Attribute configuration

Message-ID: <20050519173256.GA29039@petdance.com>

p4raw-id: //depot/perl@24508

31 files changed, 473 insertions, 216 deletions

diff --git a/Configure b/Configure
index e3dc44f0d8..3e62682c12 100755
--- a/Configure
+++ b/Configure
@@ -339,7 +339,13 @@ d_aintl=''
 d_alarm=''
 asctime_r_proto=''
 d_asctime_r=''
-d_attribut=''
+d_attribute_format=''
+d_attribute_malloc=''
+d_attribute_nonnull=''
+d_attribute_noreturn=''
+d_attribute_pure=''
+d_attribute_unused=''
+d_attribute_warn_unused_result=''
 d_bcmp=''
 d_bcopy=''
 d_bzero=''
@@ -9878,21 +9884,21 @@ eval $inlibc
 set atoll d_atoll
 eval $inlibc
 
-: Look for GNU-cc style attribute checking
-case "$d_attribut" in
+: Look for GCC-style attribute format
+case "$d_attribute_format" in
 '')
 echo " "
-echo "Checking whether your compiler can handle __attribute__ ..." >&4
+echo "Checking whether your compiler can handle __attribute__((format)) ..." >&4
 $cat >attrib.c <<'EOCP'
 #include <stdio.h>
-void croak (char* pat,...) __attribute__((__format__(__printf__,1,2),noreturn));
+void my_special_printf(char* pat,...) __attribute__((__format__(__printf__,1,2)));
 EOCP
 if $cc $ccflags -c attrib.c >attrib.out 2>&1 ; then
 	if $contains 'warning' attrib.out >/dev/null 2>&1; then
-		echo "Your C compiler doesn't fully support __attribute__."
+		echo "Your C compiler doesn't support __attribute__((format))."
 		val="$undef"
 	else
-		echo "Your C compiler supports __attribute__."
+		echo "Your C compiler supports __attribute__((format))."
 		val="$define"
 	fi
 else
@@ -9900,9 +9906,177 @@ else
 	val="$undef"
 fi
 ;;
-*) val="$d_attribut" ;;
+*) val="$d_attribute_format" ;;
 esac
-set d_attribut
+set d_attribute_format
+eval $setvar
+$rm -f attrib*
+
+: Look for GCC-style attribute malloc
+case "$d_attribute_malloc" in
+'')
+echo " "
+echo "Checking whether your compiler can handle __attribute__((malloc)) ..." >&4
+$cat >attrib.c <<'EOCP'
+#include <stdio.h>
+char *go_get_some_memory( int how_many_bytes ) __attribute__((malloc));
+EOCP
+if $cc $ccflags -c attrib.c >attrib.out 2>&1 ; then
+	if $contains 'warning' attrib.out >/dev/null 2>&1; then
+		echo "Your C compiler doesn't support __attribute__((malloc))."
+		val="$undef"
+	else
+		echo "Your C compiler supports __attribute__((malloc))."
+		val="$define"
+	fi
+else
+	echo "Your C compiler doesn't seem to understand __attribute__ at all."
+	val="$undef"
+fi
+;;
+*) val="$d_attribute_malloc" ;;
+esac
+set d_attribute_malloc
+eval $setvar
+$rm -f attrib*
+
+: Look for GCC-style attribute nonnull
+case "$d_attribute_nonnull" in
+'')
+echo " "
+echo "Checking whether your compiler can handle __attribute__((nonnull(1))) ..." >&4
+$cat >attrib.c <<'EOCP'
+#include <stdio.h>
+void do_something (char *some_pointer,...) __attribute__((nonnull(1)));
+EOCP
+if $cc $ccflags -c attrib.c >attrib.out 2>&1 ; then
+	if $contains 'warning' attrib.out >/dev/null 2>&1; then
+		echo "Your C compiler doesn't support __attribute__((nonnull))."
+		val="$undef"
+	else
+		echo "Your C compiler supports __attribute__((nonnull))."
+		val="$define"
+	fi
+else
+	echo "Your C compiler doesn't seem to understand __attribute__ at all."
+	val="$undef"
+fi
+;;
+*) val="$d_attribute_nonnull" ;;
+esac
+set d_attribute_nonnull
+eval $setvar
+$rm -f attrib*
+
+: Look for GCC-style attribute noreturn
+case "$d_attribute_noreturn" in
+'')
+echo " "
+echo "Checking whether your compiler can handle __attribute__((noreturn)) ..." >&4
+$cat >attrib.c <<'EOCP'
+#include <stdio.h>
+void fall_over_dead( void ) __attribute__((noreturn));
+EOCP
+if $cc $ccflags -c attrib.c >attrib.out 2>&1 ; then
+	if $contains 'warning' attrib.out >/dev/null 2>&1; then
+		echo "Your C compiler doesn't support __attribute__((noreturn))."
+		val="$undef"
+	else
+		echo "Your C compiler supports __attribute__((noreturn))."
+		val="$define"
+	fi
+else
+	echo "Your C compiler doesn't seem to understand __attribute__ at all."
+	val="$undef"
+fi
+;;
+*) val="$d_attribute_noreturn" ;;
+esac
+set d_attribute_noreturn
+eval $setvar
+$rm -f attrib*
+
+: Look for GCC-style attribute pure
+case "$d_attribute_pure" in
+'')
+echo " "
+echo "Checking whether your compiler can handle __attribute__((pure)) ..." >&4
+$cat >attrib.c <<'EOCP'
+#include <stdio.h>
+int square( int n ) __attribute__((pure));
+EOCP
+if $cc $ccflags -c attrib.c >attrib.out 2>&1 ; then
+	if $contains 'warning' attrib.out >/dev/null 2>&1; then
+		echo "Your C compiler doesn't support __attribute__((pure))."
+		val="$undef"
+	else
+		echo "Your C compiler supports __attribute__((pure))."
+		val="$define"
+	fi
+else
+	echo "Your C compiler doesn't seem to understand __attribute__ at all."
+	val="$undef"
+fi
+;;
+*) val="$d_attribute_pure" ;;
+esac
+set d_attribute_pure
+eval $setvar
+$rm -f attrib*
+
+: Look for GCC-style attribute unused
+case "$d_attribute_unused" in
+'')
+echo " "
+echo "Checking whether your compiler can handle __attribute__((unused)) ..." >&4
+$cat >attrib.c <<'EOCP'
+#include <stdio.h>
+int do_something( int dummy __attribute__((unused)), int n );
+EOCP
+if $cc $ccflags -c attrib.c >attrib.out 2>&1 ; then
+	if $contains 'warning' attrib.out >/dev/null 2>&1; then
+		echo "Your C compiler doesn't support __attribute__((unused))."
+		val="$undef"
+	else
+		echo "Your C compiler supports __attribute__((unused))."
+		val="$define"
+	fi
+else
+	echo "Your C compiler doesn't seem to understand __attribute__ at all."
+	val="$undef"
+fi
+;;
+*) val="$d_attribute_unused" ;;
+esac
+set d_attribute_unused
+eval $setvar
+$rm -f attrib*
+
+: Look for GCC-style attribute warn_unused_result
+case "$d_attribute_warn_unused_result" in
+'')
+echo " "
+echo "Checking whether your compiler can handle __attribute__((warn_unused_result)) ..." >&4
+$cat >attrib.c <<'EOCP'
+#include <stdio.h>
+int I_will_not_be_ignored(void) __attribute__((warn_unused_result));
+EOCP
+if $cc $ccflags -c attrib.c >attrib.out 2>&1 ; then
+	if $contains 'warning' attrib.out >/dev/null 2>&1; then
+		echo "Your C compiler doesn't support __attribute__((warn_unused_result))."
+		val="$undef"
+	else
+		echo "Your C compiler supports __attribute__((warn_unused_result))."
+		val="$define"
+	fi
+else
+	echo "Your C compiler doesn't seem to understand __attribute__ at all."
+	val="$undef"
+fi
+;;
+*) val="$d_attribute_warn_unused_result" ;;
+esac
+set d_attribute_warn_unused_result
 eval $setvar
 $rm -f attrib*
 
