# a glorified C pre-processor parser import sys, re, string from utils import * from defaults import * debugTokens = False debugDirectiveTokenizer = False debugLineParsing = False debugCppExpr = False debugOptimIf01 = False ##################################################################################### ##################################################################################### ##### ##### ##### C P P T O K E N S ##### ##### ##### ##################################################################################### ##################################################################################### # the list of supported C-preprocessor tokens # plus a couple of C tokens as well tokEOF = "\0" tokLN = "\n" tokSTRINGIFY = "#" tokCONCAT = "##" tokLOGICAND = "&&" tokLOGICOR = "||" tokSHL = "<<" tokSHR = ">>" tokEQUAL = "==" tokNEQUAL = "!=" tokLT = "<" tokLTE = "<=" tokGT = ">" tokGTE = ">=" tokELLIPSIS = "..." tokSPACE = " " tokDEFINED = "defined" tokLPAREN = "(" tokRPAREN = ")" tokNOT = "!" tokPLUS = "+" tokMINUS = "-" tokMULTIPLY = "*" tokDIVIDE = "/" tokMODULUS = "%" tokBINAND = "&" tokBINOR = "|" tokBINXOR = "^" tokCOMMA = "," tokLBRACE = "{" tokRBRACE = "}" tokARROW = "->" tokINCREMENT = "++" tokDECREMENT = "--" tokNUMBER = "<number>" tokIDENT = "<ident>" tokSTRING = "<string>" class Token: """a simple class to hold information about a given token. each token has a position in the source code, as well as an 'id' and a 'value'. the id is a string that identifies the token's class, while the value is the string of the original token itself. for example, the tokenizer concatenates a series of spaces and tabs as a single tokSPACE id, whose value if the original spaces+tabs sequence.""" def __init__(self): self.id = None self.value = None self.lineno = 0 self.colno = 0 def set(self,id,val=None): self.id = id if val: self.value = val else: self.value = id return None def copyFrom(self,src): self.id = src.id self.value = src.value self.lineno = src.lineno self.colno = src.colno def __repr__(self): if self.id == tokIDENT: return "(ident %s)" % self.value if self.id == tokNUMBER: return "(number %s)" % self.value if self.id == tokSTRING: return "(string '%s')" % self.value if self.id == tokLN: return "<LN>" if self.id == tokEOF: return "<EOF>" if self.id == tokSPACE and self.value == "\\": # this corresponds to a trailing \ that was transformed into a tokSPACE return "<\\>" return self.id def __str__(self): if self.id == tokIDENT: return self.value if self.id == tokNUMBER: return self.value if self.id == tokSTRING: return self.value if self.id == tokEOF: return "<EOF>" if self.id == tokSPACE: if self.value == "\\": # trailing \ return "\\\n" else: return self.value return self.id class BadExpectedToken(Exception): def __init__(self,msg): print msg ##################################################################################### ##################################################################################### ##### ##### ##### C P P T O K E N I Z E R ##### ##### ##### ##################################################################################### ##################################################################################### # list of long symbols, i.e. those that take more than one characters cppLongSymbols = [ tokCONCAT, tokLOGICAND, tokLOGICOR, tokSHL, tokSHR, tokELLIPSIS, tokEQUAL,\ tokNEQUAL, tokLTE, tokGTE, tokARROW, tokINCREMENT, tokDECREMENT ] class CppTokenizer: """an abstract class used to convert some input text into a list of tokens. real implementations follow and differ in the format of the input text only""" def __init__(self): """initialize a new CppTokenizer object""" self.eof = False # end of file reached ? self.text = None # content of current line, with final \n stripped self.line = 0 # number of current line self.pos = 0 # current character position in current line self.len = 0 # length of current line text self.held = Token() def setLineText(self,line): """set the content of the (next) current line. should be called by fillLineText() in derived classes""" self.text = line self.len = len(line) self.pos = 0 def fillLineText(self): """refresh the content of 'line' with a new line of input""" # to be overriden self.eof = True def markPos(self,tok): """mark the position of the current token in the source file""" if self.eof or self.pos > self.len: tok.lineno = self.line + 1 tok.colno = 0 else: tok.lineno = self.line tok.colno = self.pos def peekChar(self): """return the current token under the cursor without moving it""" if self.eof: return tokEOF if self.pos > self.len: self.pos = 0 self.line += 1 self.fillLineText() if self.eof: return tokEOF if self.pos == self.len: return tokLN else: return self.text[self.pos] def peekNChar(self,n): """try to peek the next n chars on the same line""" if self.pos + n > self.len: return None return self.text[self.pos:self.pos+n] def skipChar(self): """increment the token cursor position""" if not self.eof: self.pos += 1 def skipNChars(self,n): if self.pos + n <= self.len: self.pos += n else: while n > 0: self.skipChar() n -= 1 def nextChar(self): """retrieve the token at the current cursor position, then skip it""" result = self.peekChar() self.skipChar() return result def getEscape(self): # try to get all characters after a backslash (\) result = self.nextChar() if result == "0": # octal number ? num = self.peekNChar(3) if num != None: isOctal = True for d in num: if not d in "01234567": isOctal = False break if isOctal: result += num self.skipNChars(3) elif result == "x" or result == "X": # hex number ? num = self.peekNChar(2) if