#!/usr/bin/python3 -tt

# Copyright 2012 Jussi Pakkanen

# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at

#     http://www.apache.org/licenses/LICENSE-2.0

# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import subprocess, os.path

class EnvironmentException(Exception):
    def __init(self, text):
        Exception.__init__(self, text)

def detect_c_compiler(execmd):
    exelist = execmd.split()
    p = subprocess.Popen(exelist + ['--version'], stdout=subprocess.PIPE)
    (out, err) = p.communicate()
    out = out.decode()
    if (out.startswith('cc ') or out.startswith('gcc')) and \
        'Free Software Foundation' in out:
        return GnuCCompiler(exelist)
    raise EnvironmentException('Unknown compiler "' + execmd + '"')

class CCompiler():
    def __init__(self, exelist):
        if type(exelist) == type(''):
            self.exelist = [exelist]
        elif type(exelist) == type([]):
            self.exelist = exelist
        else:
            raise TypeError('Unknown argument to CCompiler')

    def get_exelist(self):
        return self.exelist
    
    def get_compile_only_flags(self):
        return ['-c']
    
    def get_output_flags(self):
        return ['-o']
    
    def can_compile(self, filename):
        suffix = filename.split['.'][-1]
        if suffix == 'c' or suffix == 'h':
            return True
        return False
    
    def name_string(self):
        return ' '.join(self.exelist)
    
    def sanity_check(self, work_dir):
        source_name = os.path.join(work_dir, 'sanitycheck.c')
        binary_name = os.path.join(work_dir, 'sanitycheck')
        ofile = open(source_name, 'w')
        ofile.write('int main(int argc, char **argv) { return 0; }\n')
        ofile.close()
        pc = subprocess.Popen(self.exelist + [source_name, '-o', binary_name])
        pc.wait()
        if pc.returncode != 0:
            raise RuntimeError('Compiler %s can not compile programs.' % self.name_string())
        pe = subprocess.Popen(binary_name)
        pe.wait()
        if pe.returncode != 0:
            raise RuntimeError('Executables created by compiler %s are not runnable.' % self.name_string())

class GnuCCompiler(CCompiler):
    std_warn_flags = ['-Wall', '-Winvalid-pch']
    std_opt_flags = ['-O2']
    
    def __init__(self, exelist):
        CCompiler.__init__(self, exelist)

    def get_std_warn_flags(self):
        return GnuCCompiler.std_warn_flags

    def get_std_opt_flags(self):
        return GnuCCompiler.std_opt_flags

def shell_quote(cmdlist):
    return ["'" + x + "'" for x in cmdlist]

def test_cmd_line_building():
    src_file = 'file.c'
    dst_file = 'file.o'
    gnuc = detect_c_compiler('/usr/bin/cc')
    cmds = gnuc.get_exelist()
    cmds += gnuc.get_std_warn_flags()
    cmds += gnuc.get_compile_only_flags()
    cmds.append(src_file)
    cmds += gnuc.get_output_flags()
    cmds.append(dst_file)
    cmd_line = ' '.join(shell_quote(cmds))
    print(cmd_line)

if __name__ == '__main__':
    test_cmd_line_building()