I\'d like to add some macros to ease (un)setting a specific warning around routines that we are deprecating internally.
I\'d like to turn this:
#pragma c
void Foo() __attribute__((deprecated));
#define MY_DEPRECATED_BEGIN \
_Pragma("clang diagnostic push") \
_Pragma("clang diagnostic warning \"-Wdeprecated-declarations\"")
int main()
{
MY_DEPRECATED_BEGIN
Foo();
#pragma clang diagnostic pop
}
The short answer to your technical question is that C99 provides the _Pragma("foo")
construct, which is equivalent to #pragma foo
but is processed slightly later, and doesn't need to be on a line by itself.
Your other problem is that -Wdeprecated-declarations
doesn't do what you think it does. Simply declaring a function as deprecated will never give you a diagnostic, because __attribute__((deprecated))
is supposed to be used (generally in header files). What causes the diagnostic is if you use a deprecated function — and it's at that point that the setting of -Wdeprecated
becomes relevant.
If you really just want to deprecate Foo
iff MY_DEPRECATED
is set, then the right way to do that is
#ifdef MY_DEPRECATED
#define ATTRIBUTE_DEPRECATED __attribute__((deprecated))
#else
#define ATTRIBUTE_DEPRECATED
#endif
void Foo() ATTRIBUTE_DEPRECATED;
You can use this solution:
#define NS_SUPPRESS_DIRECT_USE(expr) _Pragma("clang diagnostic push") \
_Pragma("clang diagnostic ignored \"-Wdeprecated-declarations\"")\
expr\
_Pragma("clang diagnostic pop")
Then just add it:
NS_SUPPRESS_DIRECT_USE(
Foo();
);