diff --git a/libguile/control.c b/libguile/control.c index c3ad5407b..6a060f4d8 100644 --- a/libguile/control.c +++ b/libguile/control.c @@ -33,16 +33,15 @@ SCM scm_sys_default_prompt_tag; SCM scm_c_make_prompt (SCM k, SCM *fp, SCM *sp, scm_t_uint8 *abort_ip, - scm_t_uint8 escape_only_p, scm_t_int64 vm_cookie) + scm_t_uint8 escape_only_p, scm_t_int64 vm_cookie, + SCM winds) { scm_t_bits tag; - SCM ret; struct scm_prompt_registers *regs; tag = scm_tc7_prompt; if (escape_only_p) tag |= (SCM_F_PROMPT_ESCAPE<<8); - ret = scm_words (tag, 5); regs = scm_gc_malloc_pointerless (sizeof (*regs), "prompt registers"); regs->fp = fp; @@ -50,11 +49,8 @@ scm_c_make_prompt (SCM k, SCM *fp, SCM *sp, scm_t_uint8 *abort_ip, regs->ip = abort_ip; regs->cookie = vm_cookie; - SCM_SET_CELL_OBJECT (ret, 1, k); - SCM_SET_CELL_WORD (ret, 2, (scm_t_bits)regs); - SCM_SET_CELL_OBJECT (ret, 3, scm_i_dynwinds ()); - - return ret; + return scm_double_cell (tag, SCM_UNPACK (k), (scm_t_bits)regs, + SCM_UNPACK (winds)); } /* Only to be called if the SCM_PROMPT_SETJMP returns 1 */ diff --git a/libguile/control.h b/libguile/control.h index 806a8eef0..923a45e0c 100644 --- a/libguile/control.h +++ b/libguile/control.h @@ -27,8 +27,7 @@ #define SCM_PROMPT_ESCAPE_P(x) (SCM_PROMPT_FLAGS (x) & SCM_F_PROMPT_ESCAPE) #define SCM_PROMPT_TAG(x) (SCM_CELL_OBJECT ((x), 1)) #define SCM_PROMPT_REGISTERS(x) ((struct scm_prompt_registers*)SCM_CELL_WORD ((x), 2)) -#define SCM_PROMPT_DYNENV(x) (SCM_CELL_OBJECT ((x), 3)) -#define SCM_PROMPT_HANDLER(x) (SCM_CELL_OBJECT ((x), 4)) +#define SCM_PROMPT_DYNWINDS(x) (SCM_CELL_OBJECT ((x), 3)) #define SCM_PROMPT_SETJMP(p) (SCM_I_SETJMP (SCM_PROMPT_REGISTERS (p)->regs)) @@ -48,7 +47,8 @@ SCM_INTERNAL SCM scm_sys_default_prompt_tag; SCM_INTERNAL SCM scm_c_make_prompt (SCM k, SCM *fp, SCM *sp, scm_t_uint8 *abort_ip, scm_t_uint8 escape_only_p, - scm_t_int64 vm_cookie); + scm_t_int64 vm_cookie, + SCM winds); SCM_INTERNAL SCM scm_i_prompt_pop_abort_args_x (SCM prompt); SCM_INTERNAL void scm_c_abort (SCM vm, SCM tag, size_t n, SCM *argv, diff --git a/libguile/eval.c b/libguile/eval.c index 1dc2bc4cd..ba358a7b3 100644 --- a/libguile/eval.c +++ b/libguile/eval.c @@ -432,7 +432,7 @@ eval (SCM x, SCM env) vm = scm_the_vm (); prompt = scm_c_make_prompt (eval (CAR (mx), env), SCM_VM_DATA (vm)->fp, SCM_VM_DATA (vm)->sp, SCM_VM_DATA (vm)->ip, - 0, -1); + 0, -1, scm_i_dynwinds ()); handler = eval (CDDR (mx), env); scm_i_set_dynwinds (scm_cons (prompt, scm_i_dynwinds ())); diff --git a/libguile/throw.c b/libguile/throw.c index 7f6564570..04bcba83e 100644 --- a/libguile/throw.c +++ b/libguile/throw.c @@ -512,8 +512,8 @@ pre_init_catch (SCM tag, SCM thunk, SCM handler, SCM pre_unwind_handler) vm = scm_the_vm (); prompt = scm_c_make_prompt (scm_fluid_ref (scm_sys_default_prompt_tag), SCM_VM_DATA (vm)->fp, SCM_VM_DATA (vm)->sp, - SCM_VM_DATA (vm)->ip, 1, -1); - scm_i_set_dynwinds (scm_cons (prompt, scm_i_dynwinds ())); + SCM_VM_DATA (vm)->ip, 1, -1, scm_i_dynwinds ()); + scm_i_set_dynwinds (scm_cons (prompt, SCM_PROMPT_DYNWINDS (prompt))); if (SCM_PROMPT_SETJMP (prompt)) { diff --git a/libguile/vm-i-system.c b/libguile/vm-i-system.c index 262bb876d..e21a9109e 100644 --- a/libguile/vm-i-system.c +++ b/libguile/vm-i-system.c @@ -995,7 +995,7 @@ VM_DEFINE_INSTRUCTION (89, continuation_call, "continuation-call", 0, -1, 0) VM_DEFINE_INSTRUCTION (94, partial_cont_call, "partial-cont-call", 0, -1, 0) { - SCM vmcont, intwinds; + SCM