dmake/msdos/spawn.c

   1 /* RCS  $Id: spawn.c,v 1.3 2007-10-15 15:43:28 ihi Exp $
   2 --
   3 -- SYNOPSIS
   4 --      Spawnvpe code to emulate spawnvpe call common to DOS compilers.
   5 --
   6 -- DESCRIPTION
   7 --  This implementation is further integrated into dmake in that it
   8 --  determines the program to execute and if it's extension is either
   9 --  .bat or .ksh it executes it using the appropriate shell based on the
  10 --  setting of .MKSARGS.  If .MKSARGS is set then in addition
  11 --  to the command tail getting built the arguments are also passed in the
  12 --  environment pursuant to the published MKS argument passing conventions.
  13 --  If the variable Swap_on_exec is set and the DOS OS supports it
  14 --  then the dmake executable image is swapped to secondary storage prior
  15 --  to running the child process.  This is requested by setting the
  16 --  appropriate flag in the call to exec.
  17 --
  18 --  This and the exec.asm routine are derived from work that was supplied
  19 --  to me by Kent Williams (williams@umaxc.weeg.uiowa.edu) and by
  20 --      Len Reed, (..!gatech!holos0!lbr or holos0!lbr@gatech.edu., Holos
  21 --  Software, Inc., Tucker, Ga.).  I sincerely acknowledge their help since
  22 --  their Turbo C, and MSC 6.0 code lead directly to this combined
  23 --  swapping exec that hopefully works with either compiler in all memory
  24 --  models.
  25 --
  26 -- AUTHOR
  27 --      Dennis Vadura, dvadura@dmake.wticorp.com
  28 --
  29 -- WWW
  30 --      http://dmake.wticorp.com/
  31 --
  32 -- COPYRIGHT
  33 --      Copyright (c) 1996,1997 by WTI Corp.  All rights reserved.
  34 --
  35 --      This program is NOT free software; you can redistribute it and/or
  36 --      modify it under the terms of the Software License Agreement Provided
  37 --      in the file <distribution-root>/readme/license.txt.
  38 --
  39 -- LOG
  40 --      Use cvs log to obtain detailed change logs.
  41 */
  42
  43 #include <stdio.h>
  44 #include <stdlib.h>
  45
  46 #if defined(_MSC_VER) && _MSC_VER >= 600
  47     /* Ignore the MSC 6.0 library's "const"-riddled prototype
  48        for spawnvpe.
  49     */
  50 # define spawnvpe _ignore_msc_spawnvpe
  51 # include <process.h>
  52 # undef spawnvpe
  53   int spawnvpe(int, char *, char **, char **);
  54 #else
  55 # include <process.h>
  56 #endif
  57
  58 #include <dos.h>
  59 #include <errno.h>
  60 #include <string.h>
  61 #include <alloc.h>
  62 #include <fcntl.h>
  63 #include "extern.h"
  64 #include "dosdta.h"
  65 #include "exec.h"
  66 #include "sysintf.h"
  67
  68 extern int Interrupted;
  69
  70 /* variables and functions local to this file */
  71 static char     *_findexec ANSI((char *, int *));
  72 static char    **_getpath ANSI(());
  73 static char far *_dos_alloc ANSI((uint16));
  74
  75 static uint16 _swap_mask;
  76 static int    _mks_args;
  77 static char   dot_com[] = ".COM",
  78           dot_exe[] = ".EXE",
  79               dot_bat[] = ".BAT",
  80           dot_ksh[] = ".KSH";
  81
  82 /* Kinds of executables */
  83 #define SCR 1
  84 #define COM 2
  85 #define EXE 4
  86 #define ALL (SCR|COM|EXE)
  87
  88 /* How to make a long pointer */
  89 #define CF(x) (char far *)x
  90
  91 /* Make sure we know how to get a segment out of a long pointer */
  92 #ifndef FP_SEG
  93 #define FP_SEG(fp)  ((unsigned)((unsigned long)(fp) >> 16))
  94 #endif
  95
  96 iz81252 changed the parameters for Pack_argv() but this file did not get fixed!