@@ -20631,7 +20805,13 @@ d_archlib='$d_archlib'
 d_asctime_r='$d_asctime_r'
 d_atolf='$d_atolf'
 d_atoll='$d_atoll'
-d_attribut='$d_attribut'
+d_attribute_format='$d_attribute_format'
+d_attribute_malloc='$d_attribute_malloc'
+d_attribute_nonnull='$d_attribute_nonnull'
+d_attribute_noreturn='$d_attribute_noreturn'
+d_attribute_pure='$d_attribute_pure'
+d_attribute_unused='$d_attribute_unused'
+d_attribute_warn_unused_result='$d_attribute_warn_unused_result'
 d_bcmp='$d_bcmp'
 d_bcopy='$d_bcopy'
 d_bsd='$d_bsd'
diff --git a/Cross/config.sh-arm-linux b/Cross/config.sh-arm-linux
index afe4d48a37..6b7e992113 100644
--- a/Cross/config.sh-arm-linux
+++ b/Cross/config.sh-arm-linux
@@ -111,7 +111,13 @@ d_archlib='define'
 d_asctime_r='undef'
 d_atolf='undef'
 d_atoll='define'
-d_attribut='define'
+d_attribute_format='undef'
+d_attribute_malloc='undef'
+d_attribute_nonnull='undef'
+d_attribute_noreturn='undef'
+d_attribute_pure='undef'
+d_attribute_unused='undef'
+d_attribute_warn_unused_result='undef'
 d_bcmp='define'
 d_bcopy='define'
 d_bsd='undef'
diff --git a/NetWare/config.wc b/NetWare/config.wc
index 7ea7b1e233..8808b8cad8 100644
--- a/NetWare/config.wc
+++ b/NetWare/config.wc
@@ -97,7 +97,13 @@ d_archlib='define'
 d_asctime_r='undef'
 d_atolf='undef'
 d_atoll='undef'
-d_attribut='undef'
+d_attribute_format='undef'
+d_attribute_malloc='undef'
+d_attribute_nonnull='undef'
+d_attribute_noreturn='undef'
+d_attribute_pure='undef'
+d_attribute_unused='undef'
+d_attribute_warn_unused_result='undef'
 d_bcmp='undef'
 d_bcopy='undef'
 d_bsd='define'
diff --git a/Porting/Glossary b/Porting/Glossary
index 41eec75fd9..99b8e34e7a 100644
--- a/Porting/Glossary
+++ b/Porting/Glossary
@@ -406,10 +406,42 @@ d_atoll (atoll.U):
 	This variable conditionally defines the HAS_ATOLL symbol, which
 	indicates to the C program that the atoll() routine is available.
 
