1 /* Utilities to execute a program in a subprocess (possibly linked by pipes
2    with other subprocesses), and wait for it.  Generic MSDOS specialization.
3    Copyright (C) 1996-2020 Free Software Foundation, Inc.
4 
5 This file is part of the libiberty library.
6 Libiberty is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Library General Public
8 License as published by the Free Software Foundation; either
9 version 2 of the License, or (at your option) any later version.
10 
11 Libiberty is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14 Library General Public License for more details.
15 
16 You should have received a copy of the GNU Library General Public
17 License along with libiberty; see the file COPYING.LIB.  If not,
18 write to the Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor,
19 Boston, MA 02110-1301, USA.  */
20 
21 #include "pex-common.h"
22 
23 #include <stdio.h>
24 #include <errno.h>
25 #ifdef NEED_DECLARATION_ERRNO
26 extern int errno;
27 #endif
28 #ifdef HAVE_STRING_H
29 #include <string.h>
30 #endif
31 #ifdef HAVE_STDLIB_H
32 #include <stdlib.h>
33 #endif
34 
35 #include "safe-ctype.h"
36 #include <process.h>
37 
38 /* The structure we keep in obj->sysdep.  */
39 
40 #define PEX_MSDOS_FILE_COUNT 3
41 
42 #define PEX_MSDOS_FD_OFFSET 10
43 
44 struct pex_msdos
45 {
46   /* An array of file names.  We refer to these using file descriptors
47      of 10 + array index.  */
48   const char *files[PEX_MSDOS_FILE_COUNT];
49   /* Exit statuses of programs which have been run.  */
50   int *statuses;
51 };
52 
53 static int pex_msdos_open (struct pex_obj *, const char *, int);
54 static int pex_msdos_open (struct pex_obj *, const char *, int);
55 static int pex_msdos_fdindex (struct pex_msdos *, int);
56 static pid_t pex_msdos_exec_child (struct pex_obj *, int, const char *,
57 				  char * const *, char * const *,
58 				  int, int, int, int,
59 				  int, const char **, int *);
60 static int pex_msdos_close (struct pex_obj *, int);
61 static pid_t pex_msdos_wait (struct pex_obj *, pid_t, int *, struct pex_time *,
62 			   int, const char **, int *);
63 static void pex_msdos_cleanup (struct pex_obj *);
64 
65 /* The list of functions we pass to the common routines.  */
66 
67 const struct pex_funcs funcs =
68 {
69   pex_msdos_open,
70   pex_msdos_open,
71   pex_msdos_exec_child,
72   pex_msdos_close,
73   pex_msdos_wait,
74   NULL, /* pipe */
75   NULL, /* fdopenr */
76   NULL, /* fdopenw */
77   pex_msdos_cleanup
78 };
79 
80 /* Return a newly initialized pex_obj structure.  */
81 
82 struct pex_obj *
pex_init(int flags,const char * pname,const char * tempbase)83 pex_init (int flags, const char *pname, const char *tempbase)
84 {
85   struct pex_obj *ret;
86   int i;
87 
88   /* MSDOS does not support pipes.  */
89   flags &= ~ PEX_USE_PIPES;
90 
91   ret = pex_init_common (flags, pname, tempbase, funcs);
92 
93   ret->sysdep = XNEW (struct pex_msdos);
94   for (i = 0; i < PEX_MSDOS_FILE_COUNT; ++i)
95     ret->files[i] = NULL;
96   ret->statuses = NULL;
97 
98   return ret;
99 }
100 
101 /* Open a file.  FIXME: We ignore the binary argument, since we have
102    no way to handle it.  */
103 
104 static int
pex_msdos_open(struct pex_obj * obj,const char * name,int binary ATTRIBUTE_UNUSED)105 pex_msdos_open (struct pex_obj *obj, const char *name,
106 		int binary ATTRIBUTE_UNUSED)
107 {
108   struct pex_msdos *ms;
109   int i;
110 
111   ms = (struct pex_msdos *) obj->sysdep;
112 
113   for (i = 0; i < PEX_MSDOS_FILE_COUNT; ++i)
114     {
115       if (ms->files[i] == NULL)
116 	{
117 	  ms->files[i] = xstrdup (name);
118 	  return i + PEX_MSDOS_FD_OFFSET;
119 	}
120     }
121 
122   abort ();
123 }
124 
125 /* Get the index into msdos->files associated with an open file
126    descriptor.  */
127 
128 static int
pex_msdos_fdindex(struct pex_msdos * ms,int fd)129 pex_msdos_fdindex (struct pex_msdos *ms, int fd)
130 {
131   fd -= PEX_MSDOS_FD_OFFSET;
132   if (fd < 0 || fd >= PEX_MSDOS_FILE_COUNT || ms->files[fd] == NULL)
133     abort ();
134   return fd;
135 }
136 
137 
138 /* Close a file.  */
139 
140 static int
pex_msdos_close(struct pex_obj * obj,int fd)141 pex_msdos_close (struct pex_obj *obj, int fd)
142 {
143   struct pex_msdos *ms;
144   int fdinex;
145 
146   ms = (struct pex_msdos *) obj->sysdep;
147   fdindex = pe_msdos_fdindex (ms, fd);
148   free (ms->files[fdindex]);
149   ms->files[fdindex] = NULL;
150 }
151 
152 /* Execute a child.  */
153 
154 static pid_t
