Suppressing particular warnings for particular lines of code

Suppressing particular warnings for particular lines of code

[Yang Zhang]

In Java, you can insert @SuppressWarnings(...) annotations before a line 
to tell javac to suppress certain warnings for that line.  Is there 
anything similar for gcc?
-- 
Yang Zhang
http://www.mit.edu/~y_z/

Re: Suppressing particular warnings for particular lines of code

[Yang Zhang]

Yang Zhang wrote:
> In Java, you can insert @SuppressWarnings(...) annotations before a line 
> to tell javac to suppress certain warnings for that line.  Is there 
> anything similar for gcc?

Anyone?

Re: Suppressing particular warnings for particular lines of code

[John (Eljay) Love-Jensen]

Hi Yang,

>> In Java, you can insert @SuppressWarnings(...) annotations before a line
>> to tell javac to suppress certain warnings for that line.  Is there
>> anything similar for gcc?

> Anyone?

For gcc, there are the compile line switches, such as -Wall, -Wextra, and
other -Wsomething which enable (or using -Wno-something, disable) the
warning.

There are no #pragma directives to disable warnings in-line with the code.

HTH,
--Eljay

Re: Suppressing particular warnings for particular lines of code

[Yang Zhang]

John (Eljay) Love-Jensen wrote:
> Hi Yang,
> 
>>> In Java, you can insert @SuppressWarnings(...) annotations before a line
>>> to tell javac to suppress certain warnings for that line.  Is there
>>> anything similar for gcc?
> 
>> Anyone?
> 
> For gcc, there are the compile line switches, such as -Wall, -Wextra, and
> other -Wsomething which enable (or using -Wno-something, disable) the
> warning.

Yeah, I know about these - they only apply to the entire source file, 
whereas I'm interested in disabling warnings for particular lines.

> 
> There are no #pragma directives to disable warnings in-line with the code.

I sense an itch here - write a grep-like tool that can filter out 
warnings from gcc based on the presence of certain tokens in your source 
file.  For instance, inserting

   // SuppressWarning(conversion)

into your source should cause the tool to filter out -Wconversion 
warnings for the following line.

Have to think/experiment more about how to deal with multi-line 
statements, though - not sure how gcc numbers lines in its warnings. 
Also, this still won't work with -Werror (which is something I use), as 
gcc itself will refuse to continue with the compilation.
--
Yang Zhang
http://www.mit.edu/~y_z/

Re: Suppressing particular warnings for particular lines of code

[Brian Dessent]

Yang Zhang wrote:

> > There are no #pragma directives to disable warnings in-line with the code.
> 
> I sense an itch here - write a grep-like tool that can filter out
> warnings from gcc based on the presence of certain tokens in your source
> file.  For instance, inserting

From 4.2 and on gcc does support a form of #pragma control of
diagnostics, see
<http://gcc.gnu.org/onlinedocs/gcc/Diagnostic-Pragmas.html>.  However it
doesn't work the way you probably want, in that the setting is for the
whole file, not per-function.  I think per-function support was in fact
part of the original plan but I don't know that anyone is currently
working on it.

Brian