hdr_parser.py

#!/usr/bin/env python
 
from __future__ import print_function
import sys, re, io
 
 
"""
Each declaration is [funcname, return_value_type /* in C, not in Python */, <list_of_modifiers>, <list_of_arguments>, original_return_type, docstring],
where each element of <list_of_arguments> is 4-element list itself:
[argtype, argname, default_value /* or "" if none */, <list_of_modifiers>]
where the list of modifiers is yet another nested list of strings
   (currently recognized are "/O" for output argument, "/S" for static (i.e. class) methods
   and "/A value" for the plain C arrays with counters)
original_return_type is None if the original_return_type is the same as return_value_type
"""
 
 
class CppHeaderParser(object):
 
    def __init__(self):
        self.BLOCK_TYPE = 0
        self.BLOCK_NAME = 1
        self.PROCESS_FLAG = 2
        self.PUBLIC_SECTION = 3
        self.CLASS_DECL = 4
 
        self.namespaces = set()
 
    def batch_replace(self, s, pairs):
        for before, after in pairs:
            s = s.replace(before, after)
        return s
 
    def get_macro_arg(self, arg_str, npos):
        npos2 = npos3 = arg_str.find("(", npos)
        if npos2 < 0:
            print("Error: no arguments for the macro at %d" % (self.lineno,))
            sys.exit(-1)
        balance = 1
        while 1:
            t, npos3 = self.find_next_token(arg_str, ['(', ')'], npos3 + 1)
            if npos3 < 0:
                print("Error: no matching ')' in the macro call at %d" % (self.lineno,))
                sys.exit(-1)
            if t == '(':
                balance += 1
            if t == ')':
                balance -= 1
                if balance == 0:
                    break
 
        return arg_str[npos2 + 1:npos3].strip(), npos3
 
    def parse_arg(self, arg_str, argno):
        """
        Parses <arg_type> [arg_name]
        Returns arg_type, arg_name, modlist, argno, where
        modlist is the list of wrapper-related modifiers (such as "output argument", "has counter", ...)
        and argno is the new index of an anonymous argument.
        That is, if no arg_str is just an argument type without argument name, the argument name is set to
        "arg" + str(argno), and then argno is incremented.
        """
        modlist = []
 
        # pass 0: extracts the modifiers
        if "CV_OUT" in arg_str:
            modlist.append("/O")
            arg_str = arg_str.replace("CV_OUT", "")
 
        if "CV_IN_OUT" in arg_str:
            modlist.append("/IO")
            arg_str = arg_str.replace("CV_IN_OUT", "")
 
        isarray = False
        npos = arg_str.find("CV_CARRAY")
        if npos >= 0:
            isarray = True
            macro_arg, npos3 = self.get_macro_arg(arg_str, npos)
 
            modlist.append("/A " + macro_arg)
            arg_str = arg_str[:npos] + arg_str[npos3 + 1:]
 
        npos = arg_str.find("CV_CUSTOM_CARRAY")
        if npos >= 0:
            isarray = True
            macro_arg, npos3 = self.get_macro_arg(arg_str, npos)
 
            modlist.append("/CA " + macro_arg)
            arg_str = arg_str[:npos] + arg_str[npos3 + 1:]
 
        npos = arg_str.find("const")
        if npos >= 0:
            modlist.append("/C")
 
        npos = arg_str.find("&")
        if npos >= 0:
            modlist.append("/Ref")
 
        arg_str = arg_str.strip()
        word_start = 0
        word_list = []
        npos = -1
 
        # print self.lineno, ":\t", arg_str
 
        # pass 1: split argument type into tokens
        while 1:
            npos += 1
            t, npos = self.find_next_token(arg_str, [" ", "&", "*", "<", ">", ","], npos)
            w = arg_str[word_start:npos].strip()
            if w == "operator":
                word_list.append("operator " + arg_str[npos:].strip())
                break
            if w not in ["", "const"]:
                word_list.append(w)
            if t not in ["", " ", "&"]:
                word_list.append(t)
            if not t:
                break
            word_start = npos + 1
            npos = word_start - 1
 
        arg_type = ""
        arg_name = ""
        angle_stack = []
 