pex_msdos_exec_child(struct pex_obj * obj,int flags,const char * executable,char * const * argv,char * const * env,int in,int out,int toclose ATTRIBUTE_UNUSED,int errdes ATTRIBUTE_UNUSED,const char ** errmsg,int * err)155 pex_msdos_exec_child (struct pex_obj *obj, int flags, const char *executable,
156 		      char * const * argv, char * const * env, int in, int out,
157 		      int toclose ATTRIBUTE_UNUSED,
158 		      int errdes ATTRIBUTE_UNUSED, const char **errmsg,
159 		      int *err)
160 {
161   struct pex_msdos *ms;
162   char *temp_base;
163   int temp_base_allocated;
164   char *rf;
165   int inindex;
166   char *infile;
167   int outindex;
168   char *outfile;
169   char *scmd;
170   FILE *argfile;
171   int i;
172   int status;
173 
174   ms = (struct pex_msdos *) obj->sysdep;
175 
176   /* FIXME: I don't know how to redirect stderr, so we ignore ERRDES
177      and PEX_STDERR_TO_STDOUT.  */
178 
179   temp_base = obj->temp_base;
180   if (temp_base != NULL)
181     temp_base_allocated = 0;
182   else
183     {
184       temp_base = choose_temp_base ();
185       temp_base_allocated = 1;
186     }
187 
188   rf = concat (temp_base, ".gp", NULL);
189 
190   if (temp_base_allocated)
191     free (temp_base);
192 
193   if (in == STDIN_FILE_NO)
194     {
195       inindex = -1;
196       infile = "";
197     }
198   else
199     {
200       inindex = pex_msdos_fdindex (ms, in);
201       infile = ms->files[inindex];
202     }
203 
204   if (out == STDOUT_FILE_NO)
205     {
206       outindex = -1;
207       outfile = "";
208     }
209   else
210     {
211       outindex = pex_msdos_fdindex (ms, out);
212       outfile = ms->files[outindex];
213     }
214 
215   scmd = XNEWVEC (char, strlen (program)
216 		  + ((flags & PEXECUTE_SEARCH) != 0 ? 4 : 0)
217 		  + strlen (rf)
218 		  + strlen (infile)
219 		  + strlen (outfile)
220 		  + 10);
221   sprintf (scmd, "%s%s @%s%s%s%s%s",
222 	   program,
223 	   (flags & PEXECUTE_SEARCH) != 0 ? ".exe" : "",
224 	   rf,
225 	   inindex != -1 ? " <" : "",
226 	   infile,
227 	   outindex != -1 ? " >" : "",
228 	   outfile);
229 
230   argfile = fopen (rf, "w");
231   if (argfile == NULL)
232     {
233       *err = errno;
234       free (scmd);
235       free (rf);
236       *errmsg = "cannot open temporary command file";
237       return (pid_t) -1;
238     }
239 
240   for (i = 1; argv[i] != NULL; ++i)
241     {
242       char *p;
243 
244       for (p = argv[i]; *p != '\0'; ++p)
245 	{
246 	  if (*p == '"' || *p == '\'' || *p == '\\' || ISSPACE (*p))
247 	    putc ('\\', argfile);
248 	  putc (*p, argfile);
249 	}
250       putc ('\n', argfile);
251     }
252 
253   fclose (argfile);
254 
255   status = system (scmd);
256 
257   if (status == -1)
258     {
259       *err = errno;
260       remove (rf);
261       free (scmd);
262       free (rf);
263       *errmsg = "system";
264       return (pid_t) -1;
265     }
266 
267   remove (rf);
268   free (scmd);
269   free (rf);
270 
271   /* Save the exit status for later.  When we are called, obj->count
272      is the number of children which have executed before this
273      one.  */
274   ms->statuses = XRESIZEVEC(int, ms->statuses, obj->count + 1);
275   ms->statuses[obj->count] = status;
276 
277   return (pid_t) obj->count;
278 }
279 
280 /* Wait for a child process to complete.  Actually the child process
281    has already completed, and we just need to return the exit
282    status.  */
283 
284 static pid_t
pex_msdos_wait(struct pex_obj * obj,pid_t pid,int * status,struct pex_time * time,int done ATTRIBUTE_UNUSED,const char ** errmsg ATTRIBUTE_UNUSED,int * err ATTRIBUTE_UNUSED)285 pex_msdos_wait (struct pex_obj *obj, pid_t pid, int *status,
286 		struct pex_time *time, int done ATTRIBUTE_UNUSED,
287 		const char **errmsg ATTRIBUTE_UNUSED,
288 		int *err ATTRIBUTE_UNUSED)
289 {
290   struct pex_msdos *ms;
291 
292   ms = (struct pex_msdos *) obj->sysdep;
293 
294   if (time != NULL)
295     memset (time, 0, sizeof *time);
296 
297   *status = ms->statuses[pid];
298 
299   return 0;
300 }
301 
302 /* Clean up the pex_msdos structure.  */
303 
304 static void
pex_msdos_cleanup(struct pex_obj * obj)305 pex_msdos_cleanup (struct pex_obj  *obj)
306 {
307   struct pex_msdos *ms;
308   int i;
309 
310   ms = (struct pex_msdos *) obj->sysdep;
311   for (i = 0; i < PEX_MSDOS_FILE_COUNT; ++i)
312     free (msdos->files[i]);
313   free (msdos->statuses);
314   free (msdos);
315   obj->sysdep = NULL;
316 }
317