test19.cpp: In function 'int func2(Data1*, Data1*)':
test19.cpp:16:11: warning: Using variable 'ptr3' without checking for null pointer
     ptr3->val = 100;
           ^
test19.cpp: In function 'int func6(Data1*, Data1*)':
test19.cpp:52:11: warning: Using variable 'ptr3' without checking for null pointer
     ptr3->val = 100;
           ^
test19.cpp: In function 'int func7(Data1*, Data1*)':
test19.cpp:66:11: warning: Using parameter 'ptr1' without checking for null pointer
     ptr1->val = 100;
           ^
test19.cpp:67:11: warning: Using variable 'ptr3' without checking for null pointer
     ptr3->val = 200;
           ^
test19.cpp: In function 'int func8(Data1*, Data1*)':
test19.cpp:81:11: warning: Using parameter 'ptr1' without checking for null pointer
     ptr1->val = 100;
           ^
test19.cpp:82:11: warning: Using variable 'ptr3' without checking for null pointer
     ptr3->val = 200;
           ^