1 /* Find near-matches for macros.
2    Copyright (C) 2016-2020 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 "tree.h"
25 #include "cpplib.h"
26 #include "spellcheck-tree.h"
27 #include "c-family/c-spellcheck.h"
28 #include "selftest.h"
29 
30 /* Return true iff STR begin with an underscore and either an uppercase
31    letter or another underscore, and is thus, for C and C++, reserved for
32    use by the implementation.  */
33 
34 bool
name_reserved_for_implementation_p(const char * str)35 name_reserved_for_implementation_p (const char *str)
36 {
37   if (str[0] != '_')
38     return false;
39   return (str[1] == '_' || ISUPPER(str[1]));
40 }
41 
42 /* Return true iff HASHNODE is a macro that should be offered as a
43    suggestion for a misspelling.  */
44 
45 static bool
should_suggest_as_macro_p(cpp_hashnode * hashnode)46 should_suggest_as_macro_p (cpp_hashnode *hashnode)
47 {
48   if (!cpp_macro_p (hashnode))
49     return false;
50 
51   /* Don't suggest names reserved for the implementation, but do
52      suggest the builtin macros such as __FILE__, __LINE__ etc.  */
53   if (cpp_user_macro_p (hashnode)
54       && name_reserved_for_implementation_p ((const char *)hashnode->ident.str))
55     return false;
56 
57   return true;
58 }
59 
60 /* A callback for cpp_forall_identifiers, for use by best_macro_match's ctor.
61    Process HASHNODE and update the best_macro_match instance pointed to be
62    USER_DATA.  */
63 
64 static int
find_closest_macro_cpp_cb(cpp_reader *,cpp_hashnode * hashnode,void * user_data)65 find_closest_macro_cpp_cb (cpp_reader *, cpp_hashnode *hashnode,
66 			   void *user_data)
67 {
68   if (!should_suggest_as_macro_p (hashnode))
69     return 1;
70 
71   best_macro_match *bmm = (best_macro_match *)user_data;
72   bmm->consider (hashnode);
73 
74   /* Keep iterating.  */
75   return 1;
76 }
77 
78 /* Constructor for best_macro_match.
79    Use find_closest_macro_cpp_cb to find the closest matching macro to
80    NAME within distance < best_distance_so_far. */
81 
best_macro_match(tree goal,edit_distance_t best_distance_so_far,cpp_reader * reader)82 best_macro_match::best_macro_match (tree goal,
83 				    edit_distance_t best_distance_so_far,
84 				    cpp_reader *reader)
85 : best_match <goal_t, candidate_t> (goal, best_distance_so_far)
86 {
87   cpp_forall_identifiers (reader, find_closest_macro_cpp_cb, this);
88 }
89 
90 #if CHECKING_P
91 
92 namespace selftest {
93 
94 /* Selftests.  */
95 
96 /* Verify that name_reserved_for_implementation_p is sane.  */
97 
98 static void
test_name_reserved_for_implementation_p()99 test_name_reserved_for_implementation_p ()
100 {
101   ASSERT_FALSE (name_reserved_for_implementation_p (""));
102   ASSERT_FALSE (name_reserved_for_implementation_p ("foo"));
103   ASSERT_FALSE (name_reserved_for_implementation_p ("_"));
104   ASSERT_FALSE (name_reserved_for_implementation_p ("_foo"));
105   ASSERT_FALSE (name_reserved_for_implementation_p ("_42"));
106   ASSERT_TRUE (name_reserved_for_implementation_p ("_Foo"));
107   ASSERT_TRUE (name_reserved_for_implementation_p ("__"));
108   ASSERT_TRUE (name_reserved_for_implementation_p ("__foo"));
109 }
110 
111 /* Run all of the selftests within this file.  */
112 
113 void
c_spellcheck_cc_tests()114 c_spellcheck_cc_tests ()
115 {
116   test_name_reserved_for_implementation_p ();
117 }
118 
119 } // namespace selftest
120 
121 #endif /* #if CHECKING_P */
122