reactos/base/shell/cmd/parser.c
Hermès Bélusca-Maïto 3f892a8d6b
[CMD] Add missing memory allocation NULL checks (#161). CORE-8304
Adapted from a patch by Jacob S. Preciado.

Bring also the code suggestions emitted during review.
2018-08-21 14:02:24 +02:00

1034 lines
26 KiB
C

/*
* PARSER.C - command parsing.
*/
#include "precomp.h"
#define C_OP_LOWEST C_MULTI
#define C_OP_HIGHEST C_PIPE
static const TCHAR OpString[][3] = { _T("&"), _T("||"), _T("&&"), _T("|") };
static const TCHAR RedirString[][3] = { _T("<"), _T(">"), _T(">>") };
static const TCHAR *const IfOperatorString[] =
{
_T("cmdextversion"),
_T("defined"),
_T("errorlevel"),
_T("exist"),
#define IF_MAX_UNARY IF_EXIST
_T("=="),
_T("equ"),
_T("gtr"),
_T("geq"),
_T("lss"),
_T("leq"),
_T("neq"),
#define IF_MAX_COMPARISON IF_NEQ
};
/* These three characters act like spaces to the parser in most contexts */
#define STANDARD_SEPS _T(",;=")
static BOOL IsSeparator(TCHAR Char)
{
return _istspace(Char) || (Char && _tcschr(STANDARD_SEPS, Char));
}
enum
{
TOK_END,
TOK_NORMAL,
TOK_OPERATOR,
TOK_REDIRECTION,
TOK_BEGIN_BLOCK,
TOK_END_BLOCK
};
static BOOL bParseError;
static BOOL bLineContinuations;
static TCHAR ParseLine[CMDLINE_LENGTH];
static TCHAR *ParsePos;
static TCHAR CurChar;
static TCHAR CurrentToken[CMDLINE_LENGTH];
static int CurrentTokenType;
static int InsideBlock;
static TCHAR ParseChar(void)
{
TCHAR Char;
if (bParseError)
return (CurChar = 0);
restart:
/*
* Although CRs can be injected into a line via an environment
* variable substitution, the parser ignores them - they won't
* even separate tokens.
*/
do
{
Char = *ParsePos++;
}
while (Char == _T('\r'));
if (!Char)
{
ParsePos--;
if (bLineContinuations)
{
if (!ReadLine(ParseLine, TRUE))
{
/* ^C pressed, or line was too long */
bParseError = TRUE;
}
else if (*(ParsePos = ParseLine))
{
goto restart;
}
}
}
return (CurChar = Char);
}
static void ParseError(void)
{
error_syntax(CurrentTokenType != TOK_END ? CurrentToken : NULL);
bParseError = TRUE;
}
/*
* Yes, cmd has a Lexical Analyzer. Whenever the parser gives an "xxx was
* unexpected at this time." message, it shows what the last token read was.
*/
static int ParseToken(TCHAR ExtraEnd, TCHAR *Separators)
{
TCHAR *Out = CurrentToken;
TCHAR Char;
int Type;
BOOL bInQuote = FALSE;
for (Char = CurChar; Char && Char != _T('\n'); Char = ParseChar())
{
bInQuote ^= (Char == _T('"'));
if (!bInQuote)
{
if (Separators != NULL)
{
if (_istspace(Char) || _tcschr(Separators, Char))
{
/* Skip leading separators */
if (Out == CurrentToken)
continue;
break;
}
}
/* Check for numbered redirection */
if ((Char >= _T('0') && Char <= _T('9') &&
(ParsePos == &ParseLine[1] || IsSeparator(ParsePos[-2]))
&& (*ParsePos == _T('<') || *ParsePos == _T('>'))))
{
break;
}
if (Char == ExtraEnd)
break;
if (InsideBlock && Char == _T(')'))
break;
if (_tcschr(_T("&|<>"), Char))
break;
if (Char == _T('^'))
{
Char = ParseChar();
/* Eat up a \n, allowing line continuation */
if (Char == _T('\n'))
Char = ParseChar();
/* Next character is a forced literal */
}
}
if (Out == &CurrentToken[CMDLINE_LENGTH - 1])
break;
*Out++ = Char;
}
/* Check if we got at least one character before reaching a special one.
