void
ExpressionParser::_ParseCommand(debugger_command_pipe_segment& segment)
{
fTokenizer.SetCommandMode(false);
const Token& token = _EatToken(TOKEN_IDENTIFIER);
fTokenizer.SetCommandMode(true);
bool ambiguous;
debugger_command* command = find_debugger_command(token.string, true,
ambiguous);
if (command == NULL) {
if (ambiguous) {
snprintf(sTempBuffer, sizeof(sTempBuffer),
"Ambiguous command \"%s\". Use tab completion or enter "
"\"help %s\" get a list of matching commands.\n", token.string,
token.string);
} else {
snprintf(sTempBuffer, sizeof(sTempBuffer),
"Unknown command \"%s\". Enter \"help\" to get a list of "
"all supported commands.\n", token.string);
}
parse_exception(sTempBuffer, -1);
}
// allocate temporary buffer for the argument vector
char** argv = (char**)checked_malloc(kMaxArgumentCount * sizeof(char*));
int argc = 0;
argv[argc++] = (char*)command->name;
// get the arguments
if ((command->flags & B_KDEBUG_DONT_PARSE_ARGUMENTS) != 0) {
_GetUnparsedArgument(argc, argv);
} else {
while (fTokenizer.NextToken().type != TOKEN_END_OF_LINE) {
fTokenizer.RewindToken();
if (!_ParseArgument(argc, argv))
break;
}
}
if (segment.index > 0) {
if (argc >= kMaxArgumentCount)
parse_exception("too many arguments for command", 0);
else
argc++;
}
segment.command = command;
segment.argc = argc;
segment.argv = argv;
segment.invocations = 0;
}
bool
ExpressionParser::_ParseArgument(int& argc, char** argv)
{
const Token& token = fTokenizer.NextToken();
switch (token.type) {
case TOKEN_OPENING_PARENTHESIS:
{
// this starts an expression
fTokenizer.SetCommandMode(false);
uint64 value = _ParseExpression();
fTokenizer.SetCommandMode(true);
_EatToken(TOKEN_CLOSING_PARENTHESIS);
snprintf(sTempBuffer, sizeof(sTempBuffer), "%" B_PRIu64, value);
_AddArgument(argc, argv, sTempBuffer);
return true;
}
case TOKEN_OPENING_BRACKET:
{
// this starts a sub command
int returnValue;
uint64 value = _ParseCommandPipe(returnValue);
_EatToken(TOKEN_CLOSING_BRACKET);
snprintf(sTempBuffer, sizeof(sTempBuffer), "%" B_PRIu64, value);
_AddArgument(argc, argv, sTempBuffer);
return true;
}
case TOKEN_STRING:
case TOKEN_UNKNOWN:
_AddArgument(argc, argv, token.string);
return true;
case TOKEN_CLOSING_PARENTHESIS:
case TOKEN_CLOSING_BRACKET:
case TOKEN_PIPE:
case TOKEN_SEMICOLON:
// those don't belong to us
fTokenizer.RewindToken();
return false;
default:
{
snprintf(sTempBuffer, sizeof(sTempBuffer), "unexpected token "
"\"%s\"", token.string);
parse_exception(sTempBuffer, token.position);
return false;
}
}
}
uint64
ExpressionParser::EvaluateCommand(const char* expressionString, int& returnCode)
{
fTokenizer.SetTo(expressionString);
// Allowed are command or assignment. A command always starts with an
// identifier, an assignment either with an identifier (variable name) or
// a dereferenced address.
const Token& token = fTokenizer.NextToken();
uint64 value = 0;
while (true) {
int32 startPosition = token.position;
if (token.type == TOKEN_IDENTIFIER) {
fTokenizer.NextToken();
if (token.type & TOKEN_ASSIGN_FLAG) {
// an assignment
fTokenizer.SetPosition(startPosition);
value = _ParseExpression(true);
returnCode = 0;
} else {
// no assignment, so let's assume it's a command
fTokenizer.SetPosition(startPosition);
fTokenizer.SetCommandMode(true);
value = _ParseCommandPipe(returnCode);
}
} else if (token.type == TOKEN_STAR) {
// dereferenced address -- assignment
fTokenizer.SetPosition(startPosition);
value = _ParseExpression(true);
returnCode = 0;
} else
parse_exception("expected command or assignment", token.position);
// might be chained with ";"
if (fTokenizer.NextToken().type != TOKEN_SEMICOLON)
break;
fTokenizer.SetCommandMode(false);
fTokenizer.NextToken();
}
if (token.type != TOKEN_END_OF_LINE)
parse_exception("parse error", token.position);
return value;
}
status_t
ExpressionParser::ParseNextCommandArgument(const char** expressionString,
char* buffer, size_t bufferSize)
{
fTokenizer.SetTo(*expressionString);
fTokenizer.SetCommandMode(true);
if (fTokenizer.NextToken().type == TOKEN_END_OF_LINE)
return B_ENTRY_NOT_FOUND;
fTokenizer.RewindToken();
char* argv[2];
int argc = 0;
if (!_ParseArgument(argc, argv))
return B_BAD_VALUE;
strlcpy(buffer, argv[0], bufferSize);
const Token& token = fTokenizer.NextToken();
if (token.type == TOKEN_END_OF_LINE)
*expressionString = NULL;
else
*expressionString += token.position;
return B_OK;
}
uint64
ExpressionParser::_ParseAtom()
{
const Token& token = fTokenizer.NextToken();
if (token.type == TOKEN_END_OF_LINE)
parse_exception("unexpected end of expression", token.position);
if (token.type == TOKEN_CONSTANT)
return token.value;
if (token.type == TOKEN_IDENTIFIER) {
if (!is_debug_variable_defined(token.string)) {
snprintf(sTempBuffer, sizeof(sTempBuffer),
"variable '%s' undefined", token.string);
parse_exception(sTempBuffer, token.position);
}
return get_debug_variable(token.string, 0);
}
if (token.type == TOKEN_OPENING_PARENTHESIS) {
uint64 value = _ParseExpression();
_EatToken(TOKEN_CLOSING_PARENTHESIS);
return value;
}
// it can only be a "[ command ]" expression now
fTokenizer.RewindToken();
_EatToken(TOKEN_OPENING_BRACKET);
fTokenizer.SetCommandMode(true);
int returnValue;
uint64 value = _ParseCommandPipe(returnValue);
fTokenizer.SetCommandMode(false);
_EatToken(TOKEN_CLOSING_BRACKET);
return value;
}