        # print self.lineno, ":\t", word_list
 
        # pass 2: decrypt the list
        wi = -1
        prev_w = ""
        for w in word_list:
            wi += 1
            if w == "*":
                if prev_w == "char" and not isarray:
                    arg_type = arg_type[:-len("char")] + "c_string"
                else:
                    arg_type += w
                continue
            elif w == "<":
                arg_type += "_"
                angle_stack.append(0)
            elif w == "," or w == '>':
                if not angle_stack:
                    print("Error at %d: argument contains ',' or '>' not within template arguments" % (self.lineno,))
                    sys.exit(-1)
                if w == ",":
                    arg_type += "_and_"
                elif w == ">":
                    if angle_stack[0] == 0:
                        print("Error at %s:%d: template has no arguments" % (self.hname, self.lineno))
                        sys.exit(-1)
                    if angle_stack[0] > 1:
                        arg_type += "_end_"
                    angle_stack[-1:] = []
            elif angle_stack:
                arg_type += w
                angle_stack[-1] += 1
            elif arg_type == "struct":
                arg_type += " " + w
            elif arg_type and arg_type != "~":
                arg_name = " ".join(word_list[wi:])
                break
            else:
                arg_type += w
            prev_w = w
 
        counter_str = ""
        add_star = False
        if ("[" in arg_name) and not ("operator" in arg_str):
            # print arg_str
            p1 = arg_name.find("[")
            p2 = arg_name.find("]", p1 + 1)
            if p2 < 0:
                print("Error at %d: no closing ]" % (self.lineno,))
                sys.exit(-1)
            counter_str = arg_name[p1 + 1:p2].strip()
            if counter_str == "":
                counter_str = "?"
            if not isarray:
                modlist.append("/A " + counter_str.strip())
            arg_name = arg_name[:p1]
            add_star = True
 
        if not arg_name:
            if arg_type.startswith("operator"):
                arg_type, arg_name = "", arg_type
            else:
                arg_name = "arg" + str(argno)
                argno += 1
 
        while arg_type.endswith("_end_"):
            arg_type = arg_type[:-len("_end_")]
 
        if add_star:
            arg_type += "*"
 
        arg_type = self.batch_replace(arg_type, [("std::", ""), ("cv::", ""), ("::", "_")])
 
        return arg_type, arg_name, modlist, argno
 
    def parse_enum(self, decl_str):
        l = decl_str
        ll = l.split(",")
        if ll[-1].strip() == "":
            ll = ll[:-1]
        prev_val = ""
        prev_val_delta = -1
        decl = []
        for pair in ll:
            pv = pair.split("=")
            if len(pv) == 1:
                prev_val_delta += 1
                val = ""
                if prev_val:
                    val = prev_val + "+"
                val += str(prev_val_delta)
            else:
                prev_val_delta = 0
                prev_val = val = pv[1].strip()
            decl.append(["const " + self.get_dotted_name(pv[0].strip()), val, [], [], None, ""])
        return decl
 
    def parse_class_decl(self, decl_str):
        """
        Parses class/struct declaration start in the form:
           {class|struct} [CV_EXPORTS] <class_name> [: public <base_class1> [, ...]]
        Returns class_name1, <list of base_classes>
        """
        l = decl_str
        modlist = []
        if "VISP_EXPORT" in l:
            l = l.replace("VISP_EXPORT", "")
 
        # INFO: Keep things simple for now, later uncomment and read these
        # if "CV_EXPORTS_W_SIMPLE" in l:
        #     l = l.replace("CV_EXPORTS_W_SIMPLE", "")
        #     modlist.append("/Simple")
        # npos = l.find("CV_EXPORTS_AS")
        # if npos >= 0:
        #     macro_arg, npos3 = self.get_macro_arg(l, npos)
        #     modlist.append("=" + macro_arg)
        #     l = l[:npos] + l[npos3+1:]
 
        l = self.batch_replace(l, [("public virtual ", " "), ("public ", " "), ("::", ".")]).strip()
        ll = re.split(r'\s+|\s*[,:]\s*', l)
        ll = [le for le in ll if le]
        classname = ll[1]
        bases = ll[2:]
        return classname, bases, modlist
 
