Remove obsolete Tru64 UNIX V5.1B support

Tristan Gingold gingold@adacore.com
Tue Mar 6 08:57:00 GMT 2012


Rainer,

On Mar 5, 2012, at 6:14 PM, Rainer Orth wrote:

> The Tru64 UNIX V5.1 port has been obsoleted in GCC 4.7, and it's now
> time to remove it from mainline.  The following patch does just that,
> and should be mostly uncontroversial, like removing target-specific
> fixincludes hacks, files, and testsuite support.
> 
> Then, there are target-specific features only used by this port (like
> support for #pragma extern_prefix),

[…]

> * As I've mentioned, I've ripped out the #pragma extern_prefix support:
>  while VMS has something similar, it doesn't use the common code.

in fact VMS use some of the already existing #pragma extern_prefix support.  You're removing too much code here !

Commenting only the relevant part:

> diff --git a/gcc/c-family/c-cppbuiltin.c b/gcc/c-family/c-cppbuiltin.c
> --- a/gcc/c-family/c-cppbuiltin.c
> +++ b/gcc/c-family/c-cppbuiltin.c
> @@ -1,6 +1,6 @@
>  /* Define builtin-in macros for the C family front ends.
> -   Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011
> -   Free Software Foundation, Inc.
> +   Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010,
> +   2011, 2012 Free Software Foundation, Inc.
>  
>  This file is part of GCC.
>  
> @@ -886,9 +886,6 @@ c_cpp_builtins (cpp_reader *pfile)
>    /* Show the availability of some target pragmas.  */
>    cpp_define (pfile, "__PRAGMA_REDEFINE_EXTNAME");
>  
> -  if (targetm.handle_pragma_extern_prefix)
> -    cpp_define (pfile, "__PRAGMA_EXTERN_PREFIX");

VMS doesn't reference this macro, so you could remove it.


> -
>    /* Make the choice of the stack protector runtime visible to source code.
>       The macro names and values here were chosen for compatibility with an
>       earlier implementation, i.e. ProPolice.  */
> diff --git a/gcc/c-family/c-pragma.c b/gcc/c-family/c-pragma.c
> --- a/gcc/c-family/c-pragma.c
> +++ b/gcc/c-family/c-pragma.c
> @@ -1,6 +1,6 @@
>  /* Handle #pragma, system V.4 style.  Supports #pragma weak and #pragma pack.
>     Copyright (C) 1992, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
> -   2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
> +   2006, 2007, 2008, 2009, 2010, 2012 Free Software Foundation, Inc.
>  
>  This file is part of GCC.
>  
> @@ -369,37 +369,26 @@ handle_pragma_weak (cpp_reader * ARG_UNU
>      }
>  }
>  
> -/* GCC supports two #pragma directives for renaming the external
> +/* GCC supports a #pragma directive for renaming the external
>     symbol associated with a declaration (DECL_ASSEMBLER_NAME), for
> -   compatibility with the Solaris and Tru64 system headers.  GCC also
> +   compatibility with the Solaris system headers.  GCC also
>     has its own notation for this, __asm__("name") annotations.
>  
>     Corner cases of these features and their interaction:
>  
> -   1) Both pragmas silently apply only to declarations with external
> +   1) The pragma silently applies only to declarations with external
>        linkage (that is, TREE_PUBLIC || DECL_EXTERNAL).  Asm labels
>        do not have this restriction.
>  
> -   2) In C++, both #pragmas silently apply only to extern "C" declarations.
> +   2) In C++, the #pragma silently applies only to extern "C" declarations.
>        Asm labels do not have this restriction.
>  
> -   3) If any of the three ways of changing DECL_ASSEMBLER_NAME is
> +   3) If any of the two ways of changing DECL_ASSEMBLER_NAME is
>        applied to a decl whose DECL_ASSEMBLER_NAME is already set, and the
>        new name is different, a warning issues and the name does not change.
>  
>     4) The "source name" for #pragma redefine_extname is the DECL_NAME,
> -      *not* the DECL_ASSEMBLER_NAME.
> -
> -   5) If #pragma extern_prefix is in effect and a declaration occurs
> -      with an __asm__ name, the #pragma extern_prefix is silently
> -      ignored for that declaration.
> -
> -   6) If #pragma extern_prefix and #pragma redefine_extname apply to
> -      the same declaration, whichever triggered first wins, and a warning
> -      is issued.  (We would like to have #pragma redefine_extname always
> -      win, but it can appear either before or after the declaration, and
> -      if it appears afterward, we have no way of knowing whether a modified
> -      DECL_ASSEMBLER_NAME is due to #pragma extern_prefix.)  */
> +      *not* the DECL_ASSEMBLER_NAME.  */

I think the comments would still apply.

