Handle more error cases if the user tries to declare a method.

ctx.cpp

@@ -2653,10 +2653,14 @@ FunctionEmitContext::maskedStore(llvm::Value *value, llvm::Value *ptr,
         // individually with what turns into a recursive call to
         // makedStore()
         for (int i = 0; i < collectionType->GetElementCount(); ++i) {
+            const Type *eltType = collectionType->GetElementType(i);
+            if (eltType == NULL) {
+                Assert(m->errorCount > 0);
+                continue;
+            }
             llvm::Value *eltValue = ExtractInst(value, i, "value_member");
             llvm::Value *eltPtr = 
                 AddElementOffset(ptr, i, ptrType, "struct_ptr_ptr");
-            const Type *eltType = collectionType->GetElementType(i);
             const Type *eltPtrType = PointerType::GetUniform(eltType);
             StoreInst(eltValue, eltPtr, mask, eltType, eltPtrType);
         }

type.cpp

@@ -1820,6 +1820,7 @@ StructType::StructType(const std::string &n, const llvm::SmallVector<const Type
             else if (CastType<FunctionType>(type) != NULL) {
                 Error(elementPositions[i], "Method declarations are not "
                       "supported.");
+                return;
             }
             else
                 elementTypes.push_back(type->LLVMType(g->ctx));
@@ -2904,7 +2905,11 @@ FunctionType::LLVMFunctionType(llvm::LLVMContext *ctx, bool includeMask) const {
         return NULL;
     }
 
-    return llvm::FunctionType::get(returnType->LLVMType(g->ctx), callTypes, false);
+    llvm::Type *llvmReturnType = returnType->LLVMType(g->ctx);
+    if (llvmReturnType == NULL)
+        return NULL;
+
+    return llvm::FunctionType::get(llvmReturnType, callTypes, false);
 }