* If so, return them and leave the special for the next call. */
if (Out != CurrentToken)
{
Type = TOK_NORMAL;
}
else if (Char == _T('('))
{
Type = TOK_BEGIN_BLOCK;
*Out++ = Char;
ParseChar();
}
else if (Char == _T(')'))
{
Type = TOK_END_BLOCK;
*Out++ = Char;
ParseChar();
}
else if (Char == _T('&') || Char == _T('|'))
{
Type = TOK_OPERATOR;
*Out++ = Char;
Char = ParseChar();
/* check for && or || */
if (Char == Out[-1])
{
*Out++ = Char;
ParseChar();
}
}
else if ((Char >= _T('0') && Char <= _T('9'))
|| (Char == _T('<') || Char == _T('>')))
{
Type = TOK_REDIRECTION;
if (Char >= _T('0') && Char <= _T('9'))
{
*Out++ = Char;
Char = ParseChar();
}
*Out++ = Char;
Char = ParseChar();
if (Char == Out[-1])
{
/* Strangely, the tokenizer allows << as well as >>... (it
* will cause an error when trying to parse it though) */
*Out++ = Char;
Char = ParseChar();
}
if (Char == _T('&'))
{
*Out++ = Char;
while (IsSeparator(Char = ParseChar()))
;
if (Char >= _T('0') && Char <= _T('9'))
{
*Out++ = Char;
ParseChar();
}
}
}
else
{
Type = TOK_END;
}
*Out = _T('\0');
return CurrentTokenType = Type;
}
static BOOL ParseRedirection(REDIRECTION **List)
{
TCHAR *Tok = CurrentToken;
BYTE Number;
REDIR_MODE RedirMode;
REDIRECTION *Redir;
if (*Tok >= _T('0') && *Tok <= _T('9'))
Number = *Tok++ - _T('0');
else
Number = *Tok == _T('<') ? 0 : 1;
if (*Tok++ == _T('<'))
{
RedirMode = REDIR_READ;
if (*Tok == _T('<'))
goto fail;
}
else
{
RedirMode = REDIR_WRITE;
if (*Tok == _T('>'))
{
RedirMode = REDIR_APPEND;
Tok++;
}
}
if (!*Tok)
{
/* The file name was not part of this token, so it'll be the next one */
if (ParseToken(0, STANDARD_SEPS) != TOK_NORMAL)
goto fail;
Tok = CurrentToken;
}
/* If a redirection for this handle number already exists, delete it */
while ((Redir = *List))
{
if (Redir->Number == Number)
{
*List = Redir->Next;
cmd_free(Redir);
continue;
}
List = &Redir->Next;
}
Redir = cmd_alloc(FIELD_OFFSET(REDIRECTION, Filename[_tcslen(Tok) + 1]));
if (!Redir)
{
WARN("Cannot allocate memory for Redir!\n");
goto fail;
}
Redir->Next = NULL;
Redir->OldHandle = INVALID_HANDLE_VALUE;
Redir->Number = Number;
Redir->Mode = RedirMode;
_tcscpy(Redir->Filename, Tok);
*List = Redir;
return TRUE;
fail:
ParseError();
FreeRedirection(*List);
*List = NULL;
return FALSE;
}
static PARSED_COMMAND *ParseCommandOp(int OpType);
/* Parse a parenthesized block */
static PARSED_COMMAND *ParseBlock(REDIRECTION *RedirList)
{
PARSED_COMMAND *Cmd, *Sub, **NextPtr;
Cmd = cmd_alloc(sizeof(PARSED_COMMAND));
if (!Cmd)
{
WARN("Cannot allocate memory for Cmd!\n");
ParseError();
FreeRedirection(RedirList);
return NULL;
}