-d_attribut (d_attribut.U):
-	This variable conditionally defines HASATTRIBUTE, which
-	indicates the C compiler can check for function attributes,
-	such as printf formats.
+d_attribute_format (d_attribut_format.U):
+	This variable conditionally defines HASATTRIBUTE_FORMAT, which
+	indicates the C compiler can check for printf-like formats.
+
+d_attribute_malloc (d_attribute_malloc.U):
+	This variable conditionally defines HASATTRIBUTE_MALLOC, which
+	indicates the C compiler can understand functions as having
+	malloc-like semantics.
+
+d_attribute_nonnull (d_attribute_nonnull.U):
+	This variable conditionally defines HASATTRIBUTE_NONNULL, which
+	indicates that the C compiler can know that certain arguments
+	must not be NULL, and will check accordingly at compile time.
+
+d_attribute_noreturn (d_attribute_noreturn.U):
+	This variable conditionally defines HASATTRIBUTE_NORETURN, which
+	indicates that the C compiler can know that certain functions
+	are guaranteed never to return.
+
+d_attribute_pure (d_attribute_pure.U):
+	This variable conditionally defines HASATTRIBUTE_PURE, which
+	indicates that the C compiler can know that certain functions
+	are "pure" functions, meaning that they have no side effects, and
+	only rely on function input and/or global data for their results.
+
+d_attribute_unused (d_attribute_unused.U):
+	This variable conditionally defines HASATTRIBUTE_UNUSED, which
+	indicates that the C compiler can know that certain variables
+	and arguments may not always be used, and to not throw warnings
+	if they don't get used.
+
+d_attribute_warn_unused_result (d_attribute_warn_unused_result.U):
+	This variable conditionally defines
+	HASATTRIBUTE_WARN_UNUSED_RESULT, which indicates that the C
+	compiler can know that certain functions have a return values
+	that must not be ignored, such as malloc() or open().
 
 d_bcmp (d_bcmp.U):
 	This variable conditionally defines the HAS_BCMP symbol if
diff --git a/Porting/config.sh b/Porting/config.sh
index 006c38db28..2b208fbedf 100644
--- a/Porting/config.sh
+++ b/Porting/config.sh
@@ -111,7 +111,13 @@ d_archlib='define'
 d_asctime_r='undef'
 d_atolf='undef'
 d_atoll='define'
-d_attribut='define'
+d_attribute_format='undef'
+d_attribute_malloc='undef'
+d_attribute_nonnull='undef'
+d_attribute_noreturn='undef'
+d_attribute_pure='undef'
+d_attribute_unused='undef'
+d_attribute_warn_unused_result='undef'
 d_bcmp='define'
 d_bcopy='define'
 d_bsd='undef'
diff --git a/Porting/pumpkin.pod b/Porting/pumpkin.pod
index ff1e5bd5f9..37e68f89ea 100644
--- a/Porting/pumpkin.pod
+++ b/Porting/pumpkin.pod
@@ -711,45 +711,6 @@ branches.
 
 =head2 Other tests
 
-=over 4
-
-=item CHECK_FORMAT
-
-If you have gcc, you can test the correct use of printf-style
-arguments.  Run C<Configure> with S<-Dccflags='-DCHECK_FORMAT
--Wformat'> (and S<-Dcc=gcc>, if you are not on a system where C<cc>
-is C<gcc>) and run C<make>.  The compiler will produce warnings of
-incorrect use of format arguments.  
-
-As of change 23767, CHECK_FORMAT changes perl-defined formats
-to obscure (but standard) formats, and then traps the obscure
-format.  The resulting perl executable operates properly but 
-you should not use the executable produced by this process.
-
-=over 4
-
-=item *
- 
-A more accurate approach is the following commands:
-
-    make clean
-    make all OPTIMIZE='-DCHECK_FORMAT -Wformat' >& make.log  
-    perl -nwe 'print if /^\S+:/ and not /^make\b/' make.log
-
-=item *
-
-A more thorough approach to compiler warnings is
-
-    make clean
-    make miniperl OPTIMIZE=-O\ -DCHECK_FORMAT >& make.log
-    make all OPTIMIZE=-O\ -DCHECK_FORMAT\ -Wall\ -Wno-unused\
-			    -Wno-uninitialized >>& make.log
-    perl -nwe 'print if /^\S+:/ and not /^make\b/' make.log
-
-=back
-
-(-Wformat support by Robin Barker.)
-
 =item gcc -ansi -pedantic
 
 Configure -Dgccansipedantic [ -Dcc=gcc ] will enable (via the cflags script,
diff --git a/XSUB.h b/XSUB.h
index 8997778491..b59a95f8ac 100644
--- a/XSUB.h
+++ b/XSUB.h
@@ -92,8 +92,8 @@ is a lexical $_ in scope.
 #  define XS(name) EXPORT_C void name(pTHX_ CV* cv)
 #endif
 #ifndef XS
-#  if defined(HASATTRIBUTE)
-#    define XS(name) void name(pTHX_ CV* cv __attribute__((unused)))
+#  ifdef HASATTRIBUTE_UNUSED
+#    define XS(name) void name(pTHX_ CV* cv __attribute__unused__)
 #  else
 #    define XS(name) void name(pTHX_ CV* cv)
 #  endif
diff --git a/config_h.SH b/config_h.SH
index da368ceae9..78f262d92f 100644
--- a/config_h.SH
+++ b/config_h.SH
@@ -3727,17 +3727,40 @@ sed <<!GROK!THIS! >$CONFIG_H -e 's!^#undef\(.*/\)\*!/\*#define\1 \*!' -e 's!^#un
 #define M_VOID			/* Xenix strikes again */
 #endif
 
-/* HASATTRIBUTE:
- *	This symbol indicates the C compiler can check for function attributes,
- *	such as printf formats. This is normally only supported by GNU cc.
- */
-#$d_attribut HASATTRIBUTE 	/**/
-#ifndef HASATTRIBUTE
-#ifdef __attribute__
-#undef __attribute__
-#endif
-#define __attribute__(_arg_)
-#endif
+/* HASATTRIBUTE_FORMAT:
+ *	Can we handle GCC attribute for checking printf-style formats
+ */
+#$d_attribute_format HASATTRIBUTE_FORMAT	/**/
+
+/* HASATTRIBUTE_MALLOC:
+ *	Can we handle GCC attribute for malloc-style functions.
+ */
+#$d_attribute_malloc HASATTRIBUTE_MALLOC	/**/
+
+/* HASATTRIBUTE_NONNULL:
+ *	Can we handle GCC attribute for nonnull function parms.
+ */
+#$d_attribute_nonnull HASATTRIBUTE_NONNULL	/**/
+
+/* HASATTRIBUTE_NORETURN:
+ *	Can we handle GCC attribute for functions that do not return
+ */
+#$d_attribute_noreturn HASATTRIBUTE_NORETURN	/**/
+
+/* HASATTRIBUTE_PURE:
+ *	Can we handle GCC attribute for pure functions
+ */
+#$d_attribute_pure HASATTRIBUTE_PURE	/**/
+
+/* HASATTRIBUTE_UNUSED:
+ *	Can we handle GCC attribute for unused variables and arguments
+ */
+#$d_attribute_unused HASATTRIBUTE_UNUSED	/**/
+
+/* HASATTRIBUTE_WARN_UNUSED_RESULT:
+ *	Can we handle GCC attribute for warning on unused results
+ */
+#$d_attribute_warn_unused_result HASATTRIBUTE_WARN_UNUSED_RESULT	/**/
 
