The patch gives an error message on "for T'Object_Size use 0;".
Tested on x86_64-pc-linux-gnu, committed on trunk
2019-08-20 Bob Duff <d...@adacore.com>
gcc/ada/
* sem_ch13.adb (Object_Size): Give an error for zero. It really
rubs me the wrong way that we don't honor "for T'Object_Size use
0;", but it's not important enough to fix. In any case, if we're
not going to obey the clause, we should give an error.
gcc/testsuite/
* gnat.dg/object_size1.adb: New testcase.--- gcc/ada/sem_ch13.adb
+++ gcc/ada/sem_ch13.adb
@@ -5812,6 +5812,9 @@ package body Sem_Ch13 is
if ASIS_Mode then
null;
+ elsif Size <= 0 then
+ Error_Msg_N ("Object_Size must be positive", Expr);
+
elsif Is_Scalar_Type (U_Ent) then
if Size /= 8 and then Size /= 16 and then Size /= 32
and then UI_Mod (Size, 64) /= 0
--- /dev/null
new file mode 100644
+++ gcc/testsuite/gnat.dg/object_size1.adb
@@ -0,0 +1,13 @@
+-- { dg-do compile }
+
+with Text_IO; use Text_IO;
+
+procedure Object_Size1 is
+ type Zero_Size_Type is (Solo);
+
+ for Zero_Size_Type'Size use 0;
+ for Zero_Size_Type'Object_Size use 0; -- { dg-error "Object_Size must be positive" }
+begin
+ Put_Line (Zero_Size_Type'Size'Image);
+ Put_Line (Zero_Size_Type'Object_Size'Image);
+end Object_Size1;