num != None: isHex = True for d in num: if not d in "012345678abcdefABCDEF": isHex = False break if isHex: result += num self.skipNChars(2) elif result == "u" or result == "U": # unicode char ? num = self.peekNChar(4) if num != None: isHex = True for d in num: if not d in "012345678abcdefABCDEF": isHex = False break if isHex: result += num self.skipNChars(4) return result def nextRealToken(self,tok): """return next CPP token, used internally by nextToken()""" c = self.nextChar() if c == tokEOF or c == tokLN: return tok.set(c) if c == '/': c = self.peekChar() if c == '/': # C++ comment line self.skipChar() while 1: c = self.nextChar() if c == tokEOF or c == tokLN: break return tok.set(tokLN) if c == '*': # C comment start self.skipChar() value = "/*" prev_c = None while 1: c = self.nextChar() if c == tokEOF: return tok.set(tokEOF,value) if c == '/' and prev_c == '*': break prev_c = c value += c value += "/" return tok.set(tokSPACE,value) c = '/' if c.isspace(): while 1: c2 = self.peekChar() if c2 == tokLN or not c2.isspace(): break c += c2 self.skipChar() return tok.set(tokSPACE,c) if c == '\\': if debugTokens: print "nextRealToken: \\ found, next token is '%s'" % repr(self.peekChar()) if self.peekChar() == tokLN: # trailing \ # eat the tokLN self.skipChar() # we replace a trailing \ by a tokSPACE whose value is # simply "\\". this allows us to detect them later when # needed. return tok.set(tokSPACE,"\\") else: # treat as a single token here ? c +=self.getEscape() return tok.set(c) if c == "'": # chars c2 = self.nextChar() c += c2 if c2 == '\\': c += self.getEscape() while 1: c2 = self.nextChar() if c2 == tokEOF: break c += c2 if c2 == "'": break return tok.set(tokSTRING, c) if c == '"': # strings quote = 0 while 1: c2 = self.nextChar() if c2 == tokEOF: return tok.set(tokSTRING,c) c += c2 if not quote: if c2 == '"': return tok.set(tokSTRING,c) if c2 == "\\": quote = 1 else: quote = 0 if c >= "0" and c <= "9": # integers ? while 1: c2 = self.peekChar() if c2 == tokLN or (not c2.isalnum() and c2 != "_"): break c += c2 self.skipChar() return tok.set(tokNUMBER,c) if c.isalnum() or c == "_": # identifiers ? while 1: c2 = self.peekChar() if c2 == tokLN or (not c2.isalnum() and c2 != "_"): break c += c2 self.skipChar() if c == tokDEFINED: return tok.set(tokDEFINED) else: return tok.set(tokIDENT,c) # check special symbols for sk in cppLongSymbols: if c == sk[0]: sklen = len(sk[1:]) if self.pos + sklen <= self.len and \ self.text[self.pos:self.pos+sklen] == sk[1:]: self.pos += sklen return tok.set(sk) return tok.set(c) def nextToken(self,tok): """return the next token from the input text. this function really updates 'tok', and does not return a new one""" self.markPos(tok) self.nextRealToken(tok) def getToken(self): tok = Token() self.nextToken(tok) if debugTokens: print "getTokens: %s" % repr(tok) return tok def toTokenList(self): """convert the input text of a CppTokenizer into a direct list of token objects. tokEOF is stripped from the result""" result = [] while 1: tok = Token() self.nextToken(tok) if tok.id == tokEOF: break result.append(tok) return result class CppLineTokenizer(CppTokenizer): """a CppTokenizer derived class that accepts a single line of text as input""" def __init__(self,line,lineno=1): CppTokenizer.__init__(self) self.line = lineno self.setLineText(line) class CppLinesTokenizer(CppTokenizer): """a CppTokenizer derived class that accepts a list of texdt lines as input. the lines must not have a trailing \n""" def __init__(self,lines=[],lineno=1): """initialize a CppLinesTokenizer. you can later add lines using addLines()""" CppTokenizer.__init__(self) self.line = lineno self.lines = lines self.index = 0 self.count = len(lines) if self.count > 0: self.fillLineText() else: self.eof = True def addLine(self,line): """add a line to a CppLinesTokenizer. this can be done after tokenization happens""" if self.count == 0: self.setLineText(line) self.index = 1 self.lines.append(line) self.count += 1 self.eof = False def fillLineText(self): if self.index < self.count: self.setLineText(self.lines[self.index]) self.index += 1 else: self.eof = True class CppFileTokenizer(CppTokenizer): def __init__(self,file,lineno=1): CppTokenizer.__init__(self) self.file = file self.line = lineno def fillLineText(self): line = self.file.readline() if len(line) > 0: if line[-1] == '\n': line = line[:-1] if len(line) > 0 and line[-1] == "\r": line = line[:-1] self.setLineText(line) else: self.eof = True # Unit testing # class CppTokenizerTester: """a class used to test CppTokenizer classes""" def __init__(self,tokenizer=None): self.tokenizer = tokenizer self.token = Token() def setTokenizer(self,tokenizer): self.tokenizer = tokenizer def expect(self,id): self.tokenizer.nextToken(self.token) tokid = self.token.id if tokid == id: return if self.token.value == id and (tokid == tokIDENT or tokid == tokNUMBER): return raise BadExpectedToken, "### BAD TOKEN: '%s' expecting '%s'" % (self.token.id,id) def expectToken(self,id,line,col): self.expect(id) if self.token.lineno != line: raise BadExpectedToken, "### BAD LINENO: token '%s' got '%d' expecting '%d'" % (id,self.token.lineno,line) if self.token.colno != col: raise BadExpectedToken, "### BAD COLNO: '%d' expecting '%d'" % (self.token.colno,col) def expectTokenVal(self,id,value,line,col): self.expectToken(id,line,col) if self.token.value != value: raise BadExpectedToken, "### BAD VALUE: '%s' expecting '%s'" % (self.token.value,value) def expectList(self,list): for item in list: self.expect(item) def test_CppTokenizer(): tester = CppTokenizerTester() tester.setTokenizer( CppLineTokenizer("#an/example && (01923_xy)") ) tester.expectList( ["#", "an", "/", "example", tokSPACE, tokLOGICAND, tokSPACE, tokLPAREN, "01923_xy", \ tokRPAREN, tokLN, tokEOF] ) tester.setTokenizer( CppLineTokenizer("FOO(BAR) && defined(BAZ)") ) tester.expectList( ["FOO", tokLPAREN, "BAR", tokRPAREN, tokSPACE, tokLOGICAND, tokSPACE, tokDEFINED, tokLPAREN, "BAZ", tokRPAREN, tokLN, tokEOF] ) tester.setTokenizer( CppLinesTokenizer( ["/*", "#", "*/"] ) ) tester.expectList( [ tokSPACE, tokLN, tokEOF ] ) tester.setTokenizer( CppLinesTokenizer( ["first", "second"] ) ) tester.expectList( [ "first", tokLN, "second", tokLN, tokEOF ] ) tester.setTokenizer( CppLinesTokenizer( ["first second", " third"] ) ) tester.expectToken( "first", 1, 0 ) tester.expectToken( tokSPACE, 1, 5 ) tester.expectToken( "second", 1, 6 ) tester.expectToken( tokLN, 1, 12 ) tester.expectToken( tokSPACE, 2, 0 ) tester.expectToken( "third", 2, 2 ) tester.setTokenizer( CppLinesTokenizer( [ "boo /* what the", "hell */" ] ) ) tester.expectList( [ "boo", tokSPACE ] ) tester.expectTokenVal( tokSPACE, "/* what the\nhell */", 1, 4 ) tester.expectList( [ tokLN, tokEOF ] ) tester.setTokenizer( CppLinesTokenizer( [ "an \\", " example" ] ) ) tester.expectToken( "an", 1, 0 ) tester.expectToken( tokSPACE, 1, 2 ) tester.expectTokenVal( tokSPACE, "\\", 1, 3 ) tester.expectToken( tokSPACE, 2, 0 ) tester.expectToken( "example", 2, 1 ) tester.expectToken( tokLN, 2, 8 ) return True ##################################################################################### ##################################################################################### ##### ##### ##### C P P E X P R E S S I O N S ##### ##### ##### ##################################################################################### ##################################################################################### class CppExpr: """a class that models the condition of #if directives into an expression tree. each node in the tree is of the form (op,arg) or (op,arg1,arg2) where "op" is a string describing the operation""" unaries = [ "!", "~" ] binaries = [ "+", "-", "<", "<=", ">=", ">", "&&", "||", "*", "/", "%", "&", "|", "^", "<<", ">>", "==", "!=", "?", ":" ] precedences = { "?": 1, ":": 1, "||": 2, "&&": 3, "|": 4, "^": 5, "&": 6, "==": 7, "!=": 7, "<": 8, "<=": 8, ">": 8, ">=": 8, "<<": 9, ">>": 9, "+": 10, "-": 10, "*": 11, "/": 11, "%": 11, "!": 12, "~": 12 } re_cpp_constant = re.compile(r"((\d|\w|_)+)") def __init__(self, tokens): """initialize a CppExpr. 'tokens' must be a CppToken list""" self.tok = tokens self.n = len(tokens) self.i = 0 if debugCppExpr: print "CppExpr: trying to parse %s" % repr(tokens) self.expr = self.parseExpression(0) if debugCppExpr: print "CppExpr: got " + repr(self.expr) if self.i != self.n: print 'crap at end of input (%d != %d): %s' % (self.i, self.n, repr(tokens)) raise def throw(self, exception, msg): if self.i < self.n: tok = self.tok[self.i] print "%d:%d: %s" % (tok.lineno,tok.colno,msg) else: print "EOF: %s" % msg raise exception(msg) def skip_spaces(self): """skip spaces in input token list""" while self.i < self.n: t = self.tok[self.i] if t.id != tokSPACE and t.id != tokLN: break self.i += 1 def expectId(self, id): """check that a given token id is at the current position, then skip over it""" self.skip_spaces() if self.i >= self.n or self.tok[self.i].id != id: self.throw(BadExpectedToken,self.i,"### expecting '%s' in expression, got '%s'" % (id, self.tok[self.i].id)) self.i += 1 def expectIdent(self): self.skip_spaces() if self.i >= self.n or self.tok[self.i].id != tokIDENT: self.throw(BadExpectedToken, self.i,"### expecting identifier in expression, got '%s'" % (id, self.tok[self.i].id)) self.i += 1 def is_decimal(self): v = self.tok[self.i].value[:] while len(v) > 0 and v[-1] in "ULul": v = v[:-1] for digit in v: if not digit.isdigit(): return None self.i += 1 return ("int", string.atoi(v)) def is_hexadecimal(self): v = self.tok[self.i].value[:] while len(v) > 0 and v[-1] in "ULul": v = v[:-1] if len(v) > 2 and (v[0:2] == "0x" or v[0:2] == "0X"): for digit in v[2:]: if not digit in "0123456789abcdefABCDEF": return None # for a hex expression tuple, the argument # is the value as an integer self.i += 1 return ("hex", int(v[2:], 16)) return None def is_integer(self): if self.tok[self.i].id != tokNUMBER: return None c = self.is_decimal() if c: return c c = self.is_hexadecimal() if c: return c return None def is_number(self): t = self.tok[self.i] if t.id == tokMINUS and self.i+1 < self.n: self.i += 1 c = self.is_integer() if c: op, val = c return (op, -val) if t.id == tokPLUS and self.i+1 < self.n: c = self.is_integer() if c: return c return self.is_integer() def is_defined(self): t = self.tok[self.i] if t.id != tokDEFINED: return None # we have the defined keyword, check the rest self.i += 1 self.skip_spaces() used_parens = 0 if self.i < self.n and self.tok[self.i].id == tokLPAREN: used_parens = 1 self.i += 1 self.skip_spaces() if self.i >= self.n: self.throw(CppConstantExpected,i,"### 'defined' must be followed by macro name or left paren") t = self.tok[self.i] if t.id != tokIDENT: self.throw(CppConstantExpected,i,"### 'defined' must be followed by macro name") self.i += 1 if used_parens: self.expectId(tokRPAREN) return ("defined", t.value) def is_call_or_ident(self): self.skip_spaces() if self.i >= self.n: return None t = self.tok[self.i] if t.id != tokIDENT: return None name = t.value self.i += 1 self.skip_spaces() if self.i >= self.n or self.tok[self.i].id != tokLPAREN: return ("ident", name) params = [] depth = 1 self.i += 1 j = self.i while