From: Justin Squirek <squi...@adacore.com>
The following patch fixes an issue in the compiler whereby certain flavors of
access comparisons may be incorrectly constant-folded out of contract
expressions - notably in postcondition expressions featuring a reference to
'Old.
gcc/ada/
* checks.adb (Install_Null_Excluding_Check): Avoid non-null
optimizations when assertions are enabled.
Tested on x86_64-pc-linux-gnu, committed on master.
---
gcc/ada/checks.adb | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)
diff --git a/gcc/ada/checks.adb b/gcc/ada/checks.adb
index 9f3c679ed7e..0d472964ff5 100644
--- a/gcc/ada/checks.adb
+++ b/gcc/ada/checks.adb
@@ -8437,7 +8437,18 @@ package body Checks is
Right_Opnd => Make_Null (Loc)),
Reason => CE_Access_Check_Failed));
- Mark_Non_Null;
+ -- Mark the entity of N "non-null" except when assertions are enabled -
+ -- since expansion becomes much more complicated (especially when it
+ -- comes to contracts) due to the generation of wrappers and wholesale
+ -- moving of declarations and statements which may happen.
+
+ -- Additionally, it is assumed that extra checks will exist with
+ -- assertions enabled so some potentially redundant checks are
+ -- acceptable.
+
+ if not Assertions_Enabled then
+ Mark_Non_Null;
+ end if;
end Install_Null_Excluding_Check;
-----------------------------------------
--
2.40.0
