges for the operators.  */
 261   if (loc.m_combined_loc == UNKNOWN_LOCATION)
 262     return true;
 263
 264   /* If we don't have the operator location, then use the
 265      combined location.  */
 266   if (loc.m_operator_loc == UNKNOWN_LOCATION)
 267     return false;
 268
 269   /* We have both operator location and combined location: only use the
 270      operator location if we have locations for both arguments.  */
 271   return (EXPR_HAS_LOCATION (arg0)
 272           && EXPR_HAS_LOCATION (arg1));
 273 }