[zvm commit] r207 - trunk/zvm
codesite...@google.com
Date: Mon Jul 21 22:29:27 2008
New Revision: 207
Modified:
trunk/zvm/zcpu.py
Log:
* zvm/zcpu.py (ZCpu.op_jump): fix off-by-2 error. See comment.
Also, explicitly raise 'NotImplemented' errors on opcodes we haven't
written yet. This makes it much easier to figure out where we're
going wrong when we crash.
Modified: trunk/zvm/zcpu.py
==============================================================================
--- trunk/zvm/zcpu.py (original)
+++ trunk/zvm/zcpu.py Mon Jul 21 22:29:27 2008
@@ -26,6 +26,9 @@
class ZCpuDivideByZero(ZCpuError):
"Divide by zero error"
+class ZCpuNotImplemented(ZCpuError):
+ "Opcode not yet implemented"
+
class ZCpu(object):
def __init__(self, zmem, zopdecoder, zstack, zobjects, zstring, zui):
self._memory = zmem
@@ -156,7 +159,7 @@
log("Execution started")
while True:
current_pc = self._opdecoder.program_counter
- log("Next opcode %x" % current_pc)
+ log("Reading next opcode at address %x" % current_pc)
(opcode_class, opcode_number,
operands) = self._opdecoder.get_next_instruction()
implemented, func = self._get_handler(opcode_class,
@@ -190,7 +193,8 @@
def op_jg(self, *args):
"""TODO: Write docstring here."""
-
+ raise ZCpuNotImplemented
+
def op_dec_chk(self, variable, test_value):
"""Decrement the variable, and branch if the value becomes
less than test_value."""
@@ -209,9 +213,11 @@
def op_jin(self, *args):
"""TODO: Write docstring here."""
+ raise ZCpuNotImplemented
def op_test(self, *args):
"""TODO: Write docstring here."""
+ raise ZCpuNotImplemented
def op_or(self, a, b):
"""Bitwise OR between the two arguments."""
@@ -223,24 +229,27 @@
def op_test_attr(self, *args):
"""TODO: Write docstring here."""
-
+ raise ZCpuNotImplemented
+
def op_set_attr(self, *args):
"""TODO: Write docstring here."""
-
+ raise ZCpuNotImplemented
+
def op_clear_attr(self, *args):
"""TODO: Write docstring here."""
-
+ raise ZCpuNotImplemented
+
def op_store(self, variable, value):
"""Store the given value to the given variable."""
self._write_result(value, store_addr=variable)
def op_insert_obj(self, *args):
"""TODO: Write docstring here."""
+ raise ZCpuNotImplemented
def op_loadw(self, base, offset):
"""Store in the given result register the word value at
(base+2*offset)."""
-
val = self._memory.read_word(base + 2*offset)
self._write_result(val)
@@ -252,13 +261,16 @@
def op_get_prop(self, *args):
"""TODO: Write docstring here."""
+ raise ZCpuNotImplemented
def op_get_prop_addr(self, *args):
"""TODO: Write docstring here."""
-
+ raise ZCpuNotImplemented
+
def op_get_next_prop(self, *args):
"""TODO: Write docstring here."""
-
+ raise ZCpuNotImplemented
+
def op_add(self, a, b):
"""Signed 16-bit addition."""
result = self._unmake_signed(
@@ -287,18 +299,23 @@
def op_mod(self, *args):
"""TODO: Write docstring here."""
-
+ raise ZCpuNotImplemented
+
def op_call_2s(self, *args):
"""TODO: Write docstring here."""
-
+ raise ZCpuNotImplemented
+
def op_call_2n(self, *args):
"""TODO: Write docstring here."""
+ raise ZCpuNotImplemented
def op_set_colour(self, *args):
"""TODO: Write docstring here."""
+ raise ZCpuNotImplemented
def op_throw(self, *args):
"""TODO: Write docstring here."""
+ raise ZCpuNotImplemented
## 1OP opcodes (opcodes 128-175)
@@ -308,15 +325,19 @@
def op_get_sibling(self, *args):
"""TODO: Write docstring here."""
+ raise ZCpuNotImplemented
def op_get_child(self, *args):
"""TODO: Write docstring here."""
+ raise ZCpuNotImplemented
def op_get_parent(self, *args):
"""TODO: Write docstring here."""
+ raise ZCpuNotImplemented
def op_get_prop_len(self, *args):
"""TODO: Write docstring here."""
+ raise ZCpuNotImplemented
def op_inc(self, variable):
"""Increment the given value."""
