[PATCH] D79465: Fix line lengths w/ comments in align

[Jake Merdich via Phabricator via cfe-commits]

JakeMerdichAMD created this revision.
Herald added a project: clang.
Herald added a subscriber: cfe-commits.
JakeMerdichAMD added a project: clang-format.
JakeMerdichAMD added reviewers: MyDeveloperDay, krasimir, VelocityRa, sylvestre.ledru, sammccall, enyquist.
JakeMerdichAMD added a comment.

The failing case in this commit looks like the following after formatting (with alignconsecutiveassignments and a specific column limit)

  int x = 0;
  int yy = 1; ///specificlennospace
  int zzz = 2;

See PR43845 for more failing cases besides this.


When a '//comment' trails a consecutive alignment, it adds a whitespace
replacement within the comment token. This wasn't handled correctly in
the alignment code, which treats it as a whole token and thus double
counts it.

This can wrongly trigger the "line too long, it'll wrap" alignment-break
condition with specific lengths, causing the alignment to break for
seemingly no reason.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D79465

Files:
  clang/lib/Format/WhitespaceManager.cpp
  clang/unittests/Format/FormatTest.cpp


Index: clang/unittests/Format/FormatTest.cpp
===================================================================
--- clang/unittests/Format/FormatTest.cpp
+++ clang/unittests/Format/FormatTest.cpp
@@ -11564,6 +11564,16 @@
                "  x = 1;\n"
                "y = 1;\n",
                Alignment);
+
+  Alignment.ReflowComments = true;
+  Alignment.ColumnLimit = 50;
+  EXPECT_EQ("int x   = 0;\n"
+            "int yy  = 1; /// specificlennospace\n"
+            "int zzz = 2;\n",
+            format("int x   = 0;\n"
+                   "int yy  = 1; ///specificlennospace\n"
+                   "int zzz = 2;\n",
+                   Alignment));
 }
 
 TEST_F(FormatTest, AlignConsecutiveDeclarations) {
Index: clang/lib/Format/WhitespaceManager.cpp
===================================================================
--- clang/lib/Format/WhitespaceManager.cpp
+++ clang/lib/Format/WhitespaceManager.cpp
@@ -410,8 +410,11 @@
 
     unsigned ChangeMinColumn = Changes[i].StartOfTokenColumn;
     int LineLengthAfter = -Changes[i].Spaces;
-    for (unsigned j = i; j != e && Changes[j].NewlinesBefore == 0; ++j)
-      LineLengthAfter += Changes[j].Spaces + Changes[j].TokenLength;
+    for (unsigned j = i; j != e && Changes[j].NewlinesBefore == 0; ++j) {
+      LineLengthAfter += Changes[j].Spaces;
+      if (!Changes[j].IsInsideToken)
+        LineLengthAfter += Changes[j].TokenLength;
+    }
     unsigned ChangeMaxColumn = Style.ColumnLimit - LineLengthAfter;
 
     // If we are restricted by the maximum column width, end the sequence.


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D79465.262280.patch
Type: text/x-patch
Size: 1554 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/cfe-commits/attachments/20200506/f94d74e7/attachment.bin>