  97 PUBLIC int
  98 spawnvpe(mode, program, av, ep)/*
  99 =================================
 100    Spawn a process using an environment and a vector of arguments.
 101    The code computes a new environment, puts the MKS arguments into
 102    it if need be, and calls the appropriate routines to search the
 103    path and to invoke the process. */
 104 int  mode;
 105 char *program;
 106 char **av;
 107 char **ep;
 108 {
 109    char pwd[PATH_MAX+1];
 110    char **envp = ep;        /* Cause we are going to mess with it. */
 111    char **argv = av;        /* Same with this one.             */
 112    char cmdtail[129];
 113    char far *environment;
 114    char *tail;
 115    char *swptmp;
 116    unsigned int envsize;
 117    unsigned int cmdsize;
 118    int  cmdtailen;
 119    int  i;
 120    int  doswap;
 121
 122    /* First check to see if we can find the program to execute this way we
 123     * don't alloc the environment and other such stuff prior to figuring out
 124     * we don't know how to run the program. */
 125 find_program:
 126    if((program = _findexec(program, &i)) == NIL(char)) {
 127       errno = ENOENT;
 128       return( -1 );
 129    }
 130
 131    /* i is set to TRUE in _findexec if the exec is a shell
 132     * script (either .BAT or .KSH file), returns FALSE for all others. */
 133    if( i && !Packed_shell ) {
 134       /* Restore the spaces into the command line that were erased by
 135        * the previous call to Pack_argv.  This enables us to repack the
 136        * command as a shell command using Pack_argv again. */
 137       for( i=0; argv[i] != NIL(char); i++ ) {
 138          int x = strlen(argv[i]);
 139          if( argv[i+1] != NIL(char) ) argv[i][x] = ' ';
 140       }
 141
 142       argv = Pack_argv( FALSE, TRUE, *argv );
 143       Packed_shell = TRUE; /* Previous call implies shell = TRUE. */
 144
 145       /* Go and find the program again, I hate goto's but it seems silly to
 146        * use tail recursion here just for aesthetic purity. */
 147       program = *argv;
 148       goto find_program;
 149    }
 150
 151    /* Compute size of *argv vector for passing as MKS style arguments */
 152    cmdsize = strlen(*argv)+2;
 153
 154    /* So we have decided on a program to run, therefore pack the command tail
 155     * and build the environment to pass to the exec code.  This loop packs the
 156     * DOS command tail, and computes the size of all arguments for the MKS
 157     * argument passing convention.  Note that we reserve one less byte in the
 158     * command tail if we are not using MKS style argument passing.
 159     *
 160     * Make sure the command tail contains at leat a space.  Some commands fail
 161     * to work if the command tail is only a \r, STUPID DOS! */
 162    cmdtailen = ((_mks_args = ((Glob_attr & A_MKSARGS) != 0)) != 0)?3:2;
 163    tail      = cmdtail+1;
 164
 165    if( argv[1] != NIL(char) )
 166       for( i=1; argv[i] != NIL(char); i++ ) {
 167      int arglen = strlen(argv[i]);
 168
 169      cmdsize += arglen+2;       /* Compute all args size for MKS */
 170
 171      if( (cmdtailen += arglen+1) <= 128 ) {
 172         register char *p = argv[i];
 173         tail[-1] = ' ';     /* put in the space */
 174         while( *tail++ = *p++ );    /* put in the arg   */
 175      }
 176      else if( !_mks_args ) {
 177         errno = E2BIG;      /* unless its MKS exit if arglist */
 178         return(-1);         /* is too long.           */
 179      }
 180       }
 181    else
 182       *tail++ = ' ';