@@ -326,9 +347,11 @@
def op_dec(self, *args):
"""TODO: Write docstring here."""
+ raise ZCpuNotImplemented
def op_print_addr(self, string_byte_address):
"""TODO: Write docstring here."""
+ raise ZCpuNotImplemented
def op_call_1s(self, routine_address):
"""Call the given routine and store the return value."""
@@ -336,24 +359,37 @@
def op_remove_obj(self, *args):
"""TODO: Write docstring here."""
+ raise ZCpuNotImplemented
def op_print_obj(self, *args):
"""TODO: Write docstring here."""
+ raise ZCpuNotImplemented
def op_ret(self, *args):
"""TODO: Write docstring here."""
+ raise ZCpuNotImplemented
def op_jump(self, offset):
"""Jump unconditionally to the given branch offset. This
opcode does not follow the usual branch decision algorithm,
and so we do not call the _branch method to dispatch the call."""
+
+ old_pc = self._opdecoder.program_counter
+
# The offset to the jump instruction is known to be a 2-byte
# signed integer. We need to make it signed before applying
# the offset.
if (offset >= 2**15):
- offset = - 2**16 + offset
- log("Jump unconditionally to offset %d" % offset)
- self._opdecoder.program_counter += offset
+ offset = - 2**16 + offset
+ log("Jump unconditionally to relative offset %d" % offset)
+
+ # Apparently reading the 2 bytes of operand *isn't* supposed
+ # to increment the PC, thus we need to apply this offset to PC
+ # that's still pointing at the 'jump' opcode. Hence the -2
+ # modifier below.
+ new_pc = self._opdecoder.program_counter + offset - 2
+ self._opdecoder.program_counter = new_pc
+ log("PC has changed from from %x to %x" % (old_pc, new_pc))
def op_print_paddr(self, string_paddr):
@@ -364,11 +400,11 @@
def op_load(self, *args):
"""TODO: Write docstring here."""
-
+ raise ZCpuNotImplemented
def op_not(self, *args):
"""TODO: Write docstring here."""
-
+ raise ZCpuNotImplemented
def op_call_1n(self, routine_addr):
"""Call the given routine, and discard the return value."""
@@ -379,11 +415,11 @@
def op_rtrue(self, *args):
"""TODO: Write docstring here."""
-
+ raise ZCpuNotImplemented
def op_rfalse(self, *args):
"""TODO: Write docstring here."""
-
+ raise ZCpuNotImplemented
def op_print(self):
"""Print the embedded ZString."""
@@ -392,63 +428,63 @@
def op_print_ret(self, *args):
"""TODO: Write docstring here."""
-
+ raise ZCpuNotImplemented
def op_nop(self, *args):
"""TODO: Write docstring here."""
-
+ raise ZCpuNotImplemented
def op_save(self, *args):
"""TODO: Write docstring here."""
-
+ raise ZCpuNotImplemented
def op_save_v4(self, *args):
"""TODO: Write docstring here."""
-
+ raise ZCpuNotImplemented
def op_restore(self, *args):
"""TODO: Write docstring here."""
-
+ raise ZCpuNotImplemented
def op_restore_v4(self, *args):
"""TODO: Write docstring here."""
-
+ raise ZCpuNotImplemented
def op_restart(self, *args):
"""TODO: Write docstring here."""
-
+ raise ZCpuNotImplemented
def op_ret_popped(self, *args):
"""TODO: Write docstring here."""
-
+ raise ZCpuNotImplemented
def op_pop(self, *args):
"""TODO: Write docstring here."""
-
+ raise ZCpuNotImplemented
def op_catch(self, *args):
"""TODO: Write docstring here."""
-
+ raise ZCpuNotImplemented
def op_quit(self, *args):
"""TODO: Write docstring here."""
-
+ raise ZCpuNotImplemented
def op_new_line(self, *args):
"""TODO: Write docstring here."""
-
+ raise ZCpuNotImplemented
def op_show_status(self, *args):
"""TODO: Write docstring here."""
-
+ raise ZCpuNotImplemented
def op_verify(self, *args):
"""TODO: Write docstring here."""
-
+ raise ZCpuNotImplemented
def op_piracy(self, *args):
"""TODO: Write docstring here."""
-
+ raise ZCpuNotImplemented
## VAR opcodes (opcodes 224-255)
@@ -488,11 +524,11 @@
def op_sread_v4(self, *args):
"""TODO: Write docstring here."""
-
+ raise ZCpuNotImplemented
def op_aread(self, *args):
"""TODO: Write docstring here."""
