Improve derived class casting support. (#272)

Author: gysit

tools/cgeist/Lib/clang-mlir.cc

@@ -3297,8 +3297,8 @@ mlir::Value MLIRScanner::GetAddressOfDerivedClass(
 
     // Add the offset.
 
-    mlir::Type nt = getMLIRType(
-        Glob.CGM.getContext().getLValueReferenceType(Base->getType()));
+    mlir::Type nt = getMLIRType(Glob.CGM.getContext().getLValueReferenceType(
+        QualType(RD->getTypeForDecl(), 0)));
 
     mlir::Value Offset = nullptr;
     if (isLLVMStructABI(RD, /*ST*/ nullptr)) {
@@ -3326,16 +3326,18 @@ mlir::Value MLIRScanner::GetAddressOfDerivedClass(
     }
 
     mlir::Value ptr = value;
-    if (auto PT = ptr.getType().dyn_cast<LLVM::LLVMPointerType>())
+    if (auto PT = ptr.getType().dyn_cast<LLVM::LLVMPointerType>()) {
       ptr = builder.create<LLVM::BitcastOp>(
           loc,
           LLVM::LLVMPointerType::get(builder.getI8Type(), PT.getAddressSpace()),
           ptr);
-    else
+    } else {
+      unsigned memorySpace =
+          ptr.getType().cast<mlir::MemRefType>().getMemorySpaceAsInt();
       ptr = builder.create<polygeist::Memref2PointerOp>(
-          loc,
-          LLVM::LLVMPointerType::get(builder.getI8Type(), PT.getAddressSpace()),
+          loc, LLVM::LLVMPointerType::get(builder.getI8Type(), memorySpace),
           ptr);
+    }
 
     mlir::Value idx[] = {Offset};
     ptr = builder.create<LLVM::GEPOp>(loc, ptr.getType(), ptr, idx);
@@ -3511,7 +3513,7 @@ ValueCategory MLIRScanner::VisitCastExpr(CastExpr *E) {
       if (auto MT = ptr.getType().dyn_cast<MemRefType>())
         nullptr_llvm =
             builder.create<polygeist::Pointer2MemrefOp>(loc, MT, nullptr_llvm);
-      val = builder.create<arith::SelectOp>(loc, ne, val, nullptr_llvm);
+      val = builder.create<arith::SelectOp>(loc, ne, ptr, nullptr_llvm);
     }
     return ValueCategory(val, se.isReference);
   }

tools/cgeist/Test/Verification/base_cast.cpp

@@ -0,0 +1,76 @@
+// RUN: cgeist %s --function=* -S | FileCheck %s
+// RUN: cgeist %s --function=* --struct-abi=0 -memref-abi=0 -S | FileCheck %s --check-prefix CHECK-STR
+
+
+struct A {
+  int val1;
+  int val2;
+};
+
+struct B {
+  bool bool1;
+};
+
+struct C : B, A {
+  int val3;
+};
+
+struct D : C {
+  int val3;
+  bool bool2;
+};
+
+C* castAtoC(A *a) {
+  // A -> C
+  return static_cast<C *>(a);
+};
+
+D* castBtoD(B *b) {
+  // B -> C -> D
+  return static_cast<D *>(b);
+}
+
+D* castAtoD(A *b) {
+  // A -> C -> D
+  return static_cast<D *>(b);
+}
+
+int main() {
+    C c;
+    D d;
+    c.val3 = 2;
+    d.val3 = 2;
+    return 
+      castAtoC(&c)->val3 + // expect nonzero offset due to A -> C
+      castBtoD(&d)->val3 + 
+      castAtoD(&d)->val3;  // expect nonzero offset due to A -> C
+}
+
+// CHECK:   func.func @_Z8castAtoCP1A(
+// CHECK-NEXT:     polygeist.memref2pointer
+// CHECK-NEXT:     llvm.getelementptr {{.*}}[-1]
+// CHECK-NEXT:     llvm.bitcast
+// CHECK-NEXT:     return
+// CHECK:   func.func @_Z8castBtoDP1B(
+// CHECK-NEXT:     polygeist.memref2pointer
+// CHECK-NEXT:     llvm.bitcast
+// CHECK-NEXT:     return
+// CHECK:   func.func @_Z8castAtoDP1A(
+// CHECK-NEXT:     polygeist.memref2pointer
+// CHECK-NEXT:     llvm.getelementptr {{.*}}[-1]
+// CHECK-NEXT:     llvm.bitcast
+// CHECK-NEXT:     return
+// CHECK:    func.func @main()
+// CHECK:    call @_Z8castAtoCP1A(
+// CHECK:    call @_Z8castBtoDP1B(
+// CHECK:    call @_Z8castAtoDP1A(
+
+// CHECK-STR:   func.func @_Z8castAtoCP1A(
+// CHECK-STR-NEXT:     llvm.bitcast
+// CHECK-STR-NEXT:     llvm.getelementptr {{.*}}[-4]
+// CHECK-STR-NEXT:     llvm.bitcast
+// CHECK-STR-NEXT:     return
+// CHECK-STR:   func.func @_Z8castBtoDP1B(
+// CHECK-STR-NEXT:     llvm.bitcast
+// CHECK-STR-NEXT:     llvm.bitcast
+// CHECK-STR-NEXT:     return