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

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;
}
```

Reviewed By: owenpan

Differential Revision: https://reviews.llvm.org/D125528

2 files changed, 36 insertions, 0 deletions

diff --git a/clang/lib/Format/WhitespaceManager.cpp b/clang/lib/Format/WhitespaceManager.cpp
index 4c130abd83c3..f5a0b9963b5d 100644
--- a/clang/lib/Format/WhitespaceManager.cpp
+++ b/clang/lib/Format/WhitespaceManager.cpp
@@ -414,6 +414,7 @@ AlignTokenSequence(const FormatStyle &Style, unsigned Start, unsigned End,
            --Previous) {
         Changes[Previous + 1].Spaces -= Shift;
         Changes[Previous].Spaces += Shift;
+        Changes[Previous].StartOfTokenColumn += Shift;
       }
     }
   }
diff --git a/clang/unittests/Format/FormatTest.cpp b/clang/unittests/Format/FormatTest.cpp
index 136a25fa8946..b621fe7e06f1 100644
--- a/clang/unittests/Format/FormatTest.cpp
+++ b/clang/unittests/Format/FormatTest.cpp
@@ -13687,6 +13687,21 @@ TEST_F(FormatTest, ConfigurableUseOfTab) {
                "int bbbbbbbb; // x\n",
                Tab);
 
+  FormatStyle TabAlignment = Tab;
+  TabAlignment.AlignConsecutiveDeclarations = FormatStyle::ACS_Consecutive;
+  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"
@@ -13729,6 +13744,26 @@ TEST_F(FormatTest, ConfigurableUseOfTab) {
                    " \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"