From: Gary Dismukes <dismukes@adacore.com>
The compiler rejects various cases of container aggregates with
iterated_element_associations that include a loop_parameter_subtype_indication
or that include the "reverse" keyword. The fixes are in the parser, for
naccepting the syntax for these cases, as well as for properly accounting
for reverse iterators in the analyzer and expander.
gcc/ada/
* exp_aggr.adb
(Expand_Container_Aggregate.Expand_Iterated_Component): Set the
Reverse_Present flag when creating the loop's iteration_scheme.
* gen_il-gen-gen_nodes.adb: Add flag Reverse_Present to
N_Iterated_Component_Association nodes.
* par-ch3.adb (P_Constraint_Op): Remove testing for and ignoring
of Tok_In following a constraint. It's allowed for "in" to follow
a constraint of loop_parameter_subtype_indication of an
iterator_specification, so it shouldn't be ignored.
* par-ch4.adb (P_Iterated_Component_Association): Account for
"reverse" following the "in" in an iterated_component_association,
and set the Reverse_Present flag on the
N_Iterated_Component_Association node. Add handling for a ":"
following the identifier in an iterator_specification of an
iterated_element_association, sharing the code with the "of" case
(which backs up to the identifier at the beginning of the
iterator_specification). Fix incorrect trailing comment following
the call to Scan.
(Build_Iterated_Element_Association): Set the Reverse_Present flag
on an N_Loop_Parameter_Specification node of an
N_Iterated_Element_Association.
* par-ch5.adb (P_Iterator_Specification): Remove error-recovery
and error code that reports "subtype indication is only legal on
an element iterator", as that error can no longer be emitted (and
was formerly only reported on one fixedbugs test).
* sem_aggr.adb
(Resolve_Container_Aggregate.Resolve_Iterated_Association): When
creating an N_Iterator_Specification for an
N_Iterated_Component_Association, set the Reverse_Present flag of
the N_Iterated_Specification from the flag on the latter.
* sinfo.ads: Add comments for the Reverse_Present flag, which is
now allowed on nodes of kind N_Iterated_Component_Association.
Tested on x86_64-pc-linux-gnu, committed on master.
---
gcc/ada/exp_aggr.adb | 1 +
gcc/ada/gen_il-gen-gen_nodes.adb | 1 +
gcc/ada/par-ch3.adb | 4 ----
gcc/ada/par-ch4.adb | 12 +++++++++++-
gcc/ada/par-ch5.adb | 12 ------------
gcc/ada/sem_aggr.adb | 2 +-
gcc/ada/sinfo.ads | 6 ++++++
7 files changed, 20 insertions(+), 18 deletions(-)
@@ -7019,6 +7019,7 @@ package body Exp_Aggr is
Loop_Parameter_Specification =>
Make_Loop_Parameter_Specification (Loc,
Defining_Identifier => Loop_Id,
+ Reverse_Present => Reverse_Present (Comp),
Discrete_Subtype_Definition => L_Range));
end if;
end if;
@@ -1489,6 +1489,7 @@ begin -- Gen_IL.Gen.Gen_Nodes
Sy (Iterator_Specification, Node_Id, Default_Empty),
Sy (Expression, Node_Id, Default_Empty),
Sy (Discrete_Choices, List_Id),
+ Sy (Reverse_Present, Flag),
Sy (Box_Present, Flag),
Sm (Loop_Actions, List_Id)));
@@ -1196,10 +1196,6 @@ package body Ch3 is
elsif Token = Tok_Left_Paren then
return P_Index_Or_Discriminant_Constraint;
- elsif Token = Tok_In then
- Ignore (Tok_In);
- return P_Constraint_Opt;
-
-- One more possibility is e.g. 1 .. 10 (i.e. missing RANGE keyword)
elsif Token = Tok_Identifier or else
@@ -3584,6 +3584,7 @@ package body Ch4 is
Iter_Spec : Node_Id;
Loop_Spec : Node_Id;
State : Saved_Scan_State;
+ In_Reverse : Boolean := False;
procedure Build_Iterated_Element_Association;
-- If the iterator includes a key expression or a filter, it is
@@ -3602,6 +3603,8 @@ package body Ch4 is
New_Node (N_Loop_Parameter_Specification, Prev_Token_Ptr);
Set_Defining_Identifier (Loop_Spec, Id);
+ Set_Reverse_Present (Loop_Spec, In_Reverse);
+
Choice := First (Discrete_Choices (Assoc_Node));
Assoc_Node :=
New_Node (N_Iterated_Element_Association, Prev_Token_Ptr);
@@ -3644,6 +3647,13 @@ package body Ch4 is
when Tok_In =>
Set_Defining_Identifier (Assoc_Node, Id);
T_In;
+
+ if Token = Tok_Reverse then
+ Scan; -- past REVERSE
+ Set_Reverse_Present (Assoc_Node, True);
+ In_Reverse := True;
+ end if;
+
Set_Discrete_Choices (Assoc_Node, P_Discrete_Choice_List);
-- The iterator may include a filter
@@ -3673,7 +3683,7 @@ package body Ch4 is
TF_Arrow;
Set_Expression (Assoc_Node, P_Expression);
- when Tok_Of =>
+ when Tok_Colon | Tok_Of =>
Restore_Scan_State (State);
Scan; -- past OF
Iter_Spec := P_Iterator_Specification (Id);
@@ -1836,18 +1836,6 @@ package body Ch5 is
elsif Token = Tok_In then
Scan; -- past IN
- elsif Prev_Token = Tok_In
- and then Present (Subtype_Indication (Node1))
- then
- -- Simplest recovery is to transform it into an element iterator.
- -- Error message on 'in" has already been emitted when parsing the
- -- optional constraint.
-
- Set_Of_Present (Node1);
- Error_Msg_N
- ("subtype indication is only legal on an element iterator",
- Subtype_Indication (Node1));
-
else
return Error;
end if;
@@ -3818,7 +3818,7 @@ package body Sem_Aggr is
Defining_Identifier =>
Relocate_Node (Defining_Identifier (Comp)),
Name => Copy,
- Reverse_Present => False,
+ Reverse_Present => Reverse_Present (Comp),
Iterator_Filter => Empty,
Subtype_Indication => Empty);
begin
@@ -4203,6 +4203,11 @@ package Sinfo is
-- At most one of (Defining_Identifier, Iterator_Specification)
-- is present at a time, in which case the other one is empty.
+ -- The Reverse_Present flag is present for cases where semantic analysis
+ -- later changes the association to have an N_Iterator_Specification
+ -- rather than a Defining_Identifier (due to the "discrete choice"
+ -- being resolved as an iterator name), and needs to set that flag on
+ -- the N_Iterator_Specification node.
-- N_Iterated_Component_Association
-- Sloc points to FOR
@@ -4210,6 +4215,7 @@ package Sinfo is
-- Iterator_Specification
-- Expression
-- Discrete_Choices
+ -- Reverse_Present
-- Loop_Actions
-- Box_Present