[PATCH] D55125: [clang-tidy] Fix a false positive in misc-redundant-expression check

[Alexander Kornienko via Phabricator via cfe-commits]

alexfh added inline comments.


================
Comment at: clang-tidy/misc/RedundantExpressionCheck.cpp:601
 
+static bool compareToks(Token &T1, Token &T2, const SourceManager &SM) {
+  if (T1.getLength() != T2.getLength())
----------------
Should this function compare token kinds first?


================
Comment at: clang-tidy/misc/RedundantExpressionCheck.cpp:602
+static bool compareToks(Token &T1, Token &T2, const SourceManager &SM) {
+  if (T1.getLength() != T2.getLength())
+    return false;
----------------
`Token::getLength()` will assert-fail for annotation tokens.


================
Comment at: clang-tidy/misc/RedundantExpressionCheck.cpp:605
+  return strncmp(SM.getCharacterData(T1.getLocation()),
+                 SM.getCharacterData(T2.getLocation()), T1.getLength()) == 0;
+}
----------------
JonasToth wrote:
> This operation could overflow if `len(T1) > len(T2)` and `T2` is the last token of the file. I think `std::min(T1.getLength(), T2.getLength())` would be better.
This code is only executed when they have the same length.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D55125/new/

https://reviews.llvm.org/D55125