Function _Validate_CALL_Clause

src/ast/ast_validations.c:1084–1174

validate a CALL clause

// validate a CALL clause
static VISITOR_STRATEGY _Validate_CALL_Clause
(
	const cypher_astnode_t *n,  // ast-node
	bool start,                 // first traversal
	ast_visitor *visitor        // visitor
) {
	validations_ctx *vctx = AST_Visitor_GetContext(visitor);

	if(start) {
		vctx->clause = cypher_astnode_type(n);
		// introduce aliases in the clause to the bounded vars environment
		_AST_GetProcCallAliases(n, vctx->defined_identifiers);

		/* Make sure procedure calls are valid:
		* 1. procedure exists
		* 2. number of arguments to procedure is as expected
		* 3. yield refers to procedure output */

		ProcedureCtx *proc = NULL;
		rax *rax = NULL;

		// Make sure procedure exists.
		const char *proc_name = cypher_ast_proc_name_get_value(cypher_ast_call_get_proc_name(n));
		proc = Proc_Get(proc_name);

		if(proc == NULL) {
			ErrorCtx_SetError("Procedure `%s` is not registered", proc_name);
			goto cleanup;
		}

		// Validate num of arguments.
		if(proc->argc != PROCEDURE_VARIABLE_ARG_COUNT) {
			unsigned int given_arg_count = cypher_ast_call_narguments(n);
			if(Procedure_Argc(proc) != given_arg_count) {
				ErrorCtx_SetError("Procedure `%s` requires %d arguments, got %d", proc_name, proc->argc,
									given_arg_count);
				goto cleanup;
			}
		}

		rax = raxNew();

		// validate projections
		uint proj_count = cypher_ast_call_nprojections(n);
		// collect call projections
		for(uint j = 0; j < proj_count; j++) {
			const cypher_astnode_t *proj = cypher_ast_call_get_projection(n, j);
			const cypher_astnode_t *ast_exp = cypher_ast_projection_get_expression(proj);
			ASSERT(cypher_astnode_type(ast_exp) == CYPHER_AST_IDENTIFIER);
			const char *identifier = cypher_ast_identifier_get_name(ast_exp);

			// make sure each yield output is mentioned only once
			if(!raxInsert(rax, (unsigned char *)identifier, strlen(identifier), NULL, NULL)) {
				ErrorCtx_SetError("Variable `%s` already declared", identifier);
				goto cleanup;
			}

			// make sure procedure is aware of output