Re: [PATCH] driver, cppdefault: Unbreak bootstrap on Debian/Ubuntu [PR107059]

[Richard Biener <rguenther@suse.de>]

On Thu, 29 Sep 2022, Jakub Jelinek wrote:

> Hi!
> 
> My recent change to enable _Float{16,32,64,128,32x,64x,128x} for C++
> apparently broke bootstrap on some Debian/Ubuntu setups.
> Those multiarch targets put some headers into
> /usr/include/x86_64-linux-gnu/bits/ etc. subdirectory instead of
> /usr/include/bits/.
> This is handled by
>     /* /usr/include comes dead last.  */
>     { NATIVE_SYSTEM_HEADER_DIR, NATIVE_SYSTEM_HEADER_COMPONENT, 0, 0, 1, 2 },
>     { NATIVE_SYSTEM_HEADER_DIR, NATIVE_SYSTEM_HEADER_COMPONENT, 0, 0, 1, 0 },
> in cppdefault.cc, where the 2 in the last element of the first initializer
> means the entry is ignored on non-multiarch and suffixed by the multiarch
> dir otherwise, so installed gcc has search path like:
>  /home/jakub/gcc/obj01inst/usr/local/bin/../lib/gcc/x86_64-pc-linux-gnu/13.0.0/include
>  /home/jakub/gcc/obj01inst/usr/local/bin/../lib/gcc/x86_64-pc-linux-gnu/13.0.0/include-fixed
>  /usr/local/include
>  /usr/include/x86_64-linux-gnu
>  /usr/include
> (when installed with DESTDIR=/home/jakub/gcc/obj01inst).
> Now, when fixincludes is run, it is processing the whole /usr/include dir
> and all its subdirectories, so floatn{,-common.h} actually go into
> .../include-fixed/x86_64-linux-gnu/bits/floatn{,-common.h}
> because that is where they appear in /usr/include too.
> In some setups, /usr/include also contains /usr/include/bits -> x86_64-linux-gnu/bits
> symlink and after the r13-2896 tweak it works.
> In other setups there is no /usr/include/bits symlink and when one
> #include <bits/floatn.h>
> given the above search path, it doesn't find the fixincluded header,
> as
> /home/jakub/gcc/obj01inst/usr/local/bin/../lib/gcc/x86_64-pc-linux-gnu/13.0.0/include-fixed/bits/floatn.h
> doesn't exist and
> /home/jakub/gcc/obj01inst/usr/local/bin/../lib/gcc/x86_64-pc-linux-gnu/13.0.0/include-fixed/x86_64-linux-gnu/bits/floatn.h
> isn't searched and so
> /usr/include/x86_64-linux-gnu/bits/floatn.h
> wins and we fail because of typedef whatever _Float128; and similar.
> The following patch ought to fix this.  The first hunk by arranging that
> the installed search path actually looks like:
>  /home/jakub/gcc/obj01inst/usr/local/bin/../lib/gcc/x86_64-pc-linux-gnu/13.0.0/include
>  /home/jakub/gcc/obj01inst/usr/local/bin/../lib/gcc/x86_64-pc-linux-gnu/13.0.0/include-fixed/x86_64-linux-gnu
>  /home/jakub/gcc/obj01inst/usr/local/bin/../lib/gcc/x86_64-pc-linux-gnu/13.0.0/include-fixed
>  /usr/local/include
>  /usr/include/x86_64-linux-gnu
>  /usr/include
> and thus for include-fixed it treats it the same as /usr/include.
> The second FIXED_INCLUDE_DIR entry there is:
>     { FIXED_INCLUDE_DIR, "GCC", 0, 0, 0,
>       /* A multilib suffix needs adding if different multilibs use
>          different headers.  */
> #ifdef SYSROOT_HEADERS_SUFFIX_SPEC
>       1
> #else
>       0
> #endif
>     },
> where SYSROOT_HEADERS_SUFFIX_SPEC is defined only on vxworks or mips*-mti-linux
> and arranges for multilib path to be appended there.  Neither of those
> systems is multiarch.
> This isn't enough, because when using the -B option, the driver adds
> -isystem .../include-fixed in another place, so the second hunk modifies
> that spot the same.
> /home/jakub/gcc/obj01/gcc/xgcc -B /home/jakub/gcc/obj01/gcc/
> then has search path:
>  /home/jakub/gcc/obj01/gcc/include
>  /home/jakub/gcc/obj01/gcc/include-fixed/x86_64-linux-gnu
>  /home/jakub/gcc/obj01/gcc/include-fixed
>  /usr/local/include
>  /usr/include/x86_64-linux-gnu
>  /usr/include
> which again is what I think we want to achieve.
> 
> Bootstrapped/regtested on x86_64-linux (Debian on GCCFarm, though with the
> /usr/include/bits -> x86_64-linux-gnu/bits symlink).  Ok for trunk?

OK.

Thanks,
Richard.

> 2022-09-29  Jakub Jelinek  <jakub@redhat.com>
> 
> 	PR bootstrap/107059
> 	* cppdefault.cc (cpp_include_defaults): If SYSROOT_HEADERS_SUFFIX_SPEC
> 	isn't defined, add FIXED_INCLUDE_DIR entry with multilib flag 2
> 	before FIXED_INCLUDE_DIR entry with multilib flag 0.
> 	* gcc.cc (do_spec_1): If multiarch_dir, add
> 	include-fixed/multiarch_dir paths before include-fixed paths.
> 
> --- gcc/cppdefault.cc.jj	2022-01-18 11:58:59.411984500 +0100
> +++ gcc/cppdefault.cc	2022-09-28 12:11:47.923603783 +0200
> @@ -74,6 +74,9 @@ const struct default_include cpp_include
>  #endif
>  #ifdef FIXED_INCLUDE_DIR
>      /* This is the dir for fixincludes.  */
> +#ifndef SYSROOT_HEADERS_SUFFIX_SPEC
> +    { FIXED_INCLUDE_DIR, "GCC", 0, 0, 0, 2 },
> +#endif
>      { FIXED_INCLUDE_DIR, "GCC", 0, 0, 0,
>        /* A multilib suffix needs adding if different multilibs use
>  	 different headers.  */
> --- gcc/gcc.cc	2022-09-23 09:02:56.809314447 +0200
> +++ gcc/gcc.cc	2022-09-28 21:02:29.751933657 +0200
> @@ -6400,6 +6400,18 @@ do_spec_1 (const char *spec, int inswitc
>  	      if (*sysroot_hdrs_suffix_spec)
>  		info.append = concat (info.append, dir_separator_str,
>  				      multilib_dir, NULL);
> +	      else if (multiarch_dir)
> +		{
> +		  /* For multiarch, search include-fixed/<multiarch-dir>
> +		     before include-fixed.  */
> +		  info.append = concat (info.append, dir_separator_str,
> +					multiarch_dir, NULL);
> +		  info.append_len = strlen (info.append);
> +		  for_each_path (&include_prefixes, false, info.append_len,
> +				 spec_path, &info);
> +
> +		  info.append = "include-fixed";
> +		}
>  	      info.append_len = strlen (info.append);
>  	      for_each_path (&include_prefixes, false, info.append_len,
>  			     spec_path, &info);
> 
> 	Jakub
> 
> 

-- 
Richard Biener <rguenther@suse.de>
SUSE Software Solutions Germany GmbH, Frankenstrasse 146, 90461 Nuernberg,
Germany; GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman;
HRB 36809 (AG Nuernberg)