Cmd->Type = C_BLOCK;
Cmd->Next = NULL;
Cmd->Subcommands = NULL;
Cmd->Redirections = RedirList;
/* Read the block contents */
NextPtr = &Cmd->Subcommands;
InsideBlock++;
while (1)
{
Sub = ParseCommandOp(C_OP_LOWEST);
if (Sub)
{
*NextPtr = Sub;
NextPtr = &Sub->Next;
}
else if (bParseError)
{
InsideBlock--;
FreeCommand(Cmd);
return NULL;
}
if (CurrentTokenType == TOK_END_BLOCK)
break;
/* Skip past the \n */
ParseChar();
}
InsideBlock--;
/* Process any trailing redirections */
while (ParseToken(0, STANDARD_SEPS) == TOK_REDIRECTION)
{
if (!ParseRedirection(&Cmd->Redirections))
{
FreeCommand(Cmd);
return NULL;
}
}
return Cmd;
}
/* Parse an IF statement */
static PARSED_COMMAND *ParseIf(void)
{
int Type;
PARSED_COMMAND *Cmd;
Cmd = cmd_alloc(sizeof(PARSED_COMMAND));
if (!Cmd)
{
WARN("Cannot allocate memory for Cmd!\n");
ParseError();
return NULL;
}
memset(Cmd, 0, sizeof(PARSED_COMMAND));
Cmd->Type = C_IF;
Type = CurrentTokenType;
if (_tcsicmp(CurrentToken, _T("/I")) == 0)
{
Cmd->If.Flags |= IFFLAG_IGNORECASE;
Type = ParseToken(0, STANDARD_SEPS);
}
if (_tcsicmp(CurrentToken, _T("not")) == 0)
{
Cmd->If.Flags |= IFFLAG_NEGATE;
Type = ParseToken(0, STANDARD_SEPS);
}
if (Type != TOK_NORMAL)
{
FreeCommand(Cmd);
ParseError();
return NULL;
}
/* Check for unary operators */
for (; Cmd->If.Operator <= IF_MAX_UNARY; Cmd->If.Operator++)
{
if (_tcsicmp(CurrentToken, IfOperatorString[Cmd->If.Operator]) == 0)
{
if (ParseToken(0, STANDARD_SEPS) != TOK_NORMAL)
{
FreeCommand(Cmd);
ParseError();
return NULL;
}
Cmd->If.RightArg = cmd_dup(CurrentToken);
goto condition_done;
}
}
/* It must be a two-argument (comparison) operator. It could be ==, so
* the equals sign can't be treated as whitespace here. */
Cmd->If.LeftArg = cmd_dup(CurrentToken);
ParseToken(0, _T(",;"));
/* The right argument can come immediately after == */
if (_tcsnicmp(CurrentToken, _T("=="), 2) == 0 && CurrentToken[2])
{
Cmd->If.RightArg = cmd_dup(&CurrentToken[2]);
goto condition_done;
}
for (; Cmd->If.Operator <= IF_MAX_COMPARISON; Cmd->If.Operator++)
{
if (_tcsicmp(CurrentToken, IfOperatorString[Cmd->If.Operator]) == 0)
{
if (ParseToken(0, STANDARD_SEPS) != TOK_NORMAL)
break;
Cmd->If.RightArg = cmd_dup(CurrentToken);
goto condition_done;
}
}
FreeCommand(Cmd);
ParseError();
return NULL;
condition_done:
Cmd->Subcommands = ParseCommandOp(C_OP_LOWEST);
if (Cmd->Subcommands == NULL)
{
FreeCommand(Cmd);
return NULL;
}
if (_tcsicmp(CurrentToken, _T("else")) == 0)
{
Cmd->Subcommands->Next = ParseCommandOp(C_OP_LOWEST);
if (Cmd->Subcommands->Next == NULL)
{
FreeCommand(Cmd);
return NULL;
}
}
return Cmd;
}
/*
* Parse a FOR command.
