Tristan,
>> * 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 !
oops, seems I was too eager to get rid of the cruft ;-)
> 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.
It's not even used in the Tru64 UNIX system headers; I suppose it was
introduced for symmetry with __PRAGMA_REDEFINE_EXTNAME.
>> -/* 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.
Ok. I had assumed that the vms handling of #pragma extern_prefix is
completely independent of the one in c-pragma.c.
>> -/* #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!
Yup, will do.
>> /* 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.
Ok, I'll keep it and add a comment referencing that use.
I'll rework the patch accordingly (also incorporating the other review
comments), most likely over the weekend. I'll try an i386-solaris x
alpha-vms cross build to ensure cc1 at least builds.
> Thank you Rainer for all the Tru64 maintainership work!
Thanks, it has been an interesting journey :-)
Rainer
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Rainer Orth, Center for Biotechnology, Bielefeld University
