1/* Find the correct compiler.
2   Copyright (C) 2014 Free Software Foundation, Inc.
3
4This file is part of GCC.
5
6GCC is free software; you can redistribute it and/or modify it under
7the terms of the GNU General Public License as published by the Free
8Software Foundation; either version 3, or (at your option) any later
9version.
10
11GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12WARRANTY; without even the implied warranty of MERCHANTABILITY or
13FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14for more details.
15
16You should have received a copy of the GNU General Public License
17along with GCC; see the file COPYING3.  If not see
18<http://www.gnu.org/licenses/>.  */
19
20#include <config.h>
21#include <string>
22#include <dirent.h>
23#include <stdlib.h>
24
25#include "libiberty.h"
26#include "xregex.h"
27#include "findcomp.hh"
28
29class scanner
30{
31public:
32
33  scanner (const std::string &dir)
34  {
35    m_dir = opendir (dir.c_str ());
36  }
37
38  ~scanner ()
39  {
40    if (m_dir != NULL)
41      closedir (m_dir);
42  }
43
44  const char *next ()
45  {
46    if (m_dir == NULL)
47      return NULL;
48
49    struct dirent *entry = readdir (m_dir);
50    if (entry == NULL)
51      return NULL;
52
53    return entry->d_name;
54  }
55
56private:
57
58  DIR *m_dir;
59};
60
61static bool
62search_dir (const regex_t &regexp, const std::string &dir, std::string *result)
63{
64  scanner scan (dir);
65  const char *filename;
66
67  while ((filename = scan.next ()) != NULL)
68    {
69      if (regexec (&regexp, filename, 0, NULL, 0) == 0)
70	{
71	  *result = filename;
72	  return true;
73	}
74    }
75
76  return false;
77}
78
79class tokenizer
80{
81public:
82
83  tokenizer (const char *str)
84    : m_str (str),
85      m_pos (0)
86  {
87  }
88
89  bool done () const
90  {
91    return m_pos == std::string::npos;
92  }
93
94  std::string next ()
95  {
96    std::string::size_type last_pos = m_pos;
97    std::string::size_type colon = m_str.find(':', last_pos);
98
99    std::string result;
100    if (colon == std::string::npos)
101      {
102	m_pos = colon;
103	result = m_str.substr(last_pos, colon);
104      }
105    else
106      {
107	m_pos = colon + 1;
108	result = m_str.substr(last_pos, colon - last_pos);
109      }
110    if (result == "")
111      result = ".";
112
113    return result;
114  }
115
116private:
117
118  std::string m_str;
119  std::string::size_type m_pos;
120};
121
122bool
123find_compiler (const regex_t &regexp, std::string *result)
124{
125  const char *cpath = getenv ("PATH");
126
127  if (cpath == NULL)
128    return false;
129
130  tokenizer dirs (cpath);
131  while (!dirs.done ())
132    {
133      std::string dir = dirs.next ();
134      if (search_dir (regexp, dir, result))
135	return true;
136    }
137
138  return false;
139}
140