[COMMITTED] ada: Add warning on frontend inlining of Subprogram_Variant

[COMMITTED] ada: Add warning on frontend inlining of Subprogram_Variant

[Marc Poulhiès]

From: Piotr Trojanek <trojanek@adacore.com>

We already warned when contracts like pre/postcondition appear together
with pragma Inline_Always and they are ignored by the frontend inlining.

For consistency we now also warn for Subprogram_Variant, which is
similarly ignored even though this contract is only meaningful for
recursive subprograms and those can't be inlined anyway (but error about
this might only be emitted when full compilation is done).

gcc/ada/

	* sem_prag.adb
	(Check_Postcondition_Use_In_Inlined_Subprogram): Mention
	Subprogram_Variant in the comment.
	(Analyze_Subprogram_Variant_In_Decl_Part): Warn when contract is
	ignored because of pragma Inline_Always and frontend inlining.

Tested on x86_64-pc-linux-gnu, committed on master.

---
 gcc/ada/sem_prag.adb | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/gcc/ada/sem_prag.adb b/gcc/ada/sem_prag.adb
index dbc8584e211..feaf486c348 100644
--- a/gcc/ada/sem_prag.adb
+++ b/gcc/ada/sem_prag.adb
@@ -208,9 +208,10 @@ package body Sem_Prag is
      (Prag    : Node_Id;
       Spec_Id : Entity_Id);
    --  Subsidiary to the analysis of pragmas Contract_Cases, Postcondition,
-   --  Precondition, Refined_Post, and Test_Case. Emit a warning when pragma
-   --  Prag is associated with subprogram Spec_Id subject to Inline_Always,
-   --  assertions are enabled and inling is done in the frontend.
+   --  Precondition, Refined_Post, Subprogram_Variant, and Test_Case. Emit a
+   --  warning when pragma Prag is associated with subprogram Spec_Id subject
+   --  to Inline_Always, assertions are enabled and inling is done in the
+   --  frontend.
 
    procedure Check_State_And_Constituent_Use
      (States   : Elist_Id;
@@ -29627,6 +29628,11 @@ package body Sem_Prag is
             End_Scope;
          end if;
 
+         --  Currently it is not possible to inline Subprogram_Variant on a
+         --  subprogram subject to pragma Inline_Always.
+
+         Check_Postcondition_Use_In_Inlined_Subprogram (N, Spec_Id);
+
       --  Otherwise the pragma is illegal
 
       else
-- 
2.40.0