Step 8 passes

nasm/step8_macros.asm

@@ -13,14 +13,12 @@ global  _start
 %include "reader.asm"           ; String -> Data structures
 %include "core.asm"             ; Core functions
 %include "printer.asm"          ; Data structures -> String
+%include "exceptions.asm"       ; Error handling
         
 section .bss
         
 ;; Top-level (REPL) environment
 repl_env:resq 1
-
-;; Error handler list
-error_handler: resq 1
         
 section .data
 
@@ -80,134 +78,6 @@ section .data
         static run_script_string, db "(load-file ",34
 section .text
 
-;; ----------------------------------------------
-;; 
-;; Error handling
-;;
-;; A handler consists of:
-;;  - A stack pointer address to reset to
-;;  - An address to jump to
-;;  - An optional data structure to pass
-;;
-;; When jumped to, an error handler will be given:
-;;   - the object thrown in RSI
-;;   - the optional data structure in RDI
-;; 
-        
-
-;; Add an error handler to the front of the list
-;;
-;; Input: RSI - Stack pointer
-;;        RDI - Address to jump to
-;;        RCX - Data structure. Set to zero for none.
-;;            If not zero, reference count incremented
-;;
-;; Modifies registers:
-;;    RAX
-;;    RBX
-error_handler_push:
-        call alloc_cons
-        ; car will point to a list (stack, addr, data)
-        ; cdr will point to the previous handler
-        mov [rax], BYTE (block_cons + container_list + content_pointer)
-        mov rbx, [error_handler]
-        cmp rbx, 0              ; Check if previous handler was zero
-        je .create_handler      ; Zero, so leave null
-        ; Not zero, so create pointer to it
-        mov [rax + Cons.typecdr], BYTE content_pointer
-        mov [rax + Cons.cdr], rbx
-
-        ; note: not incrementing reference count, since
-        ; we're replacing one reference with another
-.create_handler:
-        mov [error_handler], rax ; new error handler
-        
-        mov rdx, rax
-        call alloc_cons
-        mov [rdx + Cons.car], rax
-        ; Store stack pointer
-        mov [rax], BYTE (block_cons + container_list + content_function)
-        mov [rax + Cons.car], rsi ; stack pointer
-        
-        mov rdx, rax
-        call alloc_cons
-        mov [rdx + Cons.typecdr], BYTE content_pointer
-        mov [rdx + Cons.cdr], rax
-        ; Store function pointer to jump to 
-        mov [rax], BYTE (block_cons + container_list + content_pointer)
-        mov [rax + Cons.car], rdi
-
-        ; Check if there is an object to pass to handler
-        cmp rcx, 0
-        je .done
-
-        ; Set the final CDR to point to the object
-        mov [rax + Cons.typecdr], BYTE content_pointer
-        mov [rax + Cons.cdr], rcx
-
-        mov rsi, rcx
-        call incref_object
-        
-.done:
-        ret
-        
-        
-;; Removes an error handler from the list
-;;
-;; Modifies registers:
-;;    RSI
-;;    RAX
-;;    RCX
-error_handler_pop:
-        ; get the address
-        mov rsi, [error_handler]
-        cmp rsi, 0
-        je .done                ; Nothing to remove
-        
-        push rsi
-        mov rsi, [rsi + Cons.cdr] ; next handler
-        mov [error_handler], rsi
-        call incref_object        ; needed because releasing soon
-        
-        pop rsi                 ; handler being removed
-        call release_cons
-        
-.done:
-        ret
-        
-        
-;; Throw an error
-;;   Object to pass to handler should be in RSI
-error_throw:
-        ; Get the next error handler
-        mov rax, [error_handler]
-        cmp rax, 0
-        je .no_handler
-        
-        ; Got a handler
-        mov rax, [rax + Cons.car] ; handler
-        mov rbx, [rax + Cons.car] ; stack pointer
-        mov rax, [rax + Cons.cdr]
-        mov rcx, [rax + Cons.car] ; function
-        mov rdi, [rax + Cons.cdr] ; data structure
-
-        ; Reset stack
-        mov rsp, rbx
-
-        ; Jump to the handler
-        jmp rcx
-        
-.no_handler:
-        ; Print the object in RSI then quit
-        cmp rsi, 0
-        je .done                ; nothing to print
-        mov rdi, 1              ; print_readably
-        call pr_str
-        mov rsi, rax
-        call print_string
-.done:
-        jmp quit_error
-        
 ;; ----------------------------------------------
 ;; Evaluates a form
 ;;
@@ -1450,6 +1320,8 @@ eval:
         mov rsi, r15
         call incref_object
         pop rax
+
+        ; Binds
         
         call alloc_cons
         mov [rax], BYTE (block_cons + container_function + content_pointer)