    def parse_func_decl_no_wrap(self, decl_str, static_method=False, docstring=""):
        decl_str = (decl_str or "").strip()
        virtual_method = False
        explicit_method = False
        if decl_str.startswith("explicit"):
            decl_str = decl_str[len("explicit"):].lstrip()
            explicit_method = True
        if decl_str.startswith("virtual"):
            decl_str = decl_str[len("virtual"):].lstrip()
            virtual_method = True
        if decl_str.startswith("static"):
            decl_str = decl_str[len("static"):].lstrip()
            static_method = True
 
        fdecl = decl_str.replace("CV_OUT", "").replace("CV_IN_OUT", "")
        fdecl = fdecl.strip().replace("\t", " ")
        while "  " in fdecl:
            fdecl = fdecl.replace("  ", " ")
        fname = fdecl[:fdecl.find("(")].strip()
        fnpos = fname.rfind(" ")
        if fnpos < 0:
            fnpos = 0
        fname = fname[fnpos:].strip()
        rettype = fdecl[:fnpos].strip()
 
        if rettype.endswith("operator"):
            fname = ("operator " + fname).strip()
            rettype = rettype[:rettype.rfind("operator")].strip()
            if rettype.endswith("::"):
                rpos = rettype.rfind(" ")
                if rpos >= 0:
                    fname = rettype[rpos + 1:].strip() + fname
                    rettype = rettype[:rpos].strip()
                else:
                    fname = rettype + fname
                    rettype = ""
 
        apos = fdecl.find("(")
        if fname.endswith("operator"):
            fname += " ()"
            apos = fdecl.find("(", apos + 1)
 
        fname = "cv." + fname.replace("::", ".")
        decl = [fname, rettype, [], [], None, docstring]
 
        # inline constructor implementation
        implmatch = re.match(r"(\‍(.*?\‍))\s*:\s*(\w+\‍(.*?\‍),?\s*)+", fdecl[apos:])
        if bool(implmatch):
            fdecl = fdecl[:apos] + implmatch.group(1)
 
        args0str = fdecl[apos + 1:fdecl.rfind(")")].strip()
 
        if args0str != "" and args0str != "void":
            args0str = re.sub(r"\‍([^)]*\‍)", lambda m: m.group(0).replace(',', "@comma@"), args0str)
            args0 = args0str.split(",")
 
            args = []
            narg = ""
            for arg in args0:
                narg += arg.strip()
                balance_paren = narg.count("(") - narg.count(")")
                balance_angle = narg.count("<") - narg.count(">")
                if balance_paren == 0 and balance_angle == 0:
                    args.append(narg.strip())
                    narg = ""
 
            for arg in args:
                dfpos = arg.find("=")
                defval = ""
                if dfpos >= 0:
                    defval = arg[dfpos + 1:].strip()
                else:
                    dfpos = arg.find("CV_DEFAULT")
                    if dfpos >= 0:
                        defval, pos3 = self.get_macro_arg(arg, dfpos)
                    else:
                        dfpos = arg.find("CV_WRAP_DEFAULT")
                        if dfpos >= 0:
                            defval, pos3 = self.get_macro_arg(arg, dfpos)
                if dfpos >= 0:
                    defval = defval.replace("@comma@", ",")
                    arg = arg[:dfpos].strip()
                pos = len(arg) - 1
                while pos >= 0 and (arg[pos] in "_[]" or arg[pos].isalpha() or arg[pos].isdigit()):
                    pos -= 1
                if pos >= 0:
                    aname = arg[pos + 1:].strip()
                    atype = arg[:pos + 1].strip()
                    if aname.endswith("&") or aname.endswith("*") or (aname in ["int", "String", "Mat"]):
                        atype = (atype + " " + aname).strip()
                        aname = ""
                else:
                    atype = arg
                    aname = ""
                if aname.endswith("]"):
                    bidx = aname.find('[')
                    atype += aname[bidx:]
                    aname = aname[:bidx]
                decl[3].append([atype, aname, defval, []])
 
        if static_method:
            decl[2].append("/S")
        if virtual_method:
            decl[2].append("/V")
        if explicit_method:
            decl[2].append("/E")
        if bool(re.match(r".*\‍)\s*(const)?\s*=\s*0", decl_str)):
            decl[2].append("/A")
        if bool(re.match(r".*\‍)\s*const(\s*=\s*0)?", decl_str)):
            decl[2].append("/C")
        if "virtual" in decl_str:
            print(decl_str)
        return decl
 
    def parse_func_decl(self, decl_str, docstring=""):
        """
        Parses the function or method declaration in the form:
        [[VISP_EXPORTS] <rettype>]
            [~]<function_name>
            (<arg_type1> <arg_name1>[=<default_value1>] [, <arg_type2> <arg_name2>[=<default_value2>] ...])
            [const] {; | <function_body>}
 