self.i < self.n: id = self.tok[self.i].id if id == tokLPAREN: depth += 1 elif depth == 1 and (id == tokCOMMA or id == tokRPAREN): while j < self.i and self.tok[j].id == tokSPACE: j += 1 k = self.i while k > j and self.tok[k-1].id == tokSPACE: k -= 1 param = self.tok[j:k] params.append(param) if id == tokRPAREN: break j = self.i+1 elif id == tokRPAREN: depth -= 1 self.i += 1 if self.i >= self.n: return None self.i += 1 return ("call", (name, params)) # Implements the "precedence climbing" algorithm from http://www.engr.mun.ca/~theo/Misc/exp_parsing.htm. # The "classic" algorithm would be fine if we were using a tool to generate the parser, but we're not. # Dijkstra's "shunting yard" algorithm hasn't been necessary yet. def parseExpression(self, minPrecedence): self.skip_spaces() if self.i >= self.n: return None node = self.parsePrimary() while self.token() != None and self.isBinary(self.token()) and self.precedence(self.token()) >= minPrecedence: op = self.token() self.nextToken() rhs = self.parseExpression(self.precedence(op) + 1) node = (op.id, node, rhs) return node def parsePrimary(self): op = self.token() if self.isUnary(op): self.nextToken() return (op.id, self.parseExpression(self.precedence(op))) primary = None if op.id == tokLPAREN: self.nextToken() primary = self.parseExpression(0) self.expectId(tokRPAREN) elif op.id == "?": self.nextToken() primary = self.parseExpression(0) self.expectId(":") elif op.id == tokNUMBER: primary = self.is_number() elif op.id == tokIDENT: primary = self.is_call_or_ident() elif op.id == tokDEFINED: primary = self.is_defined() else: self.throw(BadExpectedToken, "didn't expect to see a %s in factor" % (self.tok[self.i].id)) self.skip_spaces() return primary; def isBinary(self, token): return token.id in self.binaries def isUnary(self, token): return token.id in self.unaries def precedence(self, token): return self.precedences.get(token.id) def token(self): if self.i >= self.n: return None return self.tok[self.i] def nextToken(self): self.i += 1 self.skip_spaces() if self.i >= self.n: return None return self.tok[self.i] def dump_node(self, e): op = e[0] line = "(" + op if op == "int": line += " %d)" % e[1] elif op == "hex": line += " 0x%x)" % e[1] elif op == "ident": line += " %s)" % e[1] elif op == "defined": line += " %s)" % e[1] elif op == "call": arg = e[1] line += " %s [" % arg[0] prefix = "" for param in arg[1]: par = "" for tok in param: par += str(tok) line += "%s%s" % (prefix, par) prefix = "," line += "])" elif op in CppExpr.unaries: line += " %s)" % self.dump_node(e[1]) elif op in CppExpr.binaries: line += " %s %s)" % (self.dump_node(e[1]), self.dump_node(e[2])) else: line += " ?%s)" % repr(e[1]) return line def __repr__(self): return self.dump_node(self.expr) def source_node(self, e): op = e[0] if op == "int": return "%d" % e[1] if op == "hex": return "0x%x" % e[1] if op == "ident": # XXX: should try to expand return e[1] if op == "defined": return "defined(%s)" % e[1] prec = CppExpr.precedences.get(op,1000) arg = e[1] if op in CppExpr.unaries: arg_src = self.source_node(arg) arg_op = arg[0] arg_prec = CppExpr.precedences.get(arg[0],1000) if arg_prec < prec: return "!(" + arg_src + ")" else: return "!" + arg_src if op in CppExpr.binaries: arg2 = e[2] arg1_op = arg[0] arg2_op = arg2[0] arg1_src = self.source_node(arg) arg2_src = self.source_node(arg2) if CppExpr.precedences.get(arg1_op,1000) < prec: arg1_src = "(%s)" % arg1_src if CppExpr.precedences.get(arg2_op,1000) < prec: arg2_src = "(%s)" % arg2_src return "%s %s %s" % (arg1_src, op, arg2_src) return "???" def __str__(self): return self.source_node(self.expr) def int_node(self,e): if e[0] == "int": return e[1] elif e[1] == "hex": return int(e[1],16) else: return None def toInt(self): return self.int_node(self.expr) def optimize_node(self, e, macros={}): op = e[0] if op == "defined": op, name = e if macros.has_key(name): if macros[name] == kCppUndefinedMacro: return ("int", 0) else: try: value = int(macros[name]) return ("int", value) except: return ("defined", macros[name]) if kernel_remove_config_macros and name.startswith("CONFIG_"): return ("int", 0) return e elif op == "ident": op, name = e if macros.has_key(name): try: value = int(macros[name]) expanded = ("int", value) except: expanded = ("ident", macros[name]) return self.optimize_node(expanded, macros) return e elif op == "!": op, v = e v = self.optimize_node(v, macros) if v[0] == "int": if v[1] == 0: return ("int", 1) else: return ("int", 0) return ('!', v) elif op == "&&": op, l, r = e l = self.optimize_node(l, macros) r = self.optimize_node(r, macros) li = self.int_node(l) ri = self.int_node(r) if li != None: if li == 0: return ("int", 0) else: return r elif ri != None: if ri == 0: return ("int", 0) else: return l return (op, l, r) elif op == "||": op, l, r = e l = self.optimize_node(l, macros) r = self.optimize_node(r, macros) li = self.int_node(l) ri = self.int_node(r) if li != None: if li == 0: return r else: return ("int", 1) elif ri != None: if ri == 0: return l else: return ("int", 1) return (op, l, r) else: return e def optimize(self,macros={}): self.expr = self.optimize_node(self.expr, macros) def is_equal_node(self,e1,e2): if e1[0] != e2[0] or len(e1) != len(e2): return False op = e1[0] if op == "int" or op == "hex" or op == "!" or op == "defined": return e1[0] == e2[0] return self.is_equal_node(e1[1],e2[1]) and self.is_equal_node(e1[2],e2[2]) def is_equal(self,other): return self.is_equal_node(self.expr,other.expr) def test_cpp_expr(expr, expected): e = CppExpr( CppLineTokenizer( expr ).toTokenList() ) s1 = repr(e) if s1 != expected: print "[FAIL]: expression '%s' generates '%s', should be '%s'" % (expr, s1, expected) global failure_count failure_count += 1 def test_cpp_expr_optim(expr, expected, macros={}): e = CppExpr( CppLineTokenizer( expr ).toTokenList() ) e.optimize(macros) s1 = repr(e) if s1 != expected: print "[FAIL]: optimized expression '%s' generates '%s' with macros %s, should be '%s'" % (expr, s1, macros, expected) global failure_count failure_count += 1 def test_cpp_expr_source(expr, expected): e = CppExpr( CppLineTokenizer( expr ).toTokenList() ) s1 = str(e) if s1 != expected: print "[FAIL]: source expression '%s' generates '%s', should be '%s'" % (expr, s1, expected) global failure_count failure_count += 1 def test_CppExpr(): test_cpp_expr("0", "(int 0)") test_cpp_expr("1", "(int 1)") test_cpp_expr("(0)", "(int 0)") test_cpp_expr("1 && 1", "(&& (int 1) (int 1))") test_cpp_expr("1 && 0", "(&& (int 1) (int 0))") test_cpp_expr("EXAMPLE", "(ident EXAMPLE)") test_cpp_expr("EXAMPLE - 3", "(- (ident EXAMPLE) (int 3))") test_cpp_expr("defined(EXAMPLE)", "(defined EXAMPLE)") test_cpp_expr("defined ( EXAMPLE ) ", "(defined EXAMPLE)") test_cpp_expr("!defined(EXAMPLE)", "(! (defined EXAMPLE))") test_cpp_expr("defined(ABC) || defined(BINGO)", "(|| (defined ABC) (defined BINGO))") test_cpp_expr("FOO(BAR)", "(call FOO [BAR])") test_cpp_expr("A == 1 || defined(B)", "(|| (== (ident A) (int 1)) (defined B))") test_cpp_expr_optim("0", "(int 0)") test_cpp_expr_optim("1", "(int 1)") test_cpp_expr_optim("1 && 1", "(int 1)") test_cpp_expr_optim("1 && 0", "(int 0)") test_cpp_expr_optim("0 && 1", "(int 0)") test_cpp_expr_optim("0 && 0", "(int 0)") test_cpp_expr_optim("1 || 1", "(int 1)") test_cpp_expr_optim("1 || 0", "(int 1)") test_cpp_expr_optim("0 || 1", "(int 1)") test_cpp_expr_optim("0 || 0", "(int 0)") test_cpp_expr_optim("A", "(ident A)") test_cpp_expr_optim("A", "(int 1)", { "A": 1 }) test_cpp_expr_optim("A || B", "(int 1)", { "A": 1 }) test_cpp_expr_optim("A || B", "(int 1)", { "B": 1 }) test_cpp_expr_optim("A && B", "(ident B)", { "A": 1 }) test_cpp_expr_optim("A && B", "(ident A)", { "B": 1 }) test_cpp_expr_optim("A && B", "(&& (ident A) (ident B))") test_cpp_expr_optim("EXAMPLE", "(ident EXAMPLE)") test_cpp_expr_optim("EXAMPLE - 3", "(- (ident EXAMPLE) (int 3))") test_cpp_expr_optim("defined(EXAMPLE)", "(defined EXAMPLE)") test_cpp_expr_optim("defined(EXAMPLE)", "(defined XOWOE)", { "EXAMPLE": "XOWOE" }) test_cpp_expr_optim("defined(EXAMPLE)", "(int 0)", { "EXAMPLE": kCppUndefinedMacro}) test_cpp_expr_optim("!defined(EXAMPLE)", "(! (defined EXAMPLE))") test_cpp_expr_optim("!defined(EXAMPLE)", "(! (defined XOWOE))", { "EXAMPLE" : "XOWOE" }) test_cpp_expr_optim("!defined(EXAMPLE)", "(int 1)", { "EXAMPLE" : kCppUndefinedMacro }) test_cpp_expr_optim("defined(A) || defined(B)", "(|| (defined A) (defined B))") test_cpp_expr_optim("defined(A) || defined(B)", "(int 1)", { "A" : "1" }) test_cpp_expr_optim("defined(A) || defined(B)", "(int 1)", { "B" : "1" }) test_cpp_expr_optim("defined(A) || defined(B)", "(defined A)", { "B" : kCppUndefinedMacro }) test_cpp_expr_optim("defined(A) || defined(B)", "(int 0)", { "A" : kCppUndefinedMacro, "B" : kCppUndefinedMacro }) test_cpp_expr_optim("defined(A) && defined(B)", "(&& (defined A) (defined B))") test_cpp_expr_optim("defined(A) && defined(B)", "(defined B)", { "A" : "1" }) test_cpp_expr_optim("defined(A) && defined(B)", "(defined A)", { "B" : "1" }) test_cpp_expr_optim("defined(A) && defined(B)", "(int 0)", { "B" : kCppUndefinedMacro }) test_cpp_expr_optim("defined(A) && defined(B)", "(int 0)", { "A" : kCppUndefinedMacro }) test_cpp_expr_optim("A == 1 || defined(B)", "(|| (== (ident A) (int 1)) (defined B))" ) test_cpp_expr_optim("defined(__KERNEL__) || !defined(__GLIBC__) || (__GLIBC__ < 2)", "(|| (! (defined __GLIBC__)) (< (ident __GLIBC__) (int 2)))", { "__KERNEL__": kCppUndefinedMacro }) test_cpp_expr_source("0", "0") test_cpp_expr_source("1", "1") test_cpp_expr_source("1 && 1", "1 && 1") test_cpp_expr_source("1 && 0", "1 && 0") test_cpp_expr_source("0 && 1", "0 && 1") test_cpp_expr_source("0 && 0", "0 && 0") test_cpp_expr_source("1 || 1", "1 || 1") test_cpp_expr_source("1 || 0", "1 || 0") test_cpp_expr_source("0 || 1", "0 || 1") test_cpp_expr_source("0 || 0", "0 || 0") test_cpp_expr_source("EXAMPLE", "EXAMPLE") test_cpp_expr_source("EXAMPLE - 3", "EXAMPLE - 3") test_cpp_expr_source("defined(EXAMPLE)", "defined(EXAMPLE)") test_cpp_expr_source("defined EXAMPLE", "defined(EXAMPLE)") test_cpp_expr_source("A == 1 || defined(B)", "A == 1 || defined(B)") ##################################################################################### ##################################################################################### ##### ##### ##### C P P B L O C K ##### ##### ##### ##################################################################################### ##################################################################################### class Block: """a class used to model a block of input source text. there are two block types: - directive blocks: contain the tokens of a single pre-processor directive (e.g. #if) - text blocks, contain the tokens of non-directive blocks the cpp parser class below will transform an input source file into a list of Block objects (grouped in a BlockList object for convenience)""" def __init__(self,tokens,directive=None,lineno=0): """initialize a new block, if 'directive' is None, this is a text block NOTE: this automatically converts '#ifdef MACRO' into '#if defined(MACRO)' and '#ifndef MACRO' into '#if !defined(MACRO)'""" if directive == "ifdef": tok = Token() tok.set(tokDEFINED) tokens = [ tok ] + tokens directive = "if" elif directive == "ifndef": tok1 = Token() tok2 = Token() tok1.set(tokNOT) tok2.set(tokDEFINED) tokens = [ tok1, tok2 ] + tokens directive = "if" self.tokens = tokens self.directive = directive if lineno > 0: self.lineno = lineno else: self.lineno = self.tokens[0].lineno if self.isIf(): self.expr = CppExpr( self.tokens ) def isDirective(self): """returns True iff this is a directive block""" return self.directive != None def isConditional(self): """returns True iff this is a conditional directive block""" return self.directive in ["if","ifdef","ifndef","else","elif","endif"] def isDefine(self): """returns the macro name in a #define directive, or None otherwise""" if self.directive != "define": return None return self.tokens[0].value def isIf(self): """returns True iff this is an #if-like directive block""" return self.directive in ["if","ifdef","ifndef","elif"] def isInclude(self): """checks whether this is a #include directive. if true, then returns the corresponding file name (with brackets or double-qoutes). None otherwise""" if self.directive != "include": return None if self.tokens[0].id == tokSTRING: # a double-quote include, that's easy return self.tokens[0].value # we only want the bracket part, not any comments or junk after it if self.tokens[0].id == "<": i = 0 tok = self.tokens n = len(tok) while i < n and tok[i].id != ">": i += 1 if i >= n: return None return string.join([ str(x) for x in tok[:i+1] ],"") else: return None def removeWhiteSpace(self): # Remove trailing whitespace and empty lines # All whitespace is also contracted to a single space if self.directive != None: return tokens = [] line = 0 # index of line start space = -1 # index of first space, or -1 ii = 0 nn = len(self.tokens) while ii < nn: tok = self.tokens[ii] # If we find a space, record its position if this is the first # one the line start or the previous character. Don't append # anything to tokens array yet though. if tok.id == tokSPACE: if space < 0: space = ii ii += 1 continue # If this is a line space, ignore the spaces we found previously # on the line, and remove empty lines. if tok.id == tokLN: old_line = line old_space = space ii += 1 line = ii space = -1 if old_space == old_line: # line only contains spaces continue if ii-1 == old_line: # line is empty continue tokens.append(tok) continue # Other token, append any space range if any, converting each # one to a single space character, then append the token. if space >= 0: jj = space space = -1 while jj < ii: tok2 = self.tokens[jj] tok2.value = " " tokens.append(tok2) jj += 1 tokens.append(tok) ii += 1 self.tokens = tokens def writeWithWarning(self,out,warning,left_count,repeat_count): # removeWhiteSpace() will sometimes creates non-directive blocks # without any tokens. These come from blocks that only contained # empty lines and spaces. They should not be printed in the final # output, and then should not be counted for this operation. # if not self.directive and self.tokens == []: return left_count if self.directive: out.write(str(self).rstrip() + "\n") left_count -= 1 if left_count == 0: out.write(warning) left_count = repeat_count else: for tok in self.tokens: out.write(str(tok)) if tok.id == tokLN: left_count -= 1 if left_count == 0: out.write(warning) left_count = repeat_count return left_count def __repr__(self): """generate the representation of a given block""" if self.directive: result = "#%s " % self.directive if self.isIf(): result += repr(self.expr) else: for tok in self.tokens: result += repr(tok) else: result = "" for tok in self.tokens: result += repr(tok) return result def __str__(self): """generate the string representation of a given block""" if self.directive: if self.directive == "if": # small optimization to re-generate #ifdef and #ifndef e = self.expr.expr op = e[0] if op == "defined": result = "#ifdef %s" % e[1] elif op == "!" and e[1][0] == "defined": result = "#ifndef %s" % e[1][1] else: result = "#if " + str(self.expr) else: result = "#%s" % self.directive if len(self.tokens): result += " " for tok in self.tokens: result += str(tok) else: result = "" for tok in self.tokens: result += str(tok) return result class BlockList: """a convenience class used to hold and process a list of blocks returned by the cpp parser""" def __init__(self,blocks): self.blocks = blocks def __len__(self): return len(self.blocks) def __getitem__(self,n): return self.blocks[n] def __repr__(self): return repr(self.blocks) def __str__(self): result = "" for b in self.blocks: result += str(b) if b.isDirective(): result = result.rstrip() + '\n' return result def optimizeIf01(self): """remove the code between #if 0 .. #endif in a BlockList""" self.blocks = optimize_if01(self.blocks) def optimizeMacros(self, macros): """remove known defined and undefined macros from a BlockList""" for b in self.blocks: if b.isIf(): b.expr.optimize(macros) def removeMacroDefines(self,macros): """remove known macro definitions from a BlockList""" self.blocks = remove_macro_defines(self.blocks,macros) def removeWhiteSpace(self): for b in self.blocks: b.removeWhiteSpace() def optimizeAll(self,macros): self.optimizeMacros(macros) self.optimizeIf01() return def findIncludes(self): """return the list of included files in a BlockList""" result = [] for b in self.blocks: i = b.isInclude() if i: result.append(i) return result def write(self,out): out.write(str(self)) def writeWithWarning(self,out,warning,repeat_count): left_count = repeat_count for b in self.blocks: left_count = b.writeWithWarning(out,warning,left_count,repeat_count) def