Thank you for all your responses. I successfully ran IWYU on my code,
although it took some time to build the tool. My next step is to analyze
the output and implement the necessary fixes.
Thanks,
Rajeev
On Mon, Aug 11, 2025 at 1:39 AM Basile Starynkevitch <
basile@xxxxxxxxxxxxxxxxx> wrote:
> On Sun, 2025-08-10 at 22:02 +0200, Jonathan Wakely wrote:
> >
> >
> > On Sun, 10 Aug 2025, 20:28 Basile Starynkevitch, <
> basile@xxxxxxxxxxxxxxxxx> wrote:
> > > On Sun, 2025-08-10 at 23:38 +0530, Rajeev Bansal via Gcc-help wrote:
> > > > Hello,
> > > >
> > > > I am working on a large C/C++ project compiled with GCC and am
> looking for
> > > > ways to identify unnecessary header files. I'm wondering if there's
> a tool
> > > > similar to `include-what-you-use` (IWYU) that can help with this
> > > > information in gcc.
> > > >
> > > > Any advice or recommendations would be greatly appreciated.
> > >
> > > In addition of the previous reply, don't forget link time optimization
> and precompiled headers in GCC. Sometimes both are improving things.
> > >
> > > Observe that even the optimization level is known (and used) in some
> Linux system header files.
> > > (so your goal depend upon the compilation options)
> >
> >
> > how is this answer related to the question?!
>
>
>
> Simply because a header file "gee.h" might contain
>
> #if __OPTIMIZE__
> #include "boo.h" /* which declare foo */
> static inline int bar(int y) { return foo(y)+2; }
> #else
> int bar (int);
> #endif
>
> Hence the set of included header files depend upon the optimization levels
>
> (IIRC the Qt library might use similar tricks; in addition Qt is
> generating C++ code at build time)
>
> Regards.
>
> --
> Basile STARYNKEVITCH <basile@xxxxxxxxxxxxxxxxx>
> 8 rue de la Faïencerie
> http://starynkevitch.net/Basile/
> 92340 Bourg-la-Reine https://github.com/bstarynk
> France
> https://github.com/RefPerSys/RefPerSys
>
