clang-format: Fix bug when aligning trailing /**/-comments in macros.

Previously this could lead to a column limit violation with the
required escaped newlines.

llvm-svn: 207351

clang/lib/Format/WhitespaceManager.cpp

@@ -154,8 +154,9 @@ void WhitespaceManager::alignTrailingComments() {
       continue;
 
     unsigned ChangeMinColumn = Changes[i].StartOfTokenColumn;
-    // FIXME: Correctly handle ChangeMaxColumn in PP directives.
     unsigned ChangeMaxColumn = Style.ColumnLimit - Changes[i].TokenLength;
+    if (i + 1 != e && Changes[i + 1].ContinuesPPDirective)
+      ChangeMaxColumn -= 2;
     // If this comment follows an } in column 0, it probably documents the
     // closing of a namespace and we don't want to align it.
     bool FollowsRBraceInColumn0 = i > 0 && Changes[i].NewlinesBefore == 0 &&

clang/unittests/Format/FormatTest.cpp

@@ -832,6 +832,17 @@ TEST_F(FormatTest, UnderstandsSingleLineComments) {
                    " // first\n"
                    "// at start\n"
                    "otherLine();"));
+
+  verifyFormat(
+      "#define A                                                  \\\n"
+      "  int i; /* iiiiiiiiiiiiiiiiiiiii */                       \\\n"
+      "  int jjjjjjjjjjjjjjjjjjjjjjjj; /* */",
+      getLLVMStyleWithColumns(60));
+  verifyFormat(
+      "#define A                                                   \\\n"
+      "  int i;                        /* iiiiiiiiiiiiiiiiiiiii */ \\\n"
+      "  int jjjjjjjjjjjjjjjjjjjjjjjj; /* */",
+      getLLVMStyleWithColumns(61));
 }
 
 TEST_F(FormatTest, KeepsParameterWithTrailingCommentsOnTheirOwnLine) {