* Syntax is: FOR [options] %var IN (list) DO command
*/
static PARSED_COMMAND *ParseFor(void)
{
PARSED_COMMAND *Cmd;
TCHAR List[CMDLINE_LENGTH];
TCHAR *Pos = List;
Cmd = cmd_alloc(sizeof(PARSED_COMMAND));
if (!Cmd)
{
WARN("Cannot allocate memory for Cmd!\n");
ParseError();
return NULL;
}
memset(Cmd, 0, sizeof(PARSED_COMMAND));
Cmd->Type = C_FOR;
while (1)
{
if (_tcsicmp(CurrentToken, _T("/D")) == 0)
Cmd->For.Switches |= FOR_DIRS;
else if (_tcsicmp(CurrentToken, _T("/F")) == 0)
{
Cmd->For.Switches |= FOR_F;
if (!Cmd->For.Params)
{
ParseToken(0, STANDARD_SEPS);
if (CurrentToken[0] == _T('/') || CurrentToken[0] == _T('%'))
break;
Cmd->For.Params = cmd_dup(CurrentToken);
}
}
else if (_tcsicmp(CurrentToken, _T("/L")) == 0)
Cmd->For.Switches |= FOR_LOOP;
else if (_tcsicmp(CurrentToken, _T("/R")) == 0)
{
Cmd->For.Switches |= FOR_RECURSIVE;
if (!Cmd->For.Params)
{
ParseToken(0, STANDARD_SEPS);
if (CurrentToken[0] == _T('/') || CurrentToken[0] == _T('%'))
break;
StripQuotes(CurrentToken);
Cmd->For.Params = cmd_dup(CurrentToken);
}
}
else
break;
ParseToken(0, STANDARD_SEPS);
}
/* Make sure there aren't two different switches specified
* at the same time, unless they're /D and /R */
if ((Cmd->For.Switches & (Cmd->For.Switches - 1)) != 0
&& Cmd->For.Switches != (FOR_DIRS | FOR_RECURSIVE))
{
goto error;
}
/* Variable name should be % and just one other character */
if (CurrentToken[0] != _T('%') || _tcslen(CurrentToken) != 2)
goto error;
Cmd->For.Variable = CurrentToken[1];
ParseToken(0, STANDARD_SEPS);
if (_tcsicmp(CurrentToken, _T("in")) != 0)
goto error;
if (ParseToken(_T('('), STANDARD_SEPS) != TOK_BEGIN_BLOCK)
goto error;
while (1)
{
int Type;
/* Pretend we're inside a block so the tokenizer will stop on ')' */
InsideBlock++;
Type = ParseToken(0, STANDARD_SEPS);
InsideBlock--;
if (Type == TOK_END_BLOCK)
break;
if (Type == TOK_END)
{
/* Skip past the \n */
ParseChar();
continue;
}
if (Type != TOK_NORMAL)
goto error;
if (Pos != List)
*Pos++ = _T(' ');
if (Pos + _tcslen(CurrentToken) >= &List[CMDLINE_LENGTH])
goto error;
Pos = _stpcpy(Pos, CurrentToken);
}
*Pos = _T('\0');
Cmd->For.List = cmd_dup(List);
ParseToken(0, STANDARD_SEPS);
if (_tcsicmp(CurrentToken, _T("do")) != 0)
goto error;
Cmd->Subcommands = ParseCommandOp(C_OP_LOWEST);
if (Cmd->Subcommands == NULL)
{
FreeCommand(Cmd);
return NULL;
}
return Cmd;
error:
FreeCommand(Cmd);
ParseError();
return NULL;
}
/* Parse a REM command */
static PARSED_COMMAND *ParseRem(void)
{
/* Just ignore the rest of the line */
while (CurChar && CurChar != _T('\n'))
ParseChar();
return NULL;
}
static DECLSPEC_NOINLINE PARSED_COMMAND *ParseCommandPart(REDIRECTION *RedirList)
{
TCHAR ParsedLine[CMDLINE_LENGTH];
PARSED_COMMAND *Cmd;
PARSED_COMMAND *(*Func)(void);
TCHAR *Pos = _stpcpy(ParsedLine, CurrentToken) + 1;
DWORD_PTR TailOffset = Pos - ParsedLine;
/* Check for special forms */
if ((Func = ParseFor, _tcsicmp(ParsedLine, _T("for")) == 0) ||
(Func = ParseIf, _tcsicmp(ParsedLine, _T("if")) == 0) ||
(Func = ParseRem, _tcsicmp(ParsedLine, _T("rem")) == 0))
{
ParseToken(0, STANDARD_SEPS);
/* Do special parsing only if it's not followed by /? */
if (_tcscmp(CurrentToken, _T("/?")) != 0)
{
if (RedirList)
{
ParseError();
FreeRedirection(RedirList);
return NULL;
}
return Func();
}
Pos = _stpcpy(Pos, _T(" /?"));
}
/* Now get the tail */
while (1)
{
