[Ada] Temporarily simplify legality checks for Inox case statements
Commit Message
INOX (which is enabled via -gnatX) supports composite case-statement selectors.
As a temporary measure, simplify the coverage-related compile-time checks
for such case statements via two changes: an others choice is always
required for such a case statement, and no legality checks relating to
overlapping of case choices are performed.
Tested on x86_64-pc-linux-gnu, committed on trunk
gcc/ada/
* sem_case.adb: Define a new Boolean constant,
Simplified_Composite_Coverage_Rules, initialized to True. Setting
this constant to True has two effects: 1- Representative value
sets are not fully initialized - this is done to avoid capacity
problems, as well as for performance. 2- In
Check_Case_Pattern_Choices, the only legality check performed is a
check that a "when others =>" choice is present.
@@ -106,6 +106,14 @@ package body Sem_Case is
package Composite_Case_Ops is
+ Simplified_Composite_Coverage_Rules : constant Boolean := True;
+ -- Indicates that, as a temporary stopgap, we implement
+ -- simpler coverage-checking rules when casing on a
+ -- composite selector:
+ -- 1) Require that an Others choice must be given, regardless
+ -- of whether all possible values are covered explicitly.
+ -- 2) No legality checks regarding overlapping choices.
+
function Box_Value_Required (Subtyp : Entity_Id) return Boolean;
-- If result is True, then the only allowed value (in a choice
-- aggregate) for a component of this (sub)type is a box. This rule
@@ -263,7 +271,6 @@ package body Sem_Case is
type Bound_Values is array (Positive range <>) of Node_Id;
end Choice_Analysis;
-
end Composite_Case_Ops;
procedure Expand_Others_Choice
@@ -2526,6 +2533,14 @@ package body Sem_Case is
for P in Part_Id loop
Insert_Representative (Component_Bounds (P).Low, P);
end loop;
+
+ if Simplified_Composite_Coverage_Rules then
+ -- Omit other representative values to avoid capacity
+ -- problems building data structures only used in
+ -- compile-time checks that will not be performed.
+ return Result;
+ end if;
+
for C of Choices_Bounds loop
if not C.Is_Others then
for P in Part_Id loop
@@ -3368,8 +3383,6 @@ package body Sem_Case is
--------------------------------
procedure Check_Case_Pattern_Choices is
- -- ??? Need to Free/Finalize value sets allocated here.
-
package Ops is new Composite_Case_Ops.Choice_Analysis
(Case_Statement => N);
use Ops;
@@ -3394,8 +3407,14 @@ package body Sem_Case is
Covered : Value_Set := Empty;
-- The union of all alternatives seen so far
-
begin
+ if Composite_Case_Ops.Simplified_Composite_Coverage_Rules then
+ if not (for some Choice of Info => Choice.Is_Others) then
+ Error_Msg_N ("others choice required", N);
+ end if;
+ return;
+ end if;
+
for Choice of Info loop
if Choice.Is_Others then
Others_Seen := True;