 /* HAS_CRYPT:
  *	This symbol, if defined, indicates that the crypt routine is available
diff --git a/configure.com b/configure.com
index e306ff4ae0..bccbf2fbd2 100644
--- a/configure.com
+++ b/configure.com
@@ -5417,7 +5417,13 @@ $ WC "d_alarm='define'"
 $ WC "d_archlib='define'"
 $ WC "d_atolf='" + d_atolf + "'"
 $ WC "d_atoll='" + d_atoll + "'"
-$ WC "d_attribut='" + d_attribut + "'"
+$ WC "d_attribute_format='" + d_attribut + "'"
+$ WC "d_attribute_malloc='undef'"
+$ WC "d_attribute_nonnull='undef'"
+$ WC "d_attribute_noreturn='undef'"
+$ WC "d_attribute_pure='undef'"
+$ WC "d_attribute_unused='undef'"
+$ WC "d_attribute_warn_unused_result='undef'"
 $ WC "d_bcmp='" + d_bcmp + "'"
 $ WC "d_bcopy='" + d_bcopy + "'"
 $ WC "d_bincompat3='undef'"
diff --git a/epoc/config.sh b/epoc/config.sh
index 6dd70772cb..9553265f30 100644
--- a/epoc/config.sh
+++ b/epoc/config.sh
@@ -103,7 +103,13 @@ d_archlib='define'
 d_asctime_r='undef'
 d_atolf='undef'
 d_atoll='undef'
-d_attribut='undef'
+d_attribute_format='undef'
+d_attribute_malloc='undef'
+d_attribute_nonnull='undef'
+d_attribute_noreturn='undef'
+d_attribute_pure='undef'
+d_attribute_unused='undef'
+d_attribute_warn_unused_result='undef'
 d_bcmp='define'
 d_bcopy='define'
 d_bsd='undef'
diff --git a/hints/next_3_0.sh b/hints/next_3_0.sh
index b444578830..06d122ac96 100644
--- a/hints/next_3_0.sh
+++ b/hints/next_3_0.sh
@@ -16,7 +16,7 @@ echo find it.  By default, it is placed in /usr/local/include/gdbm.h.	>&4
 echo It will not be found there.  Try moving it to			>&4
 echo /NextDeveloper/Headers/bsd/gdbm.h.					>&4
 
-ccflags="$ccflags -DUSE_NEXT_CTYPE -DNEXT30_NO_ATTRIBUTE"
+ccflags="$ccflags -DUSE_NEXT_CTYPE"
 POSIX_cflags='ccflags="-posix $ccflags"'
 useposix='undef'
 ldflags="$ldflags -u libsys_s"
@@ -51,3 +51,11 @@ d_setpgid='undef'
 # (Thanks to Andreas Koenig <k@franz.ww.tu-berlin.de>)
 ranlib='sleep 5; /bin/ranlib' 
 
+# Doesn't support attributes, so we'll set that here.
+d_attribute_format='undef'
+d_attribute_malloc='undef'
+d_attribute_nonnull='undef'
+d_attribute_noreturn='undef'
+d_attribute_pure='undef'
+d_attribute_unused='undef'
+d_attribute_warn_unused_result='undef'
diff --git a/hints/vmesa.sh b/hints/vmesa.sh
index 5fad22bf8b..bda26fcb14 100644
--- a/hints/vmesa.sh
+++ b/hints/vmesa.sh
@@ -25,7 +25,13 @@ d_alarm='define'
 d_archlib='define'
 # randbits='15'
 archobjs="vmesa.o"
-d_attribut='undef'
+d_attribute_format='undef'
+d_attribute_malloc='undef'
+d_attribute_nonnull='undef'
+d_attribute_noreturn='undef'
+d_attribute_pure='undef'
+d_attribute_unused='undef'
+d_attribute_warn_unused_result='undef'
 d_bcmp='define'
 d_bcopy='define'
 d_bsd='undef'
diff --git a/malloc.c b/malloc.c
index 1ff10bec4b..affe76371e 100644
--- a/malloc.c
+++ b/malloc.c
@@ -409,7 +409,7 @@
 #  ifndef pTHX
 #     define pTHX		void
 #     define pTHX_
-#     ifdef HASATTRIBUTE
+#     ifdef HASATTRIBUTE_UNUSED
 #        define dTHX		extern int Perl___notused PERL_UNUSED_DECL
 #     else
 #        define dTHX            extern int Perl___notused
diff --git a/mg.c b/mg.c
index baad04f718..1611d1fb7d 100644
--- a/mg.c
+++ b/mg.c
@@ -468,12 +468,7 @@ Perl_magic_regdatum_set(pTHX_ SV *sv, MAGIC *mg)
 {
     (void)sv; (void)mg;
     Perl_croak(aTHX_ PL_no_modify);
-    /* NOT REACHED */
-#ifndef HASATTRIBUTE_NORETURN
-    /* No __attribute__((noreturn)), so the compiler doesn't know that
-     * croak never returns. */
-    return 0;
-#endif
+    NORETURN_FUNCTION_END;
 }
 