        Returns the function declaration entry:
        [<func name>, <return value C-type>, <list of modifiers>, <list of arguments>, <original return type>, <docstring>] (see above)
        """
 
        # TODO Lets see how many functions can I add if I remove EXPORT constrain
        # if self.wrap_mode:
        #     if not (("VISP_EXPORT" in decl_str)):
        #         return []
 
        static_method = False
        if "VISP_EXPORT" in decl_str:
            static_method = True
 
        top = self.block_stack[-1]
        func_modlist = []
 
        virtual_method = False
        pure_virtual_method = False
        const_method = False
 
        # filter off some common prefixes, which are meaningless for Python wrappers.
        # note that we do not strip "static" prefix, which does matter;
        # it means class methods, not instance methods
        # INFO: Handle friend methods. open-cv didn't have any
        # INFO: Handle unsigned args/return type too. open-cv didn't have any
        # TODO: I'm removing `unsigned` keyword from function declaration
        decl_str = self.batch_replace(decl_str, [("static inline", ""),("inline", ""),
                                                 ("VISP_EXPORT", ""), ("VP_EXPLICIT", ""), ("friend", ""),('explicit','')
                                      ,("unsigned","")]).strip()
 
        if decl_str.strip().startswith('virtual'):
            virtual_method = True
 
        decl_str = decl_str.replace('virtual', '')
 
        end_tokens = decl_str[decl_str.rfind(')'):].split()
        const_method = 'const' in end_tokens
        pure_virtual_method = '=' in end_tokens and '0' in end_tokens
 
        context = top[0]
        if decl_str.startswith("static") and (context == "class" or context == "struct"):
            decl_str = decl_str[len("static"):].lstrip()
            static_method = True
 
        args_begin = decl_str.find("(")
        # INFO: open-cv had some CV-API thing here. I guess VISP doesn't need such
        if args_begin < 0:
            print("Error at %d: no args in '%s'" % (self.lineno, decl_str))
            sys.exit(-1)
 
        decl_start = decl_str[:args_begin].strip()
        # INFO: Handle operator (). Not operator << or + or any other
        if decl_start.endswith("operator"):
            args_begin = decl_str.find("(", args_begin + 1)
            if args_begin < 0:
                print("Error at %d: no args in '%s'" % (self.lineno, decl_str))
                sys.exit(-1)
            decl_start = decl_str[:args_begin].strip()
            # TODO: normalize all type of operators
            if decl_start.endswith("()"):
                decl_start = decl_start[0:-2].rstrip() + " ()"
 
        # INFO: Its not () operator but some other operator, like +,-,*
        if 'operator' in decl_str:
            return decl_str,"operator","","","",""
 
        # constructor/destructor case
        if bool(re.match(r"^(\w+::)*(?P<x>\w+)::~?(?P=x)$", decl_start)):
            decl_start = "void " + decl_start
 
        rettype, funcname, modlist, argno = self.parse_arg(decl_start, -1)
 
        # determine original return type, hack for return types with underscore
        original_type = None
        i = decl_start.rfind(funcname)
        if i > 0:
            original_type = decl_start[:i].replace("&", "").replace("const", "").strip()
 
        if argno >= 0:
            classname = top[1]
            if rettype == classname or rettype == "~" + classname:
                rettype, funcname = "", rettype
            else:
                if bool(re.match(r"\w+\s+\‍(\*\w+\‍)\s*\‍(.*\‍)", decl_str)):
                    return []  # function typedef
                elif bool(re.match(r"\w+\s+\‍(\w+::\*\w+\‍)\s*\‍(.*\‍)", decl_str)):
                    return []  # class method typedef
                elif bool(re.match("[A-Z_]+", decl_start)):
                    return []  # it seems to be a macro instantiation
                elif "__declspec" == decl_start:
                    return []
                elif bool(re.match(r"\w+\s+\‍(\*\w+\‍)\‍[\d+\‍]", decl_str)):
                    return []  # exotic - dynamic 2d array
                else:
                    # print rettype, funcname, modlist, argno
                    print("Error at %s:%d the function/method name is missing: '%s'" % (
                    self.hname, self.lineno, decl_start))
 
