Op: Remove previous check before delete

Unlike `cbdb::pfree`, the overloaded `delete` keyword checks whether the pointer is null.

So we don't need to check if the current pointer is null when call the `delete`.

Author: jiaqizho

contrib/pax_storage/CMakeLists.txt

@@ -47,7 +47,9 @@ option(BUILD_PAX_FORMAT "Build pax format lib" OFF)
 
 if (ENBALE_DEBUG)
   ADD_DEFINITIONS(-DENBALE_DEBUG)
-	SET(CMAKE_BUILD_TYPE "Debug")
+  # Use to build compile_commands.json
+  set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
+  SET(CMAKE_BUILD_TYPE "Debug")
   SET(CMAKE_CXX_FLAGS_DEBUG "$ENV{CXXFLAGS} -O0 -Wall -g -ggdb")
   SET(CMAKE_CXX_FLAGS_RELEASE "$ENV{CXXFLAGS} -O3 -Wall")
 else()

contrib/pax_storage/src/cpp/access/pax_scanner.cc

@@ -85,7 +85,7 @@ void PaxScanDesc::EndScan(TableScanDesc scan) {
 
   delete desc->reused_buffer_;
   delete desc->reader_;
-  if (desc->filter_) delete desc->filter_;
+  delete desc->filter_;
 
 #ifdef VEC_BUILD
   delete desc->vec_adapter_;

contrib/pax_storage/src/cpp/comm/comm_test.cc

@@ -0,0 +1,35 @@
+
+#include "comm/cbdb_wrappers.h"
+#include "comm/gtest_wrappers.h"
+
+namespace pax::tests {
+class CommTest : public ::testing::Test {
+ public:
+  void SetUp() override {
+    MemoryContext comm_test_memory_context = AllocSetContextCreate(
+        (MemoryContext)NULL, "CommTestMemoryContext", 1 * 1024 * 1024,
+        1 * 1024 * 1024, 1 * 1024 * 1024);
+    MemoryContextSwitchTo(comm_test_memory_context);
+  }
+
+  void TearDown() override {}
+};
+
+TEST_F(CommTest, TestDeleteOperator) {
+  // In standard C++, we allow the delete null operation
+  // In Pax, we overloaded the delete operator which used
+  // `pfree` to free the memory. `pfree` not allow pass NULL.
+  // But we still need to conform the overloaded delete operation
+  // to the semantics of c++ which achieve a complete semantic replacement.
+  auto obj = new int32();
+  delete obj;
+  obj = nullptr;
+  delete obj;
+
+  auto array_obj = new int32[10];
+  delete[] array_obj;
+  array_obj = nullptr;
+  delete[] array_obj;
+}
+
+}  // namespace pax::tests

contrib/pax_storage/src/cpp/storage/columns/pax_columns.cc

@@ -26,7 +26,7 @@ PaxColumns::PaxColumns(
         encoding_option.is_sign = false;
         encoding_option.compress_lvl = column_encoding_types[i];
 
-        auto pax_non_fixed_column = new PaxNonFixedEncodingColumn(
+        auto pax_non_fixed_column = new PaxNonFixedEncodingColumn(  //
             DEFAULT_CAPACITY, std::move(encoding_option));
         // current memory will copy from tuple, so should take over it
         pax_non_fixed_column->SetMemTakeOver(true);
@@ -76,7 +76,7 @@ PaxColumns::PaxColumns() : row_nums_(0) { data_ = new DataBuffer<char>(0); }
 
 PaxColumns::~PaxColumns() {
   for (auto column : columns_) {
-    if (column) delete column;
+    delete column;
   }
   delete data_;
 }

contrib/pax_storage/src/cpp/storage/columns/pax_encoding_column.cc

@@ -31,10 +31,10 @@ PaxEncodingColumn<T>::PaxEncodingColumn(
 
 template <typename T>
 PaxEncodingColumn<T>::~PaxEncodingColumn() {
-  if (encoder_) delete encoder_;
-  if (decoder_) delete decoder_;
-  if (shared_data_) delete shared_data_;
-  if (compressor_) delete compressor_;
+  delete encoder_;
+  delete decoder_;
+  delete shared_data_;
+  delete compressor_;
 }
 
 template <typename T>

contrib/pax_storage/src/cpp/storage/columns/pax_encoding_non_fixed_column.cc

@@ -41,8 +41,8 @@ PaxNonFixedEncodingColumn::PaxNonFixedEncodingColumn(
 }
 
 PaxNonFixedEncodingColumn::~PaxNonFixedEncodingColumn() {
-  if (compressor_) delete compressor_;
-  if (shared_data_) delete shared_data_;
+  delete compressor_;
+  delete shared_data_;
 }
 
 void PaxNonFixedEncodingColumn::Set(DataBuffer<char> *data,