Declarations must come first, or some compilers aren't happy.

[p5sagit/p5-mst-13.2.git] / sv.c

diff --git a/sv.c b/sv.c
index 7f8a6b3..16bc44d 100644 (file)
--- a/sv.c
+++ b/sv.c
@@ -1233,9 +1233,43 @@ struct body_details {
 #define HADNV FALSE
 #define NONV TRUE
 
+#ifdef PURIFY
+/* With -DPURFIY we allocate everything directly, and don't use arenas.
+   This seems a rather elegant way to simplify some of the code below.  */
+#define HASARENA FALSE
+#else
 #define HASARENA TRUE
+#endif
 #define NOARENA FALSE
 
+/* A macro to work out the offset needed to subtract from a pointer to (say)
+
+typedef struct {
+    STRLEN     xpv_cur;
+    STRLEN     xpv_len;
+} xpv_allocated;
+
+to make its members accessible via a pointer to (say)
+
+struct xpv {
+    NV         xnv_nv;
+    STRLEN     xpv_cur;
+    STRLEN     xpv_len;
+};
+
+*/
+
+#define relative_STRUCT_OFFSET(longer, shorter, member) \
+    STRUCT_OFFSET(shorter, member) - STRUCT_OFFSET(longer, member)
+
+/* Calculate the length to copy. Specifically work out the length less any
+   final padding the compiler needed to add.  See the comment in sv_upgrade
+   for why copying the padding proved to be a bug.  */
+
+#define copy_length(type, last_member) \
+       STRUCT_OFFSET(type, last_member) \
+       + sizeof (((type*)SvANY((SV*)0))->last_member)
+
 static const struct body_details bodies_by_type[] = {
     {0, 0, 0, FALSE, NONV, NOARENA},
     /* IVs are in the head, so the allocation size is 0  */
@@ -1247,24 +1281,20 @@ static const struct body_details bodies_by_type[] = {
     {0, 0, 0, FALSE, NONV, NOARENA},
     /* 8 bytes on most ILP32 with IEEE doubles */
     {sizeof(xpv_allocated),
-     STRUCT_OFFSET(XPV, xpv_len) + sizeof (((XPV*)SvANY((SV*)0))->xpv_len)
-     + STRUCT_OFFSET(xpv_allocated, xpv_cur) - STRUCT_OFFSET(XPV, xpv_cur),
-     + STRUCT_OFFSET(xpv_allocated, xpv_cur) - STRUCT_OFFSET(XPV, xpv_cur)
-     , FALSE, NONV, HASARENA},
+     copy_length(XPV, xpv_len)
+     + relative_STRUCT_OFFSET(XPV, xpv_allocated, xpv_cur),
+     + relative_STRUCT_OFFSET(XPV, xpv_allocated, xpv_cur),
+     FALSE, NONV, HASARENA},
     /* 12 */
     {sizeof(xpviv_allocated),
-     STRUCT_OFFSET(XPVIV, xiv_u) + sizeof (((XPVIV*)SvANY((SV*)0))->xiv_u)
-     + STRUCT_OFFSET(xpviv_allocated, xpv_cur) - STRUCT_OFFSET(XPVIV, xpv_cur),
-     + STRUCT_OFFSET(xpviv_allocated, xpv_cur) - STRUCT_OFFSET(XPVIV, xpv_cur)
-    , FALSE, NONV, HASARENA},
+     copy_length(XPVIV, xiv_u)
+     + relative_STRUCT_OFFSET(XPVIV, xpviv_allocated, xpv_cur),
+     + relative_STRUCT_OFFSET(XPVIV, xpviv_allocated, xpv_cur),
+     FALSE, NONV, HASARENA},
     /* 20 */
-    {sizeof(XPVNV),
-     STRUCT_OFFSET(XPVNV, xiv_u) + sizeof (((XPVNV*)SvANY((SV*)0))->xiv_u),
-     0, FALSE, HADNV, HASARENA},
+    {sizeof(XPVNV), copy_length(XPVNV, xiv_u), 0, FALSE, HADNV, HASARENA},
     /* 28 */
-    {sizeof(XPVMG),
-     STRUCT_OFFSET(XPVMG, xmg_stash) + sizeof (((XPVMG*)SvANY((SV*)0))->xmg_stash),
-     0, FALSE, HADNV, HASARENA},
+    {sizeof(XPVMG), copy_length(XPVMG, xmg_stash), 0, FALSE, HADNV, HASARENA},
     /* 36 */
     {sizeof(XPVBM), sizeof(XPVBM), 0, TRUE, HADNV, HASARENA},
     /* 48 */
@@ -1273,20 +1303,16 @@ static const struct body_details bodies_by_type[] = {
     {sizeof(XPVLV), sizeof(XPVLV), 0, TRUE, HADNV, HASARENA},
     /* 20 */
     {sizeof(xpvav_allocated),
-     STRUCT_OFFSET(XPVAV, xmg_stash)
-     + sizeof (((XPVAV*)SvANY((SV *)0))->xmg_stash)
-     + STRUCT_OFFSET(xpvav_allocated, xav_fill)
-     - STRUCT_OFFSET(XPVAV, xav_fill),
-     STRUCT_OFFSET(xpvav_allocated, xav_fill)
-     - STRUCT_OFFSET(XPVAV, xav_fill), TRUE, HADNV, HASARENA},
+     copy_length(XPVAV, xmg_stash)
+     + relative_STRUCT_OFFSET(XPVAV, xpvav_allocated, xav_fill),
+     relative_STRUCT_OFFSET(XPVAV, xpvav_allocated, xav_fill),
+     TRUE, HADNV, HASARENA},
     /* 20 */
     {sizeof(xpvhv_allocated),
-     STRUCT_OFFSET(XPVHV, xmg_stash)
-     + sizeof (((XPVHV*)SvANY((SV *)0))->xmg_stash)
-     + STRUCT_OFFSET(xpvhv_allocated, xhv_fill)
-     - STRUCT_OFFSET(XPVHV, xhv_fill),
-     STRUCT_OFFSET(xpvhv_allocated, xhv_fill)
-     - STRUCT_OFFSET(XPVHV, xhv_fill), TRUE, HADNV, HASARENA},
+     copy_length(XPVHV, xmg_stash)
+     + relative_STRUCT_OFFSET(XPVHV, xpvhv_allocated, xhv_fill),
+     relative_STRUCT_OFFSET(XPVHV, xpvhv_allocated, xhv_fill),
+     TRUE, HADNV, HASARENA},
     /* 76 */
     {sizeof(XPVCV), sizeof(XPVCV), 0, TRUE, HADNV, HASARENA},
     /* 80 */
@@ -1551,7 +1577,8 @@ Perl_sv_upgrade(pTHX_ register SV *sv, U32 new_type)
     case SVt_PV:
 
