[PATCH] libdwfl: do not dlopen libdebuginfod.so in --disable-libdebuginfod mode

[Dmitry V. Levin]

Hi Mark,

On Sun, Aug 30, 2020 at 10:40:29PM +0200, Mark Wielaard wrote:
> Hi Dmitry,
> 
> On Thu, Aug 20, 2020 at 11:27:24PM +0300, Dmitry V. Levin wrote:
> > debuginfod-client.c used to try to dlopen libdebuginfod.so even if
> > libdebuginfod was completely disabled using --disable-libdebuginfod.
> > 
> > Fix this by disabling build of debuginfod-client.c and disabling all
> > __libdwfl_debuginfod_* invocations in --disable-libdebuginfod mode.
> 
> To be honest I really hope libdebuginfod is only disabled for
> bootstrapping reasons and that people will use
> --enable-libdebuginfod=dummy.
> 
> That said, your patch makes sense if people explicitly choose to
> --disable-libdebuginfod and it handles --enable-libdebuginfod=dummy
> correctly.
> 
> To double check I removed all references to debuginfod_client from
> libdwflP.h when libdebuginfod is disabled. And things look fine in
> that case too. I think it makes sense to add this to your patch. See
> attached.

Yes, it definitely makes sense, thanks.

> Thanks,
> 
> Mark

> diff --git a/libdwfl/libdwflP.h b/libdwfl/libdwflP.h
> index 25753de2..ad6779ad 100644
> --- a/libdwfl/libdwflP.h
> +++ b/libdwfl/libdwflP.h
> @@ -40,7 +40,10 @@
>  
>  #include "../libdw/libdwP.h"	/* We need its INTDECLs.  */
>  #include "../libdwelf/libdwelfP.h"
> +
> +#ifdef ENABLE_LIBDEBUGINFOD
>  #include "../debuginfod/debuginfod.h"
> +#endif
>  
>  typedef struct Dwfl_Process Dwfl_Process;
>  
> @@ -115,8 +118,9 @@ struct Dwfl_User_Core
>  struct Dwfl
>  {
>    const Dwfl_Callbacks *callbacks;
> +#ifdef ENABLE_LIBDEBUGINFOD
>    debuginfod_client *debuginfod;
> -
> +#endif
>    Dwfl_Module *modulelist;    /* List in order used by full traversals.  */
>  
>    Dwfl_Process *process;
> @@ -631,6 +635,7 @@ extern Dwfl_Error __libdw_open_elf (int fd, Elf **elfp) internal_function;
>  extern bool __libdwfl_dynamic_vaddr_get (Elf *elf, GElf_Addr *vaddrp)
>    internal_function;
>  
> +#ifdef ENABLE_LIBDEBUGINFOD
>  /* Internal interface to libdebuginfod (if installed).  */
>  int
>  __libdwfl_debuginfod_find_executable (Dwfl *dwfl,
> @@ -642,6 +647,7 @@ __libdwfl_debuginfod_find_debuginfo (Dwfl *dwfl,
>  				     size_t build_id_len);
>  void
>  __libdwfl_debuginfod_end (debuginfod_client *c);
> +#endif
>  
>  
>  /* These are working nicely for --core, but are not ready to be


-- 
ldv