#!/usr/bin/env python
# Copyright 2012 The Chromium Authors
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
""" Lexer for PPAPI IDL """
#
# IDL Lexer
#
# The lexer is uses the PLY lex library to build a tokenizer which understands
# WebIDL tokens.
#
# WebIDL, and WebIDL regular expressions can be found at:
# http://dev.w3.org/2006/webapi/WebIDL/
# PLY can be found at:
# http://www.dabeaz.com/ply/
from __future__ import print_function
import os.path
import re
import sys
#
# Try to load the ply module, if not, then assume it is in the third_party
# directory, relative to ppapi
#
try:
from ply import lex
except:
module_path, module_name = os.path.split(__file__)
third_party = os.path.join(module_path, '..', '..', 'third_party')
sys.path.append(third_party)
from ply import lex
from idl_option import GetOption, Option, ParseOptions
Option('output', 'Generate output.')
#
# IDL Lexer
#
class IDLLexer(object):
# 'tokens' is a value required by lex which specifies the complete list
# of valid token types.
tokens = [
# Symbol and keywords types
'COMMENT',
'DESCRIBE',
'ENUM',
'LABEL',
'SYMBOL',
'INLINE',
'INTERFACE',
'STRUCT',
'TYPEDEF',
'OR',
# Extra WebIDL keywords
'CALLBACK',
'DICTIONARY',
'OPTIONAL',
'STATIC',
# Invented for apps use
'NAMESPACE',
# Data types
'FLOAT',
'OCT',
'INT',
'HEX',
'STRING',
# Operators
'LSHIFT',
'RSHIFT'
]
# 'keywords' is a map of string to token type. All SYMBOL tokens are
# matched against keywords, to determine if the token is actually a keyword.
keywords = {
'describe' : 'DESCRIBE',
'enum' : 'ENUM',
'label' : 'LABEL',
'interface' : 'INTERFACE',
'readonly' : 'READONLY',
'struct' : 'STRUCT',
'typedef' : 'TYPEDEF',
'callback' : 'CALLBACK',
'dictionary' : 'DICTIONARY',
'optional' : 'OPTIONAL',
'static' : 'STATIC',
'namespace' : 'NAMESPACE',
'or' : 'OR',
}
# 'literals' is a value expected by lex which specifies a list of valid
# literal tokens, meaning the token type and token value are identical.
literals = '"*.(){}[],;:=+-/~|&^?'
# Token definitions
#
# Lex assumes any value or function in the form of 't_<TYPE>' represents a
# regular expression where a match will emit a token of type <TYPE>. In the
# case of a function, the function is called when a match is made. These
# definitions come from WebIDL.
# 't_ignore' is a special match of items to ignore
t_ignore = ' \t'
# Constant values
t_FLOAT = r'-?(\d+\.\d*|\d*\.\d+)([Ee][+-]?\d+)?|-?\d+[Ee][+-]?\d+'
t_INT = r'-?[0-9]+[uU]?'
t_OCT = r'-?0[0-7]+'
t_HEX = r'-?0[Xx][0-9A-Fa-f]+'
t_LSHIFT = r'<<'
t_RSHIFT = r'>>'
# A line ending '\n', we use this to increment the line number
def t_LINE_END(self, t):
r'\n+'
self.AddLines(len(t.value))
# We do not process escapes in the IDL strings. Strings are exclusively
# used for attributes, and not used as typical 'C' constants.
def t_STRING(self, t):
r'"[^"]*"'
t.value = t.value[1:-1]
self.AddLines(t.value.count('\n'))
return t
# A C or C++ style comment: /* xxx */ or //
def t_COMMENT(self, t):
r'(/\*(.|\n)*?\*/)|(//.*(\n[ \t]*//.*)*)'
self.AddLines(t.value.count('\n'))
return t
# Return a "preprocessor" inline block
def t_INLINE(self, t):
r'\#inline (.|\n)*?\#endinl.*'
self.AddLines(t.value.count('\n'))
return t
# A symbol or keyword.
def t_KEYWORD_SYMBOL(self, t):
r'_?[A-Za-z][A-Za-z_0-9]*'
# All non-keywords are assumed to be symbols
t.type = self.keywords.get(t.value, 'SYMBOL')
# We strip leading underscores so that you can specify symbols with the same
# value as a keywords (E.g. a dictionary named 'interface').
if t.value[0] == '_':
t.value = t.value[1:]
return t
def t_ANY_error(self, t):
msg = "Unrecognized input"
