diff mbox series

[Ada] Spurious warning on object declaration with address clause

Message ID 20180521150511.GA78448@adacore.com
State New
Headers show
Series [Ada] Spurious warning on object declaration with address clause | expand

Commit Message

Pierre-Marie de Rodat May 21, 2018, 3:05 p.m. UTC 
The compiler warns on an object declaration with default initialization
and an address clause, to indicate that the overlay implied by the address
clause might affect a value elsewhere. The warning is suppressed if the type
carries the Suppress_Initialization aspect. With this patch the compiler
also inhibits the warning if the aspect is specified for the object itself.

Tested on x86_64-pc-linux-gnu, committed on trunk

2018-05-21  Ed Schonberg  <schonberg@adacore.com>

gcc/ada/

	* freeze.adb (Warn_Overlay): Do not emit a wawrning on an object
	declaration with an explicit address clause and a type with default
	initialization, if the declaration carries an aspect
	Suppress_Initialization.

gcc/testsuite/

	* gnat.dg/suppress_initialization.adb,
	gnat.dg/suppress_initialization_pkg.ads: New testcase.
diff mbox series

Patch

--- gcc/ada/freeze.adb
+++ gcc/ada/freeze.adb
@@ -8690,11 +8690,14 @@  package body Freeze is
       --  tested for because predefined String types are initialized by inline
       --  code rather than by an init_proc). Note that we do not give the
       --  warning for Initialize_Scalars, since we suppressed initialization
-      --  in this case. Also, do not warn if Suppress_Initialization is set.
+      --  in this case. Also, do not warn if Suppress_Initialization is set
+      --  either on the type, or on the object via pragma or aspect.
 
       if Present (Expr)
         and then not Is_Imported (Ent)
         and then not Initialization_Suppressed (Typ)
+        and then not (Ekind (Ent) = E_Variable
+                        and then Initialization_Suppressed (Ent))
         and then (Has_Non_Null_Base_Init_Proc (Typ)
                    or else Is_Access_Type (Typ)
                    or else (Normalize_Scalars

--- /dev/null
new file mode 100644
+++ gcc/testsuite/gnat.dg/suppress_initialization.adb
@@ -0,0 +1,8 @@ 
+--  { dg-do compile }
+
+with Suppress_Initialization_Pkg;
+
+procedure Suppress_Initialization is
+begin
+   Suppress_Initialization_Pkg.Read;
+end Suppress_Initialization;

--- /dev/null
new file mode 100644
+++ gcc/testsuite/gnat.dg/suppress_initialization_pkg.ads
@@ -0,0 +1,31 @@ 
+with Interfaces; use Interfaces;
+with System;
+
+package Suppress_Initialization_Pkg is
+
+   type Discriminated_Type (Foo : Unsigned_8 := 0) is record
+      case Foo is
+         when 0 =>
+            Bar  : Boolean;
+         when 1 =>
+            Baz  : Unsigned_32;
+         when others =>
+            null;
+      end case;
+   end record;
+
+   for Discriminated_Type use record
+      Foo at 0 range  0 ..  7;
+      Bar at 1 range  0 ..  0;
+      Baz at 1 range  0 .. 31;
+   end record;
+
+   External : Discriminated_Type
+   with
+     Volatile,
+     Suppress_Initialization,
+     Address => System'To_Address (16#1234_5678#);
+
+   procedure Read;
+
+end Suppress_Initialization_Pkg;