GDV-55: [C++] Added validation to projector build. (apache#33)

Validating the input schema and expressions during the projector build.

Author: praveenbingo

cpp/src/gandiva/codegen/CMakeLists.txt

@@ -32,6 +32,7 @@ add_library(gandiva SHARED
   projector.cc
   status.cc
   tree_expr_builder.cc
+  expr_validator.cc
   ${BC_FILE_PATH_CC})
 
 # For users of gandiva library (including integ tests), include-dir is :

cpp/src/gandiva/codegen/expr_decomposer.cc

@@ -28,17 +28,18 @@
 namespace gandiva {
 
 // Decompose a field node - simply seperate out validity & value arrays.
-void ExprDecomposer::Visit(const FieldNode &node) {
+Status ExprDecomposer::Visit(const FieldNode &node) {
   auto desc = annotator_.CheckAndAddInputFieldDescriptor(node.field());
 
   DexPtr validity_dex = std::make_shared<VectorReadValidityDex>(desc);
   DexPtr value_dex = std::make_shared<VectorReadValueDex>(desc);
   result_ = std::make_shared<ValueValidityPair>(validity_dex, value_dex);
+  return Status::OK();
 }
 
 // Decompose a field node - wherever possible, merge the validity vectors of the
 // child nodes.
-void ExprDecomposer::Visit(const FunctionNode &node) {
+Status ExprDecomposer::Visit(const FunctionNode &node) {
   auto desc = node.descriptor();
   FunctionSignature signature(desc->name(),
                               desc->params(),
@@ -84,10 +85,11 @@ void ExprDecomposer::Visit(const FunctionNode &node) {
                                                                local_bitmap_idx);
     result_ = std::make_shared<ValueValidityPair>(validity_dex, value_dex);
   }
+  return Status::OK();
 }
 
 // Decompose an IfNode
-void ExprDecomposer::Visit(const IfNode &node) {
+Status ExprDecomposer::Visit(const IfNode &node) {
   // Add a local bitmap to track the output validity.
   node.condition()->Accept(*this);
   auto condition_vv = result();
@@ -111,11 +113,13 @@ void ExprDecomposer::Visit(const IfNode &node) {
                                            is_terminal_else);
 
   result_ = std::make_shared<ValueValidityPair>(validity_dex, value_dex);
+  return Status::OK();
 }
 
-void ExprDecomposer::Visit(const LiteralNode &node) {
+Status ExprDecomposer::Visit(const LiteralNode &node) {
   auto value_dex = std::make_shared<LiteralDex>(node.return_type(), node.holder());
   result_ = std::make_shared<ValueValidityPair>(value_dex);
+  return Status::OK();
 }
 
 // The bolow functions use a stack to detect :

cpp/src/gandiva/codegen/expr_decomposer.h

@@ -49,10 +49,10 @@ class ExprDecomposer : public NodeVisitor {
   FRIEND_TEST(TestExprDecomposer, TestInternalIf);
   FRIEND_TEST(TestExprDecomposer, TestParallelIf);
 
-  void Visit(const FieldNode &node) override;
-  void Visit(const FunctionNode &node) override;
-  void Visit(const IfNode &node) override;
-  void Visit(const LiteralNode &node) override;
+  Status Visit(const FieldNode &node) override;
+  Status Visit(const FunctionNode &node) override;
+  Status Visit(const IfNode &node) override;
+  Status Visit(const LiteralNode &node) override;
 