        assert(new_type_details->size);
-#ifndef PURIFY
+       /* We always allocated the full length item with PURIFY. To do this
+          we fake things so that arena is false for all 16 types..  */
        if(new_type_details->arena) {
            /* This points to the start of the allocated area.  */
            new_body_inline(new_body, new_type_details->size, new_type);
@@ -1560,10 +1587,6 @@ Perl_sv_upgrade(pTHX_ register SV *sv, U32 new_type)
        } else {
            new_body = new_NOARENAZ(new_type_details);
        }
-#else
-       /* We always allocated the full length item with PURIFY */
-       new_body = new_NOARENAZ(new_type_details);
-#endif
        SvANY(sv) = new_body;
 
        if (old_type_details->copy) {
@@ -5471,7 +5494,6 @@ Perl_sv_clear(pTHX_ register SV *sv)
     SvFLAGS(sv) &= SVf_BREAK;
     SvFLAGS(sv) |= SVTYPEMASK;
 
-#ifndef PURIFY
     if (sv_type_details->arena) {
        del_body(((char *)SvANY(sv) - sv_type_details->offset),
                 &PL_body_roots[type]);
@@ -5479,11 +5501,6 @@ Perl_sv_clear(pTHX_ register SV *sv)
     else if (sv_type_details->size) {
        my_safefree(SvANY(sv));
     }
-#else
-    if (sv_type_details->size) {
-       my_safefree(SvANY(sv));
-    }
-#endif
 }
 
 /*
@@ -10021,7 +10038,6 @@ Perl_sv_dup(pTHX_ SV *sstr, CLONE_PARAMS* param)
            case SVt_PVIV:
            case SVt_PV:
                assert(sv_type_details->copy);
-#ifndef PURIFY
                if (sv_type_details->arena) {
                    new_body_inline(new_body, sv_type_details->copy, sv_type);
                    new_body
@@ -10029,10 +10045,6 @@ Perl_sv_dup(pTHX_ SV *sstr, CLONE_PARAMS* param)
                } else {
                    new_body = new_NOARENA(sv_type_details);
                }
-#else
-               /* We always allocated the full length item with PURIFY */
-               new_body = new_NOARENA(sv_type_details);
-#endif
            }
            assert(new_body);
            SvANY(dstr) = new_body;