Align declarations that are preceded by different number of commas.

[nikola]

Summary

Having a template with more than one template argument breaks alignment of consecutive declarations. Something like this won't be correctly aligned:

int x;
std::pair<int, bool> y;

[djasper]

I think this will also be solved by https://reviews.llvm.org/D21279.

[nikola]

Thanks for letting me know, that patch looks more complete so I'll abandon this. I hope it lands soon!

lib/Format/WhitespaceManager.cpp

 // finalize the previous sequence.
 template <typename F>
 static void AlignTokens(const FormatStyle &Style, F &&Matches,
-                        SmallVector<WhitespaceManager::Change, 16> &Changes) {
+                        SmallVector<WhitespaceManager::Change, 16> &Changes,
+                        bool AligningAssignments) {
   unsigned MinColumn = 0;
   unsigned MaxColumn = UINT_MAX;
 

   unsigned NestingLevelOfLastMatch = 0;
   unsigned NestingLevel = 0;
 
-  // Keep track of the number of commas before the matching tokens, we will only
-  // align a sequence of matching tokens if they are preceded by the same number
-  // of commas.
+  // Keep track of the number of commas before the matching tokens, when
+  // aligning assignments we will only align a sequence of matching tokens
+  // if they are preceded by the same number of commas.
   unsigned CommasBeforeLastMatch = 0;
   unsigned CommasBeforeMatch = 0;
 

       continue;
 
     // If there is more than one matching token per line, or if the number of
-    // preceding commas, or the scope depth, do not match anymore, end the
-    // sequence.
-    if (FoundMatchOnLine || CommasBeforeMatch != CommasBeforeLastMatch ||
-        NestingLevel != NestingLevelOfLastMatch)
+    // preceding commas when aligning assignments, or the scope depth, do not
+    // match anymore, end the sequence.
+    if (FoundMatchOnLine || NestingLevel != NestingLevelOfLastMatch ||
+        (AligningAssignments && CommasBeforeMatch != CommasBeforeLastMatch))
       AlignCurrentSequence();
 
     CommasBeforeLastMatch = CommasBeforeMatch;

 
                 return C.Kind == tok::equal;
               },
-              Changes);
+              Changes, true);
 }
 
 void WhitespaceManager::alignConsecutiveDeclarations() {

   //   SomeVeryLongType const& v3;
 
   AlignTokens(Style, [](Change const &C) { return C.IsStartOfDeclName; },
-              Changes);
+              Changes, false);
 }
 
 void WhitespaceManager::alignTrailingComments() {

unittests/Format/FormatTest.cpp

   verifyFormat("int      oneTwoThree{0}; // comment\n"
                "unsigned oneTwo;         // comment",
                Alignment);
+  verifyFormat("template <typename T, typename U> struct pair {};\n"
+               "int                a;\n"
+               "pair<double, char> b;",
+               Alignment);
   EXPECT_EQ("float const a = 5;\n"
             "\n"
             "int oneTwoThree = 123;",