                    # TODO: Dont abort on an error. Just ignore and move
                    # sys.exit(-1)
                    return []
 
        if self.wrap_mode and (("::" in funcname) or funcname.startswith("~")):
            # if there is :: in function name (and this is in the header file),
            # it means, this is inline implementation of a class method.
            # Thus the function has been already declared within the class and we skip this repeated
            # declaration.
            # Also, skip the destructors, as they are always wrapped
            return []
 
        funcname = self.get_dotted_name(funcname)
 
        if not self.wrap_mode:
            decl = self.parse_func_decl_no_wrap(decl_str, static_method, docstring)
            decl[0] = funcname
            return decl
 
        arg_start = args_begin + 1
        npos = arg_start - 1
        balance = 1
        angle_balance = 0
        # scan the argument list; handle nested parentheses
        args_decls = []
        args = []
        argno = 1
 
        while balance > 0:
            npos += 1
            t, npos = self.find_next_token(decl_str, ["(", ")", ",", "<", ">"], npos)
            if not t:
                print("Error: no closing ')' at %d" % (self.lineno,))
                print(decl_str)
                print(decl_str[arg_start:])
                sys.exit(-1)
            if t == "<":
                angle_balance += 1
            if t == ">":
                angle_balance -= 1
            if t == "(":
                balance += 1
            if t == ")":
                balance -= 1
 
            if (t == "," and balance == 1 and angle_balance == 0) or balance == 0:
                # process next function argument
                a = decl_str[arg_start:npos].strip()
                # print "arg = ", a
                arg_start = npos + 1
                if a:
                    eqpos = a.find("=")
                    defval = ""
                    modlist = []
                    if eqpos >= 0:
                        defval = a[eqpos + 1:].strip()
                    else:
                        eqpos = a.find("CV_DEFAULT")
                        if eqpos >= 0:
                            defval, pos3 = self.get_macro_arg(a, eqpos)
                        else:
                            eqpos = a.find("CV_WRAP_DEFAULT")
                            if eqpos >= 0:
                                defval, pos3 = self.get_macro_arg(a, eqpos)
                    if defval == "nullptr":
                        defval = "0"
                    if eqpos >= 0:
                        a = a[:eqpos].strip()
                    arg_type, arg_name, modlist, argno = self.parse_arg(a, argno)
                    if self.wrap_mode:
                        mat = "vpMatrix"
 
                        vector_mat = "vector_{}".format("vpMatrix")
                        vector_mat_template = "vector<{}>".format("vpMatrix")
 
                        if arg_type == "InputArray":
                            arg_type = mat
                        elif arg_type == "InputOutputArray":
                            arg_type = mat
                            modlist.append("/IO")
                        elif arg_type == "OutputArray":
                            arg_type = mat
                            modlist.append("/O")
                        elif arg_type == "InputArrayOfArrays":
                            arg_type = vector_mat
                        elif arg_type == "InputOutputArrayOfArrays":
                            arg_type = vector_mat
                            modlist.append("/IO")
                        elif arg_type == "OutputArrayOfArrays":
                            arg_type = vector_mat
                            modlist.append("/O")
                        defval = self.batch_replace(defval, [("InputArrayOfArrays", vector_mat_template),
                                                             ("InputOutputArrayOfArrays", vector_mat_template),
                                                             ("OutputArrayOfArrays", vector_mat_template),
                                                             ("InputArray", mat),
                                                             ("InputOutputArray", mat),
                                                             ("OutputArray", mat),
                                                             ("noArray", arg_type)]).strip()
                    args.append([arg_type, arg_name, defval, modlist])
                npos = arg_start - 1
 
