diff options
Diffstat (limited to 'src/eval.c')
| -rw-r--r-- | src/eval.c | 124 |
1 files changed, 82 insertions, 42 deletions
diff --git a/src/eval.c b/src/eval.c index cb716690e3c..8ee259110f4 100644 --- a/src/eval.c +++ b/src/eval.c @@ -658,6 +658,51 @@ The return value is BASE-VARIABLE. */) return base_variable; } +static union specbinding * +default_toplevel_binding (Lisp_Object symbol) +{ + union specbinding *binding = NULL; + union specbinding *pdl = specpdl_ptr; + while (pdl > specpdl) + { + switch ((--pdl)->kind) + { + case SPECPDL_LET_DEFAULT: + case SPECPDL_LET: + if (EQ (specpdl_symbol (pdl), symbol)) + binding = pdl; + break; + } + } + return binding; +} + +DEFUN ("default-toplevel-value", Fdefault_toplevel_value, Sdefault_toplevel_value, 1, 1, 0, + doc: /* Return SYMBOL's toplevel default value. +"Toplevel" means outside of any let binding. */) + (Lisp_Object symbol) +{ + union specbinding *binding = default_toplevel_binding (symbol); + Lisp_Object value + = binding ? specpdl_old_value (binding) : Fdefault_value (symbol); + if (!EQ (value, Qunbound)) + return value; + xsignal1 (Qvoid_variable, symbol); +} + +DEFUN ("set-default-toplevel-value", Fset_default_toplevel_value, + Sset_default_toplevel_value, 2, 2, 0, + doc: /* Set SYMBOL's toplevel default value to VALUE. +"Toplevel" means outside of any let binding. */) + (Lisp_Object symbol, Lisp_Object value) +{ + union specbinding *binding = default_toplevel_binding (symbol); + if (binding) + set_specpdl_old_value (binding, value); + else + Fset_default (symbol, value); + return Qnil; +} DEFUN ("defvar", Fdefvar, Sdefvar, 1, UNEVALLED, 0, doc: /* Define SYMBOL as a variable, and return SYMBOL. @@ -706,18 +751,10 @@ usage: (defvar SYMBOL &optional INITVALUE DOCSTRING) */) else { /* Check if there is really a global binding rather than just a let binding that shadows the global unboundness of the var. */ - union specbinding *pdl = specpdl_ptr; - while (pdl > specpdl) + union specbinding *binding = default_toplevel_binding (sym); + if (binding && EQ (specpdl_old_value (binding), Qunbound)) { - if ((--pdl)->kind >= SPECPDL_LET - && EQ (specpdl_symbol (pdl), sym) - && EQ (specpdl_old_value (pdl), Qunbound)) - { - message_with_string - ("Warning: defvar ignored because %s is let-bound", - SYMBOL_NAME (sym), 1); - break; - } + set_specpdl_old_value (binding, eval_sub (XCAR (tail))); } } tail = XCDR (tail); @@ -3311,19 +3348,21 @@ unbind_to (ptrdiff_t count, Lisp_Object value) case SPECPDL_BACKTRACE: break; case SPECPDL_LET: - /* If variable has a trivial value (no forwarding), we can - just set it. No need to check for constant symbols here, - since that was already done by specbind. */ - if (XSYMBOL (specpdl_symbol (specpdl_ptr))->redirect - == SYMBOL_PLAINVAL) - SET_SYMBOL_VAL (XSYMBOL (specpdl_symbol (specpdl_ptr)), - specpdl_old_value (specpdl_ptr)); - else - /* NOTE: we only ever come here if make_local_foo was used for - the first time on this var within this let. */ - Fset_default (specpdl_symbol (specpdl_ptr), - specpdl_old_value (specpdl_ptr)); - break; + { /* If variable has a trivial value (no forwarding), we can + just set it. No need to check for constant symbols here, + since that was already done by specbind. */ + struct Lisp_Symbol *sym = XSYMBOL (specpdl_symbol (specpdl_ptr)); + if (sym->redirect == SYMBOL_PLAINVAL) + { + SET_SYMBOL_VAL (sym, specpdl_old_value (specpdl_ptr)); + break; + } + else + { /* FALLTHROUGH!! + NOTE: we only ever come here if make_local_foo was used for + the first time on this var within this let. */ + } + } case SPECPDL_LET_DEFAULT: Fset_default (specpdl_symbol (specpdl_ptr), specpdl_old_value (specpdl_ptr)); @@ -3511,24 +3550,23 @@ backtrace_eval_unrewind (int distance) case SPECPDL_BACKTRACE: break; case SPECPDL_LET: - /* If variable has a trivial value (no forwarding), we can - just set it. No need to check for constant symbols here, - since that was already done by specbind. */ - if (XSYMBOL (specpdl_symbol (tmp))->redirect - == SYMBOL_PLAINVAL) - { - struct Lisp_Symbol *sym = XSYMBOL (specpdl_symbol (tmp)); - Lisp_Object old_value = specpdl_old_value (tmp); - set_specpdl_old_value (tmp, SYMBOL_VAL (sym)); - SET_SYMBOL_VAL (sym, old_value); - break; - } - else - { - /* FALLTHROUGH! - NOTE: we only ever come here if make_local_foo was used for - the first time on this var within this let. */ - } + { /* If variable has a trivial value (no forwarding), we can + just set it. No need to check for constant symbols here, + since that was already done by specbind. */ + struct Lisp_Symbol *sym = XSYMBOL (specpdl_symbol (tmp)); + if (sym->redirect == SYMBOL_PLAINVAL) + { + Lisp_Object old_value = specpdl_old_value (tmp); + set_specpdl_old_value (tmp, SYMBOL_VAL (sym)); + SET_SYMBOL_VAL (sym, old_value); + break; + } + else + { /* FALLTHROUGH!! + NOTE: we only ever come here if make_local_foo was used for + the first time on this var within this let. */ + } + } case SPECPDL_LET_DEFAULT: { Lisp_Object sym = specpdl_symbol (tmp); @@ -3796,6 +3834,8 @@ alist of active lexical bindings. */); defsubr (&Ssetq); defsubr (&Squote); defsubr (&Sfunction); + defsubr (&Sdefault_toplevel_value); + defsubr (&Sset_default_toplevel_value); defsubr (&Sdefvar); defsubr (&Sdefvaralias); defsubr (&Sdefconst); |