On 01/08/2016 06:21 PM, Martin Sebor wrote:
The point of this warning is that there are certain cases of incompatible
types that are less serious than others - namely, those where the only
aspect of the type that is different is its signedness. Those get a more
specific warning, which is given under more restrictive conditions.
FWIW, below is a survey of a few popular compilers I have access
to and how they treat the problem and under what option. The C
code I used to test is:
void foo (char *p, signed char *q) { q = p; }
Clang (controlled by -Wpointer-sign, enabled by default):
warning: assigning to 'signed char *' from 'char *' converts
between pointers to integer types with different sign
[-Wpointer-sign]
EDG eccp (warns by default):
warning: a value of type "char *" cannot be assigned to an
entity of type "signed char *"
Intel ICC (requires -Wpointer-sign):
warning #556: a value of type "char *" cannot be assigned to
an entity of type "signed char *"
Oracle CC (warns by default):
warning: assignment type mismatch:
pointer to signed char "=" pointer to char
IBM XLC (warns by default):
1506-068 (W) Operation between types "signed char*" and "char*"
is not allowed.
Visual C (rejects code by default):
error C2440: '=': cannot convert from 'char *' to 'signed char *'
note: Types pointed to are unrelated;
Martin
