1/* Find the correct compiler.
2   Copyright (C) 2014-2022 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#include "system.h"
29
30class scanner
31{
32public:
33
34  scanner (const std::string &dir)
35  {
36    m_dir = opendir (dir.c_str ());
37  }
38
39  ~scanner ()
40  {
41    if (m_dir != NULL)
42      closedir (m_dir);
43  }
44
45  const char *next ()
46  {
47    if (m_dir == NULL)
48      return NULL;
49
50    struct dirent *entry = readdir (m_dir);
51    if (entry == NULL)
52      return NULL;
53
54    return entry->d_name;
55  }
56
57private:
58
59  DIR *m_dir;
60};
61
62static bool
63search_dir (const regex_t &regexp, const std::string &dir, std::string *result)
64{
65  scanner scan (dir);
66  const char *filename;
67
68  while ((filename = scan.next ()) != NULL)
69    {
70      if (regexec (&regexp, filename, 0, NULL, 0) == 0)
71	{
72	  *result = dir + DIR_SEPARATOR + filename;
73	  return true;
74	}
75    }
76
77  return false;
78}
79
80class tokenizer
81{
82public:
83
84  tokenizer (const char *str)
85    : m_str (str),
86      m_pos (0)
87  {
88  }
89
90  bool done () const
91  {
92    return m_pos == std::string::npos;
93  }
94
95  std::string next ()
96  {
97    std::string::size_type last_pos = m_pos;
98    std::string::size_type colon = m_str.find(':', last_pos);
99
100    std::string result;
101    if (colon == std::string::npos)
102      {
103	m_pos = colon;
104	result = m_str.substr(last_pos, colon);
105      }
106    else
107      {
108	m_pos = colon + 1;
109	result = m_str.substr(last_pos, colon - last_pos);
110      }
111    if (result == "")
112      result = ".";
113
114    return result;
115  }
116
117private:
118
119  std::string m_str;
120  std::string::size_type m_pos;
121};
122
123bool
124find_compiler (const regex_t &regexp, std::string *result)
125{
126  const char *cpath = getenv ("PATH");
127
128  if (cpath == NULL)
129    return false;
130
131  tokenizer dirs (cpath);
132  while (!dirs.done ())
133    {
134      std::string dir = dirs.next ();
135      if (search_dir (regexp, dir, result))
136	return true;
137    }
138
139  return false;
140}
141