#!/usr/bin/python
#
# Copyright (c)  2012 Yannick Brosseau <yannick.brosseau@gmail.com>
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; only version 2
# of the License.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License along
# with this program; if not, write to the Free Software Foundation, Inc.,
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

import sys
import getopt
import re
import os
import subprocess

class Usage(Exception):
    def __init__(self, msg):
        self.msg = msg

class HeaderFile:
    HEADER_TPL="""
#undef TRACEPOINT_PROVIDER
#define TRACEPOINT_PROVIDER {providerName}

#undef TRACEPOINT_INCLUDE_FILE
#define TRACEPOINT_INCLUDE_FILE ./{headerFilename}

#ifdef __cplusplus
extern "C"{{
#endif /* __cplusplus */


#if !defined({includeGuard}) || defined(TRACEPOINT_HEADER_MULTI_READ)
#define {includeGuard}

#include <lttng/tracepoint.h>

"""
    FOOTER_TPL="""
#endif /* {includeGuard} */

#include <lttng/tracepoint-event.h>

#ifdef __cplusplus
}}
#endif /* __cplusplus */

"""
    def __init__(self, filename, template):
        self.outputFilename = filename
        self.template = template

    def write(self):
        outputFile = open(self.outputFilename,"w")
        includeGuard = "_"+self.outputFilename.upper().replace(".","_")

        outputFile.write(HeaderFile.HEADER_TPL.format(providerName=self.template.domain,
                                           includeGuard = includeGuard,
                                           headerFilename = self.outputFilename))
        outputFile.write(self.template.text)
        outputFile.write(HeaderFile.FOOTER_TPL.format(includeGuard = includeGuard))
        outputFile.close()

class CFile:
    FILE_TPL="""
#define TRACEPOINT_CREATE_PROBES
/*
 * The header containing our TRACEPOINT_EVENTs.
 */
#define TRACEPOINT_DEFINE
#include "{headerFilename}"
"""
    def __init__(self, filename, template):
        self.outputFilename = filename
        self.template = template

    def write(self):
        outputFile = open(self.outputFilename,"w")

        headerFilename = self.outputFilename.replace(".c",".h")

        outputFile.write(CFile.FILE_TPL.format(
                                           headerFilename = headerFilename))
        outputFile.close()

class ObjFile:
    def __init__(self, filename, template):
        self.outputFilename = filename
        self.template = template
    def _detectCC(self):
        cc = ""
        if os.environ.has_key('CC'):
            cc = os.environ['CC']
            try:
                subprocess.call(cc,
                                stdout=subprocess.PIPE,
                                stderr=subprocess.PIPE)
            except OSError, msg:
                print "Invalid CC environment variable"
                cc = ""

        else:
            # Try c first, if that fails try gcc
            try:
                useCC = True
                subprocess.call("cc",
                                stdout=subprocess.PIPE,
                                stderr=subprocess.PIPE)
            except OSError, msg:
                useCC = False
            if useCC:
                cc = "cc"

            else:
                try:
                    useGCC = True
                    subprocess.call("gcc",
                                    stdout=subprocess.PIPE,
                                    stderr=subprocess.PIPE)
                except OSError, msg:
                    useGCC = False
                if useGCC:
                    cc = "gcc"
        return cc

    def write(self):
        cFilename = self.outputFilename.replace(".o",".c")
        cc = self._detectCC()
        if cc == "":
            raise RuntimeError("No C Compiler detected")
        if os.environ.has_key('CFLAGS'):
            cflags = os.environ['CFLAGS']
        else:
            cflags = ""

        command = cc + " -c " + cflags + " -I. -llttng-ust" + " -o " + self.outputFilename + " " + cFilename
        subprocess.call(command.split())

class TemplateFile:
    def __init__(self, filename):
        self.domain = ""
        self.inputFilename = filename
        self.parseTemplate()


    def parseTemplate(self):
        f = open(self.inputFilename,"r")

        self.text = f.read()

