From: David Mitchell Date: Mon, 16 May 2016 12:38:21 +0000 (+0100) Subject: get su_init/su_pop working under 5.23.8 X-Git-Tag: rt112246^2~15 X-Git-Url: http://git.vpit.fr/?a=commitdiff_plain;h=ded730eb90d077625077fa059f47ef321f9c42d1;p=perl%2Fmodules%2FScope-Upper.git get su_init/su_pop working under 5.23.8 In 5.23.8 there are two big differences to the way perl's context system manipulates the savestack. Firstly, pushing a scope no longer does one or two ENTER's instead the old value of PL_savestack_ix is stored as cx->blk_oldsaveix. This means that the boundaries of savestack frames are now not only specified as scopestack entries, but also as blk_oldsaveix entries. Secondly, most values that need restoring are saved in new fields in the CX structure rather than being pushed on the savestack; this means that it is quite likely that two nested scopes can share the same savestack index. This commit gets all the test scripts working that mainly test the savestack manipulation code (su_init and su_pop). It does this by: *) allowing the offset by which a savestack frame boundary is adjusted to be variable (rather than always SU_SAVE_DESTRUCTOR_SIZE), and by turning the origin array into an array of structs, one field of which is the offset for that depth. This allows multiple empty savestack frames to all trigger, by ensuring that each adjusted boundary is higher than the previous. *) padding the savestack using SAVEt_ALLOC, which allows a variable-sized chunk of savestack to be reserved, with minimal overhead during scope exit. In addition, *) the various SU_SAVE_AELEM_SIZE type macros have been rationalised and better commented; *) debugging output for su_init and su_pop has been improved *) the names of context types (for debugging) have been updated for 5.23.8 and some errors fixes for older perl versions --- diff --git a/Upper.xs b/Upper.xs index efc799a..34edf04 100644 --- a/Upper.xs +++ b/Upper.xs @@ -446,7 +446,6 @@ typedef struct { /* --- Global data --------------------------------------------------------- */ typedef struct { - char *stack_placeholder; su_unwind_storage unwind_storage; su_yield_storage yield_storage; su_uplevel_storage uplevel_storage; @@ -480,46 +479,64 @@ static void xsh_user_clone(pTHX_ const xsh_user_cxt_t *old_cxt, xsh_user_cxt_t * /* --- Stack manipulations ------------------------------------------------- */ -#define SU_SAVE_PLACEHOLDER() save_pptr(&XSH_CXT.stack_placeholder) +/* how many slots on the save stack various save types take up */ -#define SU_SAVE_DESTRUCTOR_SIZE 3 -#define SU_SAVE_PLACEHOLDER_SIZE 3 +#define SU_SAVE_DESTRUCTOR_SIZE 3 /* SAVEt_DESTRUCTOR_X */ +#define SU_SAVE_SCALAR_SIZE 3 /* SAVEt_SV */ +#define SU_SAVE_ARY_SIZE 3 /* SAVEt_AV */ +#define SU_SAVE_AELEM_SIZE 4 /* SAVEt_AELEM */ +#define SU_SAVE_HASH_SIZE 3 /* SAVEt_HV */ +#define SU_SAVE_HELEM_SIZE 4 /* SAVEt_HELEM */ +#define SU_SAVE_HDELETE_SIZE 4 /* SAVEt_DELETE */ -#define SU_SAVE_SCALAR_SIZE 3 +#define SU_SAVE_GVCV_SIZE SU_SAVE_DESTRUCTOR_SIZE + +/* the overhead of save_alloc() but not including any elements, + * of which there must be at least 1 */ +#if XSH_HAS_PERL(5, 14, 0) +# define SU_SAVE_ALLOC_SIZE 1 /* SAVEt_ALLOC */ +#else +# define SU_SAVE_ALLOC_SIZE 2 /* SAVEt_ALLOC */ +#endif -#define SU_SAVE_ARY_SIZE 3 -#define SU_SAVE_AELEM_SIZE 4 #ifdef SAVEADELETE -# define SU_SAVE_ADELETE_SIZE 3 +# define SU_SAVE_ADELETE_SIZE 3 /* SAVEt_ADELETE */ #else -# define SU_SAVE_ADELETE_SIZE SU_SAVE_DESTRUCTOR_SIZE +# define SU_SAVE_ADELETE_SIZE SU_SAVE_DESTRUCTOR_SIZE +#endif + +/* (NB: it was 4 between 5.13.1 and 5.13.7) */ +#if XSH_HAS_PERL(5, 8, 9) +# define SU_SAVE_GP_SIZE 3 /* SAVEt_GP */ +# else +# define SU_SAVE_GP_SIZE 6 /* SAVEt_GP */ #endif + +/* sometimes we don't know in advance whether we're saving or deleting + * an array/hash element. So include enough room for a variable-sized + * save_alloc() to pad it to a fixed size. + */ + #if SU_SAVE_AELEM_SIZE < SU_SAVE_ADELETE_SIZE -# define SU_SAVE_AELEM_OR_ADELETE_SIZE SU_SAVE_ADELETE_SIZE +# define SU_SAVE_AELEM_OR_ADELETE_SIZE \ + (SU_SAVE_ADELETE_SIZE + SU_SAVE_ALLOC_SIZE + 1) +#elif SU_SAVE_AELEM_SIZE > SU_SAVE_ADELETE_SIZE +# define SU_SAVE_AELEM_OR_ADELETE_SIZE \ + (SU_SAVE_AELEM_SIZE + SU_SAVE_ALLOC_SIZE + 1) #else # define SU_SAVE_AELEM_OR_ADELETE_SIZE SU_SAVE_AELEM_SIZE #endif -#define SU_SAVE_HASH_SIZE 3 -#define SU_SAVE_HELEM_SIZE 4 -#define SU_SAVE_HDELETE_SIZE 4 #if SU_SAVE_HELEM_SIZE < SU_SAVE_HDELETE_SIZE -# define SU_SAVE_HELEM_OR_HDELETE_SIZE SU_SAVE_HDELETE_SIZE +# define SU_SAVE_HELEM_OR_HDELETE_SIZE \ + (SU_SAVE_HDELETE_SIZE + SU_SAVE_ALLOC_SIZE + 1) +#elif SU_SAVE_HELEM_SIZE > SU_SAVE_HDELETE_SIZE +# define SU_SAVE_HELEM_OR_HDELETE_SIZE \ + (SU_SAVE_HELEM_SIZE + SU_SAVE_ALLOC_SIZE + 1) #else # define SU_SAVE_HELEM_OR_HDELETE_SIZE SU_SAVE_HELEM_SIZE #endif -#define SU_SAVE_GVCV_SIZE SU_SAVE_DESTRUCTOR_SIZE - -#if !XSH_HAS_PERL(5, 8, 9) -# define SU_SAVE_GP_SIZE 6 -#elif !XSH_HAS_PERL(5, 13, 0) || (SU_RELEASE && XSH_HAS_PERL_EXACT(5, 13, 0)) -# define SU_SAVE_GP_SIZE 3 -#elif !XSH_HAS_PERL(5, 13, 8) -# define SU_SAVE_GP_SIZE 4 -#else -# define SU_SAVE_GP_SIZE 3 -#endif #ifndef SvCANEXISTDELETE # define SvCANEXISTDELETE(sv) \ @@ -700,18 +717,22 @@ static void su_save_gvcv(pTHX_ GV *gv) { /* --- Actions ------------------------------------------------------------- */ +typedef struct { + I32 orig_ix; /* original savestack_ix */ + I32 offset; /* how much we bumped this savestack index */ +} su_ud_origin_elem; + typedef struct { U8 type; U8 private; - U8 pad; /* spare */ I32 depth; - I32 *origin; + su_ud_origin_elem *origin; } su_ud_common; + #define SU_UD_TYPE(U) (((su_ud_common *) (U))->type) #define SU_UD_PRIVATE(U) (((su_ud_common *) (U))->private) -#define SU_UD_PAD(U) (((su_ud_common *) (U))->pad) #define SU_UD_DEPTH(U) (((su_ud_common *) (U))->depth) #define SU_UD_ORIGIN(U) (((su_ud_common *) (U))->origin) @@ -889,20 +910,32 @@ static void su_localize(pTHX_ void *ud_) { if (SvTYPE(sv) >= SVt_PVGV) { gv = (GV *) sv; } else { + +/* new perl context implementation frees savestack *before* restoring + * PL_curcop. Temporarily restore it prematurely to make gv_fetch* + * looks up unqualified var names in the caller's package */ +#ifdef SU_HAS_NEW_CXT + COP *old_cop = PL_curcop; + PL_curcop = CX_CUR()->blk_oldcop; +#endif + #ifdef gv_fetchsv gv = gv_fetchsv(sv, GV_ADDMULTI, t); #else