Re: [PATCH] tty: vt: conmakehash: cope with abs_srctree no longer in env

["Luca Weiss" <luca.weiss@fairphone.com>]

On Thu Jul 25, 2024 at 3:20 PM CEST, max.oss.09 wrote:
> From: Max Krummenacher <max.krummenacher@toradex.com>
>
> conmakehash uses getenv("abs_srctree") from the environment to strip
> the absolute path from the generated sources.
> However since commit e2bad142bb3d ("kbuild: unexport abs_srctree and
> abs_objtree") this environment variable no longer gets set.
> Instead use basename() to indicate the used file in a comment of the
> generated source file.
>
> Fixes: 3bd85c6c97b2 ("tty: vt: conmakehash: Don't mention the full path of the input in output")
> Signed-off-by: Max Krummenacher <max.krummenacher@toradex.com>
>
> ---
>
>  drivers/tty/vt/conmakehash.c | 20 +++++++-------------
>  1 file changed, 7 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/tty/vt/conmakehash.c b/drivers/tty/vt/conmakehash.c
> index dc2177fec715..82d9db68b2ce 100644
> --- a/drivers/tty/vt/conmakehash.c
> +++ b/drivers/tty/vt/conmakehash.c
> @@ -11,6 +11,8 @@
>   * Copyright (C) 1995-1997 H. Peter Anvin
>   */
>  
> +#include <libgen.h>
> +#include <linux/limits.h>

Hi Max,

Not sure this is the best place to ask but this <linux/limits.h> include
appears to rely on this file already being installed in /usr/include and
is not taken from the Linux source tree that's being built.

This mostly manifests in building Linux kernel e.g. in Alpine Linux
package build if 'linux-headers' package is not being explicitly
installed, failing with 

  drivers/tty/vt/conmakehash.c:15:10: fatal error: linux/limits.h: No such file or directory
     15 | #include <linux/limits.h>
        |          ^~~~~~~~~~~~~~~~
  compilation terminated.

Apparently this is (understandably) also a problem when building on
macOS:
https://lore.kernel.org/all/20240807-macos-build-support-v1-11-4cd1ded85694@samsung.com/

I did try that linked patch a bit ago, but unfortunately didn't fix it
for the Alpine Linux build environment.

Any ideas?

Regards
Luca


>  #include <stdio.h>
>  #include <stdlib.h>
>  #include <sysexits.h>
> @@ -76,8 +78,8 @@ static void addpair(int fp, int un)
>  int main(int argc, char *argv[])
>  {
>    FILE *ctbl;
> -  const char *tblname, *rel_tblname;
> -  const char *abs_srctree;
> +  const char *tblname;
> +  char base_tblname[PATH_MAX];
>    char buffer[65536];
>    int fontlen;
>    int i, nuni, nent;
> @@ -102,16 +104,6 @@ int main(int argc, char *argv[])
>  	}
>      }
>  
> -  abs_srctree = getenv("abs_srctree");
> -  if (abs_srctree && !strncmp(abs_srctree, tblname, strlen(abs_srctree)))
> -    {
> -      rel_tblname = tblname + strlen(abs_srctree);
> -      while (*rel_tblname == '/')
> -	++rel_tblname;
> -    }
> -  else
> -    rel_tblname = tblname;
> -
>    /* For now we assume the default font is always 256 characters. */
>    fontlen = 256;
>  
> @@ -253,6 +245,8 @@ int main(int argc, char *argv[])
>    for ( i = 0 ; i < fontlen ; i++ )
>      nuni += unicount[i];
>  
> +  strncpy(base_tblname, tblname, PATH_MAX);
> +  base_tblname[PATH_MAX - 1] = 0;
>    printf("\
>  /*\n\
>   * Do not edit this file; it was automatically generated by\n\
> @@ -264,7 +258,7 @@ int main(int argc, char *argv[])
>  #include <linux/types.h>\n\
>  \n\
>  u8 dfont_unicount[%d] = \n\
> -{\n\t", rel_tblname, fontlen);
> +{\n\t", basename(base_tblname), fontlen);
>  
>    for ( i = 0 ; i < fontlen ; i++ )
>      {