add loop handling via
Loop object to handle StackRegs
loops stack attr on CodeGenreeator to hold the current loop object
add support for nodes While, Break, Continue
diff --git a/Lib/compiler/pycodegen.py b/Lib/compiler/pycodegen.py
index 92cbef6..66dd52d 100644
--- a/Lib/compiler/pycodegen.py
+++ b/Lib/compiler/pycodegen.py
@@ -162,6 +162,7 @@
self.code = PythonVMCode(filename=filename)
self.code.setFlags(0)
self.locals = misc.Stack()
+ self.loops = misc.Stack()
self.namespace = self.MODULE_NAMESPACE
self.curStack = 0
self.maxStack = 0
@@ -180,8 +181,6 @@
self.code.setKWArgs()
lnf = walk(func.code, LocalNameFinder(args), 0)
self.locals.push(lnf.getLocals())
-## print func.name, "(", func.argnames, ")"
-## print lnf.getLocals().items()
self.code.setLineNo(func.lineno)
walk(func.code, self)
self.code.emit('LOAD_CONST', None)
@@ -280,6 +279,8 @@
return 1
def visitCallFunc(self, node):
+ if hasattr(node, 'lineno'):
+ self.code.emit('SET_LINENO', node.lineno)
self.visit(node.node)
for arg in node.args:
self.visit(arg)
@@ -306,30 +307,76 @@
after.bind(self.code.getCurInst())
return 1
+ def startLoop(self):
+ l = Loop()
+ self.loops.push(l)
+ self.code.emit('SETUP_LOOP', l.extentAnchor)
+ return l
+
+ def finishLoop(self):
+ l = self.loops.pop()
+ i = self.code.getCurInst()
+ l.extentAnchor.bind(self.code.getCurInst())
+
def visitFor(self, node):
# three refs needed
- start = StackRef()
anchor = StackRef()
- breakAnchor = StackRef()
self.code.emit('SET_LINENO', node.lineno)
- self.code.emit('SETUP_LOOP', breakAnchor)
+ l = self.startLoop()
self.visit(node.list)
self.visit(ast.Const(0))
- start.bind(self.code.getCurInst())
+ l.startAnchor.bind(self.code.getCurInst())
self.code.setLineNo(node.lineno)
self.code.emit('FOR_LOOP', anchor)
self.push(1)
self.visit(node.assign)
self.visit(node.body)
- self.code.emit('JUMP_ABSOLUTE', start)
+ self.code.emit('JUMP_ABSOLUTE', l.startAnchor)
anchor.bind(self.code.getCurInst())
self.code.emit('POP_BLOCK')
if node.else_:
self.visit(node.else_)
- breakAnchor.bind(self.code.getCurInst())
+ self.finishLoop()
return 1
+ def visitWhile(self, node):
+ self.code.emit('SET_LINENO', node.lineno)
+ l = self.startLoop()
+ if node.else_:
+ lElse = StackRef()
+ else:
+ lElse = l.breakAnchor
+ l.startAnchor.bind(self.code.getCurInst())
+ self.code.emit('SET_LINENO', node.test.lineno)
+ self.visit(node.test)
+ self.code.emit('JUMP_IF_FALSE', lElse)
+ self.code.emit('POP_TOP')
+ self.visit(node.body)
+ self.code.emit('JUMP_ABSOLUTE', l.startAnchor)
+ # note that lElse may be an alias for l.breakAnchor
+ lElse.bind(self.code.getCurInst())
+ self.code.emit('POP_TOP')
+ self.code.emit('POP_BLOCK')
+ if node.else_:
+ self.visit(node.else_)
+ self.finishLoop()
+ return 1
+
+ def visitBreak(self, node):
+ if not self.loops:
+ raise SyntaxError, "'break' outside loop"
+ self.code.emit('SET_LINENO', node.lineno)
+ self.code.emit('BREAK_LOOP')
+
+ def visitContinue(self, node):
+ if not self.loops:
+ raise SyntaxError, "'continue' outside loop"
+ l = self.loops.top()
+ self.code.emit('SET_LINENO', node.lineno)
+ self.code.emit('JUMP_ABSOLUTE', l.startAnchor)
+
+
def visitCompare(self, node):
"""Comment from compile.c follows:
@@ -617,11 +664,11 @@
def visitAssName(self, node):
self.names.add(node.name)
-class Label:
- def __init__(self, num):
- self.num = num
- def __repr__(self):
- return "Label(%d)" % self.num
+class Loop:
+ def __init__(self):
+ self.startAnchor = StackRef()
+ self.breakAnchor = StackRef()
+ self.extentAnchor = StackRef()
class StackRef:
"""Manage stack locations for jumps, loops, etc."""
@@ -644,6 +691,9 @@
self.val = inst
def resolve(self):
+ if self.val is None:
+ print "UNRESOLVE REF", self
+ return 0
return self.val
def add_hook(hooks, type, meth):