739351d476
Change log:95336cb92b..191d55580eFull diff:95336cb92b..191d55580eRoll chromium third_party 4e16929f46..3a8f2a9e1e Change log:4e16929f46..3a8f2a9e1eChanged dependencies: * src/tools:c44a3f5eca..f524a53b81DEPS diff:95336cb92b..191d55580e/DEPS No update to Clang. TBR=titovartem@google.com, BUG=None CQ_INCLUDE_TRYBOTS=master.internal.tryserver.corp.webrtc:linux_internal Change-Id: Ic9c4a62b050383646e9fcf5cc07a5653c14ac06e Reviewed-on: https://webrtc-review.googlesource.com/76120 Reviewed-by: Patrik Höglund <phoglund@webrtc.org> Reviewed-by: Karl Wiberg <kwiberg@webrtc.org> Reviewed-by: Artem Titov <titovartem@webrtc.org> Commit-Queue: Artem Titov <titovartem@webrtc.org> Cr-Commit-Position: refs/heads/master@{#23205}
50 lines
1.7 KiB
Python
50 lines
1.7 KiB
Python
# -*- coding: utf-8 -*-
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"""
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jinja2.optimizer
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~~~~~~~~~~~~~~~~
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The jinja optimizer is currently trying to constant fold a few expressions
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and modify the AST in place so that it should be easier to evaluate it.
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Because the AST does not contain all the scoping information and the
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compiler has to find that out, we cannot do all the optimizations we
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want. For example loop unrolling doesn't work because unrolled loops would
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have a different scoping.
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The solution would be a second syntax tree that has the scoping rules stored.
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:copyright: (c) 2017 by the Jinja Team.
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:license: BSD.
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"""
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from jinja2 import nodes
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from jinja2.visitor import NodeTransformer
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def optimize(node, environment):
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"""The context hint can be used to perform an static optimization
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based on the context given."""
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optimizer = Optimizer(environment)
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return optimizer.visit(node)
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class Optimizer(NodeTransformer):
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def __init__(self, environment):
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self.environment = environment
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def fold(self, node, eval_ctx=None):
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"""Do constant folding."""
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node = self.generic_visit(node)
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try:
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return nodes.Const.from_untrusted(node.as_const(eval_ctx),
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lineno=node.lineno,
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environment=self.environment)
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except nodes.Impossible:
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return node
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visit_Add = visit_Sub = visit_Mul = visit_Div = visit_FloorDiv = \
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visit_Pow = visit_Mod = visit_And = visit_Or = visit_Pos = visit_Neg = \
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visit_Not = visit_Compare = visit_Getitem = visit_Getattr = visit_Call = \
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visit_Filter = visit_Test = visit_CondExpr = fold
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del fold
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