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[Ada] Prevent overflow in computation of aggregate size

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When computing size of a static aggregate to decide if it should be
transformed into assignments and loops we could have an overflow check.
This is mostly harmless, because colossal aggregates will likely crash
the application anyway, no matter how we transform them.

This was not detected because compiler was built with -gnatg switch that
suppresses overflow checks (they are only enabled by an explicit -gnato
switch).

gcc/ada/

	* exp_aggr.adb (Component_Count): Calculate size as an Uint and
	only then check if it is in the range of Int, as otherwise the
	multiplication of Int values can overflow.
This commit is contained in:
Piotr Trojanek 2022-03-31 20:56:58 +02:00 • committed by Pierre-Marie de Rodat
parent 8b49556e4e
commit 16b8ba101f
1 changed files with 2 additions and 2 deletions
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4
gcc/ada/exp_aggr.adb
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@ -661,10 +661,10 @@ package body Exp_Aggr is
declare
UI : constant Uint :=
Expr_Value (Hi) - Expr_Value (Lo) + 1;
(Expr_Value (Hi) - Expr_Value (Lo) + 1) * Siz;
begin
if UI_Is_In_Int_Range (UI) then
return Siz * UI_To_Int (UI);
return UI_To_Int (UI);
else
return Int'Last;
end if;