| Message ID | 20170425081240.GA36912@adacore.com |
|---|---|
| State | New |
| Headers | show |
Index: freeze.adb =================================================================== --- freeze.adb (revision 247140) +++ freeze.adb (working copy) @@ -1384,8 +1384,12 @@ begin Decl := Original_Node (Unit_Declaration_Node (Nam)); + -- The subprogram body created for the expression function is not + -- itself a freeze point. + if Scope (Nam) = Current_Scope and then Nkind (Decl) = N_Expression_Function + and then Nkind (N) /= N_Subprogram_Body then Check_Deferred (Expression (Decl)); end if;
This patch removes a spurious error on a deferred constant that appears within an expression function, when the expression is being frozen by the presence of its generated body. Such bodies are not a freeze point unless they are completions. The following must compile quietly: --- package P is package S is type T is private; No_T : constant T; function Is_Null (A_T : T) return Boolean is (A_T = No_T); private type T is null record; No_T : constant T := (null record); end; end P; Tested on x86_64-pc-linux-gnu, committed on trunk 2017-04-25 Ed Schonberg <schonberg@adacore.com> * freeze.adb (Check_Expression_Function): Do not check for the use of deferred constants if the freezing of the expression function is triggered by its generated body, rather than a premature use.