>  
>  typedef struct GTY(()) pending_redefinition_d {
>    tree oldname;
> @@ -494,30 +483,6 @@ add_to_renaming_pragma_list (tree oldnam
>    p->newname = newname;
>  }
>  
> -/* The current prefix set by #pragma extern_prefix.  */
> -GTY(()) tree pragma_extern_prefix;

This variable is referenced by gcc/config/vms/vms-c.c, so it shouldn't be removed.

> -
> -/* #pragma extern_prefix "prefix" */
> -static void
> -handle_pragma_extern_prefix (cpp_reader * ARG_UNUSED (dummy))
> -{
> -  tree prefix, x;
> -  enum cpp_ttype t;
> -
> -  if (pragma_lex (&prefix) != CPP_STRING)
> -    GCC_BAD ("malformed #pragma extern_prefix, ignored");
> -  t = pragma_lex (&x);
> -  if (t != CPP_EOF)
> -    warning (OPT_Wpragmas, "junk at end of %<#pragma extern_prefix%>");
> -
> -  if (targetm.handle_pragma_extern_prefix)
> -    /* Note that the length includes the null terminator.  */
> -    pragma_extern_prefix = (TREE_STRING_LENGTH (prefix) > 1 ? prefix : NULL);
> -  else if (warn_unknown_pragmas > in_system_header)
> -    warning (OPT_Wunknown_pragmas,
> -	     "#pragma extern_prefix not supported on this target");
> -}
> -

Currently, the #pragma __extern_prefix is handled by vms-c.c, which is slightly more powerful than the tru64 version.
It would be easier to me if the above version were removed!

>  /* Hook from the front ends to apply the results of one of the preceding
>     pragmas that rename variables.  */
>  
> @@ -580,35 +545,12 @@ maybe_apply_renaming_pragma (tree decl, 
>  	    return asmname;
>  	  }
>  
> -	/* Otherwise we use what we've got; #pragma extern_prefix is
> -	   silently ignored.  */
> +	/* Otherwise we use what we've got.  */
>  	return build_string (IDENTIFIER_LENGTH (newname),
>  			     IDENTIFIER_POINTER (newname));
>        }
>  
> -  /* If we've got an asmname, #pragma extern_prefix is silently ignored.  */
> -  if (asmname)
> -    return asmname;
> -
> -  /* If #pragma extern_prefix is in effect, apply it.  */
> -  if (pragma_extern_prefix)
> -    {
> -      const char *prefix = TREE_STRING_POINTER (pragma_extern_prefix);
> -      size_t plen = TREE_STRING_LENGTH (pragma_extern_prefix) - 1;
> -
> -      const char *id = IDENTIFIER_POINTER (DECL_NAME (decl));
> -      size_t ilen = IDENTIFIER_LENGTH (DECL_NAME (decl));
> -
> -      char *newname = (char *) alloca (plen + ilen + 1);
> -
> -      memcpy (newname,        prefix, plen);
> -      memcpy (newname + plen, id, ilen + 1);
> -
> -      return build_string (plen + ilen, newname);
> -    }
> -
> -  /* Nada.  */
> -  return 0;
> +  return asmname;
>  }

So this code shouldn't be removed because vms-c.c set pragma_extern_prefix.

> @@ -1396,7 +1338,6 @@ init_pragma (void)
>  
>    c_register_pragma_with_expansion (0, "redefine_extname",
>  				    handle_pragma_redefine_extname);
> -  c_register_pragma (0, "extern_prefix", handle_pragma_extern_prefix);

Agreed as discussed above.

>    c_register_pragma_with_expansion (0, "message", handle_pragma_message);
>  
> diff --git a/gcc/c-family/c-pragma.h b/gcc/c-family/c-pragma.h
> --- a/gcc/c-family/c-pragma.h
> +++ b/gcc/c-family/c-pragma.h
> @@ -1,6 +1,6 @@
>  /* Pragma related interfaces.
>     Copyright (C) 1995, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
> -   2007, 2008, 2009, 2010  Free Software Foundation, Inc.
> +   2007, 2008, 2009, 2010, 2012 Free Software Foundation, Inc.
>  
>  This file is part of GCC.
>  
> @@ -146,6 +146,4 @@ extern enum cpp_ttype c_lex_with_flags (
>  
>  extern void c_pp_lookup_pragma (unsigned int, const char **, const char **);
>  
> -extern GTY(()) tree pragma_extern_prefix;
> -
>  #endif /* GCC_C_PRAGMA_H */

Shouldn't be removed too.

Thank you Rainer for all the Tru64 maintainership work!

Tristan.



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