[pypy-commit] pypy release-1.6.x: FrameBlocks are _immutable_, so don't change the 'previous' attribute.

[arigo]

Author: Armin Rigo <arigo at tunes.org>
Branch: release-1.6.x
Changeset: r46466:4287a49c2e04
Date: 2011-08-12 11:59 +0200
http://bitbucket.org/pypy/pypy/changeset/4287a49c2e04/

Log:	FrameBlocks are _immutable_, so don't change the 'previous'
	attribute.

diff --git a/pypy/interpreter/pyframe.py b/pypy/interpreter/pyframe.py
--- a/pypy/interpreter/pyframe.py
+++ b/pypy/interpreter/pyframe.py
@@ -80,7 +80,7 @@
         self.escaped = True
 
     def append_block(self, block):
-        block.previous = self.lastblock
+        assert block.previous is self.lastblock
         self.lastblock = block
 
     def pop_block(self):
@@ -106,7 +106,8 @@
         while i >= 0:
             block = lst[i]
             i -= 1
-            self.append_block(block)
+            block.previous = self.lastblock
+            self.lastblock = block
 
     def get_builtin(self):
         if self.space.config.objspace.honor__builtins__:
diff --git a/pypy/interpreter/pyopcode.py b/pypy/interpreter/pyopcode.py
--- a/pypy/interpreter/pyopcode.py
+++ b/pypy/interpreter/pyopcode.py
@@ -892,16 +892,16 @@
         raise BytecodeCorruption, "old opcode, no longer in use"
 
     def SETUP_LOOP(self, offsettoend, next_instr):
-        block = LoopBlock(self, next_instr + offsettoend)
-        self.append_block(block)
+        block = LoopBlock(self, next_instr + offsettoend, self.lastblock)
+        self.lastblock = block
 
     def SETUP_EXCEPT(self, offsettoend, next_instr):
-        block = ExceptBlock(self, next_instr + offsettoend)
-        self.append_block(block)
+        block = ExceptBlock(self, next_instr + offsettoend, self.lastblock)
+        self.lastblock = block
 
     def SETUP_FINALLY(self, offsettoend, next_instr):
-        block = FinallyBlock(self, next_instr + offsettoend)
-        self.append_block(block)
+        block = FinallyBlock(self, next_instr + offsettoend, self.lastblock)
+        self.lastblock = block
 
     def SETUP_WITH(self, offsettoend, next_instr):
         w_manager = self.peekvalue()
@@ -915,8 +915,8 @@
         w_exit = self.space.get(w_descr, w_manager)
         self.settopvalue(w_exit)
         w_result = self.space.get_and_call_function(w_enter, w_manager)
-        block = WithBlock(self, next_instr + offsettoend)
-        self.append_block(block)
+        block = WithBlock(self, next_instr + offsettoend, self.lastblock)
+        self.lastblock = block
         self.pushvalue(w_result)
 
     def WITH_CLEANUP(self, oparg, next_instr):
@@ -1247,10 +1247,10 @@
 
     _immutable_ = True
 
-    def __init__(self, frame, handlerposition):
+    def __init__(self, frame, handlerposition, previous):
         self.handlerposition = handlerposition
         self.valuestackdepth = frame.valuestackdepth
-        self.previous = None # this makes a linked list of blocks
+        self.previous = previous   # this makes a linked list of blocks
 
     def __eq__(self, other):
         return (self.__class__ is other.__class__ and
diff --git a/pypy/objspace/flow/flowcontext.py b/pypy/objspace/flow/flowcontext.py
--- a/pypy/objspace/flow/flowcontext.py
+++ b/pypy/objspace/flow/flowcontext.py
@@ -406,8 +406,8 @@
         w_exit = self.space.getattr(w_manager, self.space.wrap("__exit__"))
         self.settopvalue(w_exit)
         w_result = self.space.call_method(w_manager, "__enter__")
-        block = WithBlock(self, next_instr + offsettoend)
-        self.append_block(block)
+        block = WithBlock(self, next_instr + offsettoend, self.lastblock)
+        self.lastblock = block
         self.pushvalue(w_result)
 
     # XXX Unimplemented 2.7 opcodes ----------------