From ce5b453a449e4e7729abb5128114e2687f08360d Mon Sep 17 00:00:00 2001 From: Stefan Monnier Date: Mon, 19 Apr 2010 21:50:52 -0400 Subject: Make variable forwarding explicit rather the using special values. Basically, this makes the structure of buffer-local values and object forwarding explicit in the type of Lisp_Symbols rather than use special Lisp_Objects for that. This tends to lead to slightly more verbose code, but is more C-like, simpler, and makes it easier to make sure we handled all cases, among other things by letting the compiler help us check it. * lisp.h (enum Lisp_Misc_Type, union Lisp_Misc): Removing forwarding objects. (enum Lisp_Fwd_Type, enum symbol_redirect, union Lisp_Fwd): New types. (struct Lisp_Symbol): Make the various forms of variable-forwarding explicit rather than hiding them inside Lisp_Object "values". (XFWDTYPE): New macro. (XINTFWD, XBOOLFWD, XOBJFWD, XKBOARD_OBJFWD): Redefine. (XBUFFER_LOCAL_VALUE): Remove. (SYMBOL_VAL, SYMBOL_ALIAS, SYMBOL_BLV, SYMBOL_FWD, SET_SYMBOL_VAL) (SET_SYMBOL_ALIAS, SET_SYMBOL_BLV, SET_SYMBOL_FWD): New macros. (SYMBOL_VALUE, SET_SYMBOL_VALUE): Remove. (struct Lisp_Intfwd, struct Lisp_Boolfwd, struct Lisp_Objfwd) (struct Lisp_Buffer_Objfwd, struct Lisp_Kboard_Objfwd): Remove the Lisp_Misc_* header. (struct Lisp_Buffer_Local_Value): Redefine. (BLV_FOUND, SET_BLV_FOUND, BLV_VALUE, SET_BLV_VALUE): New macros. (struct Lisp_Misc_Any): Add filler to get the right size. (struct Lisp_Free): Use struct Lisp_Misc_Any rather than struct Lisp_Intfwd. (DEFVAR_LISP, DEFVAR_LISP_NOPRO, DEFVAR_BOOL, DEFVAR_INT) (DEFVAR_KBOARD): Allocate a forwarding object. * data.c (do_blv_forwarding, store_blv_forwarding): New macros. (let_shadows_global_binding_p): New function. (union Lisp_Val_Fwd): New type. (make_blv): New function. (swap_in_symval_forwarding, indirect_variable, do_symval_forwarding) (store_symval_forwarding, swap_in_global_binding, Fboundp) (swap_in_symval_forwarding, find_symbol_value, Fset) (let_shadows_buffer_binding_p, set_internal, default_value) (Fset_default, Fmake_variable_buffer_local, Fmake_local_variable) (Fkill_local_variable, Fmake_variable_frame_local) (Flocal_variable_p, Flocal_variable_if_set_p) (Fvariable_binding_locus): * xdisp.c (select_frame_for_redisplay): * lread.c (Fintern, Funintern, init_obarray, defvar_int) (defvar_bool, defvar_lisp_nopro, defvar_lisp, defvar_kboard): * frame.c (store_frame_param): * eval.c (Fdefvaralias, Fuser_variable_p, specbind, unbind_to): * bytecode.c (Fbyte_code) : Adapt to the new symbol value structure. * buffer.c (PER_BUFFER_SYMBOL): Move from buffer.h. (clone_per_buffer_values): Only adjust markers into the current buffer. (reset_buffer_local_variables): PER_BUFFER_IDX is never -2. (Fbuffer_local_value, set_buffer_internal_1) (swap_out_buffer_local_variables): Adapt to the new symbol value structure. (DEFVAR_PER_BUFFER): Allocate a Lisp_Buffer_Objfwd object. (defvar_per_buffer): Take a new arg for the fwd object. (buffer_lisp_local_variables): Return a proper alist (different fix for bug#4138). * alloc.c (Fmake_symbol): Use SET_SYMBOL_VAL. (Fgarbage_collect): Don't handle buffer_defaults specially. (mark_object): Handle new symbol value structure rather than the old special Lisp_Misc_* objects. (gc_sweep) : Free also the buffer-local-value objects. * term.c (set_tty_color_mode): * bidi.c (bidi_initialize): Don't access the ->value field directly. * buffer.h (PER_BUFFER_VAR_OFFSET): Don't bother with a buffer_local_flags. * print.c (print_object): Get rid of impossible forwarding objects. --- src/alloc.c | 70 ++++++++++++++++++++++++++++++------------------------------- 1 file changed, 35 insertions(+), 35 deletions(-) (limited