From 3707c8feb1b68028d3967f16c9c4b89d86a14488 Mon Sep 17 00:00:00 2001
From: Piotr Trojanek <trojanek@adacore.com>
Date: Fri, 11 Feb 2022 10:40:32 +0100
Subject: [PATCH] [Ada] Fix warning about generic subprograms withed but not
 instantiated

The compiler should warn when a generic subprogram unit is withed but
not instantiated by the current main unit. This warning relies on flag
Is_Instantiated, which was wrongly set when the generic unit was also
withed and instantiated by some other unit.

This change merely reverts a fix done 20 years ago, which worked around
some spurious warning emitted with inlining enabled. Now the
Is_Instantiated flag is set similarly for generic subprograms and
generic packages.

gcc/ada/

	* atree.adb, atree.ads: Move WITH clause from spec to body; to
	prevent new warnings stopping the bootstrap.
	* fmap.adb, fname-sf.adb, libgnat/a-direct.adb,
	libgnat/s-bignum.adb: Remove unnecessary WITH clauses; to
	prevent new warnings stopping the bootstrap.
	* sem_ch12.adb (Analyze_Subprogram_Instantiation): Only set
	Is_Instantiated flag when the instance is in the extended main
	source unit.
---
 gcc/ada/atree.adb            | 1 +
 gcc/ada/atree.ads            | 1 -
 gcc/ada/fmap.adb             | 2 --
 gcc/ada/fname-sf.adb         | 2 --
 gcc/ada/libgnat/a-direct.adb | 1 -
 gcc/ada/libgnat/s-bignum.adb | 1 -
 gcc/ada/sem_ch12.adb         | 2 +-
 7 files changed, 2 insertions(+), 8 deletions(-)

diff --git a/gcc/ada/atree.adb b/gcc/ada/atree.adb
index bb4c3b46b41..08e3667dffa 100644
--- a/gcc/ada/atree.adb
+++ b/gcc/ada/atree.adb
@@ -31,6 +31,7 @@ with Opt;            use Opt;
 with Output;         use Output;
 with Sinfo.Utils;    use Sinfo.Utils;
 with System.Storage_Elements;
+with Unchecked_Conversion;
 
 package body Atree is
 
diff --git a/gcc/ada/atree.ads b/gcc/ada/atree.ads
index 417a7ab6f82..9d01cfca140 100644
--- a/gcc/ada/atree.ads
+++ b/gcc/ada/atree.ads
@@ -52,7 +52,6 @@ with Types;          use Types;
 with Seinfo;         use Seinfo;
 with System;         use System;
 with Table;
-with Unchecked_Conversion;
 
 package Atree is
 
diff --git a/gcc/ada/fmap.adb b/gcc/ada/fmap.adb
index afa9ee44330..0fa4649cd66 100644
--- a/gcc/ada/fmap.adb
+++ b/gcc/ada/fmap.adb
@@ -34,8 +34,6 @@ pragma Warnings (Off);
 with System.OS_Lib; use System.OS_Lib;
 pragma Warnings (On);
 
-with Unchecked_Conversion;
-
 with GNAT.HTable;
 
 package body Fmap is
diff --git a/gcc/ada/fname-sf.adb b/gcc/ada/fname-sf.adb
index 39ce267abd5..bb72b3004dc 100644
--- a/gcc/ada/fname-sf.adb
+++ b/gcc/ada/fname-sf.adb
@@ -30,8 +30,6 @@ with Osint;         use Osint;
 with Types;         use Types;
 with System.OS_Lib; use System.OS_Lib;
 
-with Unchecked_Conversion;
-
 package body Fname.SF is
 
    ----------------------
diff --git a/gcc/ada/libgnat/a-direct.adb b/gcc/ada/libgnat/a-direct.adb
index 2c07cc4a332..7a65587c003 100644
--- a/gcc/ada/libgnat/a-direct.adb
+++ b/gcc/ada/libgnat/a-direct.adb
@@ -38,7 +38,6 @@ use  Ada.Directories.Hierarchical_File_Names;
 with Ada.Strings.Fixed;
 with Ada.Strings.Maps;           use Ada.Strings.Maps;
 with Ada.Strings.Unbounded;      use Ada.Strings.Unbounded;
-with Ada.Unchecked_Conversion;
 with Ada.Unchecked_Deallocation;
 
 with Interfaces.C;
diff --git a/gcc/ada/libgnat/s-bignum.adb b/gcc/ada/libgnat/s-bignum.adb
index 937710290b9..93f22294f3d 100644
--- a/gcc/ada/libgnat/s-bignum.adb
+++ b/gcc/ada/libgnat/s-bignum.adb
@@ -29,7 +29,6 @@
 --                                                                          --
 ------------------------------------------------------------------------------
 
-with Ada.Unchecked_Conversion;
 with System.Generic_Bignums;
 with System.Secondary_Stack;  use System.Secondary_Stack;
 with System.Shared_Bignums;   use System.Shared_Bignums;
diff --git a/gcc/ada/sem_ch12.adb b/gcc/ada/sem_ch12.adb
index 963f353d063..6a914ec880a 100644
--- a/gcc/ada/sem_ch12.adb
+++ b/gcc/ada/sem_ch12.adb
@@ -5708,9 +5708,9 @@ package body Sem_Ch12 is
          Set_Scope (Inst_Id, Current_Scope);
 
          Set_Entity (Gen_Id, Gen_Unit);
-         Set_Is_Instantiated (Gen_Unit);
 
          if In_Extended_Main_Source_Unit (N) then
+            Set_Is_Instantiated (Gen_Unit);
             Generate_Reference (Gen_Unit, N);
          end if;