[reactos] 09/48: [CMD] Add a command tree dumper, for debugging purposes of the parser code.
https://git.reactos.org/?p=reactos.git;a=commitdiff;h=6f87d45e1cc227c84053e5...
commit 6f87d45e1cc227c84053e5da112821ea1aebe07e Author: Hermès Bélusca-Maïto hermes.belusca-maito@reactos.org AuthorDate: Sat Jun 6 20:42:56 2020 +0200 Commit: Hermès Bélusca-Maïto hermes.belusca-maito@reactos.org CommitDate: Wed Aug 19 20:35:55 2020 +0200
[CMD] Add a command tree dumper, for debugging purposes of the parser code.
This feature is also present in Windows' CMD, and has been documented e.g. at: https://www.fireeye.com/blog/threat-research/2018/11/cmd-and-conquer-de-dosf... https://www.real-sec.com/2019/08/cmd-and-conquer-de-dosfuscation-with-flare-... --- base/shell/cmd/parser.c | 315 +++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 312 insertions(+), 3 deletions(-)
diff --git a/base/shell/cmd/parser.c b/base/shell/cmd/parser.c index 2a7b653be5d..5661f12024c 100644 --- a/base/shell/cmd/parser.c +++ b/base/shell/cmd/parser.c @@ -4,6 +4,15 @@
#include "precomp.h"
+/* + * Parser debugging support. These flags are global so that their values can be + * modified at runtime from a debugger. They correspond to the public Windows' + * cmd!fDumpTokens and cmd!fDumpParse booleans. + * (Same names are used for compatibility as they are documented online.) + */ +BOOLEAN fDumpTokens = FALSE; +BOOLEAN fDumpParse = FALSE; + #define C_OP_LOWEST C_MULTI #define C_OP_HIGHEST C_PIPE static const TCHAR OpString[][3] = { _T("&"), _T("||"), _T("&&"), _T("|") }; @@ -220,7 +229,12 @@ static int ParseToken(TCHAR ExtraEnd, TCHAR *Separators) Type = TOK_END; } *Out = _T('\0'); - return CurrentTokenType = Type; + + /* Debugging support */ + if (fDumpTokens) + ConOutPrintf(_T("ParseToken: (%d) '%s'\n"), Type, CurrentToken); + + return (CurrentTokenType = Type); }
static BOOL ParseRedirection(REDIRECTION **List) @@ -763,6 +777,9 @@ static PARSED_COMMAND *ParseCommandOp(int OpType) return Cmd; }
+VOID +DumpCommand(PARSED_COMMAND *Cmd, ULONG SpacePad); + PARSED_COMMAND * ParseCommand(LPTSTR Line) { @@ -787,14 +804,19 @@ ParseCommand(LPTSTR Line) Cmd = ParseCommandOp(C_OP_LOWEST); if (Cmd) { + bIgnoreEcho = FALSE; + if (CurrentTokenType != TOK_END) ParseError(); if (bParseError) { FreeCommand(Cmd); - Cmd = NULL; + return NULL; } - bIgnoreEcho = FALSE; + + /* Debugging support */ + if (fDumpParse) + DumpCommand(Cmd, 0); } else { @@ -804,6 +826,293 @@ ParseCommand(LPTSTR Line) }
+/* + * This function is similar to EchoCommand(), but is used + * for dumping the command tree for debugging purposes. + */ +static VOID +DumpRedir(REDIRECTION* Redirections) +{ + REDIRECTION* Redir; + + if (Redirections) +#ifndef MSCMD_ECHO_COMMAND_COMPAT + ConOutPuts(_T(" Redir: ")); +#else + ConOutPuts(_T("Redir: ")); +#endif + for (Redir = Redirections; Redir; Redir = Redir->Next) + { + ConOutPrintf(_T(" %x %s%s"), Redir->Number, + RedirString[Redir->Mode], Redir->Filename); + } +} + +VOID +DumpCommand(PARSED_COMMAND *Cmd, ULONG SpacePad) +{ +/* + * This macro is like DumpCommand(Cmd, Pad); + * but