 U32
diff --git a/op.c b/op.c
index 5f36c57133..dc70613cca 100644
--- a/op.c
+++ b/op.c
@@ -4899,11 +4899,7 @@ Perl_oopsCV(pTHX_ OP *o)
     Perl_croak(aTHX_ "NOT IMPL LINE %d",__LINE__);
     /* STUB */
     (void)o;
-#ifndef HASATTRIBUTE_NORETURN
-    /* No __attribute__((noreturn)), so the compiler doesn't know that
-     * croak never returns. */
-    return 0;
-#endif
+    NORETURN_FUNCTION_END;
 }
 
 OP *
diff --git a/perl.c b/perl.c
index 5f38e64363..c6e5ee3aa5 100644
--- a/perl.c
+++ b/perl.c
@@ -1006,14 +1006,10 @@ perl_free(pTHXx)
 #pragma fini "perl_fini"
 #endif
 
-#if defined(__GNUC__) && defined(__attribute__) 
-/* want to make sure __attribute__ works here even
- * for -Dd_attribut=undef builds.
- */
-#undef __attribute__
+static void
+#if defined(__GNUC__)
+__attribute__((destructor))
 #endif
-
-static void __attribute__((destructor))
 perl_fini(void)
 {
     dVAR;
diff --git a/perl.h b/perl.h
index 1a2145c0f9..54a6d3e58e 100644
--- a/perl.h
+++ b/perl.h
@@ -190,27 +190,7 @@
 #define CALLREG_INTUIT_STRING CALL_FPTR(PL_regint_string)
 #define CALLREGFREE CALL_FPTR(PL_regfree)
 
-#if defined(SYMBIAN) && defined(__GNUC__)
-#  undef __attribute__
-#  undef __attribute__(_arg_)
-#  define HASATTRIBUTE
-#endif
-
-#ifdef HASATTRIBUTE
-#  if (defined(__GNUC__) && defined(__cplusplus)) || defined(__INTEL_COMPILER)
-#    define PERL_UNUSED_DECL
-#  else
-#    define PERL_UNUSED_DECL __attribute__((unused))
-#  endif
-#else
-#  define PERL_UNUSED_DECL
-#endif
- 
-#if defined(SYMBIAN) && defined(__GNUC__)
-#  undef __attribute__
-#  undef __attribute__(_arg_)
-#  define HASATTRIBUTE
-#endif
+#define PERL_UNUSED_DECL __attribute__unused__
 
 /* gcc -Wall:
  * for silencing unused variables that are actually used most of the time,
@@ -2550,20 +2530,17 @@ typedef pthread_key_t	perl_key;
 #  define PERL_SET_THX(t)		PERL_SET_CONTEXT(t)
 #endif
 
+/*  This replaces the previous %_ "hack" by the "%-p" hack
+    All that is required is that the perl source does not
+    use "%-p" or "%-<number>p" format.  These format will
+    still work in perl code.   RMB 2005/05/17
+*/
 #ifndef SVf
-#  ifdef CHECK_FORMAT
-#    define SVf "-p"
-#  else
-#    define SVf "_"
-#  endif
+#  define SVf "-p"
 #endif
 
 #ifndef SVf_precision
-#  ifdef CHECK_FORMAT
-#    define SVf_precision(n) "-" n "p"
-#  else
-#    define SVf_precision(n) "." n "_"
-#  endif
+#  define SVf_precision(n) "-" n "p"
 #endif
 
 #ifndef SVf32
@@ -2579,41 +2556,66 @@ typedef pthread_key_t	perl_key;
 #endif
 
 #ifndef DieNull
-#  ifdef CHECK_FORMAT
-#    define DieNull Perl_vdie(aTHX_ Nullch, Null(va_list *))
-#  else
-#    define DieNull Perl_die(aTHX_ Nullch)
+#  define DieNull Perl_vdie(aTHX_ Nullch, Null(va_list *))
+#endif
+
+/* In case Configure was not used (we are using a "canned config"
+ * such as Win32, or a cross-compilation setup, for example) try going
+ * by the gcc major and minor versions.  One useful URL is
+ * http://www.ohse.de/uwe/articles/gcc-attributes.html,
+ * but contrary to this information warn_unused_result seems
+ * not to be in gcc 3.3.5, at least. --jhi */
+#if defined __GNUC__
+#  if __GNUC__ >= 3 /* 3.0 -> */ /* XXX Verify this version */
+#    define HASATTRIBUTE_FORMAT
 #  endif
-#endif
-
-#ifndef __attribute__format__
-#  ifdef CHECK_FORMAT
-#    define __attribute__format__(x,y,z) __attribute__((format(x,y,z)))
-#  else
-#    define __attribute__format__(x,y,z)
+#  if __GNUC__ >= 3 /* 3.0 -> */
+#    define HASATTRIBUTE_MALLOC
+#  endif
+#  if __GNUC__ == 3 && __GNUC_MINOR__ >= 3 || __GNUC__ > 3 /* 3.3 -> */
+#    define HASATTRIBUTE_NONNULL
+#  endif
+#  if __GNUC__ == 2 && __GNUC_MINOR__ >= 5 || __GNUC__ > 2 /* 2.5 -> */
+#    define HASATTRIBUTE_NORETURN
+#  endif
+#  if __GNUC__ >= 3 /* gcc 3.0 -> */
+#    define HASATTRIBUTE_PURE
+#  endif
+#  if __GNUC__ >= 3 /* gcc 3.0 -> */ /* XXX Verify this version */
+#    define HASATTRIBUTE_UNUSED
+#  endif
+#  if __GNUC__ == 3 && __GNUC_MINOR__ >= 4 || __GNUC__ > 3 /* 3.4 -> */
+#    define HASATTRIBUTE_WARN_UNUSED_RESULT
 #  endif
 #endif
 
