[clang] [clang] Fix `remove{CVR|Fast}Qualifiers` with 64-bit `Qualifiers::Mask` (PR #90329)

[Daniil Kovalev via cfe-commits]

https://github.com/kovdan01 created https://github.com/llvm/llvm-project/pull/90329

After #84384, `Qualifiers::Mask` becomes 64-bit. So, operations like `Mask &= ~U32` where `U32` is `unsigned` produce undesirable results since higher 32 bits of `Mask` become zeroed while they should be preserved. Fix that by explicitly casting `unsigned` values to `uint64_t` in such operations. Signatures of fixed functions are intentionally left intact instead of changing the argument itself to `uint64_t` to keep things consistent with other functions working with the same qualifiers and to emphasize that 64-bit masks should not be used for these types of qualifiers.

>From dd3ace8376caec6bd2488a730990cf2e691a21e6 Mon Sep 17 00:00:00 2001
From: Daniil Kovalev <dkovalev at accesssoftek.com>
Date: Sat, 27 Apr 2024 10:52:43 +0300
Subject: [PATCH] [clang] Fix `remove{CVR|Fast}Qualifiers` with 64-bit
 `Qualifiers::Mask`

After #84384, `Qualifiers::Mask` becomes 64-bit. So, operations like
`Mask &= ~U32` where `U32` is `unsigned` produce undesirable results
since higher 32 bits of `Mask` become zeroed while they should be
preserved. Fix that by explicitly casting `unsigned` values to `uint64_t`
in such operations. Signatures of fixed functions are intentionally left
intact instead of changing the argument itself to `uint64_t` to keep things
consistent with other functions working with the same qualifiers and to
emphasize that 64-bit masks should not be used for these types of
qualifiers.
---
 clang/include/clang/AST/Type.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/clang/include/clang/AST/Type.h b/clang/include/clang/AST/Type.h
index dff02d4861b3db..5c7d5396658b57 100644
--- a/clang/include/clang/AST/Type.h
+++ b/clang/include/clang/AST/Type.h
@@ -480,7 +480,7 @@ class Qualifiers {
   }
   void removeCVRQualifiers(unsigned mask) {
     assert(!(mask & ~CVRMask) && "bitmask contains non-CVR bits");
-    Mask &= ~mask;
+    Mask &= ~static_cast<uint64_t>(mask);
   }
   void removeCVRQualifiers() {
     removeCVRQualifiers(CVRMask);
@@ -609,7 +609,7 @@ class Qualifiers {
   }
   void removeFastQualifiers(unsigned mask) {
     assert(!(mask & ~FastMask) && "bitmask contains non-fast qualifier bits");
-    Mask &= ~mask;
+    Mask &= ~static_cast<uint64_t>(mask);
   }
   void removeFastQualifiers() {
     removeFastQualifiers(FastMask);