        if static_method:
            func_modlist.append("/S")
        if const_method:
            func_modlist.append("/C")
        if virtual_method:
            func_modlist.append("/V")
        if pure_virtual_method:
            func_modlist.append("/PV")
 
        return [funcname, rettype, func_modlist, args, original_type, docstring]
 
    def get_dotted_name(self, name):
        """
        adds the dot-separated container class/namespace names to the bare function/class name, e.g. when we have
 
        namespace cv {
        class A {
        public:
            f(int);
        };
        }
 
        the function will convert "A" to "cv.A" and "f" to "cv.A.f".
        """
        if not self.block_stack:
            return name
        if name.startswith("vp."):
            return name
        qualified_name = (("." in name) or ("::" in name))
        n = ""
        for b in self.block_stack:
            block_type, block_name = b[self.BLOCK_TYPE], b[self.BLOCK_NAME]
            if block_type in ["file", "enum"]:
                continue
            if block_type not in ["struct", "class", "namespace"]:
                print("Error at %d: there are non-valid entries in the current block stack " % (
                self.lineno, self.block_stack))
                sys.exit(-1)
            if block_name and (block_type == "namespace" or not qualified_name):
                n += block_name + "."
        n += name.replace("::", ".")
 
        return n
 
    def parse_stmt(self, stmt, end_token, docstring=""):
        """
        parses the statement (ending with ';' or '}') or a block head (ending with '{')
 
        The function calls parse_class_decl or parse_func_decl when necessary. It returns
        <block_type>, <block_name>, <parse_flag>, <declaration>
        where the first 3 values only make sense for blocks (i.e. code blocks, namespaces, classes, enums and such)
        """
        stack_top = self.block_stack[-1]
        context = stack_top[self.BLOCK_TYPE]
 
        stmt_type = ""
        if end_token == "{":
            stmt_type = "block"
 
        if context == "block":
            print("Error at %d: should not call parse_stmt inside blocks" % (self.lineno,))
            sys.exit(-1)
 
        if context == "class" or context == "struct":
            while 1:
                colon_pos = stmt.find(":")
                if colon_pos < 0:
                    break
                w = stmt[:colon_pos].strip()
                if w in ["public", "protected", "private"]:
                    if w == "public" or (not self.wrap_mode and w == "protected"):
                        stack_top[self.PUBLIC_SECTION] = True
                    else:
                        stack_top[self.PUBLIC_SECTION] = False
                    stmt = stmt[colon_pos + 1:].strip()
                break
 
        # do not process hidden class members and template classes/functions
        if not stack_top[self.PUBLIC_SECTION] or stmt.startswith("template"):
            return stmt_type, "", False, None
 
        if end_token == "{":
            if not self.wrap_mode and stmt.startswith("typedef struct"):
                stmt_type = "struct"
                try:
                    classname, bases, modlist = self.parse_class_decl(stmt[len("typedef "):])
                except:
                    print("Error at %s:%d" % (self.hname, self.lineno))
                    exit(1)
                if classname.startswith("_Ipl"):
                    classname = classname[1:]
                decl = [stmt_type + " " + self.get_dotted_name(classname), "", modlist, [], None, docstring]
                if bases:
                    decl[1] = ": " + ", ".join([self.get_dotted_name(b).replace(".", "::") for b in bases])
                return stmt_type, classname, True, decl
 
            if stmt.startswith("class") or stmt.startswith("struct"):
                stmt_type = stmt.split()[0]
                if stmt.strip() != stmt_type:
                    try:
                        classname, bases, modlist = self.parse_class_decl(stmt)
                    except:
                        print("Error at %s:%d" % (self.hname, self.lineno))
                        exit(1)
                    decl = []
                    if ("CV_EXPORTS_W" in stmt) or ("CV_EXPORTS_AS" in stmt) or (
                    not self.wrap_mode):  # and ("CV_EXPORTS" in stmt)):
                        decl = [stmt_type + " " + self.get_dotted_name(classname), "", modlist, [], None, docstring]
                        if bases:
                            decl[1] = ": " + ", ".join([self.get_dotted_name(b).replace(".", "::") for b in bases])
                    return stmt_type, classname, True, decl
 
