[COMMITTED] ada: Fix bug in predicate checks with address clauses

[COMMITTED] ada: Fix bug in predicate checks with address clauses

[Marc Poulhiès]

From: Bob Duff <duff@adacore.com>

This patch fixes a compiler bug triggered by having a type with some
defaulted components, and a predicate, and an object of that type with
an address clause. In this case, the compiler was crashing.

gcc/ada/

	* sem_ch3.adb (Analyze_Object_Declaration): Remove predicate-check
	generation if there is an address clause. These are unnecessary,
	and cause gigi to crash.
	* exp_util.ads (Following_Address_Clause): Remove obsolete "???"
	comments. The suggested changes were done long ago.

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

---
 gcc/ada/exp_util.ads |  7 -------
 gcc/ada/sem_ch3.adb  | 11 ++++++++++-
 2 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/gcc/ada/exp_util.ads b/gcc/ada/exp_util.ads
index 24065b6f7b6..02324d23db0 100644
--- a/gcc/ada/exp_util.ads
+++ b/gcc/ada/exp_util.ads
@@ -647,13 +647,6 @@ package Exp_Util is
    --  current declarative part to look for an address clause for the object
    --  being declared, and returns the clause if one is found, returns
    --  Empty otherwise.
-   --
-   --  Note: this function can be costly and must be invoked with special care.
-   --  Possibly we could introduce a flag at parse time indicating the presence
-   --  of an address clause to speed this up???
-   --
-   --  Note: currently this function does not scan the private part, that seems
-   --  like a potential bug ???
 
    type Force_Evaluation_Mode is (Relaxed, Strict);
 
diff --git a/gcc/ada/sem_ch3.adb b/gcc/ada/sem_ch3.adb
index fb63690803b..85019dfffa5 100644
--- a/gcc/ada/sem_ch3.adb
+++ b/gcc/ada/sem_ch3.adb
@@ -4690,6 +4690,16 @@ package body Sem_Ch3 is
          elsif No (E) and then Is_Null_Record_Type (T) then
             null;
 
+         --  If there is an address clause for this object, do not generate a
+         --  predicate check here. It will be generated later, at the freezng
+         --  point. It would be wrong to generate references to the object
+         --  here, before the address has been determined.
+
+         elsif Has_Aspect (Id, Aspect_Address)
+           or else Present (Following_Address_Clause (N))
+         then
+            null;
+
          --  Do not generate a predicate check if the initialization expression
          --  is a type conversion whose target subtype statically matches the
          --  object's subtype because the conversion has been subjected to the
@@ -4709,7 +4719,6 @@ package body Sem_Ch3 is
             declare
                Check : constant Node_Id :=
                          Make_Predicate_Check (T, New_Occurrence_Of (Id, Loc));
-
             begin
                if No (Next_Decl) then
                   Append_To (List_Containing (N), Check);
-- 
2.40.0