PgQueryInternalParsetreeAndError pg_query_raw_parse()

in src/pg_query_parse.c [12:84]

• 53 lines of code
• 2 McCabe index (conditional complexity)

PgQueryInternalParsetreeAndError pg_query_raw_parse(const char* input)
{
	PgQueryInternalParsetreeAndError result = {0};
	MemoryContext parse_context = CurrentMemoryContext;

	char stderr_buffer[STDERR_BUFFER_LEN + 1] = {0};
#ifndef DEBUG
	int stderr_global;
	int stderr_pipe[2];
#endif

#ifndef DEBUG
	// Setup pipe for stderr redirection
	if (pipe(stderr_pipe) != 0) {
		PgQueryError* error = malloc(sizeof(PgQueryError));

		error->message = strdup("Failed to open pipe, too many open file descriptors")

		result.error = error;

		return result;
	}

	fcntl(stderr_pipe[0], F_SETFL, fcntl(stderr_pipe[0], F_GETFL) | O_NONBLOCK);

	// Redirect stderr to the pipe
	stderr_global = dup(STDERR_FILENO);
	dup2(stderr_pipe[1], STDERR_FILENO);
	close(stderr_pipe[1]);
#endif

	PG_TRY();
	{
		result.tree = raw_parser(input);

#ifndef DEBUG
		// Save stderr for result
		read(stderr_pipe[0], stderr_buffer, STDERR_BUFFER_LEN);
#endif

		result.stderr_buffer = strdup(stderr_buffer);
	}
	PG_CATCH();
	{
		ErrorData* error_data;
		PgQueryError* error;

		MemoryContextSwitchTo(parse_context);
		error_data = CopyErrorData();

		// Note: This is intentionally malloc so exiting the memory context doesn't free this
		error = malloc(sizeof(PgQueryError));
		error->message   = strdup(error_data->message);
		error->filename  = strdup(error_data->filename);
		error->funcname  = strdup(error_data->funcname);
		error->context   = NULL;
		error->lineno    = error_data->lineno;
		error->cursorpos = error_data->cursorpos;

		result.error = error;
		FlushErrorState();
	}
	PG_END_TRY();

#ifndef DEBUG
	// Restore stderr, close pipe
	dup2(stderr_global, STDERR_FILENO);
	close(stderr_pipe[0]);
	close(stderr_global);
#endif

	return result;
}