STRLEN len; const char *name = SvPV_const(sv, len); gv = gv_fetchpvn_flags(name, len, GV_ADDMULTI, t); +#endif +#ifdef SU_HAS_NEW_CXT + CX_CUR()->blk_oldcop = PL_curcop; #endif } XSH_D({ SV *z = newSV(0); SvUPGRADE(z, t); - su_debug_log("%p: === localize a %s\n",ud, sv_reftype(z, 0)); - su_debug_log("%p: depth=%2d scope_ix=%2d save_ix=%2d\n", + su_debug_log("%p: === localize a %s\n",ud, sv_reftype(z, 0)); + su_debug_log("%p: depth=%2d scope_ix=%2d save_ix=%2d\n", ud, SU_UD_DEPTH(ud), PL_scopestack_ix, PL_savestack_ix); SvREFCNT_dec(z); }); @@ -966,35 +999,48 @@ static void su_uid_drop(pTHX_ void *ud_) { #ifdef DEBUGGING # define SU_CXNAME(C) PL_block_type[CxTYPE(C)] #else -# if XSH_HAS_PERL(5, 11, 0) +# if XSH_HAS_PERL(5, 23, 8) static const char *su_block_type[] = { "NULL", "WHEN", "BLOCK", "GIVEN", - "LOOP_FOR", - "LOOP_PLAIN", + "LOOP_ARY", "LOOP_LAZYSV", "LOOP_LAZYIV", + "LOOP_LIST", + "LOOP_PLAIN", "SUB", "FORMAT", "EVAL", "SUBST" }; -# elif XSH_HAS_PERL(5, 9, 3) +# elif XSH_HAS_PERL(5, 11, 0) static const char *su_block_type[] = { "NULL", - "SUB", - "EVAL", "WHEN", - "SUBST", "BLOCK", - "FORMAT", "GIVEN", "LOOP_FOR", "LOOP_PLAIN", "LOOP_LAZYSV", - "LOOP_LAZYIV" + "LOOP_LAZYIV", + "SUB", + "FORMAT", + "EVAL", + "SUBST" +}; +# elif XSH_HAS_PERL(5, 10, 0) +static const char *su_block_type[] = { + "NULL", + "SUB", + "EVAL", + "LOOP", + "SUBST", + "BLOCK", + "FORMAT" + "WHEN", + "GIVEN" }; # else static const char *su_block_type[] = { @@ -1003,78 +1049,105 @@ static const char *su_block_type[] = { "EVAL", "LOOP", "SUBST", - "BLOCK" + "BLOCK", + "FORMAT" }; # endif # define SU_CXNAME(C) su_block_type[CxTYPE(C)] #endif -static void su_pop(pTHX_ void *ud) { -#define su_pop(U) su_pop(aTHX_ (U)) - I32 depth, base, mark, *origin; - depth = SU_UD_DEPTH(ud); +/* for debugging. These indicate how many ENTERs each context type + * does before the PUSHBLOCK */ +static const int su_cxt_enter_count[] = { +# if XSH_HAS_PERL(5, 23, 8) + 0 /* context pushes no longer do ENTERs */ +# elif XSH_HAS_PERL(5, 11, 0) + /* NULL WHEN BLOCK GIVEN LOOP_FOR LOOP_PLAIN LOOP_LAZYSV + * LOOP_LAZYIV SUB FORMAT EVAL SUBST */ + 0, 1, 1, 1, 2, 2, 2, 2, 1, 1, 1, 0 +# elif XSH_HAS_PERL(5, 10, 0) + /* NULL SUB EVAL LOOP SUBST BLOCK FORMAT WHEN GIVEN */ + 0, 1, 1, 2, 0, 1, 1, 1, 1 +# else + /* NULL SUB EVAL LOOP SUBST BLOCK FORMAT */ + 0, 1, 1, 2, 0, 1, 1 +# endif +}; + + + +/* push at least 'size' slots worth of padding onto the savestack */ + +static void su_ss_push_padding(pTHX_ void *ud, I32 size) { + if (size <= 0) + return; + if (size < SU_SAVE_ALLOC_SIZE + 1) /* minimum possible SAVEt_ALLOC */ + size = SU_SAVE_ALLOC_SIZE + 1; XSH_D(su_debug_log( - "%p: --- pop a %s\n" - "%p: leave scope at depth=%2d scope_ix=%2d cur_top=%2d cur_base=%2d\n", - ud, SU_CXNAME(cxstack + cxstack_ix), - ud, depth, PL_scopestack_ix,PL_savestack_ix,PL_scopestack[PL_scopestack_ix] - )); + "%p: push %2d padding at save_ix=%d\n", + ud, size, PL_savestack_ix)); + save_alloc((size - SU_SAVE_ALLOC_SIZE)*sizeof(*PL_savestack), 0); +} - origin = SU_UD_ORIGIN(ud); - mark = origin[depth]; - base = origin[depth - 1]; - XSH_D(su_debug_log("%p: original scope was %*c top=%2d base=%2d\n", - ud, 