line = self.lexobj.lineno
# If that line has not been accounted for, then we must have hit
# EoF, so compute the beginning of the line that caused the problem.
if line >= len(self.index):
# Find the offset in the line of the first word causing the issue
word = t.value.split()[0]
offs = self.lines[line - 1].find(word)
# Add the computed line's starting position
self.index.append(self.lexobj.lexpos - offs)
msg = "Unexpected EoF reached after"
pos = self.lexobj.lexpos - self.index[line]
file = self.lexobj.filename
out = self.ErrorMessage(file, line, pos, msg)
sys.stderr.write(out + '\n')
self.lex_errors += 1
def AddLines(self, count):
# Set the lexer position for the beginning of the next line. In the case
# of multiple lines, tokens can not exist on any of the lines except the
# last one, so the recorded value for previous lines are unused. We still
# fill the array however, to make sure the line count is correct.
self.lexobj.lineno += count
for i in range(count):
self.index.append(self.lexobj.lexpos)
def FileLineMsg(self, file, line, msg):
if file: return "%s(%d) : %s" % (file, line + 1, msg)
return "<BuiltIn> : %s" % msg
def SourceLine(self, file, line, pos):
caret = '\t^'.expandtabs(pos)
# We decrement the line number since the array is 0 based while the
# line numbers are 1 based.
return "%s\n%s" % (self.lines[line - 1], caret)
def ErrorMessage(self, file, line, pos, msg):
return "\n%s\n%s" % (
self.FileLineMsg(file, line, msg),
self.SourceLine(file, line, pos))
def SetData(self, filename, data):
# Start with line 1, not zero
self.lexobj.lineno = 1
self.lexobj.filename = filename
self.lines = data.split('\n')
self.index = [0]
self.lexobj.input(data)
self.lex_errors = 0
def __init__(self):
self.lexobj = lex.lex(object=self, lextab=None, optimize=0)
#
# FilesToTokens
#
# From a set of source file names, generate a list of tokens.
#
def FilesToTokens(filenames, verbose=False):
lexer = IDLLexer()
outlist = []
for filename in filenames:
data = open(filename).read()
lexer.SetData(filename, data)
if verbose: sys.stdout.write(' Loaded %s...\n' % filename)
while 1:
t = lexer.lexobj.token()
if t is None: break
outlist.append(t)
return outlist
def TokensFromText(text):
lexer = IDLLexer()
lexer.SetData('unknown', text)
outlist = []
while 1:
t = lexer.lexobj.token()
if t is None: break
outlist.append(t.value)
return outlist
#
# TextToTokens
#
# From a block of text, generate a list of tokens
#
def TextToTokens(source):
lexer = IDLLexer()
outlist = []
lexer.SetData('AUTO', source)
while 1:
t = lexer.lexobj.token()
if t is None: break
outlist.append(t.value)
return outlist
#
# TestSame
#
# From a set of token values, generate a new source text by joining with a
# single space. The new source is then tokenized and compared against the
# old set.
#
def TestSame(values1):
# Recreate the source from the tokens. We use newline instead of whitespace
# since the '//' and #inline regex are line sensitive.
text = '\n'.join(values1)
values2 = TextToTokens(text)
count1 = len(values1)
count2 = len(values2)
if count1 != count2:
print("Size mismatch original %d vs %d\n" % (count1, count2))
if count1 > count2: count1 = count2
for i in range(count1):
if values1[i] != values2[i]:
print("%d >>%s<< >>%s<<" % (i, values1[i], values2[i]))
if GetOption('output'):
sys.stdout.write('Generating original.txt and tokenized.txt\n')
open('original.txt', 'w').write(values1)
open('tokenized.txt', 'w').write(values2)
if values1 == values2:
sys.stdout.write('Same: Pass\n')
return 0
print("****************\n%s\n%s***************\n" % (values1, values2))
sys.stdout.write('Same: Failed\n')
return -1
#
# TestExpect
#
# From a set of tokens pairs, verify the type field of the second matches
# the value of the first, so that:
# INT 123 FLOAT 1.1
# will generate a passing test, where the first token is the SYMBOL INT,
# and the second token is the INT 123, third token is the SYMBOL FLOAT and
# the fourth is the FLOAT 1.1, etc...
def TestExpect(tokens):
count = len(tokens)
index = 0
errors = 0
while index < count:
type = tokens[index].value
token = tokens[index + 1]
index += 2
if type != token.type:
sys.stderr.write('Mismatch: Expected %s, but got %s = %s.\n' %
(type, token.type, token.value))
errors += 1
if not errors:
sys.stdout.write('Expect: Pass\n')
return 0
sys.stdout.write('Expect: Failed\n')
return -1
def Main(args):
filenames = ParseOptions(args)
try:
tokens = FilesToTokens(filenames, GetOption('verbose'))
values = [tok.value for tok in tokens]
if GetOption('output'): sys.stdout.write(' <> '.join(values) + '\n')
if GetOption('test'):
if TestSame(values):
return -1
if TestExpect(tokens):
return -1
return 0
except lex.LexError as le:
sys.stderr.write('%s\n' % str(le))
return -1
if __name__ == '__main__':
sys.exit(Main(sys.argv[1:]))
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