            # INFO: Unlike open-cv, visp declares enum's starting with 'enum' and 'typdef enum' both.
            # INFO: If we just check for 'enum' literal at the start, might lose 'typedef enum' literals
            if stmt.startswith("enum") or stmt.startswith("typedef enum"):
                return "enum", "", True, None
 
            if stmt.startswith("namespace"):
                stmt_list = stmt.split()
                if len(stmt_list) < 2:
                    stmt_list.append("<unnamed>")
                return stmt_list[0], stmt_list[1], True, None
            if stmt.startswith("extern") and "\"C\"" in stmt:
                return "namespace", "", True, None
 
        if end_token == "}" and context == "enum":
            decl = self.parse_enum(stmt)
            return "enum", "", False, decl
 
        if end_token == ";" and stmt.startswith("typedef"):
            # TODO: handle typedef's more intelligently
            return stmt_type, "", False, None
 
        paren_pos = stmt.find("(")
        if paren_pos >= 0:
            # assume it's function or method declaration,
            # since we filtered off the other places where '(' can normally occur:
            #   - code blocks
            #   - function pointer typedef's
            decl = self.parse_func_decl(stmt, docstring=docstring)
            # we return parse_flag == False to prevent the parser to look inside function/method bodies
            # (except for tracking the nested blocks)
            return stmt_type, "", False, decl
 
        if (context == "struct" or context == "class") and end_token == ";" and stmt:
            # looks like it's member declaration; append the members to the class declaration
            class_decl = stack_top[self.CLASS_DECL]
            if ("CV_PROP" in stmt):  # or (class_decl and ("/Map" in class_decl[2])):
                var_modlist = []
                if "CV_PROP_RW" in stmt:
                    var_modlist.append("/RW")
                stmt = self.batch_replace(stmt, [("CV_PROP_RW", ""), ("CV_PROP", "")]).strip()
                var_list = stmt.split(",")
                var_type, var_name1, modlist, argno = self.parse_arg(var_list[0], -1)
                var_list = [var_name1] + [i.strip() for i in var_list[1:]]
 
                for v in var_list:
                    class_decl[3].append([var_type, v, "", var_modlist])
            return stmt_type, "", False, None
 
        # something unknown
        return stmt_type, "", False, None
 
    def find_next_token(self, s, tlist, p=0):
        """
        Finds the next token from the 'tlist' in the input 's', starting from position 'p'.
        Returns the first occurred token and its position, or ("", len(s)) when no token is found
        """
        token = ""
        tpos = len(s)
        for t in tlist:
            pos = s.find(t, p)
            if pos < 0:
                continue
            if pos < tpos:
                tpos = pos
                token = t
        return token, tpos
 
    def parse(self, hname, wmode=True):
        """
        The main method. Parses the input file.
        Returns the list of declarations (that can be print using print_decls)
        """
        self.hname = hname
        decls = []
        f = io.open(hname, 'rt', encoding='utf-8')
        linelist = list(f.readlines())
        f.close()
 
        # states:
        SCAN = 0  # outside of a comment or preprocessor directive
        COMMENT = 1  # inside a multi-line comment
        DIRECTIVE = 2  # inside a multi-line preprocessor directive
        DOCSTRING = 3  # inside a multi-line docstring
 
        state = SCAN
 
        self.block_stack = [["file", hname, True, True, None]]
        block_head = ""
        docstring = ""
        self.lineno = 0
        self.wrap_mode = wmode
 
        for l0 in linelist:
            self.lineno += 1
 
            l = l0.strip()  # INFO: Remove Trailing Whitespaces
 
            if state == SCAN and l.startswith("#"):
                state = DIRECTIVE
                # fall through to the if state == DIRECTIVE check
 
