We call Set_Ekind on a E_Incomplete_Subtype entity, and the
Private_Dependents field vanishes. This patch resets it to zero, as
required for vanishing fields.
Tested on x86_64-pc-linux-gnu, committed on trunk
gcc/ada/
* sem_ch3.adb (Process_Incomplete_Dependents): Reset
Private_Dependents field to zero before calling Set_Ekind. Also
move Set_Etype to after Set_Ekind, because it's always best to
set the Ekind as early as possible.
* atree.adb: Improve debugging facilities for vanishing fields.diff --git a/gcc/ada/atree.adb b/gcc/ada/atree.adb
--- a/gcc/ada/atree.adb
+++ b/gcc/ada/atree.adb
@@ -29,6 +29,8 @@
-- Checks and assertions in this package are too slow, and are mostly needed
-- when working on this package itself, or on gen_il, so we disable them.
+-- To debug low-level bugs in this area, comment out the following pragmas,
+-- and run with -gnatd_v.
pragma Suppress (All_Checks);
pragma Assertion_Policy (Ignore);
@@ -868,7 +870,9 @@ package body Atree is
Old_Kind : constant Entity_Kind := Ekind (Old_N);
-- If this fails, it means you need to call Reinit_Field_To_Zero before
- -- calling Set_Ekind.
+ -- calling Set_Ekind. But we have many cases where vanishing fields are
+ -- expected to reappear after converting to/from E_Void. Other cases are
+ -- more problematic; set a breakpoint on "(non-E_Void case)" below.
begin
for J in Entity_Field_Table (Old_Kind)'Range loop
@@ -882,12 +886,14 @@ package body Atree is
Write_Str (New_Kind'Img);
Write_Str (" Nonzero field ");
Write_Str (F'Img);
- Write_Str (" is vanishing");
+ Write_Str (" is vanishing ");
Write_Eol;
- pragma Assert (New_Kind = E_Void or else Old_Kind = E_Void);
-
- raise Program_Error;
+ if New_Kind = E_Void or else Old_Kind = E_Void then
+ Write_Line (" (E_Void case)");
+ else
+ Write_Line (" (non-E_Void case)");
+ end if;
end if;
end if;
end;
diff --git a/gcc/ada/sem_ch3.adb b/gcc/ada/sem_ch3.adb
--- a/gcc/ada/sem_ch3.adb
+++ b/gcc/ada/sem_ch3.adb
@@ -21299,8 +21299,11 @@ package body Sem_Ch3 is
then
Set_Subtype_Indication
(Parent (Priv_Dep), New_Occurrence_Of (Full_T, Sloc (Priv_Dep)));
- Set_Etype (Priv_Dep, Full_T);
+ Reinit_Field_To_Zero
+ (Priv_Dep, Private_Dependents,
+ Old_Ekind => E_Incomplete_Subtype);
Set_Ekind (Priv_Dep, Subtype_Kind (Ekind (Full_T)));
+ Set_Etype (Priv_Dep, Full_T);
Set_Analyzed (Parent (Priv_Dep), False);
-- Reanalyze the declaration, suppressing the call to Enter_Name
