reactos/base/shell/cmd/call.c
Hermès Bélusca-Maïto 37bda06eed
[CMD] CALL: Fix the implementation of the CALL command, make it more compatible with Windows' CMD.
- Fail if no parameter is provided.

- The "CALL :label args..." syntax is available only when command extensions
  are enabled. Fail if this syntax is used outside of a batch context.

- Reparse the CALL command parameter with the command parser, in order
  to accurately parse and interpret it as a possible command (including
  escape carets, etc...) and not duplicate the logic.
  ** CURRENT Windows' CMD-compatibility LIMITATION ** (may be lifted in
  a "ROS-specific" running mode of CMD): only allow standard commands to
  be specified as parameter of the CALL command.

  This reparsing behaviour can be observed in Windows' CMD, by dumping
  the interpreted commands after enabling the cmd!fDumpParse flag from
  a debugger (using public symbols).

- When reparsing, we should tell the parser to NOT ignore lines that
  start with a colon, because in this situation these are to be
  considered as valid "commands" (for parsing "CALL :label").

  * For Windows' CMD-compatibility, the remaining escape carets need to
    be doubled again so that, after the new parser step, they are escaped
    back to their original form. But then we also need to do it the "buggy"
    way à la Windows, where carets in quotes are doubled either! However
    when being re-parsed, since they are in quotes they remain doubled!!
    (see "Phase 6" in https://stackoverflow.com/a/4095133/13530036 ).

  * A MSCMD_CALL_QUIRKS define allows to disable this buggy behaviour,
    and instead tell the parser to not not interpret the escape carets.

- When initializing a new batch context when the "CALL :label" syntax is
  used, ensure that we reuse the same batch file position pointer as its
  parent, so as to have correct call label ordering behaviour.

  That is,

  :label
  ECHO hi
  CALL :label
  :label
  ECHO bye

  should display:

  hi
  bye
  bye

  i.e., the CALL calls the second label instead of the first one (and
  thus entering into an infinite loop).

  Finally, the "CALL :label" syntax strips the first ':' away, so, as a
  side-effect, the command "CALL :EOF" fails (otherwise it would perform
  a "GOTO :EOF" and succeeds), while "CALL ::EOF" succeeds.