-
+ raise ZCpuNotImplemented
def op_print_char(self, char):
"""Output the given ZSCII character."""
@@ -500,7 +536,7 @@
def op_print_num(self, *args):
"""TODO: Write docstring here."""
-
+ raise ZCpuNotImplemented
def op_random(self, n):
"""Generate a random number, or seed the PRNG.
@@ -525,11 +561,11 @@
def op_push(self, *args):
"""TODO: Write docstring here."""
-
+ raise ZCpuNotImplemented
def op_pull(self, *args):
"""TODO: Write docstring here."""
-
+ raise ZCpuNotImplemented
def op_split_window(self, height):
"""Split or unsplit the window horizontally."""
@@ -543,7 +579,7 @@
def op_call_vs2(self, *args):
"""TODO: Write docstring here."""
-
+ raise ZCpuNotImplemented
def op_erase_window(self, window_number):
"""Clear the window with the given number. If # is -1, unsplit
@@ -560,7 +596,7 @@
def op_erase_line(self, *args):
"""TODO: Write docstring here."""
-
+ raise ZCpuNotImplemented
def op_set_cursor(self, x, y):
"""Set the cursor position within the active window."""
@@ -569,7 +605,7 @@
def op_get_cursor(self, *args):
"""TODO: Write docstring here."""
-
+ raise ZCpuNotImplemented
def op_set_text_style(self, text_style):
"""Set the text style."""
@@ -584,99 +620,100 @@
def op_output_stream(self, *args):
"""TODO: Write docstring here."""
-
+ raise ZCpuNotImplemented
def op_output_stream_v5(self, *args):
"""TODO: Write docstring here."""
-
+ raise ZCpuNotImplemented
def op_input_stream(self, *args):
"""TODO: Write docstring here."""
-
+ raise ZCpuNotImplemented
# This one may have been used prematurely in v3 stories. Keep an
# eye out for it if we ever get bug reports.
def op_sound_effect(self, *args):
"""TODO: Write docstring here."""
-
+ raise ZCpuNotImplemented
def op_read_char(self, *args):
"""TODO: Write docstring here."""
-
+ raise ZCpuNotImplemented
def op_scan_table(self, *args):
"""TODO: Write docstring here."""
-
+ raise ZCpuNotImplemented
def op_not_v5(self, *args):
"""TODO: Write docstring here."""
-
+ raise ZCpuNotImplemented
def op_call_vn(self, *args):
"""TODO: Write docstring here."""
-
+ raise ZCpuNotImplemented
def op_call_vn2(self, *args):
"""TODO: Write docstring here."""
-
+ raise ZCpuNotImplemented
def op_tokenize(self, *args):
"""TODO: Write docstring here."""
-
+ raise ZCpuNotImplemented
def op_encode_text(self, *args):
"""TODO: Write docstring here."""
-
+ raise ZCpuNotImplemented
def op_copy_table(self, *args):
"""TODO: Write docstring here."""
-
+ raise ZCpuNotImplemented
def op_print_table(self, *args):
"""TODO: Write docstring here."""
-
+ raise ZCpuNotImplemented
def op_check_arg_count(self, *args):
"""TODO: Write docstring here."""
-
+ raise ZCpuNotImplemented
## EXT opcodes (opcodes 256-284)
def op_save_v5(self, *args):
"""TODO: Write docstring here."""
-
+ raise ZCpuNotImplemented
def op_restore_v5(self, *args):
"""TODO: Write docstring here."""
-
+ raise ZCpuNotImplemented
def op_log_shift(self, *args):
"""TODO: Write docstring here."""
-
+ raise ZCpuNotImplemented
def op_art_shift(self, *args):
"""TODO: Write docstring here."""
-
+ raise ZCpuNotImplemented
def op_set_font(self, *args):
"""TODO: Write docstring here."""
-
+ raise ZCpuNotImplemented
def op_save_undo(self, *args):
"""TODO: Write docstring here."""
-
+ raise ZCpuNotImplemented
def op_restore_undo(self, *args):
"""TODO: Write docstring here."""
-
+ raise ZCpuNotImplemented
def op_print_unicode(self, *args):
"""TODO: Write docstring here."""
-
+ raise ZCpuNotImplemented
def op_check_unicode(self, *args):
"""TODO: Write docstring here."""
-
+ raise ZCpuNotImplemented
+
# Declaration of the opcode tables. In a Z-Machine, opcodes are
# divided into tables based on the operand type. Within each
# table, the operand is then indexed by its number. We preserve