[clang-format] Break non-trailing block comments

krasimirgg · krasimirgg · commit fe268fc1c892 · 2017-08-22T14:40:05.000Z
Summary: This patch is an alternative to https://reviews.llvm.org/D36614, by resolving a non-idempotency issue by breaking non-trailing comments: Consider formatting the following code with column limit at `V`: ``` V const /* comment comment */ A = B; ``` The comment is not a trailing comment, breaking before it doesn't bring it under the column limit. The formatter breaks after it, resulting in: ``` V const /* comment comment */ A = B; ``` For a next reformat, the formatter considers the comment as a trailing comment, so it is free to break it further, resulting in: ``` V const /* comment comment */ A = B; ``` This patch improves the situation by directly producing the third case. Reviewers: djasper Reviewed By: djasper Subscribers: cfe-commits, klimek Differential Revision: https://reviews.llvm.org/D37007 llvm-svn: 311457
diff --git a/clang/lib/Format/ContinuationIndenter.cpp b/clang/lib/Format/ContinuationIndenter.cpp
@@ -1282,7 +1282,7 @@ unsigned ContinuationIndenter::breakProtrudingToken(const FormatToken &Current,
       return 0;
     }
   } else if (Current.is(TT_BlockComment)) {
-    if (!Current.isTrailingComment() || !Style.ReflowComments ||
+    if (!Style.ReflowComments ||
         // If a comment token switches formatting, like
         // /* clang-format on */, we don't want to break it further,
         // but we may still want to adjust its indentation.
diff --git a/clang/unittests/Format/FormatTestComments.cpp b/clang/unittests/Format/FormatTestComments.cpp
@@ -2780,6 +2780,22 @@ TEST_F(FormatTestComments, AlignsBlockCommentDecorations) {
                    "* long */",
                    getLLVMStyleWithColumns(20)));
 }
+
+TEST_F(FormatTestComments, NonTrailingBlockComments) {
+  verifyFormat("const /** comment comment */ A = B;",
+               getLLVMStyleWithColumns(40));
+
+  verifyFormat("const /** comment comment comment */ A =\n"
+               "    B;",
+               getLLVMStyleWithColumns(40));
+
+  EXPECT_EQ("const /** comment comment comment\n"
+            "         comment */\n"
+            "    A = B;",
+            format("const /** comment comment comment comment */\n"
+                   "    A = B;",
+                   getLLVMStyleWithColumns(40)));
+}
 } // end namespace
 } // end namespace format
 } // end namespace clang

Original file line number	Diff line number	Diff line change
`@@ -1282,7 +1282,7 @@ unsigned ContinuationIndenter::breakProtrudingToken(const FormatToken &Current,`
`1282`	`1282`	`return 0;`
`1283`	`1283`	`}`
`1284`	`1284`	`} else if (Current.is(TT_BlockComment)) {`
`1285`		`- if (!Current.isTrailingComment() \|\| !Style.ReflowComments \|\|`
	`1285`	`+ if (!Style.ReflowComments \|\|`
`1286`	`1286`	`// If a comment token switches formatting, like`
`1287`	`1287`	`// /* clang-format on */, we don't want to break it further,`
`1288`	`1288`	`// but we may still want to adjust its indentation.`