removeComments(self): for b in self.blocks: for tok in b.tokens: if tok.id == tokSPACE: tok.value = " " def removeVarsAndFuncs(self,knownStatics=set()): """remove all extern and static declarations corresponding to variable and function declarations. we only accept typedefs and enum/structs/union declarations. however, we keep the definitions corresponding to the set of known static inline functions in the set 'knownStatics', which is useful for optimized byteorder swap functions and stuff like that. """ # state = 0 => normal (i.e. LN + spaces) # state = 1 => typedef/struct encountered, ends with ";" # state = 2 => var declaration encountered, ends with ";" # state = 3 => func declaration encountered, ends with "}" state = 0 depth = 0 blocks2 = [] skipTokens = False for b in self.blocks: if b.isDirective(): blocks2.append(b) else: n = len(b.tokens) i = 0 if skipTokens: first = n else: first = 0 while i < n: tok = b.tokens[i] tokid = tok.id # If we are not looking for the start of a new # type/var/func, then skip over tokens until # we find our terminator, managing the depth of # accolades as we go. if state > 0: terminator = False if tokid == '{': depth += 1 elif tokid == '}': if depth > 0: depth -= 1 if (depth == 0) and (state == 3): terminator = True elif tokid == ';' and depth == 0: terminator = True if terminator: # we found the terminator state = 0 if skipTokens: skipTokens = False first = i+1 i = i+1 continue # We are looking for the start of a new type/func/var # ignore whitespace if tokid in [tokLN, tokSPACE]: i = i+1 continue # Is it a new type definition, then start recording it if tok.value in [ 'struct', 'typedef', 'enum', 'union', '__extension__' ]: state = 1 i = i+1 continue # Is it a variable or function definition. If so, first # try to determine which type it is, and also extract # its name. # # We're going to parse the next tokens of the same block # until we find a semi-column or a left parenthesis. # # The semi-column corresponds to a variable definition, # the left-parenthesis to a function definition. # # We also assume that the var/func name is the last # identifier before the terminator. # j = i+1 ident = "" while j < n: tokid = b.tokens[j].id if tokid == '(': # a function declaration state = 3 break elif tokid == ';': # a variable declaration state = 2 break if tokid == tokIDENT: ident = b.tokens[j].value j += 1 if j >= n: # This can only happen when the declaration # does not end on the current block (e.g. with # a directive mixed inside it. # # We will treat it as malformed because # it's very hard to recover from this case # without making our parser much more # complex. # #print "### skip unterminated static '%s'" % ident break if ident in knownStatics: #print "### keep var/func '%s': %s" % (ident,repr(b.tokens[i:j])) pass else: # We're going to skip the tokens for this declaration #print "### skip variable /func'%s': %s" % (ident,repr(b.tokens[i:j])) if i > first: blocks2.append( Block(b.tokens[first:i])) skipTokens = True first = n i = i+1 if i > first: #print "### final '%s'" % repr(b.tokens[first:i]) blocks2.append( Block(b.tokens[first:i]) ) self.blocks = blocks2 def insertDisclaimer(self,disclaimer="/* auto-generated file, DO NOT EDIT */"): """insert your standard issue disclaimer that this is an auto-generated file, etc..""" tokens = CppLineTokenizer( disclaimer ).toTokenList() tokens = tokens[:-1] # remove trailing tokLN self.blocks = [ Block(tokens) ] + self.blocks def replaceTokens(self,replacements): """replace tokens according to the given dict""" for b in self.blocks: made_change = False if b.isInclude() == None: for tok in b.tokens: if tok.id == tokIDENT: if tok.value in replacements: tok.value = replacements[tok.value] made_change = True if made_change and b.isIf(): # Keep 'expr' in sync with 'tokens'. b.expr = CppExpr(b.tokens) class BlockParser: """a class used to convert an input source file into a BlockList object""" def __init__(self,tokzer=None): """initialize a block parser. the input source is provided through a Tokenizer object""" self.reset(tokzer) def reset(self,tokzer): self.state = 1 self.tokzer = tokzer def getBlocks(self,tokzer=None): """tokenize and parse the input source, return a BlockList object NOTE: empty and line-numbering directives are ignored and removed from the result. as a consequence, it is possible to have two successive text blocks in the result""" # state 0 => in source code # state 1 => in source code, after a LN # state 2 => in source code, after LN then some space state = 1 lastLN = 0 current = [] blocks = [] if tokzer == None: tokzer = self.tokzer while 1: tok = tokzer.getToken() if tok.id == tokEOF: break if tok.id == tokLN: state = 1 current.append(tok) lastLN = len(current) elif tok.id == tokSPACE: if state == 1: state = 2 current.append(tok) elif tok.id == "#": if state > 0: # this is the start of a directive if lastLN > 0: # record previous tokens as text block block = Block(current[:lastLN]) blocks.append(block) lastLN = 0 current = [] # skip spaces after the # while 1: tok = tokzer.getToken() if tok.id != tokSPACE: break if tok.id != tokIDENT: # empty or line-numbering, ignore it if tok.id != tokLN and tok.id != tokEOF: while 1: tok = tokzer.getToken() if tok.id == tokLN or tok.id == tokEOF: break continue directive = tok.value lineno = tok.lineno # skip spaces tok = tokzer.getToken() while tok.id == tokSPACE: tok = tokzer.getToken() # then record tokens until LN dirtokens = [] while tok.id != tokLN and tok.id != tokEOF: dirtokens.append(tok) tok = tokzer.getToken() block = Block(dirtokens,directive,lineno) blocks.append(block) state = 1 else: state = 0 current.append(tok) if len(current) > 0: block = Block(current) blocks.append(block) return BlockList(blocks) def parse(self,tokzer): return self.getBlocks( tokzer ) def parseLines(self,lines): """parse a list of text lines into a BlockList object""" return self.getBlocks( CppLinesTokenizer(lines) ) def parseFile(self,path): """parse a file into a BlockList object""" file = open(path, "rt") result = self.getBlocks( CppFileTokenizer(file) ) file.close() return result def test_block_parsing(lines,expected): blocks = BlockParser().parse( CppLinesTokenizer(lines) ) if len(blocks) != len(expected): raise BadExpectedToken, "parser.buildBlocks returned '%s' expecting '%s'" \ % (str(blocks), repr(expected)) for n in range(len(blocks)): if str(blocks[n]) != expected[n]: raise BadExpectedToken, "parser.buildBlocks()[%d] is '%s', expecting '%s'" \ % (n, str(blocks[n]), expected[n]) #for block in blocks: # print block def test_BlockParser(): test_block_parsing(["#error hello"],["#error hello"]) test_block_parsing([ "foo", "", "bar" ], [ "foo\n\nbar\n" ]) test_block_parsing([ "foo", " # ", "bar" ], [ "foo\n","bar\n" ]) test_block_parsing(\ [ "foo", " # ", " # /* ahah */ if defined(__KERNEL__) ", "bar", "#endif" ], [ "foo\n", "#ifdef __KERNEL__", "bar\n", "#endif" ] ) ##################################################################################### ##################################################################################### ##### ##### ##### B L O C K L I S T O P T I M I Z A T I O N ##### ##### ##### ##################################################################################### ##################################################################################### def remove_macro_defines( blocks, excludedMacros=set() ): """remove macro definitions like #define <macroName> ....""" result = [] for b in blocks: macroName = b.isDefine() if macroName == None or not macroName in excludedMacros: result.append(b) return result def find_matching_endif( blocks, i ): n = len(blocks) depth = 1 while i < n: if blocks[i].isDirective(): dir = blocks[i].directive if dir in [ "if", "ifndef", "ifdef" ]: depth += 1 elif depth == 1 and dir in [ "else", "elif" ]: return i elif dir == "endif": depth -= 1 if depth == 0: return i i += 1 return i def optimize_if01( blocks ): """remove the code between #if 0 .. #endif in a list of CppBlocks""" i = 0 n = len(blocks) result = [] while i < n: j = i while j < n and not blocks[j].isIf(): j += 1 if j > i: D2("appending lines %d to %d" % (blocks[i].lineno, blocks[j-1].lineno)) result += blocks[i:j] if j >= n: break expr = blocks[j].expr r = expr.toInt() if r == None: result.append(blocks[j]) i = j + 1 continue if r == 0: # if 0 => skip everything until the corresponding #endif j = find_matching_endif( blocks, j+1 ) if j >= n: # unterminated #if 0, finish here break dir = blocks[j].directive if dir == "endif": D2("remove 'if 0' .. 'endif' (lines %d to %d)" % (blocks[i].lineno, blocks[j].lineno)) i = j + 1 elif dir == "else": # convert 'else' into 'if 1' D2("convert 'if 0' .. 'else' into 'if 1' (lines %d to %d)" % (blocks[i].lineno, blocks[j-1].lineno)) blocks[j].directive = "if" blocks[j].expr = CppExpr( CppLineTokenizer("1").toTokenList() ) i = j elif dir == "elif": # convert 'elif' into 'if' D2("convert 'if 0' .. 'elif' into 'if'") blocks[j].directive = "if" i = j continue # if 1 => find corresponding endif and remove/transform them k = find_matching_endif( blocks, j+1 ) if k >= n: # unterminated #if 1, finish here D2("unterminated 'if 1'") result += blocks[j+1:k] break dir = blocks[k].directive if dir == "endif": D2("convert 'if 1' .. 'endif' (lines %d to %d)" % (blocks[j].lineno, blocks[k].lineno)) result += optimize_if01(blocks[j+1:k]) i = k+1 elif dir == "else": # convert 'else' into 'if 0' D2("convert 'if 1' .. 'else' (lines %d to %d)" % (blocks[j].lineno, blocks[k].lineno)) result += optimize_if01(blocks[j+1:k]) blocks[k].directive = "if" blocks[k].expr = CppExpr( CppLineTokenizer("0").toTokenList() ) i = k elif dir == "elif": # convert 'elif' into 'if 0' D2("convert 'if 1' .. 'elif' (lines %d to %d)" % (blocks[j].lineno, blocks[k].lineno)) result += optimize_if01(blocks[j+1:k]) blocks[k].expr = CppExpr( CppLineTokenizer("0").toTokenList() ) i = k return result def test_optimizeAll(): text = """\ #if 1 #define GOOD_1 #endif #if 0 #define BAD_2 #define BAD_3 #endif #if 1 #define GOOD_2 #else #define BAD_4 #endif #if 0 #define BAD_5 #else #define GOOD_3 #endif #if defined(__KERNEL__) #define BAD_KERNEL #endif #if defined(__KERNEL__) || !defined(__GLIBC__) || (__GLIBC__ < 2) #define X #endif #ifndef SIGRTMAX #define SIGRTMAX 123 #endif /* SIGRTMAX */ #if 0 #if 1 #define BAD_6 #endif #endif\ """ expected = """\ #define GOOD_1 #define GOOD_2 #define GOOD_3 #if !defined(__GLIBC__) || __GLIBC__ < 2 #define X #endif #ifndef __SIGRTMAX #define __SIGRTMAX 123 #endif """ out = StringOutput() lines = string.split(text, '\n') list = BlockParser().parse( CppLinesTokenizer(lines) ) #D_setlevel(2) list.replaceTokens( kernel_token_replacements ) list.optimizeAll( {"__KERNEL__":kCppUndefinedMacro} ) list.write(out) if out.get() != expected: print "[FAIL]: macro optimization failed\n" print "<<<< expecting '", print expected, print "'\n>>>> result '" print out.get(), print "'\n----" global failure_count failure_count += 1 # -- Always run the unit tests. def runUnitTests(): """run all unit tests for this program""" test_CppTokenizer() test_CppExpr() test_optimizeAll() test_BlockParser() failure_count = 0 runUnitTests() if failure_count != 0: sys.exit(1)