static void compute_function_hashkey()

in src/postgres/src_pl_plpgsql_src_pl_comp.c [158:341]


static void compute_function_hashkey(FunctionCallInfo fcinfo,
						 Form_pg_proc procStruct,
						 PLpgSQL_func_hashkey *hashkey,
						 bool forValidator);
static void plpgsql_resolve_polymorphic_argtypes(int numargs,
									 Oid *argtypes, char *argmodes,
									 Node *call_expr, bool forValidator,
									 const char *proname);
static PLpgSQL_function *plpgsql_HashTableLookup(PLpgSQL_func_hashkey *func_key);
static void plpgsql_HashTableInsert(PLpgSQL_function *function,
						PLpgSQL_func_hashkey *func_key);
static void plpgsql_HashTableDelete(PLpgSQL_function *function);
static void delete_function(PLpgSQL_function *func);

/* ----------
 * plpgsql_compile		Make an execution tree for a PL/pgSQL function.
 *
 * If forValidator is true, we're only compiling for validation purposes,
 * and so some checks are skipped.
 *
 * Note: it's important for this to fall through quickly if the function
 * has already been compiled.
 * ----------
 */


/*
 * This is the slow part of plpgsql_compile().
 *
 * The passed-in "function" pointer is either NULL or an already-allocated
 * function struct to overwrite.
 *
 * While compiling a function, the CurrentMemoryContext is the
 * per-function memory context of the function we are compiling. That
 * means a palloc() will allocate storage with the same lifetime as
 * the function itself.
 *
 * Because palloc()'d storage will not be immediately freed, temporary
 * allocations should either be performed in a short-lived memory
 * context or explicitly pfree'd. Since not all backend functions are
 * careful about pfree'ing their allocations, it is also wise to
 * switch into a short-term context before calling into the
 * backend. An appropriate context for performing short-term
 * allocations is the plpgsql_compile_tmp_cxt.
 *
 * NB: this code is not re-entrant.  We assume that nothing we do here could
 * result in the invocation of another plpgsql function.
 */


/* ----------
 * plpgsql_compile_inline	Make an execution tree for an anonymous code block.
 *
 * Note: this is generally parallel to do_compile(); is it worth trying to
 * merge the two?
 *
 * Note: we assume the block will be thrown away so there is no need to build
 * persistent data structures.
 * ----------
 */
PLpgSQL_function *
plpgsql_compile_inline(char *proc_source)
{
	char	   *func_name = "inline_code_block";
	PLpgSQL_function *function;
	ErrorContextCallback plerrcontext;
	PLpgSQL_variable *var;
	int			parse_rc;
	MemoryContext func_cxt;

	/*
	 * Setup the scanner input and error info.  We assume that this function
	 * cannot be invoked recursively, so there's no need to save and restore
	 * the static variables used here.
	 */
	plpgsql_scanner_init(proc_source);

	plpgsql_error_funcname = func_name;

	/*
	 * Setup error traceback support for ereport()
	 */
	plerrcontext.callback = plpgsql_compile_error_callback;
	plerrcontext.arg = proc_source;
	plerrcontext.previous = error_context_stack;
	error_context_stack = &plerrcontext;

	/* Do extra syntax checking if check_function_bodies is on */
	plpgsql_check_syntax = check_function_bodies;

	/* Function struct does not live past current statement */
	function = (PLpgSQL_function *) palloc0(sizeof(PLpgSQL_function));

	plpgsql_curr_compile = function;

	/*
	 * All the rest of the compile-time storage (e.g. parse tree) is kept in
	 * its own memory context, so it can be reclaimed easily.
	 */
	func_cxt = AllocSetContextCreate(CurrentMemoryContext,
									 "PL/pgSQL inline code context",
									 ALLOCSET_DEFAULT_SIZES);
	plpgsql_compile_tmp_cxt = MemoryContextSwitchTo(func_cxt);

	function->fn_signature = pstrdup(func_name);
	function->fn_is_trigger = PLPGSQL_NOT_TRIGGER;
	function->fn_input_collation = InvalidOid;
	function->fn_cxt = func_cxt;
	function->out_param_varno = -1; /* set up for no OUT param */
	function->resolve_option = plpgsql_variable_conflict;
	function->print_strict_params = plpgsql_print_strict_params;

	/*
	 * don't do extra validation for inline code as we don't want to add spam
	 * at runtime
	 */
	function->extra_warnings = 0;
	function->extra_errors = 0;

	plpgsql_ns_init();
	plpgsql_ns_push(func_name, PLPGSQL_LABEL_BLOCK);
	plpgsql_DumpExecTree = false;
	plpgsql_start_datums();

	/* Set up as though in a function returning VOID */
	function->fn_rettype = VOIDOID;
	function->fn_retset = false;
	function->fn_retistuple = false;
	/* a bit of hardwired knowledge about type VOID here */
	function->fn_retbyval = true;
	function->fn_rettyplen = sizeof(int32);

	/*
	 * Remember if function is STABLE/IMMUTABLE.  XXX would it be better to
	 * set this TRUE inside a read-only transaction?  Not clear.
	 */
	function->fn_readonly = false;

	/*
	 * Create the magic FOUND variable.
	 */
	var = plpgsql_build_variable("found", 0,
								 plpgsql_build_datatype(BOOLOID,
														-1,
														InvalidOid),
								 true);
	function->found_varno = var->dno;

	/*
	 * Now parse the function's text
	 */
	parse_rc = plpgsql_yyparse();
	if (parse_rc != 0)
		elog(ERROR, "plpgsql parser returned %d", parse_rc);
	function->action = plpgsql_parse_result;

	plpgsql_scanner_finish();

	/*
	 * If it returns VOID (always true at the moment), we allow control to
	 * fall off the end without an explicit RETURN statement.
	 */
	if (function->fn_rettype == VOIDOID)
		add_dummy_return(function);

	/*
	 * Complete the function's info
	 */
	function->fn_nargs = 0;

	plpgsql_finish_datums(function);

	/*
	 * Pop the error context stack
	 */
	error_context_stack = plerrcontext.previous;
	plpgsql_error_funcname = NULL;

	plpgsql_check_syntax = false;

	MemoryContextSwitchTo(plpgsql_compile_tmp_cxt);
	plpgsql_compile_tmp_cxt = NULL;
	return function;
}