Adjust -Whide (disabled in some useless cases).

3 files changed, 38 insertions, 3 deletions

diff --git a/src/vhdl/errorout.ads b/src/vhdl/errorout.ads
index ff7c54ada..4a3b6fdf7 100644
--- a/src/vhdl/errorout.ads
+++ b/src/vhdl/errorout.ads
@@ -344,7 +344,7 @@ private
 
    Default_Warnings : constant Warnings_Setting :=
      (Warnid_Binding | Warnid_Library | Warnid_Shared
-        | Warnid_Pure | Warnid_Specs
+        | Warnid_Pure | Warnid_Specs | Warnid_Hide
         | Warnid_Port    => (Enabled => True, Error => False),
       others             => (Enabled => False, Error => False));
 end Errorout;
diff --git a/src/vhdl/sem_assocs.adb b/src/vhdl/sem_assocs.adb
index 961ec3c5f..33b1f33b1 100644
--- a/src/vhdl/sem_assocs.adb
+++ b/src/vhdl/sem_assocs.adb
@@ -2062,6 +2062,9 @@ package body Sem_Assocs is
       Assoc : Iir;
       Inter : Iir;
 
+      --  True if -Whide is enabled (save the state).
+      Warn_Hide_Enabled : Boolean;
+
       type Param_Assoc_Type is (None, Open, Individual, Whole);
 
       type Assoc_Array is array (Natural range <>) of Param_Assoc_Type;
@@ -2150,8 +2153,15 @@ package body Sem_Assocs is
          --  declaration and that would otherwise be directly visible is
          --  hidden.
          Sem_Scopes.Open_Declarative_Region;
+
+         --  Do not warn about hidding here, way to common, way useless.
+         Warn_Hide_Enabled := Is_Warning_Enabled (Warnid_Hide);
+         Enable_Warning (Warnid_Hide, False);
+
          Sem_Scopes.Add_Declarations_From_Interface_Chain (Interface_Chain);
 
+         Enable_Warning (Warnid_Hide, Warn_Hide_Enabled);
+
          First_Named_Assoc := Assoc;
          loop
             if Formal = Null_Iir then
diff --git a/src/vhdl/sem_scopes.adb b/src/vhdl/sem_scopes.adb
index 17e3847ed..417eecf5c 100644
--- a/src/vhdl/sem_scopes.adb
+++ b/src/vhdl/sem_scopes.adb
@@ -404,6 +404,28 @@ package body Sem_Scopes is
       return Inter >= Current_Region_Start;
    end Is_In_Current_Declarative_Region;
 
+   --  Emit a warning when DECL hides PREV_DECL.
+   procedure Warning_Hide (Decl : Iir; Prev_Decl : Iir)
+   is
+   begin
+      if Get_Kind (Decl) in Iir_Kinds_Interface_Declaration
+        and then Get_Kind (Get_Parent (Decl)) = Iir_Kind_Component_Declaration
+      then
+         --  Do not warn when an interface in a component hides a declaration.
+         --  This is a common case (eg: in testbenches), and there is no real
+         --  hiding.
+         return;
+      end if;
+
+      if Decl = Prev_Decl then
+         --  Can happen in configuration.  No real hidding.
+         return;
+      end if;
+
+      Warning_Msg_Sem (Warnid_Hide, +Decl,
+                       "declaration of %i hides %n", (+Decl, +Prev_Decl));
+   end Warning_Hide;
+
    --  Add interpretation DECL to the identifier of DECL.
    --  POTENTIALLY is true if the identifier comes from a use clause.
    procedure Add_Name (Decl : Iir; Ident : Name_Id; Potentially : Boolean)
@@ -919,8 +941,11 @@ package body Sem_Scopes is
       --  declarative region if the inner region contains an homograph
       --  of this declaration; the outer declaration is the hidden
       --  within the immediate scope of the inner homograph.
-      Warning_Msg_Sem (Warnid_Hide, +Decl,
-                       "declaration of %i hides %n", (+Decl, +Current_Decl));
+      if Is_Warning_Enabled (Warnid_Hide)
+        and then not Is_Potentially_Visible (Current_Inter)
+      then
+         Warning_Hide (Decl, Current_Decl);
+      end if;
 
       Add_New_Interpretation (True);
    end Add_Name;