1 files changed, 172 insertions, 0 deletions
diff --git a/util/sconfig/yappsrt.py b/util/sconfig/yappsrt.py
new file mode 100644
index 0000000000..2ce2480f08
--- /dev/null
+++ b/util/sconfig/yappsrt.py
@@ -0,0 +1,172 @@
+# Yapps 2.0 Runtime
+#
+# This module is needed to run generated parsers.
+
+from string import *
+import exceptions
+import re
+
+class SyntaxError(Exception):
+    """When we run into an unexpected token, this is the exception to use"""
+    def __init__(self, pos=-1, msg="Bad Token"):
+	self.pos = pos
+	self.msg = msg
+    def __repr__(self):
+	if self.pos < 0: return "#<syntax-error>"
+	else: return "SyntaxError[@ char " + `self.pos` + ": " + self.msg + "]"
+
+class NoMoreTokens(Exception):
+    """Another exception object, for when we run out of tokens"""
+    pass
+
+class Scanner:
+    def __init__(self, patterns, ignore, input):
+	"""Patterns is [(terminal,regex)...]
+        Ignore is [terminal,...];
+	Input is a string"""
+	self.tokens = []
+	self.restrictions = []
+	self.input = input
+	self.pos = 0
+	self.ignore = ignore
+	# The stored patterns are a pair (compiled regex,source
+	# regex).  If the patterns variable passed in to the
+	# constructor is None, we assume that the class already has a
+	# proper .patterns list constructed
+        if patterns is not None:
+            self.patterns = []
+            for k,r in patterns:
+                self.patterns.append( (k, re.compile(r)) )
+	
+    def token(self, i, restrict=0):
+	"""Get the i'th token, and if i is one past the end, then scan 
+	for another token; restrict is a list of tokens that
+	are allowed, or 0 for any token."""
+	if i == len(self.tokens): self.scan(restrict)
+	if i < len(self.tokens):
+	    # Make sure the restriction is more restricted
+	    if restrict and self.restrictions[i]:
+		for r in restrict:
+		    if r not in self.restrictions[i]:
+			raise "Unimplemented: restriction set changed"
+	    return self.tokens[i]
+	raise NoMoreTokens()
+    
+    def __repr__(self):
+	"""Print the last 10 tokens that have been scanned in"""
+	output = ''
+	for t in self.tokens[-10:]:
+	    output = '%s\n  (@%s)  %s  =  %s' % (output,t[0],t[2],`t[3]`)
+	return output
+    
+    def scan(self, restrict):
+	"""Should scan another token and add it to the list, self.tokens,
+	and add the restriction to self.restrictions"""
+	# Keep looking for a token, ignoring any in self.ignore
+	while 1:
+	    # Search the patterns for the longest match, with earlier
+	    # tokens in the list having preference
+	    best_match = -1
+	    best_pat = '(error)'
+	    for p, regexp in self.patterns:
+		# First check to see if we're ignoring this token
+		if restrict and p not in restrict and p not in self.ignore: 
+		    continue
+		m = regexp.match(self.input, self.pos)
+		if m and len(m.group(0)) > best_match:
+		    # We got a match that's better than the previous one
+		    best_pat = p
+		    best_match = len(m.group(0))
+		    
+	    # If we didn't find anything, raise an error
+	    if best_pat == '(error)' and best_match < 0:
+		msg = "Bad Token"
+		if restrict:
+		    msg = "Trying to find one of "+join(restrict,", ")
+		raise SyntaxError(self.pos, msg)
+
+	    # If we found something that isn't to be ignored, return it
+	    if best_pat not in self.ignore:
+		# Create a token with this data
+		token = (self.pos, self.pos+best_match, best_pat,
+			 self.input[self.pos:self.pos+best_match])
+		self.pos = self.pos + best_match
+		# Only add this token if it's not in the list
+		# (to prevent looping)
+		if not self.tokens or token != self.tokens[-1]:
+		    self.tokens.append(token)
+		    self.restrictions.append(restrict)
+		return
+	    else:
+		# This token should be ignored ..
+		self.pos = self.pos + best_match
+
+class Parser:
+    def __init__(self, scanner):
+        self._scanner = scanner
+        self._pos = 0
+        
+    def _peek(self, *types):
+        """Returns the token type for lookahead; if there are any args
+        then the list of args is the set of token types to allow"""
+        tok = self._scanner.token(self._pos, types)
+        return tok[2]
+        
+    def _scan(self, type):
+        """Returns the matched text, and moves to the next token"""
+        tok = self._scanner.token(self._pos, [type])
+        if tok[2] != type:
+            raise SyntaxError(tok[0], 'Trying to find '+type)
+        self._pos = 1+self._pos
+        return tok[3]
+
+
+
+def print_error(input, err, scanner):
+    """This is a really dumb long function to print error messages nicely."""
+    p = err.pos
+    # Figure out the line number
+    line = count(input[:p], '\n')
+    print err.msg+" on line "+`line+1`+":"
+    # Now try printing part of the line
+    text = input[max(p-80,0):p+80]
+    p = p - max(p-80,0)
+
+    # Strip to the left
+    i = rfind(text[:p],'\n')
+    j = rfind(text[:p],'\r')
+    if i < 0 or (j < i and j >= 0): i = j
+    if i >= 0 and i < p: 
+	p = p - i - 1
+	text = text[i+1:]
+
+    # Strip to the right
+    i = find(text,'\n',p)
+    j = find(text,'\r',p)
+    if i < 0 or (j < i and j >= 0): i = j
+    if i >= 0: 
+	text = text[:i]
+
+    # Now shorten the text
+    while len(text) > 70 and p > 60:
+	# Cut off 10 chars
+	text = "..." + text[10:]
+	p = p - 7
+
+    # Now print the string, along with an indicator
+    print '> ',text
+    print '> ',' '*p + '^'
+    print 'List of nearby tokens:', scanner
+
+def wrap_error_reporter(parser, rule):
+    try: return getattr(parser, rule)()
+    except SyntaxError, s:
+        input = parser._scanner.input
+        try:
+            print_error(input, s, parser._scanner)
+        except ImportError:
+            print 'Syntax Error',s.msg,'on line',1+count(input[:s.pos], '\n')
+    except NoMoreTokens:
+        print 'Could not complete parsing; stopped around here:'
+        print parser._scanner
+