-/* See http://www.ohse.de/uwe/articles/gcc-attributes.html, but
- * contrary to the information warn_unused_result seems not to be in
- * gcc 3.3.5, at least. --jhi */
 
-#if __GNUC__ >= 3
+#ifdef HASATTRIBUTE_FORMAT
+#  define __attribute__format__(x,y,z)      __attribute__((format(x,y,z)))
+#endif
+#ifdef HASATTRIBUTE_MALLOC
 #  define __attribute__malloc__             __attribute__((malloc))
 #endif
-#if __GNUC__ == 3 && __GNUC_MINOR__ >= 3 || __GNUC__ > 3
+#ifdef HASATTRIBUTE_NONNULL
 #  define __attribute__nonnull__(a)         __attribute__((nonnull(a)))
 #endif
-#if __GNUC__ == 2 && __GNUC_MINOR__ >= 5 || __GNUC__ > 2
+#ifdef HASATTRIBUTE_NORETURN
 #  define __attribute__noreturn__           __attribute__((noreturn))
 #endif
-#if __GNUC__ >= 3
+#ifdef HASATTRIBUTE_PURE
 #  define __attribute__pure__               __attribute__((pure))
 #endif
-#if __GNUC__ == 3 && __GNUC_MINOR__ >= 4 || __GNUC__ > 3
+#ifdef HASATTRIBUTE_UNUSED
+#  define __attribute__unused__             __attribute__((unused))
+#endif
+#ifdef HASATTRIBUTE_WARN_UNUSED_RESULT
 #  define __attribute__warn_unused_result__ __attribute__((warn_unused_result))
 #endif
 
+/* If we haven't defined the attributes yet, define them to blank. */
+#ifndef __attribute__format__
+#  define __attribute__format__(x,y,z)
+#endif
 #ifndef __attribute__malloc__
 #  define __attribute__malloc__
 #endif
@@ -2626,12 +2628,20 @@ typedef pthread_key_t	perl_key;
 #ifndef __attribute__pure__
 #  define __attribute__pure__
 #endif
+#ifndef __attribute__unused__
+#  define __attribute__unused__
+#endif
 #ifndef __attribute__warn_unused_result__
 #  define __attribute__warn_unused_result__
 #endif
 
-#if defined(HASATTRIBUTE) && __GNUC__ >= 3
-#  define HASATTRIBUTE_NORETURN
+/* For functions that are marked as __attribute__noreturn__, it's not
+   appropriate to call return.  In either case, include the lint directive.
+ */
+#ifdef HASATTRIBUTE_NORETURN
+#  define NORETURN_FUNCTION_END /* NOT REACHED */
+#else
+#  define NORETURN_FUNCTION_END /* NOT REACHED */ return 0
 #endif
 
 /* Some unistd.h's give a prototype for pause() even though
@@ -3928,16 +3938,6 @@ struct tempsym; /* defined in pp_pack.c */
 #ifndef PERL_CALLCONV
 #  define PERL_CALLCONV
 #endif
-
-#ifndef NEXT30_NO_ATTRIBUTE
-#  ifndef HASATTRIBUTE       /* disable GNU-cc attribute checking? */
-#    ifdef  __attribute__      /* Avoid possible redefinition errors */
-#      undef  __attribute__
-#    endif
-#    define __attribute__(attr)
-#  endif
-#endif
-
 #undef PERL_CKDEF
 #undef PERL_PPDEF
 #define PERL_CKDEF(s)	OP *s (pTHX_ OP *o);
diff --git a/perlio.h b/perlio.h
index 9183948ad4..302228299f 100644
--- a/perlio.h
+++ b/perlio.h
@@ -210,19 +210,7 @@ PERL_EXPORT_C void PerlIO_clone(pTHX_ PerlInterpreter *proto,
 
 START_EXTERN_C
 #ifndef __attribute__format__
-#  ifdef CHECK_FORMAT
-#    define __attribute__format__(x,y,z) __attribute__((format(x,y,z)))
-#  else
-#    define __attribute__format__(x,y,z)
-#endif
-#endif
-#ifndef NEXT30_NO_ATTRIBUTE
-#ifndef HASATTRIBUTE		/* disable GNU-cc attribute checking? */
-#ifdef  __attribute__		/* Avoid possible redefinition errors */
-#undef  __attribute__
-#endif
-#define __attribute__(attr)
-#endif
+#  define __attribute__format__(x,y,z) __attribute__((format(x,y,z)))
 #endif
 #ifndef PerlIO_init
 PERL_EXPORT_C void PerlIO_init(pTHX);
diff --git a/plan9/config_sh.sample b/plan9/config_sh.sample
index bf78b38bf3..9ac6eb672f 100644
--- a/plan9/config_sh.sample
+++ b/plan9/config_sh.sample
@@ -111,7 +111,13 @@ d_archlib='define'
 d_asctime_r='undef'
 d_atolf='undef'
 d_atoll='define'
-d_attribut='undef'
+d_attribute_format='undef'
+d_attribute_malloc='undef'
+d_attribute_nonnull='undef'
+d_attribute_noreturn='undef'
+d_attribute_pure='undef'
+d_attribute_unused='undef'
+d_attribute_warn_unused_result='undef'
 d_bcmp='define'
 d_bcopy='define'
 d_bsd='undef'
diff --git a/plan9/genconfig.pl b/plan9/genconfig.pl
index d934659ec4..30f4af74a1 100644
--- a/plan9/genconfig.pl
+++ b/plan9/genconfig.pl
@@ -118,7 +118,13 @@ EndOfIntro
 
