Author: Carl Friedrich Bolz-Tereick <cfb...@gmx.de>
Branch: pyparser-improvements
Changeset: r93980:1c51dd151fee
Date: 2018-03-16 13:18 +0100
http://bitbucket.org/pypy/pypy/changeset/1c51dd151fee/
Log: improve error messages of ParseError
only covers very simple cases, but at least if tells you about
forgotten ':' in the line starting a block, which is the syntax
error I always make.
diff --git a/pypy/interpreter/pyparser/metaparser.py
b/pypy/interpreter/pyparser/metaparser.py
--- a/pypy/interpreter/pyparser/metaparser.py
+++ b/pypy/interpreter/pyparser/metaparser.py
@@ -164,6 +164,13 @@
else:
gram.labels.append(gram.symbol_ids[label])
gram.symbol_to_label[label] = label_index
+ first = self.first[label]
+ if len(first) == 1:
+ first, = first
+ if not first[0].isupper():
+ first = first.strip("\"'")
+ assert label_index not in
gram.token_to_error_string
+ gram.token_to_error_string[label_index] = first
return label_index
elif label.isupper():
token_index = gram.TOKENS[label]
@@ -185,7 +192,7 @@
else:
gram.labels.append(gram.KEYWORD_TOKEN)
gram.keyword_ids[value] = label_index
- return label_index
+ result = label_index
else:
try:
token_index = gram.OPERATOR_MAP[value]
@@ -196,7 +203,10 @@
else:
gram.labels.append(token_index)
gram.token_ids[token_index] = label_index
- return label_index
+ result = label_index
+ assert result not in gram.token_to_error_string
+ gram.token_to_error_string[result] = value
+ return result
def make_first(self, gram, name):
original_firsts = self.first[name]
diff --git a/pypy/interpreter/pyparser/parser.py
b/pypy/interpreter/pyparser/parser.py
--- a/pypy/interpreter/pyparser/parser.py
+++ b/pypy/interpreter/pyparser/parser.py
@@ -17,6 +17,7 @@
self.symbol_names = {}
self.symbol_to_label = {}
self.keyword_ids = {}
+ self.token_to_error_string = {}
self.dfas = []
self.labels = [0]
self.token_ids = {}
@@ -193,7 +194,7 @@
class ParseError(Exception):
def __init__(self, msg, token_type, value, lineno, column, line,
- expected=-1):
+ expected=-1, expected_str=None):
self.msg = msg
self.token_type = token_type
self.value = value
@@ -201,6 +202,7 @@
self.column = column
self.line = line
self.expected = expected
+ self.expected_str = expected_str
def __str__(self):
return "ParserError(%s, %r)" % (self.token_type, self.value)
@@ -293,10 +295,13 @@
# error.
if len(arcs) == 1:
expected = sym_id
+ expected_str = self.grammar.token_to_error_string.get(
+ arcs[0][0], None)
else:
expected = -1
+ expected_str = None
raise ParseError("bad input", token_type, value, lineno,
- column, line, expected)
+ column, line, expected, expected_str)
def classify(self, token_type, value, lineno, column, line):
"""Find the label for a token."""
diff --git a/pypy/interpreter/pyparser/pyparse.py
b/pypy/interpreter/pyparser/pyparse.py
--- a/pypy/interpreter/pyparser/pyparse.py
+++ b/pypy/interpreter/pyparser/pyparse.py
@@ -185,6 +185,9 @@
else:
new_err = error.SyntaxError
msg = "invalid syntax"
+ if e.expected_str is not None:
+ msg += " (expected '%s')" % e.expected_str
+
raise new_err(msg, e.lineno, e.column, e.line,
compile_info.filename)
else:
diff --git a/pypy/interpreter/pyparser/test/test_parser.py
b/pypy/interpreter/pyparser/test/test_parser.py
--- a/pypy/interpreter/pyparser/test/test_parser.py
+++ b/pypy/interpreter/pyparser/test/test_parser.py
@@ -321,3 +321,12 @@
assert isinstance(tree.get_child(1), parser.Nonterminal1)
+ def test_error_string(self):
+ p, gram = self.parser_for(
+ "foo: 'if' NUMBER '+' NUMBER"
+ )
+ info = py.test.raises(parser.ParseError, p.parse, "if 42")
+ info.value.expected_str is None
+ info = py.test.raises(parser.ParseError, p.parse, "if 42 42")
+ info.value.expected_str == '+'
+
diff --git a/pypy/interpreter/pyparser/test/test_pyparse.py
b/pypy/interpreter/pyparser/test/test_pyparse.py
--- a/pypy/interpreter/pyparser/test/test_pyparse.py
+++ b/pypy/interpreter/pyparser/test/test_pyparse.py
@@ -165,3 +165,11 @@
for linefeed in ["\r\n","\r"]:
tree = self.parse(fmt % linefeed)
assert expected_tree == tree
+
+ def test_error_forgotten_chars(self):
+ info = py.test.raises(SyntaxError, self.parse, "if 1\n print 4")
+ assert "(expected ':')" in info.value.msg
+ info = py.test.raises(SyntaxError, self.parse, "for i in range(10)\n
print i")
+ assert "(expected ':')" in info.value.msg
+ info = py.test.raises(SyntaxError, self.parse, "def f:\n print 1")
+ assert "(expected '(')" in info.value.msg
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