24, ' ', mark, base)); +static void su_pop(pTHX_ void *ud); - if (base < mark) { -#if XSH_HAS_PERL(5, 19, 4) - I32 save = -1; - PERL_CONTEXT *cx; -#endif - XSH_D(su_debug_log("%p: clear leftovers\n", ud)); -#if XSH_HAS_PERL(5, 19, 4) - cx = cxstack + cxstack_ix; - if (CxTYPE(cx) == CXt_SUB || CxTYPE(cx) == CXt_FORMAT) - save = PL_scopestack[cx->blk_oldscopesp - 1]; -#endif +/* push an su_pop destructor onto the savestack with suitable padding. + * first indicates that this is the first push of a destructor */ - PL_savestack_ix = mark; - leave_scope(base); +static void su_ss_push_destructor(pTHX_ void *ud, I32 depth, bool first) { + su_ud_origin_elem *origin = SU_UD_ORIGIN(ud); + I32 pad; -#if XSH_HAS_PERL(5, 19, 4) - if (CxTYPE(cx) == CXt_SUB || CxTYPE(cx) == CXt_FORMAT) - PL_scopestack[cx->blk_oldscopesp - 1] = save; -#endif + assert(first || origin[depth+1].orig_ix == PL_savestack_ix); + su_ss_push_padding(aTHX_ ud, + (origin[depth].orig_ix + origin[depth].offset) - PL_savestack_ix); + XSH_D(su_debug_log( + "%p: push destructor at save_ix=%d depth=%d scope_ix=%d\n", + ud, PL_savestack_ix, depth, PL_scopestack_ix)); + SAVEDESTRUCTOR_X(su_pop, ud); + assert(first || + PL_savestack_ix <= origin[depth+1].orig_ix + origin[depth+1].offset); +} + + +/* this is called during each leave_scope() via SAVEDESTRUCTOR_X */ + +static void su_pop(pTHX_ void *ud) { +#define su_pop(U) su_pop(aTHX_ (U)) + I32 depth, base, mark; + su_ud_origin_elem *origin; + + depth = SU_UD_DEPTH(ud); + origin = SU_UD_ORIGIN(ud); + + XSH_D(su_debug_log( "%p: ### su_pop: depth=%d\n", ud, depth)); + + depth--; + mark = PL_savestack_ix; + base = origin[depth].orig_ix; + + XSH_D(su_debug_log("%p: residual savestack frame is %d(+%d)..%d\n", + ud, base, origin[depth].offset, mark)); + + if (base < mark) { + XSH_D(su_debug_log("%p: clear leftovers at %d..%d\n", ud, base, mark)); + leave_scope(base); } - PL_savestack_ix = base; + assert(PL_savestack_ix == base); - SU_UD_DEPTH(ud) = --depth; + SU_UD_DEPTH(ud) = depth; if (depth > 0) { - U8 pad; - - if ((pad = SU_UD_PAD(ud)) > 0) { - dXSH_CXT; - do { - XSH_D(su_debug_log( - "%p: push a pad slot at depth=%2d scope_ix=%2d save_ix=%2d\n", - ud, depth, PL_scopestack_ix, PL_savestack_ix)); - SU_SAVE_PLACEHOLDER(); - } while (--pad); - } - - XSH_D(su_debug_log( - "%p: push destructor at depth=%2d scope_ix=%2d save_ix=%2d\n", - ud, depth, PL_scopestack_ix, PL_savestack_ix)); - SAVEDESTRUCTOR_X(su_pop, ud); + su_ss_push_destructor(aTHX_ ud, depth-1, 0); } else { + I32 offset = origin[0].offset; /* grab value before origin is freed */ switch (SU_UD_TYPE(ud)) { case SU_UD_TYPE_REAP: { - XSH_D(su_debug_log("%p: === reap\n%p: depth=%2d scope_ix=%2d save_ix=%2d\n", + XSH_D(su_debug_log("%p: === reap\n%p: depth=%d scope_ix=%d save_ix=%d\n", ud, ud, SU_UD_DEPTH(ud), PL_scopestack_ix, PL_savestack_ix)); SAVEDESTRUCTOR_X(su_call, SU_UD_REAP_CB(ud)); SU_UD_FREE(ud); @@ -1088,100 +1161,181 @@ static void su_pop(pTHX_ void *ud) { SAVEDESTRUCTOR_X(su_uid_drop, ud); break; } + /* perl 5.23.8 onwards is very fussy about the return from leave_scope() + * leaving PL_savestack_ix where it expects it to be */ + if (PL_savestack_ix < base + offset) { + I32 