   // stack of if nodes.
   class IfStackEntry {

cpp/src/gandiva/codegen/expr_validator.cc

@@ -0,0 +1,132 @@
+// Copyright (C) 2017-2018 Dremio Corporation
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include <string>
+#include <sstream>
+#include <vector>
+
+#include "codegen/expr_validator.h"
+
+namespace gandiva {
+
+Status ExprValidator::Validate(const ExpressionPtr &expr) {
+  if (expr == nullptr) {
+    return Status::ExpressionValidationError("Expression cannot be null.");
+  }
+  Node &root = *expr->root();
+  Status status = root.Accept(*this);
+  if (!status.ok()) {
+    return status;
+  }
+  // validate return type matches
+  // no need to check if type is supported
+  // since root type has been validated.
+  if (!root.return_type()->Equals(*expr->result()->type())) {
+    std::stringstream ss;
+    ss << "Return type of root node " << root.return_type()->name()
+       << " does not match that of expression " << *expr->result()->type();
+    return Status::ExpressionValidationError(ss.str());
+  }
+  return Status::OK();
+}
+
+Status ExprValidator::Visit(const FieldNode &node) {
+  auto llvm_type = types_->IRType(node.return_type()->id());
+  if (llvm_type == nullptr) {
+    std::stringstream ss;
+    ss << "Field "<< node.field()->name() << " has unsupported data type "
+      << node.return_type()->name();
+    return Status::ExpressionValidationError(ss.str());
+  }
+
+  auto field_in_schema_entry = field_map_.find(node.field()->name());
+
+  // validate that field is in schema.
+  if (field_in_schema_entry == field_map_.end()) {
+    std::stringstream ss;
+    ss << "Field " <<  node.field()->name() << " not in schema.";
+    return Status::ExpressionValidationError(ss.str());
+  }
+
+  FieldPtr field_in_schema = field_in_schema_entry->second;
+  // validate that field matches the definition in schema.
+  if (!field_in_schema->Equals(node.field())) {
+    std::stringstream ss;
+    ss << "Field definition in schema " <<  field_in_schema->ToString()
+       << " different from field in expression " << node.field()->ToString();
+    return Status::ExpressionValidationError(ss.str());
+  }
+  return Status::OK();
+}
+
+Status ExprValidator::Visit(const FunctionNode &node) {
+  auto desc = node.descriptor();
+  FunctionSignature signature(desc->name(),
+                              desc->params(),
+                              desc->return_type());
+  const NativeFunction *native_function = registry_.LookupSignature(signature);
+  if (native_function == nullptr) {
+    std::stringstream ss;
+    ss << "Function "<< signature.ToString() << " not supported yet. ";
+    return Status::ExpressionValidationError(ss.str());
+  }
+
+  for (auto &child : node.children()) {
+    Status status = child->Accept(*this);
+    GANDIVA_RETURN_NOT_OK(status);
+  }
+  return Status::OK();
+}
+
+Status ExprValidator::Visit(const IfNode &node) {
+  Status status = node.condition()->Accept(*this);
+  GANDIVA_RETURN_NOT_OK(status);
+  status = node.then_node()->Accept(*this);
+  GANDIVA_RETURN_NOT_OK(status);
+  status = node.else_node()->Accept(*this);
+  GANDIVA_RETURN_NOT_OK(status);
+
+  auto if_node_ret_type = node.return_type();
+  auto then_node_ret_type = node.then_node()->return_type();
+  auto else_node_ret_type = node.else_node()->return_type();
+
+  if (if_node_ret_type != then_node_ret_type) {
+    std::stringstream ss;
+    ss << "Return type of if "<< *if_node_ret_type  << " and then "
+      << then_node_ret_type->name()  << " not matching.";
+    return Status::ExpressionValidationError(ss.str());
+  }
+
+  if (if_node_ret_type != else_node_ret_type) {
+     std::stringstream ss;
+     ss << "Return type of if "<< *if_node_ret_type  << " and else "
+       << else_node_ret_type->name()  << " not matching.";
+     return Status::ExpressionValidationError(ss.str());
+  }
+
+  return Status::OK();
+}
+
+Status ExprValidator::Visit(const LiteralNode &node) {
+  auto llvm_type = types_->IRType(node.return_type()->id());
+  if (llvm_type == nullptr) {
+    std::stringstream ss;
+    ss << "Value "<< node.holder() << " has unsupported data type "
+      << node.return_type()->name();
+    return Status::ExpressionValidationError(ss.str());
+  }
+  return Status::OK();
+}
+
+} // namespace gandiva

cpp/src/gandiva/codegen/expr_validator.h

@@ -0,0 +1,74 @@
+// Copyright (C) 2017-2018 Dremio Corporation
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef GANDIVA_EXPR_VALIDATOR_H
+#define GANDIVA_EXPR_VALIDATOR_H
+
+#include <string>
+#include <unordered_map>
+
+#include "boost/functional/hash.hpp"
+#include "codegen/function_registry.h"
+#include "codegen/node_visitor.h"
+#include "codegen/node.h"
+#include "codegen/llvm_types.h"
+#include "gandiva/arrow.h"
+#include "gandiva/expression.h"
+#include "gandiva/status.h"
+
+namespace gandiva {
+
+class FunctionRegistry;
+
+/// \brief Validates the entire expression tree including
+/// data types, signatures and return types
+class ExprValidator : public NodeVisitor {
+ public:
+  explicit ExprValidator(LLVMTypes * types, SchemaPtr schema)
+    : types_(types),
+      schema_(schema) {
+      for (auto &field : schema_->fields()) {
+        field_map_[field->name()] =  field;
+      }
+    }
+
+  /// \brief Validates the root node
+  /// of an expression.
+  /// 1. Data type of fields and literals.
+  /// 2. Function signature is supported.
+  /// 3. For if nodes that return types match
+  ///    for if, then and else nodes.
+  Status Validate(const ExpressionPtr &expr);
+
+ private:
+  Status Visit(const FieldNode &node) override;
+  Status Visit(const FunctionNode &node) override;
+  Status Visit(const IfNode &node) override;
+  Status Visit(const LiteralNode &node) override;
+
+  FunctionRegistry registry_;
+
+  LLVMTypes *types_;
+
+  SchemaPtr schema_;
+
+  using FieldMap = std::unordered_map<std::string,
+                                      FieldPtr,
+                                      boost::hash<std::string>>;
+  FieldMap field_map_;
+};
+
+} // namespace gandiva
+
+#endif //GANDIVA_EXPR_VALIDATOR_H

