diff options
Diffstat (limited to 'unwind.c')
| -rw-r--r-- | unwind.c | 43 |
1 files changed, 25 insertions, 18 deletions
@@ -38,6 +38,7 @@ #include "unwind.h" static uw_frame_t *uw_stack; +static uw_frame_t *uw_env_stack; static uw_frame_t *uw_exit_point; static uw_frame_t toplevel_env; @@ -72,6 +73,10 @@ static void uw_unwind_to_exit_point(void) /* 1 means unwind only. */ longjmp(uw_stack->ca.jb, 1); abort(); + case UW_ENV: + /* Maintain consistency of unwind stack pointer */ + uw_env_stack = uw_env_stack->ev.up_env; + break; default: break; } @@ -111,35 +116,33 @@ void uw_push_block(uw_frame_t *fr, val tag) static uw_frame_t *uw_find_env(void) { - uw_frame_t *fr; - - for (fr = uw_stack; fr != 0; fr = fr->uw.up) { - if (fr->uw.type == UW_ENV) - break; - } - - return fr ? fr : &toplevel_env; + return uw_env_stack ? uw_env_stack : &toplevel_env; } void uw_push_env(uw_frame_t *fr) { uw_frame_t *prev_env = uw_find_env(); fr->ev.type = UW_ENV; - - if (prev_env) { - fr->ev.func_bindings = copy_alist(prev_env->ev.func_bindings); - } else { - fr->ev.func_bindings = nil; - } - + fr->ev.up_env = prev_env; + fr->ev.func_bindings = nil; fr->ev.up = uw_stack; uw_stack = fr; + uw_env_stack = fr; } val uw_get_func(val sym) { - uw_frame_t *env = uw_find_env(); - return cdr(assoc(env->ev.func_bindings, sym)); + uw_frame_t *env; + + for (env = uw_find_env(); env != 0; env = env->ev.up_env) { + if (env->ev.func_bindings) { + val found = assoc(env->ev.func_bindings, sym); + if (found) + return cdr(found); + } + } + + return nil; } val uw_set_func(val sym, val value) @@ -152,7 +155,11 @@ val uw_set_func(val sym, val value) void uw_pop_frame(uw_frame_t *fr) { assert (fr == uw_stack); - uw_stack = uw_stack->uw.up; + uw_stack = fr->uw.up; + if (fr->uw.type == UW_ENV) { + assert (fr == uw_env_stack); + uw_env_stack = fr->ev.up_env; + } } val uw_block_return(val tag, val result) |