1 /* Find near-matches for identifiers. 2 Copyright (C) 2015-2017 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 Levenshtein distance between two identifiers. */ 31 32 edit_distance_t 33 levenshtein_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 levenshtein_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 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 /* A callback for cpp_forall_identifiers, for use by best_macro_match's ctor. 70 Process HASHNODE and update the best_macro_match instance pointed to be 71 USER_DATA. */ 72 73 static int 74 find_closest_macro_cpp_cb (cpp_reader *, cpp_hashnode *hashnode, 75 void *user_data) 76 { 77 if (hashnode->type != NT_MACRO) 78 return 1; 79 80 best_macro_match *bmm = (best_macro_match *)user_data; 81 bmm->consider (hashnode); 82 83 /* Keep iterating. */ 84 return 1; 85 } 86 87 /* Constructor for best_macro_match. 88 Use find_closest_macro_cpp_cb to find the closest matching macro to 89 NAME within distance < best_distance_so_far. */ 90 91 best_macro_match::best_macro_match (tree goal, 92 edit_distance_t best_distance_so_far, 93 cpp_reader *reader) 94 : best_match <goal_t, candidate_t> (goal, best_distance_so_far) 95 { 96 cpp_forall_identifiers (reader, find_closest_macro_cpp_cb, this); 97 } 98 99 #if CHECKING_P 100 101 namespace selftest { 102 103 /* Selftests. */ 104 105 /* Verify that find_closest_identifier is sane. */ 106 107 static void 108 test_find_closest_identifier () 109 { 110 auto_vec<tree> candidates; 111 112 /* Verify that it can handle an empty vec. */ 113 ASSERT_EQ (NULL, find_closest_identifier (get_identifier (""), &candidates)); 114 115 /* Verify that it works sanely for non-empty vecs. */ 116 tree apple = get_identifier ("apple"); 117 tree banana = get_identifier ("banana"); 118 tree cherry = get_identifier ("cherry"); 119 candidates.safe_push (apple); 120 candidates.safe_push (banana); 121 candidates.safe_push (cherry); 122 123 ASSERT_EQ (apple, find_closest_identifier (get_identifier ("app"), 124 &candidates)); 125 ASSERT_EQ (banana, find_closest_identifier (get_identifier ("banyan"), 126 &candidates));; 127 ASSERT_EQ (cherry, find_closest_identifier (get_identifier ("berry"), 128 &candidates)); 129 ASSERT_EQ (NULL, 130 find_closest_identifier (get_identifier ("not like the others"), 131 &candidates)); 132 } 133 134 /* Run all of the selftests within this file. */ 135 136 void 137 spellcheck_tree_c_tests () 138 { 139 test_find_closest_identifier (); 140 } 141 142 } // namespace selftest 143 144 #endif /* #if CHECKING_P */ 145