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[CMD] CALL: Fix the implementation of the CALL command, make it more compatible with Windows' CMD.

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- 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.
This commit is contained in:
Hermès Bélusca-Maïto 2020-07-26 20:30:21 +02:00
parent 4f4af5d271
commit 37bda06eed
No known key found for this signature in database
GPG key ID: 3B2539C65E7B93D0
5 changed files with 218 additions and 34 deletions
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33
base/shell/cmd/batch.c
View file

@ -399,9 +399,28 @@ INT Batch(LPTSTR fullname, LPTSTR firstword, LPTSTR param, PARSED_COMMAND *Cmd)
#endif
}
/* Check if this is a "CALL :label" */
if (*firstword == _T(':'))
ret = cmd_goto(firstword);
/* If this is a "CALL :label args ...", call a subroutine of
* the current batch file, only if extensions are enabled. */
if (bEnableExtensions && (*firstword == _T(':')))
{
LPTSTR expLabel;
/* Position at the place of the parent file (which is the same as the caller) */
bc->mempos = (bc->prev ? bc->prev->mempos : 0);
/*
* Jump to the label. Strip the label's colon; as a side-effect
* this will forbid "CALL :EOF"; however "CALL ::EOF" will work!
*/
bc->current = Cmd;
++firstword;
/* Expand the label only! (simulate a GOTO command as in Windows' CMD) */
expLabel = DoDelayedExpansion(firstword);
ret = cmd_goto(expLabel ? expLabel : firstword);
if (expLabel)
cmd_free(expLabel);
}
/* If we have created a new context, don't return
* until this batch file has completed. */
@ -548,8 +567,16 @@ LPTSTR ReadBatchLine(VOID)
TRACE("ReadBatchLine(): textline: \'%s\'\n", debugstr_aw(textline));
#if 1
//
// FIXME: This is redundant, but keep it for the moment until we correctly
// hande the end-of-file situation here, in ReadLine() and in the parser.
// (In an EOF, the previous BatchGetString() call will return FALSE but
// we want not to run the ExitBatch() at first, but wait later to do it.)
//
if (textline[_tcslen(textline) - 1] != _T('\n'))
_tcscat(textline, _T("\n"));
#endif
return textline;
}

185
base/shell/cmd/call.c
View file

@ -30,58 +30,189 @@
#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)
{
TCHAR line[CMDLINE_LENGTH + 1];
TCHAR *first;
BOOL bInQuote = FALSE;
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))
TRACE("cmd_call(\'%s\')\n", debugstr_aw(param));
if (!_tcsncmp(param, _T("/?"), 2))
{
ConOutResPaging(TRUE,STRING_CALL_HELP);
ConOutResPaging(TRUE, STRING_CALL_HELP);
return 0;
}
/* Do a second round of %-variable substitutions */
if (!SubstituteVars(param, line, _T('%')))
/* Fail if no command or label has been provided */
if (*param == _T('\0'))
return (nErrorLevel = 1);
/* Find start and end of first word */
first = line;
while (_istspace(*first))
first++;
/* Ignore parser comments (starting with a colon) */
bOldIgnoreParserComments = bIgnoreParserComments;
bIgnoreParserComments = FALSE;
for (param = first; *param; param++)
#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)
{
if (!bInQuote && (_istspace(*param) || _tcschr(_T(",;="), *param)))
break;
bInQuote ^= (*param == _T('"'));
first = _tcschr(first, _T('^'));
if (first)
{
++nNumCarets;
++first;
}
}
/* Separate first word from rest of line */
memmove(param + 1, param, (_tcslen(param) + 1) * sizeof(TCHAR));
*param++ = _T('\0');
/* Re-allocate a large enough parameter string if needed */
if (nNumCarets > 0)
{
PTCHAR Src, Dest, End;
if (*first == _T(':') && bc)
// 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;
/* CALL :label - call a subroutine of the current batch file */
while (*param == _T(' '))
param++;
/* 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);
return nErrorLevel;
}
else
{
nErrorLevel = DoCommand(first, param, NULL);
}
nErrorLevel = DoCommand(first, param, NULL);
FreeCommand(Cmd);
return nErrorLevel;
}

3
base/shell/cmd/cmd.h
View file

@ -424,6 +424,9 @@ VOID ParseErrorEx(IN PCTSTR s);
extern BOOL bParseError;
extern TCHAR ParseLine[CMDLINE_LENGTH];
extern BOOL bIgnoreParserComments;
extern BOOL bHandleContinuations;
/* Prototypes from PATH.C */
INT cmd_path (LPTSTR);

19
base/shell/cmd/goto.c
View file

@ -41,7 +41,24 @@ INT cmd_goto(LPTSTR param)
TRACE("cmd_goto(\'%s\')\n", debugstr_aw(param));
if (!_tcsncmp(param, _T("/?"), 2))
/*
* Keep the help message handling here too.
* This allows us to reproduce the Windows' CMD "bug"
* (from a batch script):
*
* SET label=/?
* CALL :%%label%%
*
* calls GOTO help, due to how CALL :label functionality
* is internally implemented.
*
* See https://stackoverflow.com/q/31987023/13530036
* for more details.
*
* Note that the choice of help parsing forbids
* any label containing '/?' in it.
*/
if (_tcsstr(param, _T("/?")))
{
ConOutResPaging(TRUE, STRING_GOTO_HELP1);
return 0;

12
base/shell/cmd/parser.c
View file

@ -93,6 +93,9 @@ static BOOL bLineContinuations;
static PTCHAR ParsePos;
static PTCHAR OldParsePos;
BOOL bIgnoreParserComments = TRUE;
BOOL bHandleContinuations = TRUE;
static TCHAR CurrentToken[CMDLINE_LENGTH];
static TOK_TYPE CurrentTokenType = TOK_END;
#ifndef MSCMD_PARSER_BUGS
@ -206,6 +209,9 @@ restart:
if (!ReadLine(ParseLine, TRUE))
{
/* ^C pressed, or line was too long */
//
// FIXME: Distinguish with respect to BATCH end of file !!
//
bParseError = TRUE;
}
else
@ -445,7 +451,7 @@ ParseToken(
IN TCHAR ExtraEnd OPTIONAL,
IN PCTSTR Separators OPTIONAL)
{
return ParseTokenEx(0, ExtraEnd, Separators, TRUE);
return ParseTokenEx(0, ExtraEnd, Separators, bHandleContinuations);
}
@ -1294,7 +1300,7 @@ ParseCommandBinaryOp(
if (OpType == C_OP_LOWEST) // i.e. CP_MULTI
{
/* Ignore any parser-level comments */
if (*CurrentToken == _T(':'))
if (bIgnoreParserComments && (*CurrentToken == _T(':')))
{
/* Ignore the rest of the line, including line continuations */
while (ParseToken(0, NULL) != TOK_END)
@ -1445,7 +1451,7 @@ ParseCommandOp(
/* Parse the prefix "quiet" operator '@' as a separate command.
* Thus, @@foo@bar is parsed as: '@', '@', 'foo@bar'. */
ParseTokenEx(_T('@'), _T('('), STANDARD_SEPS, TRUE);
ParseTokenEx(_T('@'), _T('('), STANDARD_SEPS, bHandleContinuations);
return ParseCommandBinaryOp(OpType);
}