[Bug c++/90205] New: Wformat-signedness detects %d and suggests %d fixit hint

[jg at jguk dot org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90205

            Bug ID: 90205
           Summary: Wformat-signedness detects %d and suggests %d fixit
                    hint
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: jg at jguk dot org
  Target Milestone: ---

C++ trunk suggests '%d' when I '%u' is what is needed


#1 with x86-64 gcc (trunk)
<source>: In function 'int main()':
<source>:5:14: warning: format '%d' expects argument of type 'int', but
argument 2 has type 'unsigned int' [-Wformat=]
    5 |     printf("%d", i);
      |             ~^   ~
      |              |   |
      |              int unsigned int
      |             %d
Compiler returned: 0



#include <cstdio>
int main()
{
    unsigned int i = 0;
    printf("%d", i);
}



Another is %f is suggested, but the message states 'double' instead of 'float'


#1 with x86-64 gcc (trunk)
<source>: In function 'int main()':

<source>:5:14: warning: format '%d' expects argument of type 'int', but
argument 2 has type 'double' [-Wformat=]

    5 |     printf("%d", i);
      |             ~^   ~
      |              |   |
      |              int double
      |             %f
Compiler returned: 0


#include <cstdio>
int main()
{
    float i = 0;
    printf("%d", i);
}