[Bug c/35957] New: static return value type checking, no warning issued

[Bug c/35957] New: static return value type checking, no warning issued

[clemens dot kol at gmx dot at]

I hope this does not conflict with the C-standard, but why does the following
code not issue a warning about the return value of 'someFunction'?

#include <stdio.h>

unsigned int someFunction() { return 0xbadc0de; }
void someOtherFunction(unsigned char in) { printf("0x%x\n", in); }

int main(int argc, char **argv)
{
        unsigned char x;
        unsigned int y;

        x = someFunction();
        printf("0x%x\n", x);

        y = 0xbadc0de;
        someOtherFunction(y);

        return 0;
}

The return value is correctly cast to a char, but shouldn't the compiler
complain?


-- 
           Summary: static return value type checking, no warning issued
           Product: gcc
           Version: 4.2.2
            Status: UNCONFIRMED
          Severity: minor
          Priority: P3
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: clemens dot kol at gmx dot at


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35957

[Bug c/35957] static return value type checking, no warning issued

[rguenth at gcc dot gnu dot org]

------- Comment #1 from rguenth at gcc dot gnu dot org  2008-04-16 11:27 -------
Not unconditionally.  With -Wconversion it does since gcc 4.3:

t.c: In function 'main':
t.c:11: warning: conversion to 'unsigned char' from 'unsigned int' may alter
its value
t.c:15: warning: conversion to 'unsigned char' from 'unsigned int' may alter
its value


-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|                            |FIXED
   Target Milestone|---                         |4.3.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35957