gap = (base + offset) - PL_savestack_ix; + assert(gap >= SU_SAVE_ALLOC_SIZE + 1); + su_ss_push_padding(aTHX_ ud, gap); + } + assert(PL_savestack_ix == base + offset); } - XSH_D(su_debug_log("%p: --- end pop: cur_top=%2d == cur_base=%2d\n", - ud, PL_savestack_ix, PL_scopestack[PL_scopestack_ix])); + XSH_D(su_debug_log("%p: end pop: ss_ix=%d\n", ud, PL_savestack_ix)); } + /* --- Initialize the stack and the action userdata ------------------------ */ -static I32 su_init(pTHX_ void *ud, I32 cxix, I32 size) { +static void su_init(pTHX_ void *ud, I32 cxix, I32 size) { #define su_init(U, C, S) su_init(aTHX_ (U), (C), (S)) - I32 i, depth, offset, base, *origin; - U8 pad; - - XSH_D(su_debug_log("%p: ### init for cx %d\n", ud, cxix)); - - /* su_pop() is going to be called from leave_scope(), so before pushing the - * next callback, we'll want to flush the current scope stack slice first. - * However, if we want the next callback not to be processed immediately by - * the current leave_scope(), we'll need to hide it by artificially - * incrementing the scope stack marker before. For the intermediate bumps, - * we will only need a bump of SU_SAVE_DESTRUCTOR_SIZE items, but for the - * last one we will need a bump of size items. However, in order to preserve - * the natural ordering between scope stack markers, we cannot bump lower - * markers more than higher ones. This is why we bump the intermediate markers - * by the smallest multiple of SU_SAVE_PLACEHOLDER_SIZE greater or equal to - * max(SU_SAVE_DESTRUCTOR_SIZE, size). */ - - if (size <= SU_SAVE_DESTRUCTOR_SIZE) { - pad = 0; - } else { - I32 extra = size - SU_SAVE_DESTRUCTOR_SIZE; - pad = extra / SU_SAVE_PLACEHOLDER_SIZE; - if (extra % SU_SAVE_PLACEHOLDER_SIZE) - ++pad; - } - offset = SU_SAVE_DESTRUCTOR_SIZE + SU_SAVE_PLACEHOLDER_SIZE * pad; - XSH_D(su_debug_log("%p: size=%d pad=%d offset=%d\n", ud, size, pad, offset)); + I32 i, depth, base; + su_ud_origin_elem *origin; + I32 cur_cx_ix; + I32 cur_scope_ix; + + XSH_D(su_debug_log("%p: ### su_init(cxix=%d, size=%d)\n", ud, cxix, size)); depth = PL_scopestack_ix - cxstack[cxix].blk_oldscopesp; - XSH_D(su_debug_log("%p: going down to depth %d\n", ud, depth)); - - /* We need to bump all the intermediary stack markers just in case an - * exception is thrown before the target scope is reached. Indeed, in this - * case there might be arbitrary many scope frames flushed at the same time, - * and since we cannot know in advance whether this will happen or not, we - * have to make sure the final frame is protected for the actual action. But - * of course, in order to do that, we also need to bump all the previous stack - * markers. If not for this, it should have been possible to just bump the two - * next frames in su_pop(). */ - - Newx(origin, depth + 1, I32); - base = PL_scopestack_ix - depth; - origin[0] = PL_scopestack[base]; - PL_scopestack[base] += size; - for (i = 1; i < depth; ++i) { - I32 j = i + base; - /* origin[depth - i] == PL_scopestack[PL_scopestack_ix - i] */ - origin[i] = PL_scopestack[j]; - PL_scopestack[j] += offset; - } - origin[depth] = PL_savestack_ix; +#ifdef SU_HAS_NEW_CXT + depth += (cxstack_ix - cxix); /* each context