 183
 184    /* Finish the command tail set up, placing the length in the first byte,
 185     * and the \r \n \0 at the end for DOS, MKS and us respectively. */
 186    *cmdtail = tail-cmdtail-2;
 187    tail[-1] = '\r';
 188    if( _mks_args ) *tail++ = '\n';
 189    *tail = '\0';
 190
 191    /* Compute size of environment, skipping any MKS arguments passed in our
 192     * environment */
 193    for(; *envp && **envp == '~'; envp++ );
 194    for(i=0, envsize=_mks_args?cmdsize:1; envp[i] != NIL(char); i++ )
 195       envsize += strlen(envp[i]) + 1;
 196
 197    /* Check the DOS version number here.  If it is < 3.0 then we don't
 198     * even want to think about executing the swapping code.   Permanently
 199     * set swap to 0. */
 200    doswap = (_osmajor < 3) ? 0 : Swap_on_exec;
 201
 202    /* Set up temporary file for swapping */
 203    swptmp = doswap?tempnam(NIL(char),"mk"):"";
 204
 205    /* Allocate an appropriate sized environment block and align it on a
 206     * paragraph boundary.  It will later get copied to an appropriately low
 207     * place in the executable image so that when we swap out the environment
 208     * is still present.  Use
 209     *    _dos_alloc
 210     * to allocate the environment segment.  The segment is freed by the call
 211     * to exec. */
 212    environment = _dos_alloc( envsize = ((envsize+16)>>4) );
 213    *environment = '\0';
 214
 215    /* First copy the arguments preceeded by ~ character if we are using
 216     * MKS style argument passing */
 217    if( _mks_args )
 218       for(; *argv; argv++) {
 219          register char *p = *argv;
 220
 221      *environment++ = '~';
 222      while( *environment++ = *p++ );    /* Far dest, poss near ptr */
 223       }
 224
 225    /* Now stick in the current evironment vectors. */
 226    for(; *envp; envp++) {
 227       register char *p = *envp;
 228       while( *environment++ = *p++ );       /* Far dest, poss near ptr */
 229    }
 230
 231    /* Clear the interrupted flag, and exec  */
 232    Interrupted = 0;
 233
 234    /* Preserve the current working directory accross a spawn call
 235     * DOS is brain dead about this.  This way we have some hope of cleaning
 236     * up the swapping tempfiles after we return. */
 237    strcpy(pwd,Get_current_dir());
 238    i = exec(doswap,CF(program),CF(cmdtail),FP_SEG(environment),CF(swptmp));
 239    Set_dir(pwd);
 240
 241    /* Now free the temporary file name */
 242    if( doswap ) FREE(swptmp);
 243
 244    /* If swap was interrupted then quit properly from dmake. */
 245    if( Interrupted ) Quit();
 246
 247    return(i);
 248 }
 249
 250
 251 PUBLIC void
 252 Hook_std_writes( file )
 253 char *file;
 254 {
 255    if( file!= NIL(char) ) {
 256       int mode = O_BINARY | O_WRONLY | O_CREAT | O_TRUNC;
 257       int handle;
 258
 259       if (*file == '+') {
 260           ++file;             /* -F +file means append to file */
 261           mode = O_BINARY | O_WRONLY | O_CREAT | O_APPEND;
 262       }
 263       handle = open(file, mode, S_IREAD | S_IWRITE);
 264       if (handle < 0) {
 265           Fatal( "Could not open -F file");
 266       }
 267       (void) lseek(handle, 0L, SEEK_END);
 268       do_hook_std_writes(handle);
 269    }
 270    else
 271       do_unhook_std_writes();
 272 }
 273
 274
 275 /*
 276 ** _findexec finds executables on the path.
 277 ** Note that it is pretty simple to add support for other executable types
 278 ** shell scripts, etc.
 279 **
 280 ** This follows the command.com behavior very closely.
