[clang] 4dcfae6 - Fix a violated precondition in clang-format.

[Manuel Klimek via cfe-commits]

Author: Manuel Klimek
Date: 2021-12-01T14:39:00+01:00
New Revision: 4dcfae6a003aa541600e5af42c0bec5d8e1abef0

URL: https://github.com/llvm/llvm-project/commit/4dcfae6a003aa541600e5af42c0bec5d8e1abef0
DIFF: https://github.com/llvm/llvm-project/commit/4dcfae6a003aa541600e5af42c0bec5d8e1abef0.diff

LOG: Fix a violated precondition in clang-format.

Make sure we do not try to change line comments that are non-regular, i.e. do
not start with "//" or "#". This can for example happen when "//" is
broken into two lines with an escaped newline.

Added: 
    

Modified: 
    clang/lib/Format/ContinuationIndenter.cpp
    clang/unittests/Format/FormatTestComments.cpp

Removed: 
    


################################################################################
diff  --git a/clang/lib/Format/ContinuationIndenter.cpp b/clang/lib/Format/ContinuationIndenter.cpp
index f56b7c70d18e7..5073f5105d051 100644
--- a/clang/lib/Format/ContinuationIndenter.cpp
+++ b/clang/lib/Format/ContinuationIndenter.cpp
@@ -1984,11 +1984,17 @@ ContinuationIndenter::createBreakableToken(const FormatToken &Current,
   } else if (Current.is(TT_LineComment) &&
              (Current.Previous == nullptr ||
               Current.Previous->isNot(TT_ImplicitStringLiteral))) {
+    bool RegularComments = [&]() {
+      for (const FormatToken *T = &Current; T && T->is(TT_LineComment);
+           T = T->Next) {
+        if (!(T->TokenText.startswith("//") || T->TokenText.startswith("#")))
+          return false;
+      }
+      return true;
+    }();
     if (!Style.ReflowComments ||
         CommentPragmasRegex.match(Current.TokenText.substr(2)) ||
-        switchesFormatting(Current) ||
-        !(Current.TokenText.startswith("//") ||
-          Current.TokenText.startswith("#")))
+        switchesFormatting(Current) || !RegularComments)
       return nullptr;
     return std::make_unique<BreakableLineCommentSection>(
         Current, StartColumn, /*InPPDirective=*/false, Encoding, Style);

diff  --git a/clang/unittests/Format/FormatTestComments.cpp b/clang/unittests/Format/FormatTestComments.cpp
index 2a7ead62ba5b4..b5db353d4ae0a 100644
--- a/clang/unittests/Format/FormatTestComments.cpp
+++ b/clang/unittests/Format/FormatTestComments.cpp
@@ -3978,6 +3978,18 @@ TEST_F(FormatTestComments, SpaceAtLineCommentBegin) {
             format(Code, Style));
 }
 
+TEST_F(FormatTestComments, SplitCommentIntroducers) {
+  EXPECT_EQ(R"(//
+/\
+/
+)",
+            format(R"(//
+/\
+/ 
+  )",
+                   getLLVMStyleWithColumns(10)));
+}
+
 } // end namespace
 } // end namespace format
 } // end namespace clang