            # INFO: All #inlcude <visp/stg.h> are ignored
            if state == DIRECTIVE:
                if not l.endswith("\\"):
                    state = SCAN
                continue
 
            if state == COMMENT:
                pos = l.find("*/")
                if pos < 0:
                    continue
                l = l[pos + 2:]
                state = SCAN
 
            if state == DOCSTRING:
                pos = l.find("*/")
                if pos < 0:
                    docstring += l + "\n"
                    continue
                docstring += l[:pos] + "\n"
                l = l[pos + 2:]
                state = SCAN
 
            if state != SCAN:
                print("Error at %d: invalid state = %d" % (self.lineno, state))
                sys.exit(-1)
 
            while 1:
                token, pos = self.find_next_token(l, [";", "\"", "{", "}", "//", "/*"])
 
                if not token:
                    block_head += " " + l
                    break
 
                if token == "//":
                    block_head += " " + l[:pos]
                    break
 
                if token == "/*":
                    block_head += " " + l[:pos]
                    end_pos = l.find("*/", pos + 2)
 
                    # INFO: open-cv follows Javadoc style (/**) for docstring, visp follows C Style(/*!) or Javadoc style (/**)
                    if len(l) > pos + 2 and ((l[pos + 2] == "!") or (l[pos + 2] == "*")):
                        # '/**', it's a docstring
                        if end_pos < 0:
                            state = DOCSTRING
                            docstring = l[pos + 3:] + "\n"
                            break
                        else:
                            docstring = l[pos + 3:end_pos]
 
                    elif end_pos < 0:
                        state = COMMENT
                        break
                    l = l[end_pos + 2:]
                    continue
 
                if token == "\"":
                    pos2 = pos + 1
                    while 1:
                        t2, pos2 = self.find_next_token(l, ["\\", "\""], pos2)
                        if t2 == "":
                            print("Error at %d: no terminating '\"'" % (self.lineno,))
                            sys.exit(-1)
                        if t2 == "\"":
                            break
                        pos2 += 2
 
                    block_head += " " + l[:pos2 + 1]
                    l = l[pos2 + 1:]
                    continue
 
                # INFO: U reach here means token is ;
 
                stmt = (block_head + " " + l[:pos]).strip()
                stmt = " ".join(stmt.split())  # normalize the statement
                # print(stmt)
                stack_top = self.block_stack[-1]
 
                if stmt.startswith("@"):
                    # Objective C ?
                    break
 
                decl = None
                if "BEGIN_VISP_NAMESPACE" in stmt:
                  stmt = stmt.replace("BEGIN_VISP_NAMESPACE", "")
                  stmt = stmt.strip()
                if "END_VISP_NAMESPACE" in stmt:
                  stmt = stmt.replace("END_VISP_NAMESPACE", "")
                  stmt = stmt.strip()
                if stack_top[self.PROCESS_FLAG]:
                    # even if stack_top[PUBLIC_SECTION] is False, we still try to process the statement,
                    # since it can start with "public:"
                    docstring = docstring.strip()
                    stmt_type, name, parse_flag, decl = self.parse_stmt(stmt, token, docstring=docstring)
                    if decl:
                        if stmt_type == "enum":
                            for d in decl:
                                decls.append(d)
                        else:
                            decls.append(decl)
                        docstring = ""
                    if stmt_type == "namespace":
                        chunks = [block[1] for block in self.block_stack if block[0] == 'namespace'] + [name]
                        for i in range(len(chunks)):
                            if chunks[i] == "VISP_NAMESPACE_NAME":
                                chunks[i] = "visp"
                        self.namespaces.add('.'.join(chunks))
                else:
                    stmt_type, name, parse_flag = "block", "", False
 
                if token == "{":
                    if stmt_type == "class":
                        public_section = False
                    else:
                        public_section = True
                    self.block_stack.append([stmt_type, name, parse_flag, public_section, decl])
 
                if token == "}":
                    if not self.block_stack:
                        print("Error at %d: the block stack is empty" % (self.lineno,))
                    self.block_stack[-1:] = []
                    if pos + 1 < len(l) and l[pos + 1] == ';':
                        pos += 1
 
                block_head = ""
                l = l[pos + 1:]
 
        return decls
 
    def print_decls(self, decls):
        """
        Prints the list of declarations, retrieived by the parse() method
        """
        for d in decls:
            print(d[0], d[1], ";".join(d[2]))
            # Uncomment below line to see docstrings
            # print('"""\n' + d[5] + '\n"""')
            for a in d[3]:
                print("   ", a[0], a[1], a[2], end="")
                if a[3]:
                    print("; ".join(a[3]))
                else:
                    print()