Function par_modify

src/gpre/par.cpp:2263–2307

//

static act* par_modify()
{

	// Set up modify and action blocks.  This is done here to leave the
	// structure in place to cleanly handle END_MODIFY under error conditions.

	upd* modify = (upd*) MSC_alloc(UPD_LEN);
	MSC_push((gpre_nod*) modify, &cur_modify);

	// If the next token isn't a context variable, we can't continue

	gpre_sym* symbol = gpreGlob.token_global.tok_symbol;
	if (!symbol || symbol->sym_type != SYM_context)
	{
		SCHAR s[ERROR_LENGTH];
		fb_utils::snprintf(s, sizeof(s), "%s is not a valid context variable", gpreGlob.token_global.tok_string);
		PAR_error(s);
	}

	gpre_ctx* source = symbol->sym_object;
	gpre_req* request = source->ctx_request;
	if (request->req_type != REQ_for && request->req_type != REQ_cursor)
		PAR_error("invalid context for modify");

	act* action = MSC_action(request, ACT_modify);
	action->act_object = (ref*) modify;

	PAR_get_token();
	MSC_match(KW_USING);

	// Make an update context by cloning the source context

	gpre_ctx* update = MSC_context(request);
	update->ctx_symbol = source->ctx_symbol;
	update->ctx_relation = source->ctx_relation;

	// Make an update block to hold everything known about the modify

	modify->upd_request = request;
	modify->upd_source = source;
	modify->upd_update = update;
	modify->upd_level = ++request->req_level;

	return action;
}


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