One way to implement deprecation warnings is to produce warnings on calls to deprecated functions, unless you are calling from a deprecated context. This way legacy code can call legacy code without producing warnings that only amount to noise.
This is a reasonable line of thinking, and it is reflected in the implementations I see in GCC 4.2 (1) and Clang 4.0 (2) on OS X as well as Clang 3.0 (3) on Ubuntu.
However, when I compile with GCC 4.6 (4) on Ubuntu, I get deprecated warnings for all invocations of deprecated functions, independently of context. Is this a regression in functionality? Are there compiler options I can use to get the other behavior?
Example program:
int __attribute__((deprecated)) a() {
return 10;
}
int __attribute__((deprecated)) b() {
return a() * 2; //< I want to get rid of warnings from this line
}
int main() {
return b(); //< I expect a warning on this line only
}
Output from GCC 4.2 (Yes, I do get the same warning twice. I don't care about that, though):
main.cpp: In function ‘int main()’:
main.cpp:10: warning: ‘b’ is deprecated (declared at main.cpp:5)
main.cpp:10: warning: ‘b’ is deprecated (declared at main.cpp:5)
Output from GCC 4.6:
main.cpp: In function 'int b()':
main.cpp:6:9: warning: 'int a()' is deprecated (declared at main.cpp:1) [-Wdeprecated-declarations]
main.cpp:6:11: warning: 'int a()' is deprecated (declared at main.cpp:1) [-Wdeprecated-declarations]
main.cpp: In function 'int main()':
main.cpp:10:9: warning: 'int b()' is deprecated (declared at main.cpp:5) [-Wdeprecated-declarations]
main.cpp:10:11: warning: 'int b()' is deprecated (declared at main.cpp:5) [-Wdeprecated-declarations]
How can I convince GCC 4.6 that it should give me the same output as GCC 4.2?
-Wno-deprecated
will remove all deprecated warnings