[clang-format] Fix PointerAlignment: Right not working with tab indentation.

[curdeius]

Summary

Fixes https://github.com/llvm/llvm-project/issues/55407.

Given configuration:

UseTab: Always
PointerAlignment: Right
AlignConsecutiveDeclarations: true

Before, the pointer was misaligned in this code:

void f() {
	unsigned long long big;
	char	      *ptr; // misaligned
	int		   i;
}

That was due to the fact that when handling right-aligned pointers, the Spaces were changed but StartOfTokenColumn was not.

Also, a tab was used not only for indentation but for spacing too when using UseTab: ForIndentation config option:

void f() {
	unsigned long long big;
	char	      *ptr; // \t after char
	int                i;
}

[owenpan]

clang/unittests/Format/FormatTest.cpp

14222

Redundant.

[curdeius]

clang/unittests/Format/FormatTest.cpp

14222

Good catch. Will remove when landing (after the weekend probably).

clang/lib/Format/WhitespaceManager.cpp

for (unsigned i = Start; i != End; ++i) {
     if (Style.PointerAlignment == FormatStyle::PAS_Right &&
         Changes[i].Spaces != 0) {
       for (int Previous = i - 1;
            Previous >= 0 &&
            Changes[Previous].Tok->getType() == TT_PointerOrReference;
            --Previous) {
         Changes[Previous + 1].Spaces -= Shift;
         Changes[Previous].Spaces += Shift;
+        Changes[Previous].StartOfTokenColumn += Shift;
       }
     }
   }
 }
 
 // Walk through a subset of the changes, starting at StartAt, and find
 // sequences of matching tokens to align. To do so, keep track of the lines and
 // whether or not a matching token was found on a line. If a matching token is

clang/unittests/Format/FormatTest.cpp

verifyFormat("#define A                        \\\n"
                "\t\t    parameter1,  \\\n"
                "\t\t    parameter2); \\\n"
                "\t}",
                Tab);
   verifyFormat("int a;\t      // x\n"
                "int bbbbbbbb; // x\n",
                Tab);
 
+  FormatStyle TabAlignment = Tab;
+  TabAlignment.AlignConsecutiveDeclarations.Enabled = true;
+  TabAlignment.PointerAlignment = FormatStyle::PAS_Left;
+  verifyFormat("unsigned long long big;\n"
+               "char*\t\t   ptr;",
+               TabAlignment);
+  TabAlignment.PointerAlignment = FormatStyle::PAS_Middle;
+  verifyFormat("unsigned long long big;\n"
+               "char *\t\t   ptr;",
+               TabAlignment);
+  TabAlignment.PointerAlignment = FormatStyle::PAS_Right;
+  verifyFormat("unsigned long long big;\n"
+               "char\t\t  *ptr;",
+               TabAlignment);
+
   Tab.TabWidth = 4;
   Tab.IndentWidth = 8;
   verifyFormat("class TabWidth4Indent8 {\n"
                "\t\tvoid f() {\n"
                "\t\t\t\tsomeFunction(parameter1,\n"
                "\t\t\t\t\t\t\t parameter2);\n"
                "\t\t}\n"
                "};",
EXPECT_EQ("/*\n"
             "\t      in multiple lines\n"
             "       */",
             format("   /*\t \t \n"
                    " \t \t a\t\tcomment\t \t\n"
                    " \t \t in multiple lines\t\n"
                    " \t  */",
                    Tab));
 
+  TabAlignment.UseTab = FormatStyle::UT_ForIndentation;
+  TabAlignment.PointerAlignment = FormatStyle::PAS_Left;
+  verifyFormat("void f() {\n"
+               "\tunsigned long long big;\n"
+               "\tchar*              ptr;\n"
+               "}",
+               TabAlignment);
+  TabAlignment.PointerAlignment = FormatStyle::PAS_Middle;
+  verifyFormat("void f() {\n"
+               "\tunsigned long long big;\n"
+               "\tchar *             ptr;\n"
+               "}",
+               TabAlignment);
+  TabAlignment.PointerAlignment = FormatStyle::PAS_Right;
+  verifyFormat("void f() {\n"
+               "\tunsigned long long big;\n"
+               "\tchar              *ptr;\n"
+               "}",
+               TabAlignment);
+
   Tab.UseTab = FormatStyle::UT_ForIndentation;
   verifyFormat("{\n"
                "\taaaaaaaaaaaaaaaaaaaaaaaaaaaa();\n"
                "\taaaaaaaaaaaaaaaaaaaaaaaaaaaa();\n"
                "\taaaaaaaaaaaaaaaaaaaaaaaaaaaa();\n"
                "\taaaaaaaaaaaaaaaaaaaaaaaaaaaa();\n"
                "\taaaaaaaaaaaaaaaaaaaaaaaaaaaa();\n"
                "\taaaaaaaaaaaaaaaaaaaaaaaaaaaa();\n"