Fix pointer addressing and array subscripting of Objective-C interface

types.
 - I broke this in the switch to representing interfaces with opaque
   types.

 - <rdar://problem/6822660> clang crashes on subscript of interface in
   32-bit mode

llvm-svn: 70009

clang/lib/CodeGen/CGExpr.cpp

@@ -809,8 +809,9 @@ LValue CodeGenFunction::EmitArraySubscriptExpr(const ArraySubscriptExpr *E) {
     Idx = Builder.CreateIntCast(Idx, llvm::IntegerType::get(LLVMPointerWidth),
                                 IdxSigned, "idxprom");
 
-  // We know that the pointer points to a type of the correct size, unless the
+  // We know that the pointer points to a type of the correct size,
-  // size is a VLA.
+  // unless the size is a VLA or Objective-C interface.
+  llvm::Value *Address = 0;
   if (const VariableArrayType *VAT = 
         getContext().getAsVariableArrayType(E->getType())) {
     llvm::Value *VLASize = VLASizeMap[VAT];
@@ -823,10 +824,25 @@ LValue CodeGenFunction::EmitArraySubscriptExpr(const ArraySubscriptExpr *E) {
     Idx = Builder.CreateUDiv(Idx,
                              llvm::ConstantInt::get(Idx->getType(), 
                                                     BaseTypeSize));
+    Address = Builder.CreateGEP(Base, Idx, "arrayidx");
+  } else if (const ObjCInterfaceType *OIT = 
+             dyn_cast<ObjCInterfaceType>(E->getType())) {
+    llvm::Value *InterfaceSize = 
+      llvm::ConstantInt::get(Idx->getType(),
+                             getContext().getTypeSize(OIT) / 8);
+    
+    Idx = Builder.CreateMul(Idx, InterfaceSize);
+
+    llvm::Type *i8PTy = llvm::PointerType::getUnqual(llvm::Type::Int8Ty);
+    Address = Builder.CreateGEP(Builder.CreateBitCast(Base, i8PTy), 
+                                Idx, "arrayidx");
+    Address = Builder.CreateBitCast(Address, Base->getType());
+  } else {
+    Address = Builder.CreateGEP(Base, Idx, "arrayidx");
   }
   
   QualType T = E->getBase()->getType()->getAsPointerType()->getPointeeType();
-  LValue LV = LValue::MakeAddr(Builder.CreateGEP(Base, Idx, "arrayidx"),
+  LValue LV = LValue::MakeAddr(Address,
                                T.getCVRQualifiers(),
                                getContext().getObjCGCAttrKind(T));
   if (getContext().getLangOptions().ObjC1 &&

clang/lib/CodeGen/CGExprScalar.cpp

@@ -968,14 +968,27 @@ Value *ScalarExprEmitter::EmitAdd(const BinOpInfo &Ops) {
       Idx = Builder.CreateZExt(Idx, IdxType, "idx.ext");
   }
 
+  const QualType ElementType = PT->getPointeeType();
+  // Handle interface types, which are not represented with a concrete
+  // type.
+  if (const ObjCInterfaceType *OIT = dyn_cast<ObjCInterfaceType>(ElementType)) {
+    llvm::Value *InterfaceSize = 
+      llvm::ConstantInt::get(Idx->getType(),
+                             CGF.getContext().getTypeSize(OIT) / 8);
+    Idx = Builder.CreateMul(Idx, InterfaceSize);
+    const llvm::Type *i8Ty = llvm::PointerType::getUnqual(llvm::Type::Int8Ty);
+    Value *Casted = Builder.CreateBitCast(Ptr, i8Ty);
+    Value *Res = Builder.CreateGEP(Casted, Idx, "add.ptr");
+    return Builder.CreateBitCast(Res, Ptr->getType());
+  } 
+
   // Explicitly handle GNU void* and function pointer arithmetic
   // extensions. The GNU void* casts amount to no-ops since our void*
   // type is i8*, but this is future proof.
-  const QualType ElementType = PT->getPointeeType();
   if (ElementType->isVoidType() || ElementType->isFunctionType()) {
     const llvm::Type *i8Ty = llvm::PointerType::getUnqual(llvm::Type::Int8Ty);
     Value *Casted = Builder.CreateBitCast(Ptr, i8Ty);
-    Value *Res = Builder.CreateGEP(Casted, Idx, "sub.ptr");
+    Value *Res = Builder.CreateGEP(Casted, Idx, "add.ptr");
     return Builder.CreateBitCast(Res, Ptr->getType());
   } 
   
@@ -1015,6 +1028,20 @@ Value *ScalarExprEmitter::EmitSub(const BinOpInfo &Ops) {
     }
     Idx = Builder.CreateNeg(Idx, "sub.ptr.neg");
 
+    // Handle interface types, which are not represented with a concrete
+    // type.
+    if (const ObjCInterfaceType *OIT = 
+        dyn_cast<ObjCInterfaceType>(LHSElementType)) {
+      llvm::Value *InterfaceSize = 
+        llvm::ConstantInt::get(Idx->getType(),
+                               CGF.getContext().getTypeSize(OIT) / 8);
+      Idx = Builder.CreateMul(Idx, InterfaceSize);
+      const llvm::Type *i8Ty = llvm::PointerType::getUnqual(llvm::Type::Int8Ty);
+      Value *LHSCasted = Builder.CreateBitCast(Ops.LHS, i8Ty);
+      Value *Res = Builder.CreateGEP(LHSCasted, Idx, "add.ptr");
+      return Builder.CreateBitCast(Res, Ops.LHS->getType());
+    } 
+
     // Explicitly handle GNU void* and function pointer arithmetic
     // extensions. The GNU void* casts amount to no-ops since our
     // void* type is i8*, but this is future proof.

clang/test/CodeGenObjC/interface.m

@@ -0,0 +1,34 @@
+// RUN: clang-cc -triple i386-apple-darwin9 -O3 -emit-llvm -o %t %s &&
+// RUN: grep 'ret i32 385' %t
+
+void *alloca();
+
+@interface I0 {
+@public
+  int iv0;
+  int iv1;
+  int iv2;
+}
+@end
+
+static int f0(I0 *a0) {
+  return (*(a0 + 2)).iv0;
+}
+
+static int f1(I0 *a0) {
+  return a0[2].iv1;
+}
+
+static int f2(I0 *a0) {
+  return (*(a0 - 1)).iv2;
+}
+
+int g0(void) {
+  I0 *a = alloca(sizeof(*a) * 4);
+  a[2].iv0 = 5;
+  a[2].iv1 = 7;
+  a[2].iv2 = 11;
+  return f0(a) * f1(a) * f2(&a[3]);
+}
+
+