Allow Tru64 UNIX bootstrap with C++

Submitted by Rainer Orth on July 21, 2011, 12:57 p.m.

Details

Message ID yddd3h3lrk3.fsf@manam.CeBiTec.Uni-Bielefeld.DE
State New
Headers show

Commit Message

Rainer Orth July 21, 2011, 12:57 p.m.
On Tru64 UNIX, I ran into two problems with C++ bootstrap:

* gcc.c doesn't compile:

In file included from /vol/gcc/src/hg/trunk/local/gcc/../include/xregex.h:26:0,
                 from /vol/gcc/src/hg/trunk/local/gcc/gcc.c:38:
/vol/gcc/src/hg/trunk/local/gcc/../include/xregex2.h:402:13: error: conflicting declaration 'typedef int regoff_t'
/usr/include/reg_types.h:49:15: error: 'regoff_t' has a previous declaration as 'typedef off_t regoff_t'
make[3]: *** [gcc.o] Error 1

  include/xregex2.h has

/* Type for byte offsets within the string.  POSIX mandates this.  */
typedef int regoff_t;

  while <reg_types.h> has

typedef off_t regoff_t;

  with <sys/types.h>:

typedef long    off_t;			/* file offset */

  While this would conflict with C, too, I only find the xregex2.h
  typedef in C -save-temps output.  C++ is different, though:
  <sys/lc_core.h> has

/* only include when using full prototypes to avoid extra */
/* name space cruft in default case */
#ifndef _NO_PROTO
#include <nl_types.h>
#include <va_list.h>
#ifdef __cplusplus
#include <reg_types.h>
#endif
#endif

  I'm thus special-casing osf in regex2.h.  I had a look at upstream
  (gnulib) regex.h, but it is unchanged in this regard.

* lto-wrapper failed to link (also on IRIX 6.5, both of which lack
  strsignal in libc):

strsignal(int)
collect2: error: ld returned 1 exit status
make[3]: *** [lto-wrapper] Error 1

  While the object file uses the mangled form

_Z9strsignali                    | 0000000000000000 | U | 0000000000000000
lto-wrapper.o

  libiberty.a has it as a C function.

  The problem is that gcc/system.h isn't wrapped in extern "C".  Doing
  so allows the link to succeed.

The bootstraps are still running, ok for mainline if they succeed? 

Thanks.
	Rainer


2011-07-21  Rainer Orth  <ro@CeBiTec.Uni-Bielefeld.DE>

	gcc:
	* system.h [__cplusplus]: Wrap in extern "C".

	include:
	* xregex2.h [__osf__ && __cplusplus] (regoff_t): Alternative
	typedef.

Comments

Joseph S. Myers July 21, 2011, 7:53 p.m.
On Thu, 21 Jul 2011, Rainer Orth wrote:

> diff --git a/gcc/system.h b/gcc/system.h
> --- a/gcc/system.h
> +++ b/gcc/system.h
> @@ -24,6 +24,10 @@ along with GCC; see the file COPYING3.  
>  #ifndef GCC_SYSTEM_H
>  #define GCC_SYSTEM_H
>  
> +#ifdef __cplusplus
> +extern "C" {
> +#endif
> +

I don't think it's right to surround any system header includes with 
extern "C".  If a particular declaration in system.h needs to be extern 
"C", surround only that declaration (though preferably such declarations 
might go in other headers with their own extern "C").
Ian Taylor July 22, 2011, 5:52 a.m.
Rainer Orth <ro@CeBiTec.Uni-Bielefeld.DE> writes:

> diff --git a/gcc/system.h b/gcc/system.h
> --- a/gcc/system.h
> +++ b/gcc/system.h
> @@ -24,6 +24,10 @@ along with GCC; see the file COPYING3.  
>  #ifndef GCC_SYSTEM_H
>  #define GCC_SYSTEM_H
>  
> +#ifdef __cplusplus
> +extern "C" {
> +#endif
> +
>  /* We must include stdarg.h before stdio.h.  */
>  #include <stdarg.h>
>  
> @@ -969,4 +973,8 @@ helper_const_non_const_cast (const char 
>  #define DEBUG_VARIABLE
>  #endif
>  
> +#ifdef __cplusplus
> +}
> +#endif
> +
>  #endif /* ! GCC_SYSTEM_H */

I agree with Joseph that this is wrong.  We must never wrap the #include
of a system header file with extern "C".  That will simply break on some
systems.  You should only wrap extern "C" around the various HAVE_DECL
declarations.



> diff --git a/include/xregex2.h b/include/xregex2.h
> --- a/include/xregex2.h
> +++ b/include/xregex2.h
> @@ -399,7 +399,11 @@ struct re_pattern_buffer
>  typedef struct re_pattern_buffer regex_t;
>  
>  /* Type for byte offsets within the string.  POSIX mandates this.  */
> +#if defined(__osf__) && defined(__cplusplus)
> +typedef off_t regoff_t;
> +#else
>  typedef int regoff_t;
> +#endif

No, the right way to handle this is to add regoff_t to include/xregex.h.

Ian

Patch hide | download patch | download mbox

diff --git a/gcc/system.h b/gcc/system.h
--- a/gcc/system.h
+++ b/gcc/system.h
@@ -24,6 +24,10 @@  along with GCC; see the file COPYING3.  
 #ifndef GCC_SYSTEM_H
 #define GCC_SYSTEM_H
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /* We must include stdarg.h before stdio.h.  */
 #include <stdarg.h>
 
@@ -969,4 +973,8 @@  helper_const_non_const_cast (const char 
 #define DEBUG_VARIABLE
 #endif
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif /* ! GCC_SYSTEM_H */
diff --git a/include/xregex2.h b/include/xregex2.h
--- a/include/xregex2.h
+++ b/include/xregex2.h
@@ -399,7 +399,11 @@  struct re_pattern_buffer
 typedef struct re_pattern_buffer regex_t;
 
 /* Type for byte offsets within the string.  POSIX mandates this.  */
+#if defined(__osf__) && defined(__cplusplus)
+typedef off_t regoff_t;
+#else
 typedef int regoff_t;
+#endif
 
 
 /* This is the structure we store register match data in.  See