frame holds 1 scope */ +#endif + XSH_D(su_debug_log( + "%p: going down by depth=%d with scope_ix=%d save_ix=%d\n", + ud, depth, PL_scopestack_ix, PL_savestack_ix)); + + /* Artificially increase the position of each savestack frame boundary + * to make space to squeeze in a 'size' sized entry (first one) or a + * SU_SAVE_DESTRUCTOR_SIZE sized entry (higher ones). In addition, make + * sure that each boundary is higher than the previous, so that *every* + * scope exit triggers a call to leave_scope(). Each scope exit will call + * the su_pop() destructor, which is responsible for: freeing any + * savestack entries below the artificially raised floor; then pushing a + * new destructor in that space. On the final pop, the "real" savestack + * action is pushed rather than another destructor. + * + * On older perls, savestack frame boundaries are specified by a range of + * scopestack entries (one per ENTER). Each scope entry typically does + * one or two ENTERs followed by a PUSHBLOCK. Thus the + * cx->blku_oldscopesp field set by the PUSHBLOCK points to the next free + * slot, which is one above the last of the ENTERs. In the debugging + * output we indicate that by bracketing the ENTERs directly preceding + * that context push with dashes, e.g.: + * + * 13b98d8: ------------------ + * 13b98d8: ENTER origin[0] scope[3] savestack=3+3 + * 13b98d8: ENTER origin[1] scope[4] savestack=9+3 + * 13b98d8: cx=1 LOOP_LAZYIV + * 13b98d8: ------------------ + * + * In addition to context stack pushes, other activities can push ENTERs + * too, such as grep expr and XS sub calls. + * + * For newer perls (SU_HAS_NEW_CXT), a context push no longer does any + * ENTERs; instead the old savestack position is stored in the new + * cx->blk_oldsaveix field; thus this field specifies an additional + * savestack frame boundary point in addition to the scopestack entries, + * and will also need adjusting. + * + * We record the original and modified position of each boundary in the + * origin array. + * + * The passed cxix argument represents the scope we wish to inject into; + * we have to adjust all the savestack frame boundaries above (but not + * including) that context. + */ + + Newx(origin, depth, su_ud_origin_elem); + + cur_cx_ix = cxix; + cur_scope_ix = cxstack[cxix].blk_oldscopesp; +#ifdef SU_HAS_NEW_CXT + XSH_D(su_debug_log("%p: cx=%-2d %-11s\n", + ud, cur_cx_ix, SU_CXNAME(cxstack+cur_cx_ix))); + cur_cx_ix++; +#endif + + for (i = 0; cur_scope_ix < PL_scopestack_ix; i++) { + I32 *ixp; + I32 offset; + +#ifdef SU_HAS_NEW_CXT + + if ( cur_cx_ix <= cxstack_ix + && cur_scope_ix == cxstack[cur_cx_ix].blk_oldscopesp + ) + ixp = &(cxstack[cur_cx_ix++].blk_oldsaveix); + else + ixp = &PL_scopestack[cur_scope_ix++]; /* an ENTER pushed after cur context */ - SU_UD_PAD(ud) = pad; - SU_UD_DEPTH(ud) = depth; - SU_UD_ORIGIN(ud) = origin; +#else + + XSH_D({ + if (cur_cx_ix <= cxstack_ix) { + if (cur_scope_ix == cxstack[cur_cx_ix].blk_oldscopesp) { + su_debug_log( + "%p: cx=%-2d %s\n%p: ------------------\n", + ud, cur_cx_ix, SU_CXNAME(cxstack+cur_cx_ix), ud); + cur_cx_ix++; + } + else if (cur_scope_ix + su_cxt_enter_count[CxTYPE(cxstack+cur_cx_ix)] + == cxstack[cur_cx_ix].blk_oldscopesp) + su_debug_log("%p: ------------------\n", ud); + } + }); + ixp = &PL_scopestack[cur_scope_ix++]; + +#endif + + if (i == 0) + offset = size; + else { + /* we have three constraints to satisfy: + * 1) Each adjusted offset must be at least SU_SAVE_DESTRUCTOR_SIZE + * above its unadjusted boundary, so that there is space to inject a + * destructor into the outer scope. + * 2) Each adjusted boundary must be at least SU_SAVE_DESTRUCTOR_SIZE + * higher than the previous adjusted boundary, so that a new + * destructor can be added below the Nth adjusted frame boundary, + * but be within the (N-1)th adjusted frame and so be triggered on + * the next scope exit; + * 3) If the adjustment needs to be greater than SU_SAVE_DESTRUCTOR_SIZE, + * then it should be greater by an amount of at least the minimum + * pad side, so a destructor and padding can be pushed. + */ + I32 pad; + offset = SU_SAVE_DESTRUCTOR_SIZE; /* rule 1 */ + pad = (origin[i-1].orig_ix + origin[i-1].offset) + offset - (*ixp + offset); + if (pad > 0) { /* rule 2 */ + if (pad < SU_SAVE_ALLOC_SIZE + 1) /* rule 3 */ + pad = SU_SAVE_ALLOC_SIZE + 1; + offset += pad; + } + } + + origin[i].offset = offset; + origin[i].orig_ix = *ixp; + *ixp += offset; + +#ifdef SU_HAS_NEW_CXT + XSH_D({ + if (ixp == &PL_scopestack[cur_scope_ix-1]) + su_debug_log( + "%p: ENTER origin[%d] scope[%d] savestack=%d+%d\n", + ud, i, cur_scope_ix, origin[i].orig_ix, origin[i].offset); + else + su_debug_log( + "%p: cx=%-2d %-11s origin[%d] scope[%d] savestack=%d+%d\n", + ud, cur_cx_ix-1, SU_CXNAME(cxstack+cur_cx_ix-1), + i, cur_scope_ix, origin[i].orig_ix, origin[i].offset); + }); +#else + XSH_D(su_debug_log( + "%p: ENTER origin[%d] scope[%d] savestack=%d+%d\n", + ud, i, cur_scope_ix, origin[i].orig_ix, origin[i].offset)); +#endif - /* Make sure the first destructor fires by pushing enough fake slots on the - * stack. */ - if (PL_savestack_ix + SU_SAVE_DESTRUCTOR_SIZE - <= PL_scopestack[PL_scopestack_ix - 1]) { - dXSH_CXT; - do { - XSH_D(su_debug_log("%p: push a fake slot at scope_ix=%2d save_ix=%2d\n", - ud, PL_scopestack_ix, PL_savestack_ix)); - SU_SAVE_PLACEHOLDER(); - } while (PL_savestack_ix + SU_SAVE_DESTRUCTOR_SIZE - <= PL_scopestack[PL_scopestack_ix - 1]); } - XSH_D(su_debug_log("%p: push first destructor at scope_ix=%2d save_ix=%2d\n", - ud, PL_scopestack_ix, PL_savestack_ix)); - SAVEDESTRUCTOR_X(su_pop, ud); - XSH_D({ - for (i = 0; i <= depth; ++i) { - I32 j = PL_scopestack_ix - i; - su_debug_log("%p: depth=%2d scope_ix=%2d saved_floor=%2d new_floor=%2d\n", - ud, i, j, origin[depth - i], - i == 0 ? PL_savestack_ix : PL_scopestack[j]); - } - }); + assert(i == depth); - return depth; + SU_UD_DEPTH(ud) = depth; + SU_UD_ORIGIN(ud) = origin; + + su_ss_push_destructor(aTHX_ ud, depth-1, 1); } + /* --- Unwind stack -------------------------------------------------------- */ static void su_unwind(pTHX_ void *ud_) { @@ -2273,7 +2427,6 @@ static void xsh_user_global_setup(pTHX) { } static void xsh_user_local_setup(pTHX_ xsh_user_cxt_t *cxt) { - cxt->stack_placeholder = NULL; /* NewOp() calls calloc() which just zeroes the memory with memset(). */ Zero(&(cxt->unwind_storage.return_op), 1, LISTOP);