int Type = ParseToken(0, NULL);
if (Type == TOK_NORMAL)
{
if (Pos + _tcslen(CurrentToken) >= &ParsedLine[CMDLINE_LENGTH])
{
ParseError();
FreeRedirection(RedirList);
return NULL;
}
Pos = _stpcpy(Pos, CurrentToken);
}
else if (Type == TOK_REDIRECTION)
{
if (!ParseRedirection(&RedirList))
return NULL;
}
else
{
break;
}
}
*Pos++ = _T('\0');
Cmd = cmd_alloc(FIELD_OFFSET(PARSED_COMMAND, Command.First[Pos - ParsedLine]));
if (!Cmd)
{
WARN("Cannot allocate memory for Cmd!\n");
ParseError();
FreeRedirection(RedirList);
return NULL;
}
Cmd->Type = C_COMMAND;
Cmd->Next = NULL;
Cmd->Subcommands = NULL;
Cmd->Redirections = RedirList;
memcpy(Cmd->Command.First, ParsedLine, (Pos - ParsedLine) * sizeof(TCHAR));
Cmd->Command.Rest = Cmd->Command.First + TailOffset;
return Cmd;
}
static PARSED_COMMAND *ParsePrimary(void)
{
REDIRECTION *RedirList = NULL;
int Type;
while (IsSeparator(CurChar))
{
if (CurChar == _T('\n'))
return NULL;
ParseChar();
}
if (!CurChar)
return NULL;
if (CurChar == _T(':'))
{
/* "Ignore" the rest of the line.
* (Line continuations will still be parsed, though.) */
while (ParseToken(0, NULL) != TOK_END)
;
return NULL;
}
if (CurChar == _T('@'))
{
PARSED_COMMAND *Cmd;
ParseChar();
Cmd = cmd_alloc(sizeof(PARSED_COMMAND));
if (!Cmd)
{
WARN("Cannot allocate memory for Cmd!\n");
ParseError();
return NULL;
}
Cmd->Type = C_QUIET;
Cmd->Next = NULL;
/* @ acts like a unary operator with low precedence,
* so call the top-level parser */
Cmd->Subcommands = ParseCommandOp(C_OP_LOWEST);
Cmd->Redirections = NULL;
return Cmd;
}
/* Process leading redirections and get the head of the command */
while ((Type = ParseToken(_T('('), STANDARD_SEPS)) == TOK_REDIRECTION)
{
if (!ParseRedirection(&RedirList))
return NULL;
}
if (Type == TOK_NORMAL)
return ParseCommandPart(RedirList);
else if (Type == TOK_BEGIN_BLOCK)
return ParseBlock(RedirList);
else if (Type == TOK_END_BLOCK && !RedirList)
return NULL;
ParseError();
FreeRedirection(RedirList);
return NULL;
}
static PARSED_COMMAND *ParseCommandOp(int OpType)
{
PARSED_COMMAND *Cmd, *Left, *Right;
if (OpType == C_OP_HIGHEST)
Cmd = ParsePrimary();
else
Cmd = ParseCommandOp(OpType + 1);
if (Cmd && !_tcscmp(CurrentToken, OpString[OpType - C_OP_LOWEST]))
{
Left = Cmd;
Right = ParseCommandOp(OpType);
if (!Right)
{
if (!bParseError)
{
/* & is allowed to have an empty RHS */
if (OpType == C_MULTI)
return Left;
ParseError();
}
FreeCommand(Left);
return NULL;
}
Cmd = cmd_alloc(sizeof(PARSED_COMMAND));
if (!Cmd)
{
WARN("Cannot allocate memory for Cmd!\n");
ParseError();
FreeCommand(Left);
FreeCommand(Right);
return NULL;
}
Cmd->Type = OpType;
Cmd->Next = NULL;
Cmd->Redirections = NULL;
Cmd->Subcommands = Left;
Left->Next = Right;
Right->Next = NULL;
}
return Cmd;
}
PARSED_COMMAND *
ParseCommand(LPTSTR Line)
{
PARSED_COMMAND *Cmd;
if (Line)
{
if (!SubstituteVars(Line, ParseLine, _T('%')))
return NULL;
bLineContinuations = FALSE;
}
else
{
if (!ReadLine(ParseLine, FALSE))
return NULL;
bLineContinuations = TRUE;
}
bParseError = FALSE;
ParsePos = ParseLine;
CurChar = _T(' ');
Cmd = ParseCommandOp(C_OP_LOWEST);
if (Cmd)
{
if (CurrentTokenType != TOK_END)
ParseError();
if (bParseError)
{
FreeCommand(Cmd);
Cmd = NULL;
}
bIgnoreEcho = FALSE;
}
else
{
bIgnoreEcho = TRUE;
}
return Cmd;
}
/*
* Reconstruct a parse tree into text form; used for echoing
* batch file commands and FOR instances.
