Cool_Tools/bemaniutils
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mirror of synced 2024-09-24 03:18:22 +02:00
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Improve compound or detection to get rid of a few more gotos in AFP decompiler.

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This commit is contained in:
Jennifer Taylor 2021-07-15 00:12:36 +00:00
parent 1b0785960b
commit d5a8fbfb4c
2 changed files with 67 additions and 27 deletions
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92
bemani/format/afp/decompile.py
View File

@ -3031,6 +3031,31 @@ class ByteCodeDecompiler(VerboseOutput):
if not changed:
return statements, updated
def __swap_ugly_ifexprs(self, statements: Sequence[Statement]) -> Tuple[List[Statement], bool]:
# Swap if expressions that have a constant on the LHS.
changed: bool = False
def swap_ugly_ifs(statement: Statement) -> Optional[Statement]:
nonlocal changed
if isinstance(statement, IfStatement):
if isinstance(statement.cond, TwoParameterIf):
if (
isinstance(statement.cond.conditional1, (str, int, bool, float, StringConstant)) and
isinstance(statement.cond.conditional2, Expression) and
not isinstance(statement.cond.conditional2, StringConstant)
):
changed = True
return IfStatement(
statement.cond.swap(),
statement.true_statements,
statement.false_statements,
)
return statement
statements = self.__walk(statements, swap_ugly_ifs)
return statements, changed
def __drop_unneeded_else(self, statements: Sequence[Statement]) -> Tuple[List[Statement], bool]:
# If an if has an else, but the last line of the if is a break/continue/return/throw/goto
# then the else body doesn't need to exist, so hoist it up into the parent. If the false
@ -3203,38 +3228,42 @@ class ByteCodeDecompiler(VerboseOutput):
# Finally, simplify it for ease of comparison.
return combined.simplify()
def get_candidate_group(conditional: IfExpr, statement: IfStatement) -> Optional[List[IfStatement]]:
candidate_statements: List[IfStatement] = [statement]
if candidates and (not statement.false_statements) and len(statement.true_statements) == 1:
while True:
# First, is the current combination a valid combined or statement?
candidate_true_expr = get_compound_if(candidate_statements)
candidate_false_expr = candidate_true_expr.invert().simplify()
true_cond = AndIf(conditional, candidate_true_expr).simplify()
false_cond = AndIf(conditional, candidate_false_expr).simplify()
if true_cond in paths and false_cond in paths:
if len(candidate_statements) < 2:
return None
else:
return candidate_statements
# Now, try to add on the next in the layer.
new_candidate = get_child_candidate(candidate_statements[-1])
if new_candidate is None:
# There are no more candidates to try to add.
return None
# Add this to our consideration, retry the logic test.
candidate_statements.append(new_candidate)
return None
i = 0
while i < len(statements):
statement = statements[i]
if isinstance(statement, IfStatement):
# See if this is a compound if pattern.
candidate_statements: List[IfStatement] = [statement]
is_candidate = False
if candidates and (not statement.false_statements) and len(statement.true_statements) == 1:
while True:
# First, is the current combination a valid combined or statement?
candidate_true_expr = get_compound_if(candidate_statements)
candidate_false_expr = candidate_true_expr.invert().simplify()
true_cond = AndIf(parent_conditional, candidate_true_expr).simplify()
false_cond = AndIf(parent_conditional, candidate_false_expr).simplify()
if true_cond in paths and false_cond in paths:
is_candidate = True
break
# Now, try to add on the next in the layer.
new_candidate = get_child_candidate(candidate_statements[-1])
if new_candidate is None:
# There are no more candidates to try to add.
break
# Add this to our consideration, retry the logic test.
candidate_statements.append(new_candidate)
if len(candidate_statements) < 2 or not is_candidate:
candidate_statements = get_candidate_group(parent_conditional, statement)
if candidate_statements is None:
# Move past this statement, we don't care about it.
i += 1
@ -3285,6 +3314,16 @@ class ByteCodeDecompiler(VerboseOutput):
statement = statements[i]
if stmt_to_flow[statement] == false_cond:
false_statements.append(statement)
# Thigs get a little complicated here, on account of the fact that
# we might have scooped up an internal compound or. If that's the
# case, we need to grab its own else clause too.
if isinstance(statement, IfStatement):
# See if this is a compound if pattern.
new_candidate_statements = get_candidate_group(false_cond, statement)
if new_candidate_statements is not None:
false_cond = AndIf(false_cond, get_compound_if(new_candidate_statements).invert()).simplify()
i += 1
else:
# We don't need to include this statement.
@ -3393,6 +3432,7 @@ class ByteCodeDecompiler(VerboseOutput):
self.__convert_loops,
self.__swap_empty_ifs,
self.__drop_unneeded_else,
self.__swap_ugly_ifexprs,
self.__rearrange_compound_ifs,
]:
statements, changed = func(statements)

2
bemani/format/afp/types/expression.py
View File

@ -2204,7 +2204,7 @@ def value_ref(param: Any, parent_prefix: str, parens: bool = False) -> str:
return repr(param.render(parent_prefix))
elif isinstance(param, Expression):
return param.render(parent_prefix, nested=parens)
elif isinstance(param, (str, int, float)):
elif isinstance(param, (str, int, float, bool)):
return repr(param)
else:
raise Exception(f"Unsupported valueref {param} ({type(param)})")