xref: /llvm-project/clang-tools-extra/clang-tidy/GlobList.cpp (revision f94ed6f7977305db8fa6b48a85c9db2b8cc4d3b3)
1 //===--- tools/extra/clang-tidy/GlobList.cpp ------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "GlobList.h"
10 #include "llvm/ADT/STLExtras.h"
11 #include "llvm/ADT/SmallString.h"
12 
13 namespace clang::tidy {
14 
15 // Returns true if GlobList starts with the negative indicator ('-'), removes it
16 // from the GlobList.
consumeNegativeIndicator(StringRef & GlobList)17 static bool consumeNegativeIndicator(StringRef &GlobList) {
18   GlobList = GlobList.trim();
19   return GlobList.consume_front("-");
20 }
21 
22 // Extracts the first glob from the comma-separated list of globs,
23 // removes it and the trailing comma from the GlobList and
24 // returns the extracted glob.
extractNextGlob(StringRef & GlobList)25 static llvm::StringRef extractNextGlob(StringRef &GlobList) {
26   StringRef UntrimmedGlob = GlobList.substr(0, GlobList.find_first_of(",\n"));
27   StringRef Glob = UntrimmedGlob.trim();
28   GlobList = GlobList.substr(UntrimmedGlob.size() + 1);
29   return Glob;
30 }
31 
createRegexFromGlob(StringRef & Glob)32 static llvm::Regex createRegexFromGlob(StringRef &Glob) {
33   SmallString<128> RegexText("^");
34   StringRef MetaChars("()^$|*+?.[]\\{}");
35   for (char C : Glob) {
36     if (C == '*')
37       RegexText.push_back('.');
38     else if (MetaChars.contains(C))
39       RegexText.push_back('\\');
40     RegexText.push_back(C);
41   }
42   RegexText.push_back('$');
43   return {RegexText.str()};
44 }
45 
GlobList(StringRef Globs,bool KeepNegativeGlobs)46 GlobList::GlobList(StringRef Globs, bool KeepNegativeGlobs /* =true */) {
47   Items.reserve(Globs.count(',') + Globs.count('\n') + 1);
48   do {
49     GlobListItem Item;
50     Item.IsPositive = !consumeNegativeIndicator(Globs);
51     Item.Text = extractNextGlob(Globs);
52     Item.Regex = createRegexFromGlob(Item.Text);
53     if (Item.IsPositive || KeepNegativeGlobs)
54       Items.push_back(std::move(Item));
55   } while (!Globs.empty());
56 }
57 
contains(StringRef S) const58 bool GlobList::contains(StringRef S) const {
59   // Iterating the container backwards as the last match determins if S is in
60   // the list.
61   for (const GlobListItem &Item : llvm::reverse(Items)) {
62     if (Item.Regex.match(S))
63       return Item.IsPositive;
64   }
65   return false;
66 }
67 
contains(StringRef S) const68 bool CachedGlobList::contains(StringRef S) const {
69   auto Entry = Cache.try_emplace(S);
70   bool &Value = Entry.first->getValue();
71   // If the entry was just inserted, determine its required value.
72   if (Entry.second)
73     Value = GlobList::contains(S);
74   return Value;
75 }
76 
77 } // namespace clang::tidy
78