SPARK code is much more restricted in terms of possible side-effects
inside expressions. As such, there is no need for aggressive removal of
side-effects across all expressions in GNATprove mode. The benefit is
that expressions are more self-contained, without the need to get
information from hoisted constants.
Tested on x86_64-pc-linux-gnu, committed on trunk
gcc/ada/
* exp_util.adb (Remove_Side_Effects): Only remove side-effects
in GNATprove mode when this is useful.
* sem_res.adb (Set_Slice_Subtype): Make sure in GNATprove mode
to define the Itype when needed, so that run-time errors can be
analyzed.
* sem_util.adb (Enclosing_Declaration): Correctly take into
account renaming declarations.diff --git a/gcc/ada/exp_util.adb b/gcc/ada/exp_util.adb
--- a/gcc/ada/exp_util.adb
+++ b/gcc/ada/exp_util.adb
@@ -11124,6 +11124,12 @@ package body Exp_Util is
-- otherwise it generates an internal temporary. The created temporary
-- entity is marked as internal.
+ function Possible_Side_Effect_In_SPARK (Exp : Node_Id) return Boolean;
+ -- Computes whether a side-effect is possible in SPARK, which should
+ -- be handled by removing it from the expression for GNATprove. Note
+ -- that other side-effects related to volatile variables are handled
+ -- separately.
+
---------------------
-- Build_Temporary --
---------------------
@@ -11159,6 +11165,26 @@ package body Exp_Util is
return Temp_Id;
end Build_Temporary;
+ -----------------------------------
+ -- Possible_Side_Effect_In_SPARK --
+ -----------------------------------
+
+ function Possible_Side_Effect_In_SPARK (Exp : Node_Id) return Boolean is
+ begin
+ -- Side-effect removal in SPARK should only occur when not inside a
+ -- generic and not doing a preanalysis, inside an object renaming or
+ -- a type declaration or a for-loop iteration scheme.
+
+ return not Inside_A_Generic
+ and then Full_Analysis
+ and then Nkind (Enclosing_Declaration (Exp)) in
+ N_Full_Type_Declaration
+ | N_Iterator_Specification
+ | N_Loop_Parameter_Specification
+ | N_Object_Renaming_Declaration
+ | N_Subtype_Declaration;
+ end Possible_Side_Effect_In_SPARK;
+
-- Local variables
Loc : constant Source_Ptr := Sloc (Exp);
@@ -11176,11 +11202,11 @@ package body Exp_Util is
begin
-- Handle cases in which there is nothing to do. In GNATprove mode,
-- removal of side effects is useful for the light expansion of
- -- renamings. This removal should only occur when not inside a
- -- generic and not doing a preanalysis.
+ -- renamings.
if not Expander_Active
- and (Inside_A_Generic or not Full_Analysis or not GNATprove_Mode)
+ and then not
+ (GNATprove_Mode and then Possible_Side_Effect_In_SPARK (Exp))
then
return;
@@ -11218,14 +11244,6 @@ package body Exp_Util is
and then Is_Class_Wide_Type (Etype (Exp))
then
return;
-
- -- An expression which is in SPARK mode is considered side effect free
- -- if the resulting value is captured by a variable or a constant.
-
- elsif GNATprove_Mode
- and then Nkind (Parent (Exp)) = N_Object_Declaration
- then
- return;
end if;
-- The remaining processing is done with all checks suppressed
diff --git a/gcc/ada/sem_res.adb b/gcc/ada/sem_res.adb
--- a/gcc/ada/sem_res.adb
+++ b/gcc/ada/sem_res.adb
@@ -12438,9 +12438,10 @@ package body Sem_Res is
-- the point where actions for the slice are analyzed). Note that this
-- is different from freezing the itype immediately, which might be
-- premature (e.g. if the slice is within a transient scope). This needs
- -- to be done only if expansion is enabled.
+ -- to be done only if expansion is enabled, or in GNATprove mode to
+ -- capture the associated run-time exceptions if any.
- elsif Expander_Active then
+ elsif Expander_Active or GNATprove_Mode then
Ensure_Defined (Typ => Slice_Subtype, N => N);
end if;
end Set_Slice_Subtype;
diff --git a/gcc/ada/sem_util.adb b/gcc/ada/sem_util.adb
--- a/gcc/ada/sem_util.adb
+++ b/gcc/ada/sem_util.adb
@@ -7859,6 +7859,8 @@ package body Sem_Util is
or else
Nkind (Decl) in N_Later_Decl_Item
or else
+ Nkind (Decl) in N_Renaming_Declaration
+ or else
Nkind (Decl) = N_Number_Declaration)
loop
Decl := Parent (Decl);
