[COMMITTED] ada: Fix internal error on loop iterator filter with -gnatVa

[COMMITTED] ada: Fix internal error on loop iterator filter with -gnatVa

[Marc Poulhiès]

From: Eric Botcazou <ebotcazou@adacore.com>

The problem is that the condition of the iterator filter is expanded early,
before it is integrated into an if statement of the loop body, so there is
no place to attach the actions generated by this expansion.

This happens only for simple loops, i.e. with a parameter specification, so
the fix uses the same approach for them as for loops based on iterators.

gcc/ada/

	* sinfo.ads (Iterator_Filter): Document field.
	* sem_ch5.adb (Analyze_Iterator_Specification): Move comment around.
	(Analyze_Loop_Parameter_Specification): Only preanalyze the iterator
	filter, if any.
	* exp_ch5.adb (Expand_N_Loop_Statement): Analyze the new list built
	when an iterator filter is present.

Tested on x86_64-pc-linux-gnu, committed on master.

---
 gcc/ada/exp_ch5.adb |  1 +
 gcc/ada/sem_ch5.adb | 11 +++++++----
 gcc/ada/sinfo.ads   |  5 +++++
 3 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/gcc/ada/exp_ch5.adb b/gcc/ada/exp_ch5.adb
index a4c7db9f365..258459b393d 100644
--- a/gcc/ada/exp_ch5.adb
+++ b/gcc/ada/exp_ch5.adb
@@ -5678,6 +5678,7 @@ package body Exp_Ch5 is
                   New_List (Make_If_Statement (Loc,
                     Condition => Iterator_Filter (LPS),
                     Then_Statements => Stats)));
+               Analyze_List (Statements (N));
             end if;
 
             --  Deal with loop over predicates
diff --git a/gcc/ada/sem_ch5.adb b/gcc/ada/sem_ch5.adb
index f9174869a26..fa36a5a0741 100644
--- a/gcc/ada/sem_ch5.adb
+++ b/gcc/ada/sem_ch5.adb
@@ -2705,10 +2705,10 @@ package body Sem_Ch5 is
          end if;
       end if;
 
-      if Present (Iterator_Filter (N)) then
-         --  Preanalyze the filter. Expansion will take place when enclosing
-         --  loop is expanded.
+      --  Preanalyze the filter. Expansion will take place when enclosing
+      --  loop is expanded.
 
+      if Present (Iterator_Filter (N)) then
          Preanalyze_And_Resolve (Iterator_Filter (N), Standard_Boolean);
       end if;
    end Analyze_Iterator_Specification;
@@ -3424,8 +3424,11 @@ package body Sem_Ch5 is
          end;
       end if;
 
+      --  Preanalyze the filter. Expansion will take place when enclosing
+      --  loop is expanded.
+
       if Present (Iterator_Filter (N)) then
-         Analyze_And_Resolve (Iterator_Filter (N), Standard_Boolean);
+         Preanalyze_And_Resolve (Iterator_Filter (N), Standard_Boolean);
       end if;
 
       --  A loop parameter cannot be effectively volatile (SPARK RM 7.1.3(4)).
diff --git a/gcc/ada/sinfo.ads b/gcc/ada/sinfo.ads
index 0efbd4479e0..8040a59e175 100644
--- a/gcc/ada/sinfo.ads
+++ b/gcc/ada/sinfo.ads
@@ -1909,6 +1909,11 @@ package Sinfo is
    --    Present in variable reference markers. Set when the original variable
    --    reference constitutes a write of the variable.
 
+   --  Iterator_Filter
+   --    Present in N_Loop_Parameter_Specification and N_Iterator_Specification
+   --    nodes for Ada 2022. It is used to store the condition present in the
+   --    eponymous Ada 2022 construct.
+
    --  Itype
    --    Used in N_Itype_Reference node to reference an itype for which it is
    --    important to ensure that it is defined. See description of this node
-- 
2.40.0