[Bug c++/86177] New: Wnull-dereference warning for object file compile missing

[jg at jguk dot org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86177

            Bug ID: 86177
           Summary: Wnull-dereference warning for object file compile
                    missing
           Product: gcc
           Version: 8.0.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: jg at jguk dot org
  Target Milestone: ---

Hello

This doesn't give any warning that the pointer is not checked when being
compiled. If linked with second program example below, there is no issue
visible. Then crashes when runs:

jonny@asus:~/code$ ./main
Segmentation fault (core dumped)

//g++-8 -O2 -Wall -Wextra -Wnull-dereference -Wpedantic -o main -c main.cpp

void f(int *i)
{
    *i = 1;
}





//g++-8 -O2 -Wall -Wextra -Wnull-dereference -Wpedantic main1.o -o main
main2.cpp

extern void f(int* i);

int main()
{
    f(nullptr);

   // return
}