*/
VOID
EchoCommand(PARSED_COMMAND *Cmd)
{
TCHAR Buf[CMDLINE_LENGTH];
PARSED_COMMAND *Sub;
REDIRECTION *Redir;
switch (Cmd->Type)
{
case C_COMMAND:
if (SubstituteForVars(Cmd->Command.First, Buf))
ConOutPrintf(_T("%s"), Buf);
if (SubstituteForVars(Cmd->Command.Rest, Buf))
ConOutPrintf(_T("%s"), Buf);
break;
case C_QUIET:
return;
case C_BLOCK:
ConOutChar(_T('('));
Sub = Cmd->Subcommands;
if (Sub && !Sub->Next)
{
/* Single-command block: display all on one line */
EchoCommand(Sub);
}
else if (Sub)
{
/* Multi-command block: display parenthesis on separate lines */
ConOutChar(_T('\n'));
do
{
EchoCommand(Sub);
ConOutChar(_T('\n'));
Sub = Sub->Next;
} while (Sub);
}
ConOutChar(_T(')'));
break;
case C_MULTI:
case C_IFFAILURE:
case C_IFSUCCESS:
case C_PIPE:
Sub = Cmd->Subcommands;
EchoCommand(Sub);
ConOutPrintf(_T(" %s "), OpString[Cmd->Type - C_OP_LOWEST]);
EchoCommand(Sub->Next);
break;
case C_IF:
ConOutPrintf(_T("if"));
if (Cmd->If.Flags & IFFLAG_IGNORECASE)
ConOutPrintf(_T(" /I"));
if (Cmd->If.Flags & IFFLAG_NEGATE)
ConOutPrintf(_T(" not"));
if (Cmd->If.LeftArg && SubstituteForVars(Cmd->If.LeftArg, Buf))
ConOutPrintf(_T(" %s"), Buf);
ConOutPrintf(_T(" %s"), IfOperatorString[Cmd->If.Operator]);
if (SubstituteForVars(Cmd->If.RightArg, Buf))
ConOutPrintf(_T(" %s "), Buf);
Sub = Cmd->Subcommands;
EchoCommand(Sub);
if (Sub->Next)
{
ConOutPrintf(_T(" else "));
EchoCommand(Sub->Next);
}
break;
case C_FOR:
ConOutPrintf(_T("for"));
if (Cmd->For.Switches & FOR_DIRS) ConOutPrintf(_T(" /D"));
if (Cmd->For.Switches & FOR_F) ConOutPrintf(_T(" /F"));
if (Cmd->For.Switches & FOR_LOOP) ConOutPrintf(_T(" /L"));
if (Cmd->For.Switches & FOR_RECURSIVE) ConOutPrintf(_T(" /R"));
if (Cmd->For.Params)
ConOutPrintf(_T(" %s"), Cmd->For.Params);
ConOutPrintf(_T(" %%%c in (%s) do "), Cmd->For.Variable, Cmd->For.List);
EchoCommand(Cmd->Subcommands);
break;
}
for (Redir = Cmd->Redirections; Redir; Redir = Redir->Next)
{
if (SubstituteForVars(Redir->Filename, Buf))
{
ConOutPrintf(_T(" %c%s%s"), _T('0') + Redir->Number,
RedirString[Redir->Mode], Buf);
}
}
}
/*
* "Unparse" a command into a text form suitable for passing to CMD /C.
* Used for pipes. This is basically the same thing as EchoCommand, but
* writing into a string instead of to standard output.
*/
TCHAR *
Unparse(PARSED_COMMAND *Cmd, TCHAR *Out, TCHAR *OutEnd)
{
TCHAR Buf[CMDLINE_LENGTH];
PARSED_COMMAND *Sub;
REDIRECTION *Redir;
/*
* Since this function has the annoying requirement that it must avoid
* overflowing the supplied buffer, define some helper macros to make
* this less painful.
