RE: Turning warning off

3 msg	Pointer allocation problem
2 msg	movq instruction not supported?

Turning warning off
\ rod.niner (31 Aug 2006)
. \ Andrew Haley (31 Aug 2006)
. \ Kaz Kylheku (31 Aug 2006)
. . \ Young, Michael (31 Aug 2006)
. \ Kaz Kylheku (31 Aug 2006)

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Subject:	RE: Turning warning off
Group:	Gcc-help
From:	Kaz Kylheku
Date:	31 Aug 2006

> Michael Young wrote:
> Specifically, I'm looking for a way to turn off a specific
> warning inline, with the ability to restore it again -

That exists only in the form of the __attribute__ ((unused)) mechanism.

You can turn it off for an entire translation unit:

-Wno-unused

Actually you can get a little more fine-grained than that:

-Wno-unused-label
-Wno-unused-variable
-Wno-unusued-parameter
-Wno-unused-value

The -Wno-unused does all of them.

These options are not listed in the manual because ...

Each of these specific warning options also has a negative
for beginning `-Wno-' to turn off warnings; for example,
`-Wno-implicit'. This manual lists only one of the two
forms, whichever is not the default.

> analogous to the #pragma warning directive supported in MS
> VC++ (see
> http://msdn.microsoft.com/library/default.asp?url=/library/en-
> us/vclang/html/_predir_warning.asp for details).

GCC stays away from using #pragma, because of its disadvantages. For
instance, because it's a preprocessor directive, a #pragma cannot be
constructed using macros. Thus to switch among #pragma's based on the
compiler identity, you have to repeat #ifdef everywhere.

#ifdef _MSVC
#pragma warning (disable: NNNN)
#endif
...

#ifdef MSVC
#pragma warning (enable: NNNN)
#endif

The use of the __attribute__ ((unused)) extension can be hidden behind
macros.