[clang] [NFC][Clang][OpenMP] Add helper functions/utils for finding/comparing attach base-ptrs. (PR #155625)

[Alexey Bataev via cfe-commits]

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@@ -8139,6 +8433,104 @@ class MappableExprsHandler {
     }
   }
 
+  /// Returns the address corresponding to \p PointerExpr.
+  static Address getAttachPtrAddr(const Expr *PointerExpr,
+                                  CodeGenFunction &CGF) {
+    assert(PointerExpr && "Cannot get addr from null attach-ptr expr");
+    Address AttachPtrAddr = Address::invalid();
+
+    if (auto *DRE = dyn_cast<DeclRefExpr>(PointerExpr)) {
+      // If the pointer is a variable, we can use its address directly.
+      AttachPtrAddr = CGF.EmitLValue(DRE).getAddress();
+    } else if (auto *OASE = dyn_cast<ArraySectionExpr>(PointerExpr)) {
+      AttachPtrAddr =
+          CGF.EmitArraySectionExpr(OASE, /*IsLowerBound=*/true).getAddress();
+    } else if (auto *ASE = dyn_cast<ArraySubscriptExpr>(PointerExpr)) {
+      AttachPtrAddr = CGF.EmitLValue(ASE).getAddress();
+    } else if (auto *ME = dyn_cast<MemberExpr>(PointerExpr)) {
+      AttachPtrAddr = CGF.EmitMemberExpr(ME).getAddress();
+    } else if (auto *UO = dyn_cast<UnaryOperator>(PointerExpr)) {
+      if (UO->getOpcode() == UO_Deref)
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alexey-bataev wrote:

Looks like this should be an assertion

https://github.com/llvm/llvm-project/pull/155625