*/
#define CHAR(Char) \
do { \
if (Out == OutEnd) return NULL; \
*Out++ = Char; \
} while (0)
#define STRING(String) \
do { \
if (Out + _tcslen(String) > OutEnd) return NULL; \
Out = _stpcpy(Out, String); \
} while (0)
#define PRINTF(Format, ...) \
do { \
UINT Len = _sntprintf(Out, OutEnd - Out, Format, __VA_ARGS__); \
if (Len > (UINT)(OutEnd - Out)) return NULL; \
Out += Len; \
} while (0)
#define RECURSE(Subcommand) \
do { \
Out = Unparse(Subcommand, Out, OutEnd); \
if (!Out) return NULL; \
} while (0)
switch (Cmd->Type)
{
case C_COMMAND:
/* This is fragile since there could be special characters, but
* Windows doesn't bother escaping them, so for compatibility
* we probably shouldn't do it either */
if (!SubstituteForVars(Cmd->Command.First, Buf)) return NULL;
STRING(Buf);
if (!SubstituteForVars(Cmd->Command.Rest, Buf)) return NULL;
STRING(Buf);
break;
case C_QUIET:
CHAR(_T('@'));
RECURSE(Cmd->Subcommands);
break;
case C_BLOCK:
CHAR(_T('('));
for (Sub = Cmd->Subcommands; Sub; Sub = Sub->Next)
{
RECURSE(Sub);
if (Sub->Next)
CHAR(_T('&'));
}
CHAR(_T(')'));
break;
case C_MULTI:
case C_IFFAILURE:
case C_IFSUCCESS:
case C_PIPE:
Sub = Cmd->Subcommands;
RECURSE(Sub);
PRINTF(_T(" %s "), OpString[Cmd->Type - C_OP_LOWEST]);
RECURSE(Sub->Next);
break;
case C_IF:
STRING(_T("if"));
if (Cmd->If.Flags & IFFLAG_IGNORECASE)
STRING(_T(" /I"));
if (Cmd->If.Flags & IFFLAG_NEGATE)
STRING(_T(" not"));
if (Cmd->If.LeftArg && SubstituteForVars(Cmd->If.LeftArg, Buf))
PRINTF(_T(" %s"), Buf);
PRINTF(_T(" %s"), IfOperatorString[Cmd->If.Operator]);
if (!SubstituteForVars(Cmd->If.RightArg, Buf)) return NULL;
PRINTF(_T(" %s "), Buf);
Sub = Cmd->Subcommands;
RECURSE(Sub);
if (Sub->Next)
{
STRING(_T(" else "));
RECURSE(Sub->Next);
}
break;
case C_FOR:
STRING(_T("for"));
if (Cmd->For.Switches & FOR_DIRS) STRING(_T(" /D"));
if (Cmd->For.Switches & FOR_F) STRING(_T(" /F"));
if (Cmd->For.Switches & FOR_LOOP) STRING(_T(" /L"));
if (Cmd->For.Switches & FOR_RECURSIVE) STRING(_T(" /R"));
if (Cmd->For.Params)
PRINTF(_T(" %s"), Cmd->For.Params);
PRINTF(_T(" %%%c in (%s) do "), Cmd->For.Variable, Cmd->For.List);
RECURSE(Cmd->Subcommands);
break;
}
for (Redir = Cmd->Redirections; Redir; Redir = Redir->Next)
{
if (!SubstituteForVars(Redir->Filename, Buf))
return NULL;
PRINTF(_T(" %c%s%s"), _T('0') + Redir->Number,
RedirString[Redir->Mode], Buf);
}
return Out;
}
VOID
FreeCommand(PARSED_COMMAND *Cmd)
{
if (Cmd->Subcommands)
FreeCommand(Cmd->Subcommands);
if (Cmd->Next)
FreeCommand(Cmd->Next);
FreeRedirection(Cmd->Redirections);
if (Cmd->Type == C_IF)
{
cmd_free(Cmd->If.LeftArg);
cmd_free(Cmd->If.RightArg);
}
else if (Cmd->Type == C_FOR)
{
cmd_free(Cmd->For.Params);
cmd_free(Cmd->For.List);
}
cmd_free(Cmd);
}