cpp/src/gandiva/codegen/llvm_generator.h

@@ -49,6 +49,8 @@ class LLVMGenerator {
   Status Execute(const arrow::RecordBatch &record_batch,
                  const ArrayDataVector &output_vector);
 
+  LLVMTypes *types() { return types_; }
+
  private:
   LLVMGenerator();
 
@@ -59,7 +61,6 @@ class LLVMGenerator {
   llvm::Module *module() { return engine_->module(); }
   llvm::LLVMContext &context() { return *(engine_->context()); }
   llvm::IRBuilder<> &ir_builder() { return engine_->ir_builder(); }
-  LLVMTypes *types() { return types_; }
 
   /// Visitor to generate the code for a decomposed expression.
   class Visitor : public DexVisitor {

cpp/src/gandiva/codegen/node.h

@@ -23,6 +23,7 @@
 #include "codegen/node_visitor.h"
 #include "gandiva/arrow.h"
 #include "gandiva/gandiva_aliases.h"
+#include "gandiva/status.h"
 
 namespace gandiva {
 
@@ -36,7 +37,7 @@ class Node {
   const DataTypePtr &return_type() const { return return_type_; }
 
   /// Derived classes should simply invoke the Visit api of the visitor.
-  virtual void Accept(NodeVisitor &visitor) const = 0;
+  virtual Status Accept(NodeVisitor &visitor) const = 0;
 
  protected:
   DataTypePtr return_type_;
@@ -49,8 +50,8 @@ class LiteralNode : public Node {
     : Node(type),
       holder_(holder) {}
 
-  void Accept(NodeVisitor &visitor) const override {
-    visitor.Visit(*this);
+  Status Accept(NodeVisitor &visitor) const override {
+    return visitor.Visit(*this);
   }
 
   const LiteralHolder &holder() const { return holder_; }
@@ -65,8 +66,8 @@ class FieldNode : public Node {
   explicit FieldNode(FieldPtr field)
     : Node(field->type()), field_(field) {}
 
-  void Accept(NodeVisitor &visitor) const override {
-    visitor.Visit(*this);
+  Status Accept(NodeVisitor &visitor) const override {
+    return visitor.Visit(*this);
   }
 
   const FieldPtr &field() const { return field_; }
@@ -83,8 +84,8 @@ class FunctionNode : public Node {
                DataTypePtr retType)
     : Node(retType), descriptor_(descriptor), children_(children) { }
 
-  void Accept(NodeVisitor &visitor) const override {
-    visitor.Visit(*this);
+  Status Accept(NodeVisitor &visitor) const override {
+    return visitor.Visit(*this);
   }
 
   const FuncDescriptorPtr &descriptor() const { return descriptor_; }
@@ -125,8 +126,8 @@ class IfNode : public Node {
       then_node_(then_node),
       else_node_(else_node) {}
 
-  void Accept(NodeVisitor &visitor) const override {
-    visitor.Visit(*this);
+  Status Accept(NodeVisitor &visitor) const override {
+    return visitor.Visit(*this);
   }
 
   const NodePtr &condition() const { return condition_; }

cpp/src/gandiva/codegen/node_visitor.h

@@ -16,6 +16,7 @@
 #define GANDIVA_NODE_VISITOR_H
 
 #include "gandiva/logging.h"
+#include "gandiva/status.h"
 
 namespace gandiva {
 
@@ -27,10 +28,10 @@ class LiteralNode;
 /// \brief Visitor for nodes in the expression tree.
 class NodeVisitor {
  public:
-  virtual void Visit(const FieldNode &node) = 0;
-  virtual void Visit(const FunctionNode &node) = 0;
-  virtual void Visit(const IfNode &node) = 0;
-  virtual void Visit(const LiteralNode &node) = 0;
+  virtual Status Visit(const FieldNode &node) = 0;
+  virtual Status Visit(const FunctionNode &node) = 0;
+  virtual Status Visit(const IfNode &node) = 0;
+  virtual Status Visit(const LiteralNode &node) = 0;
 };
 
 } // namespace gandiva