From: Ronan Desplanques <desplanq...@adacore.com>
Before this patch, warnings handled by `Sem_Warn.Check_References` were
erroneously emitted in some cases. Here is an example of a program that,
when compiled with the `-gnatwu` switch, triggered the bug:
procedure Main is
package T is
A : Integer;
end T;
begin
T.A := 7;
end Main;
The following message was emitted:
main.adb:3:07: warning: variable "A" is never read and never assigned
[-gnatwu]
This patch mitigates the issue by restricting the cases in which
`Sem_Warn.Check_References` is called for package specifications.
Note that the recursive calls in `Sem_Warn.Check_References` can be used
to convince oneself that this patch does not remove legitimate warnings
for non-library-level package specifications.
gcc/ada/
* sem_ch7.adb (Analyze_Package_Declaration): Restrict calls to
`Sem_Warn.Check_References` and adjust comment accordingly.
Tested on x86_64-pc-linux-gnu, committed on master.
---
gcc/ada/sem_ch7.adb | 17 +++++++++++------
1 file changed, 11 insertions(+), 6 deletions(-)
diff --git a/gcc/ada/sem_ch7.adb b/gcc/ada/sem_ch7.adb
index ecb4bbe3e56..1a49a53ad63 100644
--- a/gcc/ada/sem_ch7.adb
+++ b/gcc/ada/sem_ch7.adb
@@ -1267,12 +1267,17 @@ package body Sem_Ch7 is
Is_Main_Unit => Parent (N) = Cunit (Main_Unit));
end if;
- -- Warn about references to unset objects, which is straightforward
- -- for packages with no bodies. For packages with bodies this is more
- -- complicated, because some of the objects might be set between spec
- -- and body elaboration, in nested or child packages, etc.
-
- Check_References (Id);
+ -- For package declarations at the library level, warn about
+ -- references to unset objects, which is straightforward for packages
+ -- with no bodies. For packages with bodies this is more complicated,
+ -- because some of the objects might be set between spec and body
+ -- elaboration, in nested or child packages, etc. Note that the
+ -- recursive calls in Check_References will handle nested package
+ -- specifications.
+
+ if Is_Library_Level_Entity (Id) then
+ Check_References (Id);
+ end if;
end if;
-- Set Body_Required indication on the compilation unit node
--
2.40.0
