[clang] [clang] [dataflow] use unqualified type for smart pointer matching (PR #125958)

[via cfe-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang-analysis

Author: Florian Mayer (fmayer)

<details>
<summary>Changes</summary>

one would assume that `getCanonicalTypeUnqualified` returns an
unqualified type, but sadly one would be wrong. the current logic fails
for std::optional as implemented in libcxx, because Star and Arrow types
mismatch in their const qualification.

there are other places in clang that use
getCanonicalTypeUnqualified().getUnqualifiedType().


---
Full diff: https://github.com/llvm/llvm-project/pull/125958.diff


1 Files Affected:

- (modified) clang/lib/Analysis/FlowSensitive/SmartPointerAccessorCaching.cpp (+8-4) 


``````````diff
diff --git a/clang/lib/Analysis/FlowSensitive/SmartPointerAccessorCaching.cpp b/clang/lib/Analysis/FlowSensitive/SmartPointerAccessorCaching.cpp
index c58bd309545dbf..576a0ca1594154 100644
--- a/clang/lib/Analysis/FlowSensitive/SmartPointerAccessorCaching.cpp
+++ b/clang/lib/Analysis/FlowSensitive/SmartPointerAccessorCaching.cpp
@@ -41,7 +41,8 @@ bool hasSmartPointerClassShape(const CXXRecordDecl &RD, bool &HasGet,
         HasStar = true;
         StarReturnType = MD->getReturnType()
                              .getNonReferenceType()
-                             ->getCanonicalTypeUnqualified();
+                             ->getCanonicalTypeUnqualified()
+                             .getUnqualifiedType();
       }
       break;
     case OO_Arrow:
@@ -49,7 +50,8 @@ bool hasSmartPointerClassShape(const CXXRecordDecl &RD, bool &HasGet,
         HasArrow = true;
         ArrowReturnType = MD->getReturnType()
                               ->getPointeeType()
-                              ->getCanonicalTypeUnqualified();
+                              ->getCanonicalTypeUnqualified()
+                              .getUnqualifiedType();
       }
       break;
     case OO_None: {
@@ -61,14 +63,16 @@ bool hasSmartPointerClassShape(const CXXRecordDecl &RD, bool &HasGet,
           HasGet = true;
           GetReturnType = MD->getReturnType()
                               ->getPointeeType()
-                              ->getCanonicalTypeUnqualified();
+                              ->getCanonicalTypeUnqualified()
+                              .getUnqualifiedType();
         }
       } else if (II->isStr("value")) {
         if (MD->getReturnType()->isReferenceType()) {
           HasValue = true;
           ValueReturnType = MD->getReturnType()
                                 .getNonReferenceType()
-                                ->getCanonicalTypeUnqualified();
+                                ->getCanonicalTypeUnqualified()
+                                .getUnqualifiedType();
         }
       }
     } break;

``````````

</details>


https://github.com/llvm/llvm-project/pull/125958