xref: /netbsd-src/external/gpl3/gcc.old/dist/libcc1/findcomp.cc (revision d16b7486a53dcb8072b60ec6fcb4373a2d0c27b7)
1 /* Find the correct compiler.
2    Copyright (C) 2014-2020 Free Software Foundation, Inc.
3 
4 This file is part of GCC.
5 
6 GCC is free software; you can redistribute it and/or modify it under
7 the terms of the GNU General Public License as published by the Free
8 Software Foundation; either version 3, or (at your option) any later
9 version.
10 
11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14 for more details.
15 
16 You should have received a copy of the GNU General Public License
17 along 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 
30 class scanner
31 {
32 public:
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 
57 private:
58 
59   DIR *m_dir;
60 };
61 
62 static bool
63 search_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 
80 class tokenizer
81 {
82 public:
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 
117 private:
118 
119   std::string m_str;
120   std::string::size_type m_pos;
121 };
122 
123 bool
124 find_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