author | Deepak Modgil <Deepak.Modgil@Nokia.com> |
Fri, 03 Apr 2009 17:19:34 +0100 | |
changeset 0 | ae805ac0140d |
permissions | -rw-r--r-- |
0
ae805ac0140d
DP tools release version Revision: 200912
Deepak Modgil <Deepak.Modgil@Nokia.com>
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1 |
"""Check for errs in the AST. |
ae805ac0140d
DP tools release version Revision: 200912
Deepak Modgil <Deepak.Modgil@Nokia.com>
parents:
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ae805ac0140d
DP tools release version Revision: 200912
Deepak Modgil <Deepak.Modgil@Nokia.com>
parents:
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The Python parser does not catch all syntax errors. Others, like |
ae805ac0140d
DP tools release version Revision: 200912
Deepak Modgil <Deepak.Modgil@Nokia.com>
parents:
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4 |
assignments with invalid targets, are caught in the code generation |
ae805ac0140d
DP tools release version Revision: 200912
Deepak Modgil <Deepak.Modgil@Nokia.com>
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phase. |
ae805ac0140d
DP tools release version Revision: 200912
Deepak Modgil <Deepak.Modgil@Nokia.com>
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ae805ac0140d
DP tools release version Revision: 200912
Deepak Modgil <Deepak.Modgil@Nokia.com>
parents:
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7 |
The compiler package catches some errors in the transformer module. |
ae805ac0140d
DP tools release version Revision: 200912
Deepak Modgil <Deepak.Modgil@Nokia.com>
parents:
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But it seems clearer to write checkers that use the AST to detect |
ae805ac0140d
DP tools release version Revision: 200912
Deepak Modgil <Deepak.Modgil@Nokia.com>
parents:
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errors. |
ae805ac0140d
DP tools release version Revision: 200912
Deepak Modgil <Deepak.Modgil@Nokia.com>
parents:
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""" |
ae805ac0140d
DP tools release version Revision: 200912
Deepak Modgil <Deepak.Modgil@Nokia.com>
parents:
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ae805ac0140d
DP tools release version Revision: 200912
Deepak Modgil <Deepak.Modgil@Nokia.com>
parents:
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12 |
from compiler import ast, walk |
ae805ac0140d
DP tools release version Revision: 200912
Deepak Modgil <Deepak.Modgil@Nokia.com>
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ae805ac0140d
DP tools release version Revision: 200912
Deepak Modgil <Deepak.Modgil@Nokia.com>
parents:
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14 |
def check(tree, multi=None): |
ae805ac0140d
DP tools release version Revision: 200912
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v = SyntaxErrorChecker(multi) |
ae805ac0140d
DP tools release version Revision: 200912
Deepak Modgil <Deepak.Modgil@Nokia.com>
parents:
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walk(tree, v) |
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return v.errors |
ae805ac0140d
DP tools release version Revision: 200912
Deepak Modgil <Deepak.Modgil@Nokia.com>
parents:
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ae805ac0140d
DP tools release version Revision: 200912
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parents:
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19 |
class SyntaxErrorChecker: |
ae805ac0140d
DP tools release version Revision: 200912
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parents:
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"""A visitor to find syntax errors in the AST.""" |
ae805ac0140d
DP tools release version Revision: 200912
Deepak Modgil <Deepak.Modgil@Nokia.com>
parents:
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ae805ac0140d
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parents:
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def __init__(self, multi=None): |
ae805ac0140d
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Deepak Modgil <Deepak.Modgil@Nokia.com>
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"""Create new visitor object. |
ae805ac0140d
DP tools release version Revision: 200912
Deepak Modgil <Deepak.Modgil@Nokia.com>
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ae805ac0140d
DP tools release version Revision: 200912
Deepak Modgil <Deepak.Modgil@Nokia.com>
parents:
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If optional argument multi is not None, then print messages |
ae805ac0140d
DP tools release version Revision: 200912
Deepak Modgil <Deepak.Modgil@Nokia.com>
parents:
diff
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|
26 |
for each error rather than raising a SyntaxError for the |
ae805ac0140d
DP tools release version Revision: 200912
Deepak Modgil <Deepak.Modgil@Nokia.com>
parents:
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first. |
ae805ac0140d
DP tools release version Revision: 200912
Deepak Modgil <Deepak.Modgil@Nokia.com>
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""" |
ae805ac0140d
DP tools release version Revision: 200912
Deepak Modgil <Deepak.Modgil@Nokia.com>
parents:
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self.multi = multi |
ae805ac0140d
DP tools release version Revision: 200912
Deepak Modgil <Deepak.Modgil@Nokia.com>
parents:
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self.errors = 0 |
ae805ac0140d
DP tools release version Revision: 200912
Deepak Modgil <Deepak.Modgil@Nokia.com>
parents:
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ae805ac0140d
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parents:
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32 |
def error(self, node, msg): |
ae805ac0140d
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self.errors = self.errors + 1 |
ae805ac0140d
DP tools release version Revision: 200912
Deepak Modgil <Deepak.Modgil@Nokia.com>
parents:
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34 |
if self.multi is not None: |
ae805ac0140d
DP tools release version Revision: 200912
Deepak Modgil <Deepak.Modgil@Nokia.com>
parents:
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print "%s:%s: %s" % (node.filename, node.lineno, msg) |
ae805ac0140d
DP tools release version Revision: 200912
Deepak Modgil <Deepak.Modgil@Nokia.com>
parents:
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else: |
ae805ac0140d
DP tools release version Revision: 200912
Deepak Modgil <Deepak.Modgil@Nokia.com>
parents:
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raise SyntaxError, "%s (%s:%s)" % (msg, node.filename, node.lineno) |
ae805ac0140d
DP tools release version Revision: 200912
Deepak Modgil <Deepak.Modgil@Nokia.com>
parents:
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|
ae805ac0140d
DP tools release version Revision: 200912
Deepak Modgil <Deepak.Modgil@Nokia.com>
parents:
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def visitAssign(self, node): |
ae805ac0140d
DP tools release version Revision: 200912
Deepak Modgil <Deepak.Modgil@Nokia.com>
parents:
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40 |
# the transformer module handles many of these |
ae805ac0140d
DP tools release version Revision: 200912
Deepak Modgil <Deepak.Modgil@Nokia.com>
parents:
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pass |
ae805ac0140d
DP tools release version Revision: 200912
Deepak Modgil <Deepak.Modgil@Nokia.com>
parents:
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## for target in node.nodes: |
ae805ac0140d
DP tools release version Revision: 200912
Deepak Modgil <Deepak.Modgil@Nokia.com>
parents:
diff
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43 |
## if isinstance(target, ast.AssList): |
ae805ac0140d
DP tools release version Revision: 200912
Deepak Modgil <Deepak.Modgil@Nokia.com>
parents:
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## if target.lineno is None: |
ae805ac0140d
DP tools release version Revision: 200912
Deepak Modgil <Deepak.Modgil@Nokia.com>
parents:
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|
45 |
## target.lineno = node.lineno |
ae805ac0140d
DP tools release version Revision: 200912
Deepak Modgil <Deepak.Modgil@Nokia.com>
parents:
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46 |
## self.error(target, "can't assign to list comprehension") |