[Ada] Crash on ignored Ghost expression function

This patch updates freezing to ensure that freeze nodes are inserted
into the tree when the entity being frozen is non-Ghost, and the context
is an ignored Ghost spec expression.

2018-12-11  Hristian Kirtchev  <kirtchev@adacore.com>

gcc/ada/

	* exp_util.adb (Insert_Action): Add new formal parameter
	Spec_Expr_OK.
	(Insert_Actions): Add new formal parameter Spec_Expr_OK. Update
	all calls to Insert_Actions where relevant. Honour an insertion
	from a spec expression context when requested by the caller.
	* exp_util.ads (Insert_Action): Add new formal parameter
	Spec_Expr_OK.
	(Insert_Actions): Add new formal parameter Spec_Expr_OK.
	* freeze.adb (Add_To_Result): Force the insertion of the freeze
	node even when the context is a spec expression.

gcc/testsuite/

	* gnat.dg/ghost2.adb, gnat.dg/ghost2.ads: New testcase.

From-SVN: r266996

1 files changed, 28 insertions, 13 deletions

diff --git a/gcc/ada/exp_util.ads b/gcc/ada/exp_util.ads
index ab48b74..97eccdd 100644
--- a/gcc/ada/exp_util.ads
+++ b/gcc/ada/exp_util.ads
@@ -89,39 +89,54 @@ package Exp_Util is
    --  calls, and this guarantee is preserved for the special cases above.
 
    procedure Insert_Action
-     (Assoc_Node : Node_Id;
-      Ins_Action : Node_Id);
+     (Assoc_Node   : Node_Id;
+      Ins_Action   : Node_Id;
+      Spec_Expr_OK : Boolean := False);
    --  Insert the action Ins_Action at the appropriate point as described
    --  above. The action is analyzed using the default checks after it is
    --  inserted. Assoc_Node is the node with which the action is associated.
+   --  When flag Spec_Expr_OK is set, insertions triggered in the context of
+   --  spec expressions are honoured, even though they contradict "Handling
+   --  of Default and Per-Object Expressions".
 
    procedure Insert_Action
-     (Assoc_Node : Node_Id;
-      Ins_Action : Node_Id;
-      Suppress   : Check_Id);
+     (Assoc_Node   : Node_Id;
+      Ins_Action   : Node_Id;
+      Suppress     : Check_Id;
+      Spec_Expr_OK : Boolean := False);
    --  Insert the action Ins_Action at the appropriate point as described
    --  above. The action is analyzed using the default checks as modified
    --  by the given Suppress argument after it is inserted. Assoc_Node is
-   --  the node with which the action is associated.
+   --  the node with which the action is associated. When flag Spec_Expr_OK
+   --  is set, insertions triggered in the context of spec expressions are
+   --  honoured, even though they contradict "Handling of Default and Per-
+   --  Object Expressions".
 
    procedure Insert_Actions
-     (Assoc_Node  : Node_Id;
-      Ins_Actions : List_Id);
+     (Assoc_Node   : Node_Id;
+      Ins_Actions  : List_Id;
+      Spec_Expr_OK : Boolean := False);
    --  Insert the list of action Ins_Actions at the appropriate point as
    --  described above. The actions are analyzed using the default checks
    --  after they are inserted. Assoc_Node is the node with which the actions
    --  are associated. Ins_Actions may be No_List, in which case the call has
-   --  no effect.
+   --  no effect. When flag Spec_Expr_OK is set, insertions triggered in the
+   --  context of spec expressions are honoured, even though they contradict
+   --  "Handling of Default and Per-Object Expressions".
 
    procedure Insert_Actions
-     (Assoc_Node  : Node_Id;
-      Ins_Actions : List_Id;
-      Suppress    : Check_Id);
+     (Assoc_Node   : Node_Id;
+      Ins_Actions  : List_Id;
+      Suppress     : Check_Id;
+      Spec_Expr_OK : Boolean := False);
    --  Insert the list of action Ins_Actions at the appropriate point as
    --  described above. The actions are analyzed using the default checks
    --  as modified by the given Suppress argument after they are inserted.
-   --  Assoc_Node is the node with which the actions are associated.
+   --  Assoc_Node is the node with which the actions are associated. List
    --  Ins_Actions may be No_List, in which case the call has no effect.
+   --  When flag Spec_Expr_OK is set, insertions triggered in the context of
+   --  spec expressions are honoured, even though they contradict "Handling
+   --  of Default and Per-Object Expressions".
 
    procedure Insert_Action_After
      (Assoc_Node : Node_Id;