 # Plan 9 compiler stuff
 print OUT "cc='pcc'\n";
-print OUT "d_attribut='undef'\n";
+print OUT "d_attribute_format='undef'\n";
+print OUT "d_attribute_malloc='undef'\n";
+print OUT "d_attribute_nonnull='undef'\n";
+print OUT "d_attribute_noreturn='undef'\n";
+print OUT "d_attribute_pure='undef'\n";
+print OUT "d_attribute_unused='undef'\n";
+print OUT "d_attribute_warn_unused_result='undef'\n";
 print OUT "d_socket='define'\n";
 print OUT "d_sockpair='define'\n";
 print OUT "d_sigsetjmp='define'\n";
diff --git a/scope.c b/scope.c
index 085ed164b8..50258df3c1 100644
--- a/scope.c
+++ b/scope.c
@@ -469,11 +469,7 @@ Perl_save_threadsv(pTHX_ PADOFFSET i)
 {
     Perl_croak(aTHX_ "panic: save_threadsv called in non-threaded perl");
     (void)i;
-#ifndef HASATTRIBUTE_NORETURN
-    /* No __attribute__((noreturn)), so the compiler doesn't know that
-     * croak never returns. */
-    return 0;
-#endif
+    NORETURN_FUNCTION_END;
 }
 
 void
diff --git a/sv.c b/sv.c
index 799cf526fe..66b07e2b26 100644
--- a/sv.c
+++ b/sv.c
@@ -9222,12 +9222,10 @@ Perl_sv_vcatpvfn(pTHX_ SV *sv, const char *pat, STRLEN patlen, va_list *args, SV
     /* no matter what, this is a string now */
     (void)SvPV_force(sv, origlen);
 
-    /* special-case "", "%s", and "%_" */
+    /* special-case "", "%s", and "%-p" (SVf) */
     if (patlen == 0)
 	return;
-    if (patlen == 2 && pat[0] == '%') {
-	switch (pat[1]) {
-	case 's':
+    if (patlen == 2 && pat[0] == '%' && pat[1] == 's') {
 	    if (args) {
                 const char *s = va_arg(*args, char*);
 		sv_catpv(sv, s ? s : nullstr);
@@ -9238,7 +9236,9 @@ Perl_sv_vcatpvfn(pTHX_ SV *sv, const char *pat, STRLEN patlen, va_list *args, SV
 		    SvUTF8_on(sv);
 	    }
 	    return;
-	case '_':
+    }
+    if (patlen == 3 && pat[0] == '%' &&
+	pat[1] == '-' && pat[2] == 'p') {
 	    if (args) {
 		argsv = va_arg(*args, SV*);
 		sv_catsv(sv, argsv);
@@ -9246,9 +9246,6 @@ Perl_sv_vcatpvfn(pTHX_ SV *sv, const char *pat, STRLEN patlen, va_list *args, SV
 		    SvUTF8_on(sv);
 		return;
 	    }
-	    /* See comment on '_' below */
-	    break;
-	}
     }
 
 #ifndef USE_LONG_DOUBLE
@@ -9626,23 +9623,6 @@ Perl_sv_vcatpvfn(pTHX_ SV *sv, const char *pat, STRLEN patlen, va_list *args, SV
 		    is_utf8 = TRUE;
 		}
 	    }
-	    goto string;
-
-	case '_':
-#ifdef CHECK_FORMAT
-	format_sv:
-#endif
-	    /*
-	     * The "%_" hack might have to be changed someday,
-	     * if ISO or ANSI decide to use '_' for something.
-	     * So we keep it hidden from users' code.
-	     */
-	    if (!args || vectorize)
-		goto unknown;
-	    argsv = va_arg(*args, SV*);
-	    eptr = SvPVx(argsv, elen);
-	    if (DO_UTF8(argsv))
-		is_utf8 = TRUE;
 
 	string:
 	    vectorize = FALSE;
@@ -9653,17 +9633,21 @@ Perl_sv_vcatpvfn(pTHX_ SV *sv, const char *pat, STRLEN patlen, va_list *args, SV
 	    /* INTEGERS */
 
