Re: (Potential bug) Useless warning that shouldn't exist?

[Alec Teal <a dot teal at warwick dot ac dot uk>]

Thanks for the quick reply.

Turns out there was a macro, the compiler saw:
static const float (__builtin_inff());

The library must have compiled because INFINITY isn't defined, curious 
that the use does, but my IDE didn't spot that INFINITY was a macro, it 
doesn't surprise me that somewhere in the vast wxWidgets headers it's 
there. This isn't a complaint; fear not.

Sorry to waste time. Thanks Jon.

Alec

On 11/07/13 12:36, Jonathan Wakely wrote:
> On 11 July 2013 12:33, Alec Teal <a.teal@warwick.ac.uk> wrote:
> > Hey guys,
> >
> > I'm really not sure what's wrong with this, I think it may be a bug but I am
> > not sure. Hence posting it here first. These are from a shared library, that
> > compiles fine with -Wall -Wextra, the header file is available to things
> > that use the library. Particularly this has nothing to do with a  function,
> > so why is it talking of a return type of a function?
See, I was also confused about the function thing, I'd have to be pretty 
sure before firing off an email.
> > Header file:
> > namespace sr {
> >
> > class Framebuffer;
> >
> > class Depthbuffer {
> > public:
> > *static const float INFINITY;*<--this line is what the warning is referring
> > to.
> > ...
> >
> > Implementation file:
> > namespace sr {
> >
> > const float Depthbuffer::INFINITY = 1.0f;
> > ....
> >
> > However when compiling a program that uses the library:
> >
> > if ! g++ -Isrc -MM src/Renderer.cpp >> build/Renderer.o.d ; then rm
> > build/Renderer.o.d ; exit 1 ; fi
> > g++ -Wall -Wextra -g -O0 -std=c++0x -gdwarf-2 -Wno-write-strings -I../libsr
> > -I/usr/lib/x86_64-linux-gnu/wx/include/gtk2-unicode-release-2.8
> > -I/usr/include/wx-2.8 -D_FILE_OFFSET_BITS=64 -D_LARGE_FILES -D__WXGTK__
> > -pthread -Isrc -c src/Renderer.cpp -o build/Renderer.o
> > In file included from ./libsr/libsr.h:12:0,
> >                   from src/Renderer.h:11,
> >                   from src/Renderer.cpp:8:
> > ./libsr/Framebuffer.h:17:21: warning: type qualifiers ignored on function
> > return type [-Wignored-qualifiers]
> >
> > The line it doesn't like is the one in bold, static const float INFINITY;
> >
> > What is GCC warning me about? What's wrong?
> > GCC 4.7.3
> That line is not a function, so there shouldn't be a warning about
> "function return type" -- are you sure that's the line it's referring
> too?  Is INFINITY a macro defined in some header so that you're not
> ompiling what you think you are?
EXACTLY, that isn't a function.
> Please provide a complete reproducable example, not snippets of code
> with "..." that noone else can test.
Overkill as a first step surely? I may have missed something trivial, I 
did miss something trivial.