Fixes some cmd_winetests.
2020-09-27 19:05:23 +02:00

219 lines
5.8 KiB
C

/*
* CALL.C - call internal batch command.
*
*
* History:
*
* 16 Jul 1998 (Hans B Pufal)
* started.
*
* 16 Jul 1998 (John P Price)
* Separated commands into individual files.
*
* 27-Jul-1998 (John P Price <linux-guru@gcfl.net>)
* added config.h include
*
* 04-Aug-1998 (Hans B Pufal)
* added lines to initialize for pointers (HBP004) This fixed the
* lock-up that happened sometimes when calling a batch file from
* another batch file.
*
* 07-Jan-1999 (Eric Kohl)
* Added help text ("call /?") and cleaned up.
*
* 20-Jan-1999 (Eric Kohl)
* Unicode and redirection safe!
*
* 02-Apr-2005 (Magnus Olsen <magnus@greatlord.com>)
* Remove all hardcoded strings in En.rc
*/
#include "precomp.h"
/* Enable this define for "buggy" Windows' CMD CALL-command compatibility */
#define MSCMD_CALL_QUIRKS
/*
* Perform CALL command.
*/
INT cmd_call(LPTSTR param)
{
PARSED_COMMAND* Cmd = NULL;
BOOL bOldIgnoreParserComments;
#ifndef MSCMD_CALL_QUIRKS
BOOL bOldHandleContinuations;
#else
SIZE_T nNumCarets;
#endif
PTSTR first;
TRACE("cmd_call(\'%s\')\n", debugstr_aw(param));
if (!_tcsncmp(param, _T("/?"), 2))
{
ConOutResPaging(TRUE, STRING_CALL_HELP);
return 0;
}
/* Fail if no command or label has been provided */
if (*param == _T('\0'))
return (nErrorLevel = 1);
/* Ignore parser comments (starting with a colon) */
bOldIgnoreParserComments = bIgnoreParserComments;
bIgnoreParserComments = FALSE;
#ifndef MSCMD_CALL_QUIRKS
/* Disable parsing of escape carets */
bOldHandleContinuations = bHandleContinuations;
bHandleContinuations = FALSE;
first = param;
#else
/*
* As the original escape carets have been dealt with during the first
* command parsing step, the remaining ones need to be doubled so that
* they can again survive the new parsing step done below.
* But do it the Windows' CMD "buggy" way: **all** carets are doubled,
* even those inside quotes. However, this causes carets inside quotes
* to remain doubled after the parsing step...
*/
/* Count all the carets */
nNumCarets = 0;
first = param;
while (first)
{
first = _tcschr(first, _T('^'));
if (first)
{
++nNumCarets;
++first;
}
}
/* Re-allocate a large enough parameter string if needed */
if (nNumCarets > 0)
{
PTCHAR Src, Dest, End;
// TODO: Improvement: Use the scratch TempBuf if the string is not too long.
first = cmd_alloc((_tcslen(param) + nNumCarets + 1) * sizeof(TCHAR));
if (!first)
{
WARN("Cannot allocate memory for new CALL parameter string!\n");
error_out_of_memory();
return (nErrorLevel = 1);
}
/* Copy the parameter string and double the escape carets */
Src = param;
Dest = first;
while (*Src)
{
if (*Src != _T('^'))
{
/* Copy everything before the next caret (or the end of the string) */
End = _tcschr(Src, _T('^'));
if (!End)
End = Src + _tcslen(Src);
memcpy(Dest, Src, (End - Src) * sizeof(TCHAR));
Dest += End - Src;
Src = End;
continue;
}
/* Copy the original caret and double it */
*Dest++ = *Src;
*Dest++ = *Src++;
}
*Dest = _T('\0');
}
else
{
first = param;
}
#endif
/*
* Reparse the CALL parameter string as a command.
* Note that this will trigger a second round of %-variable substitutions.
*/
Cmd = ParseCommand(first);
/* Restore the global parsing state */
#ifndef MSCMD_CALL_QUIRKS
bHandleContinuations = bOldHandleContinuations;
#endif
bIgnoreParserComments = bOldIgnoreParserComments;
/*
* If no command is there, yet no error occurred, this means that
* a whitespace label was given. Do not consider this as a failure.
*/
if (!Cmd && !bParseError)
{
#ifdef MSCMD_CALL_QUIRKS
if (first != param)
cmd_free(first);
#endif
return (nErrorLevel = 0);
}
/* Reset bParseError so as to continue running afterwards */
bParseError = FALSE;
/*
* Otherwise, if no command is there because a parse error occurred,
* or if this an unsupported command: not a standard one, including
* FOR and IF, fail and bail out.
*/
if (!Cmd || (Cmd->Type == C_FOR) || (Cmd->Type == C_IF) ||
((Cmd->Type != C_COMMAND) && (Cmd->Type != C_REM)))
{
// FIXME: Localize
ConErrPrintf(_T("%s was unexpected.\n"), first);
#ifdef MSCMD_CALL_QUIRKS
if (first != param)
cmd_free(first);
#endif
if (Cmd) FreeCommand(Cmd);
return (nErrorLevel = 1);
}
#ifdef MSCMD_CALL_QUIRKS
if (first != param)
cmd_free(first);
#endif
first = Cmd->Command.First;
param = Cmd->Command.Rest;
/* "CALL :label args ..." - Call a subroutine of the current batch file, only if extensions are enabled */
if (bEnableExtensions && (*first == _T(':')))
{
INT ret;
/* A batch context must be present */
if (!bc)
{
// FIXME: Localize
ConErrPuts(_T("Invalid attempt to call batch label outside of batch script.\n"));
FreeCommand(Cmd);
return (nErrorLevel = 1);
}
ret = Batch(bc->BatchFilePath, first, param, NULL);
nErrorLevel = (ret != 0 ? ret : nErrorLevel);
}
else
{
nErrorLevel = DoCommand(first, param, NULL);
}
FreeCommand(Cmd);
return nErrorLevel;
}
/* EOF */