HP-UX release wider match; also drop gcc opt level.

[perl5.git] / cv.h

diff --git a/cv.h b/cv.h
index 3d44a73..36afba7 100644 (file)
--- a/cv.h
+++ b/cv.h
@@ -26,10 +26,10 @@ Null CV pointer.
 =head1 CV Manipulation Functions
 
 This section documents functions to manipulate CVs which are code-values,
-or subroutines. For more information, see L<perlguts>.
+or subroutines.  For more information, see L<perlguts>.
 
 =for apidoc Am|HV*|CvSTASH|CV* cv
-Returns the stash of the CV. A stash is the symbol table hash, containing
+Returns the stash of the CV.  A stash is the symbol table hash, containing
 the package-scoped variables in the package where the subroutine was defined.
 For more information, see L<perlguts>.
 
@@ -49,7 +49,7 @@ See L<perlguts/Autoloading with XSUBs>.
 #define CvROOT(sv)     ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_root_u.xcv_root
 #define CvXSUB(sv)     ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_root_u.xcv_xsub
 #define CvXSUBANY(sv)  ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_start_u.xcv_xsubany
-#define CvGV(sv)       S_CvGV((CV *)(sv))
+#define CvGV(sv)       S_CvGV((const CV *)(sv))
 #define CvGV_set(cv,gv)        Perl_cvgv_set(aTHX_ cv, gv)
 #define CvFILE(sv)     ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_file
 #ifdef USE_ITHREADS
@@ -189,7 +189,7 @@ See L<perlguts/Autoloading with XSUBs>.
 #define XS_DYNAMIC_FILENAME    0x01    /* The filename isn't static  */
 
 PERL_STATIC_INLINE GV *
-S_CvGV(CV *sv)
+S_CvGV(const CV *sv)
 {
     return CvNAMED(sv)
        ? 0
@@ -202,6 +202,15 @@ CvNAME_HEK(CV *sv)
        ? ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_gv_u.xcv_hek
        : 0;
 }
+/* This lowers the refernce count of the previous value, but does *not*
+   increment the reference count of the new value. */
+#define CvNAME_HEK_set(cv, hek) ( \
+       CvNAME_HEK((CV *)(cv))                                           \
+           ? unshare_hek(SvANY((CV *)(cv))->xcv_gv_u.xcv_hek)    \
+           : (void)0,                                             \
+       ((XPVCV*)MUTABLE_PTR(SvANY(cv)))->xcv_gv_u.xcv_hek = (hek), \
+       CvNAMED_on(cv)                                               \
+    )
 
 /*
 =head1 CV reference counts and CvOUTSIDE
@@ -209,19 +218,19 @@ CvNAME_HEK(CV *sv)
 =for apidoc m|bool|CvWEAKOUTSIDE|CV *cv
 
 Each CV has a pointer, C<CvOUTSIDE()>, to its lexically enclosing
-CV (if any). Because pointers to anonymous sub prototypes are
+CV (if any).  Because pointers to anonymous sub prototypes are
 stored in C<&> pad slots, it is a possible to get a circular reference,
-with the parent pointing to the child and vice-versa. To avoid the
+with the parent pointing to the child and vice-versa.  To avoid the
 ensuing memory leak, we do not increment the reference count of the CV
 pointed to by C<CvOUTSIDE> in the I<one specific instance> that the parent
-has a C<&> pad slot pointing back to us. In this case, we set the
-C<CvWEAKOUTSIDE> flag in the child. This allows us to determine under what
+has a C<&> pad slot pointing back to us.  In this case, we set the
+C<CvWEAKOUTSIDE> flag in the child.  This allows us to determine under what
 circumstances we should decrement the refcount of the parent when freeing
 the child.
 
 There is a further complication with non-closure anonymous subs (i.e. those
-that do not refer to any lexicals outside that sub). In this case, the
-anonymous prototype is shared rather than being cloned. This has the
+that do not refer to any lexicals outside that sub).  In this case, the
+anonymous prototype is shared rather than being cloned.  This has the
 consequence that the parent may be freed while there are still active
 children, eg
 
@@ -237,16 +246,16 @@ and the freed BEGIN is accessed.
 To avoid this, whenever a CV and its associated pad is freed, any
 C<&> entries in the pad are explicitly removed from the pad, and if the
 refcount of the pointed-to anon sub is still positive, then that
-child's C<CvOUTSIDE> is set to point to its grandparent. This will only
+child's C<CvOUTSIDE> is set to point to its grandparent.  This will only
 occur in the single specific case of a non-closure anon prototype
 having one or more active references (such as C<$a> above).
 
 One other thing to consider is that a CV may be merely undefined
-rather than freed, eg C<undef &foo>. In this case, its refcount may
+rather than freed, eg C<undef &foo>.  In this case, its refcount may
 not have reached zero, but we still delete its pad and its C<CvROOT> etc.
 Since various children may still have their C<CvOUTSIDE> pointing at this
 undefined CV, we keep its own C<CvOUTSIDE> for the time being, so that
-the chain of lexical scopes is unbroken. For example, the following
+the chain of lexical scopes is unbroken.  For example, the following
 should print 123:
 
     my $x = 123;