def _onStatementAssignmentVariable( self, statement ):
# But now it cannot re-compute anymore:
source = statement.getAssignSource()
if source.willRaiseException( BaseException ):
result = makeStatementExpressionOnlyReplacementNode(
expression = source,
node = statement
)
return result, "new_raise", """\
Removed assignment that has source that will raise."""
variable_ref = statement.getTargetVariableRef()
variable = variable_ref.getVariable()
assert variable is not None
# Assigning from and to the same variable, can be optimized away immediately,
# there is no point in doing it. Exceptions are of course module variables
# that collide with builtin names.
if not variable.isModuleVariableReference() and \
source.isExpressionVariableRef() and \
source.getVariable() == variable:
if source.mayHaveSideEffects( self ):
result = makeStatementExpressionOnlyReplacementNode(
expression = source,
node = statement
)
return result, "new_statements", """\
Reduced assignment of variable from itself to access of it."""
else:
return None, "new_statements", """\
Removed assignment of variable from itself which is known to be defined."""
# If the assignment source has side effects, we can simply evaluate them
# beforehand, we have already visited and evaluated them before.
if source.isExpressionSideEffects():
statements = [
makeStatementExpressionOnlyReplacementNode(
side_effect,
statement
)
for side_effect in
source.getSideEffects()
]
statements.append( statement )
result = makeStatementsSequenceReplacementNode(
statements = statements,
node = statement,
)
source.replaceWith( source.getExpression() )
# Need to update it.
source = statement.getAssignSource()
result = result, "new_statements", """\
Side effects of assignments promoted to statements."""
else:
result = statement, None, None
value_friend = source.getValueFriend( self )
assert value_friend is not None
old_value_friend = None
if variable.isModuleVariableReference():
self.onModuleVariableAssigned( variable, value_friend )
elif variable.isLocalVariable():
self.onLocalVariableAssigned( variable, value_friend )
elif variable.isTempVariableReference():
self.onTempVariableAssigned( variable, value_friend )
if old_value_friend is not None:
old_value_friend.onRelease( self )
return result
def _onStatementAssignmentVariable(self, statement):
# But now it cannot re-compute anymore:
source = statement.getAssignSource()
if source.willRaiseException(BaseException):
result = makeStatementExpressionOnlyReplacementNode(
expression=source, node=statement)
return result, "new_raise", """\
Removed assignment that has source that will raise."""
variable_ref = statement.getTargetVariableRef()
variable = variable_ref.getVariable()
assert variable is not None
# Assigning from and to the same variable, can be optimized away
# immediately, there is no point in doing it. Exceptions are of course
# module variables that collide with builtin names.
if not variable.isModuleVariableReference() and \
source.isExpressionVariableRef() and \
source.getVariable() == variable:
if source.mayHaveSideEffects():
result = makeStatementExpressionOnlyReplacementNode(
expression=source, node=statement)
return result, "new_statements", """\
Reduced assignment of variable from itself to access of it."""
else:
return None, "new_statements", """\
Removed assignment of variable from itself which is known to be defined."""
# If the assignment source has side effects, we can simply evaluate them
# beforehand, we have already visited and evaluated them before.
if source.isExpressionSideEffects():
statements = [
makeStatementExpressionOnlyReplacementNode(
side_effect, statement)
for side_effect in source.getSideEffects()
]
statements.append(statement)
result = makeStatementsSequenceReplacementNode(
statements=statements,
node=statement,
)
source.replaceWith(source.getExpression())
# Need to update it.
source = statement.getAssignSource()
result = result, "new_statements", """\
Side effects of assignments promoted to statements."""
else:
result = statement, None, None
if variable.isModuleVariableReference():
self.onModuleVariableAssigned(variable, source)
elif variable.isLocalVariable():
self.onLocalVariableAssigned(variable, source)
elif variable.isTempVariableReference():
self.onTempVariableAssigned(variable, source)
return result
def _onStatementsFrame( self, statements_sequence ):
assert statements_sequence.isStatementsFrame()
new_statements = []
statements = statements_sequence.getStatements()
assert statements, statements_sequence
for count, statement in enumerate( statements ):
# May be frames embedded.
if statement.isStatementsFrame():
new_statement = self.onStatementsSequence( statement )
else:
new_statement = self.onStatement( statement )
if new_statement is not None:
if new_statement.isStatementsSequence() and not new_statement.isStatementsFrame():
new_statements.extend( new_statement.getStatements() )
else:
new_statements.append( new_statement )
if statement is not statements[-1] and new_statement.isStatementAborting():
self.signalChange(
"new_statements",
statements[ count + 1 ].getSourceReference(),
"Removed dead statements."
)
break
if not new_statements:
return None
outside_pre = []
while new_statements and not new_statements[0].mayRaiseException( BaseException ):
outside_pre.append( new_statements[0] )
del new_statements[0]
outside_post = []
while new_statements and not new_statements[-1].mayRaiseException( BaseException ):
outside_post.insert( 0, new_statements[-1] )
del new_statements[-1]
if outside_pre or outside_post:
if new_statements:
statements_sequence.setStatements( tuple( new_statements ) )
return makeStatementsSequenceReplacementNode(
statements = outside_pre + [ statements_sequence ] + outside_post,
node = statements_sequence
)
else:
return makeStatementsSequenceReplacementNode(
statements = outside_pre + outside_post,
node = statements_sequence
)
else:
if statements != new_statements:
statements_sequence.setStatements( tuple( new_statements ) )
return statements_sequence
def _onStatementsFrame(self, statements_sequence):
assert statements_sequence.isStatementsFrame()
new_statements = []
statements = statements_sequence.getStatements()
assert statements, statements_sequence
for count, statement in enumerate(statements):
# May be frames embedded.
if statement.isStatementsFrame():
new_statement = self.onStatementsSequence(statement)
else:
new_statement = self.onStatement(statement)
if new_statement is not None:
if new_statement.isStatementsSequence(
) and not new_statement.isStatementsFrame():
new_statements.extend(new_statement.getStatements())
else:
new_statements.append(new_statement)
if statement is not statements[
-1] and new_statement.isStatementAborting():
self.signalChange(
"new_statements",
statements[count + 1].getSourceReference(),
"Removed dead statements.")
break
if not new_statements:
return None
outside_pre = []
while new_statements and not new_statements[0].mayRaiseException(
BaseException):
outside_pre.append(new_statements[0])
del new_statements[0]
outside_post = []
while new_statements and not new_statements[-1].mayRaiseException(
BaseException):
outside_post.insert(0, new_statements[-1])
del new_statements[-1]
if outside_pre or outside_post:
if new_statements:
statements_sequence.setStatements(tuple(new_statements))
return makeStatementsSequenceReplacementNode(
statements=outside_pre + [statements_sequence] +
outside_post,
node=statements_sequence)
else:
return makeStatementsSequenceReplacementNode(
statements=outside_pre + outside_post,
node=statements_sequence)
else:
if statements != new_statements:
statements_sequence.setStatements(tuple(new_statements))
return statements_sequence
