From: Robin Barker <RMBarker@cpan.org>
Date: Fri, 5 Oct 2007 12:12:05 +0000 (+0100)
Subject: New [PATCH] use 5.006; use 5.10.0
X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=commitdiff_plain;h=fbc891ce838d50f87f51648f1bf049f1eb5cda7a;p=p5sagit%2Fp5-mst-13.2.git

New [PATCH] use 5.006; use 5.10.0
From: "Robin Barker" <Robin.Barker@npl.co.uk>
Message-ID: <2C2E01334A940D4792B3E115F95B7226016048DB@exchsvr1.npl.ad.local>

p4raw-id: //depot/perl@32031
---

diff --git a/pod/perldiag.pod b/pod/perldiag.pod
index 1c5128a..5286fbe 100644
--- a/pod/perldiag.pod
+++ b/pod/perldiag.pod
@@ -4943,6 +4943,9 @@ won't suddenly start understanding newer features, but at least
 they will show a sensible error message indicating the required
 minimum version.
 
+This warning is suppressed if the C<use 5.x.y> is preceded by a
+C<use 5.006> (see C<use VERSION> in L<perlfunc/use>).
+
 =item Warning: something's wrong
 
 (W) You passed warn() an empty string (the equivalent of C<warn "">) or
diff --git a/pod/perlfunc.pod b/pod/perlfunc.pod
index e6f6cc4..f3454b4 100644
--- a/pod/perlfunc.pod
+++ b/pod/perlfunc.pod
@@ -6853,9 +6853,15 @@ avoided, because it leads to misleading error messages under earlier
 versions of Perl that do not support this syntax.  The equivalent numeric
 version should be used instead.
 
+Alternatively, you can use a numeric version C<use 5.006> followed by a
+v-string version like C<use v5.10.1>, to avoid the unintuitive C<use
+5.010_001>. (older perl versions fail gracefully at the first C<use>,
+later perl versions understand the v-string syntax in the second).
+
     use v5.6.1;		# compile time version check
     use 5.6.1;		# ditto
     use 5.006_001;	# ditto; preferred for backwards compatibility
+    use 5.006; use 5.6.1;	# ditto, for compatibility and readability
 
 This is often useful if you need to check the current Perl version before
 C<use>ing library modules that have changed in incompatible ways from
diff --git a/pp_ctl.c b/pp_ctl.c
index b512686..7f37b75 100644
--- a/pp_ctl.c
+++ b/pp_ctl.c
@@ -3080,10 +3080,14 @@ PP(pp_require)
 
     sv = POPs;
     if ( (SvNIOKp(sv) || SvVOK(sv)) && PL_op->op_type != OP_DOFILE) {
-	if ( SvVOK(sv) && ckWARN(WARN_PORTABLE) )	/* require v5.6.1 */
+	if ( SvVOK(sv) && ckWARN(WARN_PORTABLE) ) {	/* require v5.6.1 */
+	    HV * hinthv = GvHV(PL_hintgv);
+	    SV ** ptr = NULL;
+	    if (hinthv) ptr = hv_fetchs(hinthv, "v_string", FALSE);
+	    if ( !(ptr && *ptr && SvIOK(*ptr) && SvIV(*ptr)) )
 		Perl_warner(aTHX_ packWARN(WARN_PORTABLE),
                         "v-string in use/require non-portable");
-
+	}
 	sv = new_version(sv);
 	if (!sv_derived_from(PL_patchlevel, "version"))
 	    upg_version(PL_patchlevel, TRUE);
@@ -3133,15 +3137,25 @@ PP(pp_require)
 	    }
 	}
 
-	/* If we request a version >= 5.9.5, load feature.pm with the
-	 * feature bundle that corresponds to the required version.
-	 * We do this only with use, not require. */
-	if (PL_compcv && vcmp(sv, sv_2mortal(upg_version(newSVnv(5.009005), FALSE))) >= 0) {
+        /* We do this only with use, not require. */
+	if (PL_compcv &&
+	  /* If we request a version >= 5.6.0, then v-string are OK
+	     so set $^H{v_string} to suppress the v-string warning */
+	    vcmp(sv, sv_2mortal(upg_version(newSVnv(5.006), FALSE))) >= 0) {
+	  HV * hinthv = GvHV(PL_hintgv);
+	  if( hinthv ) {
+	    (void)hv_stores(hinthv, "v_string", newSViv(1));
+	    PL_hints |= HINT_LOCALIZE_HH;
+	  }
+	  /* If we request a version >= 5.9.5, load feature.pm with the
+	   * feature bundle that corresponds to the required version. */
+	  if (vcmp(sv, sv_2mortal(upg_version(newSVnv(5.009005), FALSE))) >= 0) {
 	    SV *const importsv = vnormal(sv);
 	    *SvPVX_mutable(importsv) = ':';
 	    ENTER;
 	    Perl_load_module(aTHX_ 0, newSVpvs("feature"), NULL, importsv, NULL);
 	    LEAVE;
+	  }
 	}
 
 	RETPUSHYES;
diff --git a/t/lib/warnings/pp_ctl b/t/lib/warnings/pp_ctl
index d27e896..923d54c 100644
--- a/t/lib/warnings/pp_ctl
+++ b/t/lib/warnings/pp_ctl
@@ -240,3 +240,20 @@ use warnings;
     eval 'print $foo';
 }
 EXPECT
+########
+# pp_ctl.c
+use warnings;
+eval 'use 5.006; use 5.10.0';
+EXPECT
+########
+# pp_ctl.c
+use warnings;
+eval '{use 5.006;} use 5.10.0';
+EXPECT
+v-string in use/require non-portable at (eval 1) line 2.
+########
+# pp_ctl.c
+use warnings;
+eval 'use vars; use 5.10.0';
+EXPECT
+v-string in use/require non-portable at (eval 1) line 2.