        #Remove # comments (from input and output file
        removeComments = re.compile("#.*$",flags=re.MULTILINE)
        self.text = removeComments.sub("",self.text)
        #Remove // comments
        removeLineComment = re.compile("\/\/.*$",flags=re.MULTILINE)
        nolinecomment = removeLineComment.sub("",self.text)
        #Remove all spaces and lines
        cleantext = re.sub("\s*","",nolinecomment)
        #Remove multine C style comments
        nocomment = re.sub("/\*.*?\*/","",cleantext)
        entries = re.split("TRACEPOINT_.*?",nocomment)

        for entry in entries:
            if entry != '':
                decomp = re.findall("(\w*?)\((\w*?),(\w*?),", entry)
                typea = decomp[0][0]
                domain = decomp[0][1]
                name = decomp[0][2]

                if self.domain == "":
                    self.domain = domain
                else:
                    if self.domain != domain:
                        print "Warning: different domain provided (%s,%s)" % (self.domain, domain)

usage="""
 lttng-gen-tp - Generate the LTTng-UST header and source based on a simple template

 usage: lttng-gen-tp TEMPLATE_FILE [-o OUTPUT_FILE][-o OUTPUT_FILE]

 If no OUTPUT_FILE is given, the .h and .c file will be generated.
 (The basename of the template file with be used for the generated file.
  for example sample.tp will generate sample.h, sample.c and sample.o)

 When using the -o option, the OUTPUT_FILE must end with either .h, .c or .o
 The -o option can be repeated multiple times.

 The template file must contains TRACEPOINT_EVENT and TRACEPOINT_LOGLEVEL
 as per defined in the lttng/tracepoint.h file.
 See the lttng-ust(3) man page for more details on the format.
"""
def main(argv=None):
    if argv is None:
        argv = sys.argv

    try:
        try:
            opts, args = getopt.gnu_getopt(argv[1:], "ho:a", ["help"])
        except getopt.error, msg:
             raise Usage(msg)
        if len(args) == 0:
            raise Usage("No template file given")

    except Usage, err:
        print >>sys.stderr, err.msg
        print >>sys.stderr, "for help use --help"
        return 2

    outputNames = []
    for o, a in opts:
        if o in ("-h", "--help"):
            print usage
            return(0)
        if o in ("-o",""):
            outputNames.append(a)
        if o in ("-a",""):
            all = True

    doCFile = None
    doHeader = None
    doObj = None
    headerFilename = None
    cFilename = None
    objFilename = None

    if len(outputNames) > 0:
        if len(args) > 1:
            print "Cannot process more than one input if you specify an output"
            return(3)

        for outputName in outputNames:
            if outputName[-2:] == ".h":
                doHeader = True
                headerFilename = outputName
            elif outputName[-2:] == ".c":
                doCFile = True
                cFilename = outputName
            elif outputName[-2:] == ".o":
                doObj = True
                objFilename = outputName
            else:
                print "output file type unsupported"
                return(4)
    else:
        doHeader = True
        doCFile = True
        doObj = True

    # process arguments
    for arg in args:

        tpl = None
        try:
            tpl = TemplateFile(arg)
        except IOError as args:
            print "Cannot read input file " + args.filename + " " + args.strerror
            return -1
        try:
            if doHeader:
                if headerFilename:
                    curFilename = headerFilename
                else:
                    curFilename = re.sub("\.tp$",".h",arg)
                doth = HeaderFile(curFilename, tpl)
                doth.write()
            if doCFile:
                if cFilename:
                    curFilename = cFilename
                else:
                    curFilename = re.sub("\.tp$",".c",arg)
                dotc = CFile(curFilename, tpl)
                dotc.write()
            if doObj:
                if objFilename:
                    curFilename = objFilename
                else:
                    curFilename = re.sub("\.tp$",".o",arg)
                dotobj = ObjFile(curFilename, tpl)
                dotobj.write()
        except IOError as args:
            print "Cannot write output file " + args.filename + " " + args.strerror 
            return -1
        
if __name__ == "__main__":
    sys.exit(main())