clang-tools-extra/clang-tidy/GlobList.cpp

   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.
  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.
  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
  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
  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
  58 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
  68 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