avoids an extra recursive level. + * Note that it can be used ONLY for terminating commands! + */ +#define DUMP(Command, Pad) \ +do { \ + Cmd = (Command); \ + SpacePad = (Pad); \ + goto dump; \ +} while (0) + + PARSED_COMMAND *Sub; + +dump: + /* Space padding */ + ConOutPrintf(_T("%*s"), SpacePad, _T("")); + + switch (Cmd->Type) + { + case C_COMMAND: + { + /* Generic command name, and Type */ +#ifndef MSCMD_ECHO_COMMAND_COMPAT + ConOutPrintf(_T("Cmd: %s Type: %x"), + Cmd->Command.First, Cmd->Type); +#else + ConOutPrintf(_T("Cmd: %s Type: %x "), + Cmd->Command.First, Cmd->Type); +#endif + /* Arguments */ + if (Cmd->Command.Rest && *(Cmd->Command.Rest)) +#ifndef MSCMD_ECHO_COMMAND_COMPAT + ConOutPrintf(_T(" Args: `%s'"), Cmd->Command.Rest); +#else + ConOutPrintf(_T("Args: `%s' "), Cmd->Command.Rest); +#endif + /* Redirections */ + DumpRedir(Cmd->Redirections); + + ConOutChar(_T('\n')); + return; + } + + case C_QUIET: + { +#ifndef MSCMD_ECHO_COMMAND_COMPAT + ConOutChar(_T('@')); +#else + ConOutPuts(_T("@ ")); +#endif + DumpRedir(Cmd->Redirections); // FIXME: Can we have leading redirections?? + ConOutChar(_T('\n')); + + /*DumpCommand*/DUMP(Cmd->Subcommands, SpacePad + 2); + return; + } + + case C_BLOCK: + { +#ifndef MSCMD_ECHO_COMMAND_COMPAT + ConOutChar(_T('(')); +#else + ConOutPuts(_T("( ")); +#endif + DumpRedir(Cmd->Redirections); + ConOutChar(_T('\n')); + + SpacePad += 2; + + for (Sub = Cmd->Subcommands; Sub; Sub = Sub->Next) + { +#if defined(MSCMD_ECHO_COMMAND_COMPAT) && defined(MSCMD_PARSER_BUGS) + /* + * We will emulate Windows' CMD handling of "CRLF" and "&" multi-command + * enumeration within parenthesized command blocks. + */ + + if (!Sub->Next) + { + DumpCommand(Sub, SpacePad); + continue; + } + + if (Sub->Type != C_MULTI) + { + ConOutPrintf(_T("%*s"), SpacePad, _T("")); + ConOutPuts(_T("CRLF \n")); + DumpCommand(Sub, SpacePad); + continue; + } + + /* Now, Sub->Type == C_MULTI */ + + Cmd = Sub; + + ConOutPrintf(_T("%*s"), SpacePad, _T("")); + ConOutPrintf(_T("%s \n"), OpString[Cmd->Type - C_OP_LOWEST]); + // FIXME: Can we have redirections on these operator-type commands? + + SpacePad += 2; + + Cmd = Cmd->Subcommands; + DumpCommand(Cmd, SpacePad); + ConOutPrintf(_T("%*s"), SpacePad, _T("")); + ConOutPuts(_T("CRLF \n")); + DumpCommand(Cmd->Next, SpacePad); + + // NOTE: Next commands will remain indented. + +#else + + /* + * If this command is followed by another one, first display "CRLF". + * This also emulates the CRLF placement "bug" of Windows' CMD + * for the last two commands. + */ + if (Sub->Next) + { + ConOutPrintf(_T("%*s"), SpacePad, _T("")); +#ifndef MSCMD_ECHO_COMMAND_COMPAT + ConOutPuts(_T("CRLF\n")); +#else + ConOutPuts(_T("CRLF \n")); +#endif + } + DumpCommand(Sub, SpacePad); + +#endif // defined(MSCMD_ECHO_COMMAND_COMPAT) && defined(MSCMD_PARSER_BUGS) + } + + return; + } + + case C_MULTI: + case C_OR: + case C_AND: + case C_PIPE: + { +#ifndef MSCMD_ECHO_COMMAND_COMPAT + ConOutPrintf(_T("%s\n"), OpString[Cmd->Type - C_OP_LOWEST]); +#else + ConOutPrintf(_T("%s \n"), OpString[Cmd->Type - C_OP_LOWEST]); +#endif + // FIXME: Can we have redirections on these operator-type commands? + + SpacePad += 2; + + Sub = Cmd->Subcommands; + DumpCommand(Sub, SpacePad); + /*DumpCommand*/DUMP(Sub->Next, SpacePad); + return; + } + + case C_IF: + { + ConOutPuts(_T("if")); + /* NOTE: IF cannot have leading redirections */ + + if (Cmd->If.Flags & IFFLAG_IGNORECASE) + ConOutPuts(_T(" /I")); + + ConOutChar(_T('\n')); + + SpacePad += 2; + + /* + * Show the IF command condition as a command. + * If it is negated, indent the command more. + */ + if (Cmd->If.Flags & IFFLAG_NEGATE) + { + ConOutPrintf(_T("%*s"), SpacePad, _T("")); + ConOutPuts(_T("not\n")); + SpacePad += 2; + } + + ConOutPrintf(_T("%*s"), SpacePad, _T("")); + + /* + * Command name: + * - Unary operator: its name is the command name, and its argument is the command argument. + * - Binary operator: its LHS is the command name, its RHS is the command argument. + * + * Type: + * Windows' CMD (Win2k3 / Win7-10) values are as follows: + * CMDEXTVERSION Type: 0x32 / 0x34 + * ERRORLEVEL Type: 0x33 / 0x35 + * DEFINED Type: 0x34 / 0x36 + * EXIST Type: 0x35 / 0x37 + * == Type: 0x37 / 0x39 (String Comparison) + * + * For the following command: + * NOT Type: 0x36 / 0x38 + * Windows only prints it without any type / redirection. + * + * For the following command: + * EQU, NEQ, etc. Type: 0x38 / 0x3a (Generic Comparison) + * Windows displays it as command of unknown type. + */ +#ifndef MSCMD_ECHO_COMMAND_COMPAT + ConOutPrintf(_T("Cmd: %s Type: %x"), + (Cmd->If.Operator <= IF_MAX_UNARY) ? + IfOperatorString[Cmd->If.Operator] : + Cmd->If.LeftArg, + Cmd->If.Operator); +#else + ConOutPrintf(_T("Cmd: %s Type: %x "), + (Cmd->If.Operator <= IF_MAX_UNARY) ? + IfOperatorString[Cmd->If.Operator] : + Cmd->If.LeftArg, + Cmd->If.Operator); +#endif + /* Arguments */ +#ifndef MSCMD_ECHO_COMMAND_COMPAT + ConOutPrintf(_T(" Args: `%s'"), Cmd->If.RightArg); +#else + ConOutPrintf(_T("Args: `%s' "), Cmd->If.RightArg); +#endif + + ConOutChar(_T('\n')); + + if (Cmd->If.Flags & IFFLAG_NEGATE) + { + SpacePad -= 2; + } + + Sub = Cmd->Subcommands; + DumpCommand(Sub, SpacePad); + if (Sub->Next) + { + ConOutPrintf(_T("%*s"), SpacePad - 2, _T("")); + ConOutPuts(_T("else\n")); + DumpCommand(Sub->Next, SpacePad); + } + return; + } + + case C_FOR: + { + ConOutPuts(_T("for")); + /* NOTE: FOR cannot have leading redirections */ + + if (Cmd->For.Switches & FOR_DIRS) ConOutPuts(_T(" /D")); + if (Cmd->For.Switches & FOR_F) ConOutPuts(_T(" /F")); + if (Cmd->For.Switches & FOR_LOOP) ConOutPuts(_T(" /L")); + if (Cmd->For.Switches & FOR_RECURSIVE) ConOutPuts(_T(" /R")); + if (Cmd->For.Params) + ConOutPrintf(_T(" %s"), Cmd->For.Params); + ConOutPrintf(_T(" %%%c in (%s) do\n"), Cmd->For.Variable, Cmd->For.List); + /*DumpCommand*/DUMP(Cmd->Subcommands, SpacePad + 2); + return; + } + + default: + ConOutPrintf(_T("*** Unknown type: %x\n"), Cmd->Type); + break; + } + +#undef DUMP +} + /* * Reconstruct a parse tree into text form; used for echoing * batch file commands and FOR instances.
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Hermès Bélusca-Maïto