 	case 'p':
-#ifdef CHECK_FORMAT
-	    if (left) {
+	    if (left && args) {		/* SVf */
 		left = FALSE;
-	        if (!width)
-		    goto format_sv;	/* %-p	-> %_	*/
-		precis = width;
-		has_precis = TRUE;
-		width = 0;
-		goto format_sv;		/* %-Np	-> %.N_	*/	
+		if (width) {
+		    precis = width;
+		    has_precis = TRUE;
+		    width = 0;
+		}
+		if (vectorize)
+		    goto unknown;
+		argsv = va_arg(*args, SV*);
+		eptr = SvPVx(argsv, elen);
+		if (DO_UTF8(argsv))
+		    is_utf8 = TRUE;
+		goto string;
 	    }
-#endif
 	    if (alt || vectorize)
 		goto unknown;
 	    uv = PTR2UV(args ? va_arg(*args, void*) : argsv);
diff --git a/symbian/config.sh b/symbian/config.sh
index 1c1fa01b99..c0ef96b103 100644
--- a/symbian/config.sh
+++ b/symbian/config.sh
@@ -51,7 +51,13 @@ d_archlib='define'
 d_asctime_r='undef'
 d_atolf='undef'
 d_atoll='undef'
-d_attribut='undef'
+d_attribute_format='undef'
+d_attribute_malloc='undef'
+d_attribute_nonnull='undef'
+d_attribute_noreturn='undef'
+d_attribute_pure='undef'
+d_attribute_unused='undef'
+d_attribute_warn_unused_result='undef'
 d_bcmp='undef'
 d_bcopy='undef'
 d_bsd='undef'
diff --git a/t/op/sprintf.t b/t/op/sprintf.t
index c854588ce2..90ac8a76b3 100755
--- a/t/op/sprintf.t
+++ b/t/op/sprintf.t
@@ -323,6 +323,7 @@ __END__
 >%+o<       >642<         >1202<
 >%#o<       >642<         >01202<
 >%d< >$p=sprintf('%p',$p);$p=~/^[0-9a-f]+$/< >1< >Coarse hack: hex from %p?<
+>%d< >$p=sprintf('%-8p',$p);$p=~/^[0-9a-f]+\s*$/< >1< >Coarse hack: hex from %p?<
 >%#p<       >''<          >%#p INVALID<
 >%q<        >''<          >%q INVALID<
 >%r<        >''<          >%r INVALID<
diff --git a/uconfig.sh b/uconfig.sh
index 87be639524..28b0c3ea76 100755
--- a/uconfig.sh
+++ b/uconfig.sh
@@ -40,7 +40,13 @@ d_archlib='undef'
 d_asctime_r='undef'
 d_atolf='undef'
 d_atoll='undef'
-d_attribut='undef'
+d_attribute_format='undef'
+d_attribute_malloc='undef'
+d_attribute_nonnull='undef'
+d_attribute_noreturn='undef'
+d_attribute_pure='undef'
+d_attribute_unused='undef'
+d_attribute_warn_unused_result='undef'
 d_bcmp='undef'
 d_bcopy='undef'
 d_bsd='undef'
diff --git a/vms/genconfig.pl b/vms/genconfig.pl
index 2794a172a1..6e9df703eb 100644
--- a/vms/genconfig.pl
+++ b/vms/genconfig.pl
@@ -140,7 +140,14 @@ foreach (@ARGV) {
       $d_attr = 'undef';
     }
     print OUT "vms_cc_type='$cctype'\n";
-    print OUT "d_attribut='$d_attr'\n";
+    print OUT "d_attribute_format='$d_attr'\n";
+    # XXX The following attributes may be able to use $d_attr, too.
+    print OUT "d_attribute_malloc='undef'\n";
+    print OUT "d_attribute_nonnull='undef'\n";
+    print OUT "d_attribute_noreturn='undef'\n";
+    print OUT "d_attribute_pure='undef'\n";
+    print OUT "d_attribute_unused='undef'\n";
+    print OUT "d_attribute_warn_unused_result='undef'\n";
     print OUT "cc='$cc'\n";
     if ( ($cctype eq 'decc' and $archsufx eq 'VAX') || $cctype eq 'gcc') {
       # gcc and DECC for VAX requires filename in /object qualifier, so we
diff --git a/win32/config.bc b/win32/config.bc
index fe78757317..5434b33cc7 100644
--- a/win32/config.bc
+++ b/win32/config.bc
@@ -99,7 +99,13 @@ d_archlib='define'
 d_asctime_r='undef'
 d_atolf='undef'
 d_atoll='undef'
-d_attribut='undef'
+d_attribute_format='undef'
+d_attribute_malloc='undef'
+d_attribute_nonnull='undef'
+d_attribute_noreturn='undef'
+d_attribute_pure='undef'
+d_attribute_unused='undef'
+d_attribute_warn_unused_result='undef'
 d_bcmp='undef'
 d_bcopy='undef'
 d_bsd='define'
diff --git a/win32/config.gc b/win32/config.gc
index d1432dda85..f86a4a537e 100644
--- a/win32/config.gc
+++ b/win32/config.gc
@@ -99,7 +99,13 @@ d_archlib='define'
 d_asctime_r='undef'
 d_atolf='undef'
 d_atoll='undef'
-d_attribut='define'
+d_attribute_format='undef'
+d_attribute_malloc='undef'
+d_attribute_nonnull='undef'
+d_attribute_noreturn='undef'
+d_attribute_pure='undef'
+d_attribute_unused='undef'
+d_attribute_warn_unused_result='undef'
 d_bcmp='undef'
 d_bcopy='undef'
 d_bsd='define'
diff --git a/win32/config.vc b/win32/config.vc
index 0eeb4b7c9d..0baf3f54cf 100644
--- a/win32/config.vc
+++ b/win32/config.vc
@@ -99,7 +99,13 @@ d_archlib='define'
 d_asctime_r='undef'
 d_atolf='undef'
 d_atoll='undef'
-d_attribut='undef'
+d_attribute_format='undef'
+d_attribute_malloc='undef'
+d_attribute_nonnull='undef'
+d_attribute_noreturn='undef'
+d_attribute_pure='undef'
+d_attribute_unused='undef'
+d_attribute_warn_unused_result='undef'
 d_bcmp='undef'
 d_bcopy='undef'
 d_bsd='define'
diff --git a/win32/config.vc64 b/win32/config.vc64
index c2548f1d0e..c45b6bf987 100644
--- a/win32/config.vc64
+++ b/win32/config.vc64
@@ -99,7 +99,13 @@ d_archlib='define'
 d_asctime_r='undef'
 d_atolf='undef'
 d_atoll='define'
-d_attribut='undef'
+d_attribute_format='undef'
+d_attribute_malloc='undef'
+d_attribute_nonnull='undef'
+d_attribute_noreturn='undef'
+d_attribute_pure='undef'
+d_attribute_unused='undef'
+d_attribute_warn_unused_result='undef'
 d_bcmp='undef'
 d_bcopy='undef'
 d_bsd='define'
diff --git a/wince/config.ce b/wince/config.ce
index 2f63f5bddb..ff53bddb7c 100644
--- a/wince/config.ce
+++ b/wince/config.ce
@@ -97,7 +97,13 @@ d_archlib='define'
 d_asctime_r='undef'
 d_atolf='undef'
 d_atoll='undef'
-d_attribut='undef'
+d_attribute_format='undef'
+d_attribute_malloc='undef'
+d_attribute_nonnull='undef'
+d_attribute_noreturn='undef'
+d_attribute_pure='undef'
+d_attribute_unused='undef'
+d_attribute_warn_unused_result='undef'
 d_bcmp='undef'
 d_bcopy='undef'
 d_bsd='define'