to 'src/alloc.c') diff --git a/src/alloc.c b/src/alloc.c index 37ec06c7be1..c1f1094d15f 100644 --- a/src/alloc.c +++ b/src/alloc.c @@ -1365,7 +1365,7 @@ uninterrupt_malloc () pthread_mutexattr_settype (&attr, PTHREAD_MUTEX_RECURSIVE); pthread_mutex_init (&alloc_mutex, &attr); #else /* !DOUG_LEA_MALLOC */ - /* Some systems such as Solaris 2.6 doesn't have a recursive mutex, + /* Some systems such as Solaris 2.6 don't have a recursive mutex, and the bundled gmalloc.c doesn't require it. */ pthread_mutex_init (&alloc_mutex, NULL); #endif /* !DOUG_LEA_MALLOC */ @@ -3193,13 +3193,13 @@ Its value and function definition are void, and its property list is nil. */) p = XSYMBOL (val); p->xname = name; p->plist = Qnil; - p->value = Qunbound; + p->redirect = SYMBOL_PLAINVAL; + SET_SYMBOL_VAL (p, Qunbound); p->function = Qunbound; p->next = NULL; p->gcmarkbit = 0; p->interned = SYMBOL_UNINTERNED; p->constant = 0; - p->indirect_variable = 0; consing_since_gc += sizeof (struct Lisp_Symbol); symbols_consed++; return val; @@ -5581,17 +5581,42 @@ mark_object (arg) break; CHECK_ALLOCATED_AND_LIVE (live_symbol_p); ptr->gcmarkbit = 1; - mark_object (ptr->value); mark_object (ptr->function); mark_object (ptr->plist); - + switch (ptr->redirect) + { + case SYMBOL_PLAINVAL: mark_object (SYMBOL_VAL (ptr)); break; + case SYMBOL_VARALIAS: + { + Lisp_Object tem; + XSETSYMBOL (tem, SYMBOL_ALIAS (ptr)); + mark_object (tem); + break; + } + case SYMBOL_LOCALIZED: + { + struct Lisp_Buffer_Local_Value *blv = SYMBOL_BLV (ptr); + /* If the value is forwarded to a buffer or keyboard field, + these are marked when we see the corresponding object. + And if it's forwarded to a C variable, either it's not + a Lisp_Object var, or it's staticpro'd already. */ + mark_object (blv->where); + mark_object (blv->valcell); + mark_object (blv->defcell); + break; + } + case SYMBOL_FORWARDED: + /* If the value is forwarded to a buffer or keyboard field, + these are marked when we see the corresponding object. + And if it's forwarded to a C variable, either it's not + a Lisp_Object var, or it's staticpro'd already. */ + break; + default: abort (); + } if (!PURE_POINTER_P (XSTRING (ptr->xname))) MARK_STRING (XSTRING (ptr->xname)); MARK_INTERVAL_TREE (STRING_INTERVALS (ptr->xname)); - /* Note that we do not mark the obarray of the symbol. - It is safe not to do so because nothing accesses that - slot except to check whether it is nil. */ ptr = ptr->next; if (ptr) { @@ -5610,22 +5635,6 @@ mark_object (arg) switch (XMISCTYPE (obj)) { - case Lisp_Misc_Buffer_Local_Value: - { - register struct Lisp_Buffer_Local_Value *ptr - = XBUFFER_LOCAL_VALUE (obj); - /* If the cdr is nil, avoid recursion for the car. */ - if (EQ (ptr->cdr, Qnil)) - { - obj = ptr->realvalue; - goto loop; - } - mark_object (ptr->realvalue); - mark_object (ptr->buffer); - mark_object (ptr->frame); - obj = ptr->cdr; - goto loop; - } case Lisp_Misc_Marker: /* DO NOT mark thru the marker's chain. @@ -5633,17 +5642,6 @@ mark_object (arg) instead, markers are removed from the chain when freed by gc. */ break; - case Lisp_Misc_Intfwd: - case Lisp_Misc_Boolfwd: - case Lisp_Misc_Objfwd: - case Lisp_Misc_Buffer_Objfwd: - case Lisp_Misc_Kboard_Objfwd: - /* Don't bother with Lisp_Buffer_Objfwd, - since all markable slots in current buffer marked anyway. */ - /* Don't need to do Lisp_Objfwd, since the places they point - are protected with staticpro. */ - break; - case Lisp_Misc_Save_Value: #if GC_MARK_STACK { @@ -6048,6 +6046,8 @@ gc_sweep () if (!sym->gcmarkbit && !pure_p) { + if (sym->redirect == SYMBOL_LOCALIZED) + xfree (SYMBOL_BLV (sym)); sym->next = symbol_free_list; symbol_free_list = sym; #if GC_MARK_STACK -- cgit v1.2.1