vmcont, intwinds, prevwinds; POP (intwinds); POP (vmcont); SYNC_REGISTER (); @@ -1003,7 +1003,18 @@ VM_DEFINE_INSTRUCTION (94, partial_cont_call, "partial-cont-call", 0, -1, 0) { finish_args = vmcont; goto vm_error_continuation_not_rewindable; } - vm_reinstate_partial_continuation (vm, vmcont, intwinds, sp + 1 - fp, fp); + prevwinds = scm_i_dynwinds (); + vm_reinstate_partial_continuation (vm, vmcont, intwinds, sp + 1 - fp, fp, + vm_cookie); + + /* Rewind prompt jmpbuffers, if any. */ + { + SCM winds = scm_i_dynwinds (); + for (; !scm_is_eq (winds, prevwinds); winds = scm_cdr (winds)) + if (SCM_PROMPT_P (scm_car (winds)) && SCM_PROMPT_SETJMP (scm_car (winds))) + break; + } + CACHE_REGISTER (); program = SCM_FRAME_PROGRAM (fp); CACHE_PROGRAM (); @@ -1480,8 +1491,9 @@ VM_DEFINE_INSTRUCTION (83, prompt, "prompt", 4, 2, 0) SYNC_REGISTER (); /* Push the prompt onto the dynamic stack. */ - prompt = scm_c_make_prompt (k, fp, sp, ip + offset, escape_only_p, vm_cookie); - scm_i_set_dynwinds (scm_cons (prompt, scm_i_dynwinds ())); + prompt = scm_c_make_prompt (k, fp, sp, ip + offset, escape_only_p, vm_cookie, + scm_i_dynwinds ()); + scm_i_set_dynwinds (scm_cons (prompt, SCM_PROMPT_DYNWINDS (prompt))); if (SCM_PROMPT_SETJMP (prompt)) { /* The prompt exited nonlocally. Cache the regs back from the vp, and go diff --git a/libguile/vm.c b/libguile/vm.c index 85e0e7ada..142061185 100644 --- a/libguile/vm.c +++ b/libguile/vm.c @@ -231,7 +231,7 @@ vm_abort (SCM vm, size_t n, scm_t_int64 vm_cookie) static void vm_reinstate_partial_continuation (SCM vm, SCM cont, SCM intwinds, - size_t n, SCM *argv) + size_t n, SCM *argv, scm_t_int64 vm_cookie) { struct scm_vm *vp; struct scm_vm_cont *cp; @@ -267,8 +267,6 @@ vm_reinstate_partial_continuation (SCM vm, SCM cont, SCM intwinds, vp->fp = RELOC (cp->fp); vp->ip = cp->mvra; -#undef RELOC - /* now push args. ip is in a MV context. */ for (i = 0; i < n; i++) { @@ -278,14 +276,32 @@ vm_reinstate_partial_continuation (SCM vm, SCM cont, SCM intwinds, vp->sp++; *vp->sp = scm_from_size_t (n); - /* Finally, rewind the dynamic state. */ + /* Finally, rewind the dynamic state. + + We have to treat prompts specially, because we could be rewinding the + dynamic state from a different thread, or just a different position on the + C and/or VM stack -- so we need to reset the jump buffers so that an abort + comes back here, with appropriately adjusted sp and fp registers. */ { long delta = 0; SCM newwinds = scm_i_dynwinds (); for (; scm_is_pair (intwinds); intwinds = scm_cdr (intwinds), delta--) - newwinds = scm_cons (scm_car (intwinds), newwinds); + { + SCM x = scm_car (intwinds); + if (SCM_PROMPT_P (x)) + /* the jmpbuf will be reset by our caller */ + x = scm_c_make_prompt (SCM_PROMPT_TAG (x), + RELOC (SCM_PROMPT_REGISTERS (x)->fp), + RELOC (SCM_PROMPT_REGISTERS (x)->sp), + SCM_PROMPT_REGISTERS (x)->ip, + SCM_PROMPT_ESCAPE_P (x), + vm_cookie, + newwinds); + newwinds = scm_cons (x, newwinds); + } scm_dowinds (newwinds, delta); } +#undef RELOC } diff --git a/test-suite/tests/control.test b/test-suite/tests/control.test index 650f25552..d3fd1b3a9 100644 --- a/test-suite/tests/control.test +++ b/test-suite/tests/control.test @@ -204,3 +204,14 @@ (equal? (k) 1)) (pass-if "post" (equal? (fluid-ref fl) 0)))) + +(with-test-prefix "rewinding prompts" + (pass-if "nested prompts" + (let ((k (% 'a + (% 'b + (begin + (abort 'a) + (abort 'b #t)) + (lambda (k x) x)) + (lambda (k) k)))) + (k))))