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   if (GlobList.startswith("-")) {
  20     GlobList = GlobList.substr(1);
  21     return true;
  22   }
  23   return false;
  24 }
  25
  26 // Converts first glob from the comma-separated list of globs to Regex and
  27 // removes it and the trailing comma from the GlobList.
  28 static llvm::Regex consumeGlob(StringRef &GlobList) {
  29   StringRef UntrimmedGlob = GlobList.substr(0, GlobList.find_first_of(",\n"));
  30   StringRef Glob = UntrimmedGlob.trim();
  31   GlobList = GlobList.substr(UntrimmedGlob.size() + 1);
  32   SmallString<128> RegexText("^");
  33   StringRef MetaChars("()^$|*+?.[]\\{}");
  34   for (char C : Glob) {
  35     if (C == '*')
  36       RegexText.push_back('.');
  37     else if (MetaChars.contains(C))
  38       RegexText.push_back('\\');
  39     RegexText.push_back(C);
  40   }
  41   RegexText.push_back('$');
  42   return {RegexText.str()};
  43 }
  44
  45 GlobList::GlobList(StringRef Globs, bool KeepNegativeGlobs /* =true */) {
  46   Items.reserve(Globs.count(',') + Globs.count('\n') + 1);
  47   do {
  48     GlobListItem Item;
  49     Item.IsPositive = !consumeNegativeIndicator(Globs);
  50     Item.Regex = consumeGlob(Globs);
  51     if (Item.IsPositive || KeepNegativeGlobs)
  52       Items.push_back(std::move(Item));
  53   } while (!Globs.empty());
  54 }
  55
  56 bool GlobList::contains(StringRef S) const {
  57   // Iterating the container backwards as the last match determins if S is in
  58   // the list.
  59   for (const GlobListItem &Item : llvm::reverse(Items)) {
  60     if (Item.Regex.match(S))
  61       return Item.IsPositive;
  62   }
  63   return false;
  64 }
  65
  66 bool CachedGlobList::contains(StringRef S) const {
  67   auto Entry = Cache.try_emplace(S);
  68   bool &Value = Entry.first->getValue();
  69   // If the entry was just inserted, determine its required value.
  70   if (Entry.second)
  71     Value = GlobList::contains(S);
  72   return Value;
  73 }
  74
  75 } // namespace clang::tidy