clang-format: [JS] handle character classes in regexes.

Slashes in regular expressions do not need to be escaped and do not
terminate the regular expression even without a preceding backslash.

Patch by Martin Probst. Thank you.

llvm-svn: 250009

1 files changed, 12 insertions, 1 deletions

diff --git a/clang/lib/Format/Format.cpp b/clang/lib/Format/Format.cpp
index 6bfd9cb5cec..0afa9aa9ce2 100644
--- a/clang/lib/Format/Format.cpp
+++ b/clang/lib/Format/Format.cpp
@@ -876,12 +876,23 @@ private:
       return false;
 
     unsigned TokenCount = 0;
+    bool InCharacterClass = false;
     for (auto I = Tokens.rbegin() + 1, E = Tokens.rend(); I != E; ++I) {
       ++TokenCount;
       auto Prev = I + 1;
       while (Prev != E && Prev[0]->is(tok::comment))
         ++Prev;
-      if (I[0]->isOneOf(tok::slash, tok::slashequal) &&
+      // Slashes in character classes (delimited by [ and ]) do not need
+      // escaping. Escaping of the squares themselves is already handled by
+      // \c tryMergeEscapeSequence(), a plain tok::r_square must be non-escaped.
+      if (I[0]->is(tok::r_square))
+        InCharacterClass = true;
+      if (I[0]->is(tok::l_square)) {
+        if (!InCharacterClass)
+          return false;
+        InCharacterClass = false;
+      }
+      if (!InCharacterClass && I[0]->isOneOf(tok::slash, tok::slashequal) &&
           (Prev == E ||
            ((Prev[0]->isOneOf(tok::l_paren, tok::semi, tok::l_brace,
                               tok::r_brace, tok::exclaim, tok::l_square,