author | martin.trojer@nokia.com |
Fri, 31 Jul 2009 15:01:17 +0100 | |
changeset 1 | 2fb8b9db1c86 |
permissions | -rw-r--r-- |
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Initial QEMU (symbian-qemu-0.9.1-12) import
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"""Check for errs in the AST. |
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Initial QEMU (symbian-qemu-0.9.1-12) import
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The Python parser does not catch all syntax errors. Others, like |
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Initial QEMU (symbian-qemu-0.9.1-12) import
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assignments with invalid targets, are caught in the code generation |
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Initial QEMU (symbian-qemu-0.9.1-12) import
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phase. |
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Initial QEMU (symbian-qemu-0.9.1-12) import
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The compiler package catches some errors in the transformer module. |
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But it seems clearer to write checkers that use the AST to detect |
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errors. |
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""" |
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Initial QEMU (symbian-qemu-0.9.1-12) import
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Initial QEMU (symbian-qemu-0.9.1-12) import
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from compiler import ast, walk |
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def check(tree, multi=None): |
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v = SyntaxErrorChecker(multi) |
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walk(tree, v) |
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return v.errors |
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class SyntaxErrorChecker: |
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"""A visitor to find syntax errors in the AST.""" |
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def __init__(self, multi=None): |
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"""Create new visitor object. |
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If optional argument multi is not None, then print messages |
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for each error rather than raising a SyntaxError for the |
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first. |
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""" |
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self.multi = multi |
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self.errors = 0 |
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def error(self, node, msg): |
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self.errors = self.errors + 1 |
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if self.multi is not None: |
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print "%s:%s: %s" % (node.filename, node.lineno, msg) |
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else: |
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raise SyntaxError, "%s (%s:%s)" % (msg, node.filename, node.lineno) |
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def visitAssign(self, node): |
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Initial QEMU (symbian-qemu-0.9.1-12) import
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# the transformer module handles many of these |
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pass |
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## for target in node.nodes: |
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## if isinstance(target, ast.AssList): |
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## if target.lineno is None: |
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## target.lineno = node.lineno |
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## self.error(target, "can't assign to list comprehension") |