[clang-format] Fix RAS reference alignment when PAS is left or middle

[gedare]

Summary

Fixes a bug with the handling of right aligned references with left/middle alignment pointers.

Addresses Issue #63452.

https://github.com/llvm/llvm-project/issues/63452

[HazardyKnusperkeks]

Could you please split this into two reviews?

[gedare]

Split and keep right-aligned references, will put function pointers in new rev

[gedare]

In D153579#4442346, @HazardyKnusperkeks wrote:

Could you please split this into two reviews?

yes, done, will stage the other review soon. The function pointer alignment requires this fix for the formatting to be correct inside of the nested scope of the function pointer parameters.

[owenpan]

clang/lib/Format/WhitespaceManager.cpp

459

See below.

463–466

Shorter and IMO easier to follow.

[gedare]

Use suggested shorter logic

clang/lib/Format/WhitespaceManager.cpp

assert(Shift >= 0 || Changes[i].NewlinesBefore > 0 ||
                static_cast<int>(Changes[i].Tok->SpacesRequiredBefore) ||
            Changes[i].Tok->is(tok::eof));
 
     Changes[i].StartOfTokenColumn += Shift;
     if (i + 1 != Changes.size())
       Changes[i + 1].PreviousEndOfTokenColumn += Shift;
 
     // If PointerAlignment is PAS_Right, keep *s or &s next to the token
-    if (Style.PointerAlignment == FormatStyle::PAS_Right &&
+    if ((Style.PointerAlignment == FormatStyle::PAS_Right ||
+         Style.ReferenceAlignment == FormatStyle::RAS_Right) &&
         Changes[i].Spaces != 0) {
       for (int Previous = i - 1;
            Previous >= 0 &&
            Changes[Previous].Tok->getType() == TT_PointerOrReference;
            --Previous) {
+        if (Changes[Previous].Tok->is(tok::amp) ||
+            Changes[Previous].Tok->is(tok::ampamp)) {
+          if (Style.ReferenceAlignment != FormatStyle::RAS_Right &&
+              Style.ReferenceAlignment != FormatStyle::RAS_Pointer) {
+            continue;
+          }
+        } else if (Style.PointerAlignment != FormatStyle::PAS_Right) {
+          continue;
+        }
         Changes[Previous + 1].Spaces -= Shift;
         Changes[Previous].Spaces += Shift;
         Changes[Previous].StartOfTokenColumn += Shift;
       }
     }
   }
 }
 

clang/unittests/Format/FormatTest.cpp

TEST_F(FormatTest, SeparatePointerReferenceAlignment) {
   verifyFormat("int f3() { return sizeof(Foo &); }", Style);
   verifyFormat("int f4() { return sizeof(Foo &&); }", Style);
   verifyFormat("void f5() { int f6(Foo &, Bar &); }", Style);
   verifyFormat("void f5() { int f6(Foo &&, Bar &&); }", Style);
   verifyFormat("for (auto a = 0, b = 0; const Foo * c : {1, 2, 3})", Style);
   verifyFormat("for (int a = 0, b = 0; const Foo * c : {1, 2, 3})", Style);
   verifyFormat("for (int a = 0, b++; const Foo * c : {1, 2, 3})", Style);
 
+  Style.AlignConsecutiveDeclarations.Enabled = true;
+  verifyFormat("Const unsigned int * c;\n"
+               "const unsigned int * d;\n"
+               "Const unsigned int  &e;\n"
+               "const unsigned int  &f;\n"
+               "const unsigned     &&g;\n"
+               "Const unsigned       h;",
+               Style);
+
   // FIXME: we don't handle this yet, so output may be arbitrary until it's
   // specifically handled
   // verifyFormat("int Add2(BTree * &Root, char * szToAdd)", Style);
 }
 
 TEST_F(FormatTest, FormatsForLoop) {
   verifyFormat(
       "for (int VeryVeryLongLoopVariable = 0; VeryVeryLongLoopVariable < 10;\n"