1 /* Find near-matches for identifiers.
2 Copyright (C) 2015-2021 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 "tree.h"
25 #include "cpplib.h"
26 #include "spellcheck-tree.h"
27 #include "selftest.h"
28 #include "stringpool.h"
29
30 /* Calculate edit distance between two identifiers. */
31
32 edit_distance_t
get_edit_distance(tree ident_s,tree ident_t)33 get_edit_distance (tree ident_s, tree ident_t)
34 {
35 gcc_assert (TREE_CODE (ident_s) == IDENTIFIER_NODE);
36 gcc_assert (TREE_CODE (ident_t) == IDENTIFIER_NODE);
37
38 return get_edit_distance (IDENTIFIER_POINTER (ident_s),
39 IDENTIFIER_LENGTH (ident_s),
40 IDENTIFIER_POINTER (ident_t),
41 IDENTIFIER_LENGTH (ident_t));
42 }
43
44 /* Given TARGET, an identifier, and CANDIDATES, a vec of identifiers,
45 determine which element within CANDIDATES has the lowest edit
46 distance to TARGET. If there are multiple elements with the
47 same minimal distance, the first in the vector wins.
48
49 If more than half of the letters were misspelled, the suggestion is
50 likely to be meaningless, so return NULL_TREE for this case. */
51
52 tree
find_closest_identifier(tree target,const auto_vec<tree> * candidates)53 find_closest_identifier (tree target, const auto_vec<tree> *candidates)
54 {
55 gcc_assert (TREE_CODE (target) == IDENTIFIER_NODE);
56
57 best_match<tree, tree> bm (target);
58 int i;
59 tree identifier;
60 FOR_EACH_VEC_ELT (*candidates, i, identifier)
61 {
62 gcc_assert (TREE_CODE (identifier) == IDENTIFIER_NODE);
63 bm.consider (identifier);
64 }
65
66 return bm.get_best_meaningful_candidate ();
67 }
68
69 #if CHECKING_P
70
71 namespace selftest {
72
73 /* Selftests. */
74
75 /* Verify that find_closest_identifier is sane. */
76
77 static void
test_find_closest_identifier()78 test_find_closest_identifier ()
79 {
80 auto_vec<tree> candidates;
81
82 /* Verify that it can handle an empty vec. */
83 ASSERT_EQ (NULL, find_closest_identifier (get_identifier (""), &candidates));
84
85 /* Verify that it works sanely for non-empty vecs. */
86 tree apple = get_identifier ("apple");
87 tree banana = get_identifier ("banana");
88 tree cherry = get_identifier ("cherry");
89 candidates.safe_push (apple);
90 candidates.safe_push (banana);
91 candidates.safe_push (cherry);
92
93 ASSERT_EQ (apple, find_closest_identifier (get_identifier ("app"),
94 &candidates));
95 ASSERT_EQ (banana, find_closest_identifier (get_identifier ("banyan"),
96 &candidates));
97 ASSERT_EQ (cherry, find_closest_identifier (get_identifier ("berry"),
98 &candidates));
99 ASSERT_EQ (NULL,
100 find_closest_identifier (get_identifier ("not like the others"),
101 &candidates));
102 }
103
104 /* Run all of the selftests within this file. */
105
106 void
spellcheck_tree_c_tests()107 spellcheck_tree_c_tests ()
108 {
109 test_find_closest_identifier ();
110 }
111
112 } // namespace selftest
113
114 #endif /* #if CHECKING_P */
115