[PATCH] D91033: GNU nano 4.8 /tmp/edit.7czvmlx7um4go4c0/commit-message Modified [clang-tidy][NFC] Tweak GlobList to iterate backwards

[Nathan James via Phabricator via cfe-commits]

njames93 created this revision.
njames93 added reviewers: aaron.ballman, alexfh, gribozavr2.
Herald added subscribers: cfe-commits, xazax.hun.
Herald added a project: clang.
njames93 requested review of this revision.

By iterating backwards over the globs we can exit the loop as soon as we find a match.

While we're here:

- Regex doesn't need to be mutable.
- We can reserve the amount of Globs needed ahead of time.
- Using a SmallVector with size 0 is slightly more space efficient than a std::vector.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D91033

Files:
  clang-tools-extra/clang-tidy/GlobList.cpp
  clang-tools-extra/clang-tidy/GlobList.h


Index: clang-tools-extra/clang-tidy/GlobList.h
===================================================================
--- clang-tools-extra/clang-tidy/GlobList.h
+++ clang-tools-extra/clang-tidy/GlobList.h
@@ -10,9 +10,9 @@
 #define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_GLOBLIST_H
 
 #include "clang/Basic/LLVM.h"
+#include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/Support/Regex.h"
-#include <vector>
 
 namespace clang {
 namespace tidy {
@@ -39,9 +39,9 @@
 
   struct GlobListItem {
     bool IsPositive;
-    mutable llvm::Regex Regex;
+    llvm::Regex Regex;
   };
-  std::vector<GlobListItem> Items;
+  SmallVector<GlobListItem, 0> Items;
 };
 
 } // end namespace tidy
Index: clang-tools-extra/clang-tidy/GlobList.cpp
===================================================================
--- clang-tools-extra/clang-tidy/GlobList.cpp
+++ clang-tools-extra/clang-tidy/GlobList.cpp
@@ -43,6 +43,7 @@
 }
 
 GlobList::GlobList(StringRef Globs) {
+  Items.reserve(Globs.count(',') + 1);
   do {
     GlobListItem Item;
     Item.IsPositive = !ConsumeNegativeIndicator(Globs);
@@ -52,10 +53,9 @@
 }
 
 bool GlobList::contains(StringRef S) {
-  bool Contains = false;
-  for (const GlobListItem &Item : Items) {
+  for (const GlobListItem &Item : llvm::reverse(Items)) {
     if (Item.Regex.match(S))
-      Contains = Item.IsPositive;
+      return Item.IsPositive;
   }
-  return Contains;
+  return false;
 }


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