 281 */
 282 static char *
 283 _findexec( s, is_shell )/*
 284 ==========================
 285    Cloned closely from code provided by Kent Williams.  Stripped his down to
 286    a reduced search since dmake doesn't need to recompute the PATH vector
 287    each time it does the search since it cannot alter the path vector once
 288    it begins to make recipes.  Also modified it to use findfirst and findnext
 289    as provided for dirlib package that I got off the net. */
 290 char *s;
 291 int  *is_shell;
 292 {
 293    unsigned found_flags;
 294    char     **pathv = NIL(char *);
 295    char     *ext    = NIL(char);
 296    char     *buf    = NIL(char);
 297    char     *p[2];
 298    char     *dot_scr;
 299    char     *dot;
 300
 301    p[0] = ""; p[1] = NIL(char);
 302    if( strchr("./\\", *s) || s[1] == ':' )
 303       pathv = p;
 304    else if( (pathv = _getpath()) == NIL(char *) )
 305       return( NIL(char) );
 306
 307    /* Compute the extension we need if any. */
 308    if( (dot = strrchr(s,'.')) != NIL(char) &&
 309         dot > strrchr(s,'/') && dot > strrchr(s,'\\') )
 310       ext = dot+1;
 311
 312    dot_scr   = _mks_args ? dot_ksh : dot_bat;
 313    *is_shell = FALSE;
 314
 315    for( found_flags = 0; *pathv && !found_flags; pathv++ ) {
 316       DTA dta;
 317
 318       if( !ext ) {
 319      char *name;
 320      buf = Build_path( *pathv, name=DmStrJoin(s, ".???", -1, FALSE) );
 321      FREE(name);
 322       }
 323       else
 324      buf = Build_path( *pathv, s );
 325
 326       if( findfirst((char *)strupr(buf), &dta) != NIL(DTA) ) {
 327      if( !ext ) {
 328         char *dot;
 329
 330         /* search order is .com .exe (.ksh || .bat)
 331          * there has to be a '.' */
 332         do {
 333            dot = strrchr(dta.name,'.');
 334            if(0 == strcmp(dot,dot_com))
 335           found_flags |= COM;
 336            else if(0 == strcmp(dot,dot_exe))
 337           found_flags |= EXE;
 338            else if( 0 == strcmp(dot,dot_scr) )
 339           found_flags |= SCR;
 340         } while( found_flags != ALL && findnext(&dta) != NIL(DTA) );
 341
 342         if(found_flags & COM)      ext = dot_com;
 343         else if(found_flags & EXE) ext = dot_exe;
 344         else if(found_flags & SCR) {
 345            ext = dot_scr;
 346            *is_shell = TRUE;
 347         }
 348
 349         if( found_flags ) {
 350            char *name;
 351            buf = Build_path( *pathv, name=DmStrJoin(s,ext,-1,FALSE) );
 352            FREE(name);
 353            strupr(buf);
 354         }
 355      }
 356      else
 357         found_flags++;
 358       }
 359    }
 360
 361    return( found_flags ? buf : NIL(char) );
 362 }
 363
 364
 365 /*
 366 ** getpath turns the DOS path into a char *vector, It is gotten and
 367 ** transformed only once since dmake can't modify the value of PATH while
 368 ** it is making targets.
 369 */
 370 static char **
 371 _getpath()
 372 {
 373    static   char **dir = NIL(char *);
 374    register char *p;
 375
 376    if( !dir ) {
 377       register char *t;
 378       int           i;
 379       char          *semi = NIL(char);
 380
 381       if( (p = getenv("PATH")) == NIL(char) ) p = "";
 382       for( i=1, t=p; *t; t++ ) if( *t == ';' ) i++;
 383
 384       TALLOC(dir, i+1, char *);
 385       p   = DmStrDup(p);
 386
 387       for( i=0; p; p = semi ? (semi+1):NIL(char),i++ ){
 388      if( (semi = strchr(p,';')) != NIL(char) ) *semi = '\0';
 389      dir[i] = p;
 390       }
 391       dir[i]=NIL(char);
 392    }
 393
 394    return( dir );
 395 }
 396
 397
 398 static char far *
 399 _dos_alloc( size )/*
 400 ====================
 401    This routine allocates size paragraphs from DOS.  It changes the memory
 402    allocation strategy to allocate from the tail and then changes it back.
 403    to using first fit. */
 404 uint16 size;
 405 {
 406    union REGS r;
 407
 408    r.h.ah = 0x48;
 409    r.x.bx = size;
 410
 411    intdos( &r, &r );
 412    if( r.x.cflag ) No_ram();
 413
 414    return( (char far *) MK_FP(r.x.ax, 0) );
 415 }