libiberty/pex-common.h

   1 /* Utilities to execute a program in a subprocess (possibly linked by pipes
   2    with other subprocesses), and wait for it.  Shared logic.
   3    Copyright (C) 1996-2021 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 #ifndef PEX_COMMON_H
  22 #define PEX_COMMON_H
  23
  24 #include "config.h"
  25 #include "libiberty.h"
  26 #include <stdio.h>
  27
  28 /* pid_t is may defined by config.h or sys/types.h needs to be
  29    included.  */
  30 #if !defined(pid_t) && defined(HAVE_SYS_TYPES_H)
  31 #include <sys/types.h>
  32 #endif
  33
  34 #define install_error_msg "installation problem, cannot exec `%s'"
  35
  36 /* stdin file number.  */
  37 #define STDIN_FILE_NO 0
  38
  39 /* stdout file number.  */
  40 #define STDOUT_FILE_NO 1
  41
  42 /* stderr file number.  */
  43 #define STDERR_FILE_NO 2
  44
  45 /* value of `pipe': port index for reading.  */
  46 #define READ_PORT 0
  47
  48 /* value of `pipe': port index for writing.  */
  49 #define WRITE_PORT 1
  50
  51 /* The structure used by pex_init and friends.  */
  52
  53 struct pex_obj
  54 {
  55   /* Flags.  */
  56   int flags;
  57   /* Name of calling program, for error messages.  */
  58   const char *pname;
  59   /* Base name to use for temporary files.  */
  60   const char *tempbase;
  61   /* Pipe to use as stdin for next process.  */
  62   int next_input;
  63   /* File name to use as stdin for next process.  */
  64   char *next_input_name;
  65   /* Whether next_input_name was allocated using malloc.  */
  66   int next_input_name_allocated;
  67   /* If not -1, stderr pipe from the last process.  */
  68   int stderr_pipe;
  69   /* Number of child processes.  */
  70   int count;
  71   /* PIDs of child processes; array allocated using malloc.  */
  72   pid_t *children;
  73   /* Exit statuses of child processes; array allocated using malloc.  */
  74   int *status;
  75   /* Time used by child processes; array allocated using malloc.  */
  76   struct pex_time *time;
  77   /* Number of children we have already waited for.  */
  78   int number_waited;
  79   /* FILE created by pex_input_file.  */
  80   FILE *input_file;
  81   /* FILE created by pex_read_output.  */
  82   FILE *read_output;
  83   /* FILE created by pex_read_err.  */
  84   FILE *read_err;
  85   /* Number of temporary files to remove.  */
  86   int remove_count;
  87   /* List of temporary files to remove; array allocated using malloc
  88      of strings allocated using malloc.  */
  89   char **remove;
  90   /* Pointers to system dependent functions.  */
  91   const struct pex_funcs *funcs;
  92   /* For use by system dependent code.  */
  93   void *sysdep;
  94 };
  95
  96 /* Functions passed to pex_run_common.  */
  97
  98 struct pex_funcs
  99 {
 100   /* Open file NAME for reading.  If BINARY is non-zero, open in
 101      binary mode.  Return >= 0 on success, -1 on error.  */
 102   int (*open_read) (struct pex_obj *, const char */* name */, int /* binary */);
 103   /* Open file NAME for writing.  If BINARY is non-zero, open in
 104      binary mode.  Return >= 0 on success, -1 on error.  */
 105   int (*open_write) (struct pex_obj *, const char */* name */,
 106                      int /* binary */, int /* append */);
 107   /* Execute a child process.  FLAGS, EXECUTABLE, ARGV, ERR are from
 108      pex_run.  IN, OUT, ERRDES, TOCLOSE are all descriptors, from
 109      open_read, open_write, or pipe, or they are one of STDIN_FILE_NO,
 110      STDOUT_FILE_NO or STDERR_FILE_NO; if IN, OUT, and ERRDES are not
 111      STD*_FILE_NO, they should be closed.  If the descriptor TOCLOSE
 112      is not -1, and the system supports pipes, TOCLOSE should be
 113      closed in the child process.  The function should handle the
 114      PEX_STDERR_TO_STDOUT flag.  Return >= 0 on success, or -1 on
 115      error and set *ERRMSG and *ERR.  */
 116   pid_t (*exec_child) (struct pex_obj *, int /* flags */,
 117                       const char */* executable */, char * const * /* argv */,
 118                       char * const * /* env */,
 119                       int /* in */, int /* out */, int /* errdes */,
 120                       int /* toclose */, const char **/* errmsg */,
 121                       int */* err */);
 122   /* Close a descriptor.  Return 0 on success, -1 on error.  */
 123   int (*close) (struct pex_obj *, int);
 124   /* Wait for a child to complete, returning exit status in *STATUS
 125      and time in *TIME (if it is not null).  CHILD is from fork.  DONE
 126      is 1 if this is called via pex_free.  ERRMSG and ERR are as in
 127      fork.  Return 0 on success, -1 on error.  */
 128   pid_t (*wait) (struct pex_obj *, pid_t /* child */, int * /* status */,
 129                struct pex_time * /* time */, int /* done */,
 130                const char ** /* errmsg */, int * /* err */);
 131   /* Create a pipe (only called if PEX_USE_PIPES is set) storing two
 132      descriptors in P[0] and P[1].  If BINARY is non-zero, open in
 133      binary mode.  Return 0 on success, -1 on error.  */
 134   int (*pipe) (struct pex_obj *, int * /* p */, int /* binary */);
 135   /* Get a FILE pointer to read from a file descriptor (only called if
 136      PEX_USE_PIPES is set).  If BINARY is non-zero, open in binary
 137      mode.  Return pointer on success, NULL on error.  */
 138   FILE * (*fdopenr) (struct pex_obj *, int /* fd */, int /* binary */);
 139   /* Get a FILE pointer to write to the file descriptor FD (only
 140      called if PEX_USE_PIPES is set).  If BINARY is non-zero, open in
 141      binary mode.  Arrange for FD not to be inherited by the child
 142      processes.  Return pointer on success, NULL on error.  */
 143   FILE * (*fdopenw) (struct pex_obj *, int /* fd */, int /* binary */);
 144   /* Free any system dependent data associated with OBJ.  May be
 145      NULL if there is nothing to do.  */
 146   void (*cleanup) (struct pex_obj *);
 147 };
 148
 149 extern struct pex_obj *pex_init_common (int, const char *, const char *,
 150                                         const struct pex_funcs *);
 151
 152 #endif