Create sem_lib from libraries.

17 files changed, 479 insertions, 52 deletions

diff --git a/src/vhdl/configuration.adb b/src/vhdl/configuration.adb
index 6216311b9..57b09f455 100644
--- a/src/vhdl/configuration.adb
+++ b/src/vhdl/configuration.adb
@@ -24,6 +24,7 @@ with Flags;
 with Iirs_Utils; use Iirs_Utils;
 with Iirs_Walk;
 with Sem_Scopes;
+with Sem_Lib; use Sem_Lib;
 with Canon;
 
 package body Configuration is
@@ -103,7 +104,7 @@ package body Configuration is
       end if;
 
       if Flag_Load_All_Design_Units then
-         Libraries.Load_Design_Unit (Unit, From);
+         Load_Design_Unit (Unit, From);
       end if;
 
       --  Add packages from depend list.
@@ -140,7 +141,7 @@ package body Configuration is
          when Iir_Kind_Package_Declaration =>
             --  Analyze the package declaration, so that Set_Package below
             --  will set the full package (and not a stub).
-            Libraries.Load_Design_Unit (Unit, From);
+            Load_Design_Unit (Unit, From);
             Lib_Unit := Get_Library_Unit (Unit);
          when Iir_Kind_Package_Instantiation_Declaration =>
             --  The uninstantiated package is part of the dependency.
@@ -148,7 +149,7 @@ package body Configuration is
          when Iir_Kind_Configuration_Declaration =>
             --  Add entity and architecture.
             --  find all sub-configuration
-            Libraries.Load_Design_Unit (Unit, From);
+            Load_Design_Unit (Unit, From);
             Lib_Unit := Get_Library_Unit (Unit);
             Add_Design_Unit (Get_Design_Unit (Get_Entity (Lib_Unit)), Unit);
             declare
@@ -788,9 +789,9 @@ package body Configuration is
          case Iir_Kinds_Library_Unit (Kind) is
             when Iir_Kind_Architecture_Body
               | Iir_Kind_Configuration_Declaration =>
-               Libraries.Load_Design_Unit (Design, Null_Iir);
+               Load_Design_Unit (Design, Null_Iir);
             when Iir_Kind_Entity_Declaration =>
-               Libraries.Load_Design_Unit (Design, Null_Iir);
+               Load_Design_Unit (Design, Null_Iir);
                Sem_Scopes.Add_Name (Get_Library_Unit (Design));
             when Iir_Kind_Package_Declaration
               | Iir_Kind_Package_Instantiation_Declaration
diff --git a/src/vhdl/iirs_utils.adb b/src/vhdl/iirs_utils.adb
index ecb90a517..046e52b09 100644
--- a/src/vhdl/iirs_utils.adb
+++ b/src/vhdl/iirs_utils.adb
@@ -24,7 +24,6 @@ with Std_Names; use Std_Names;
 with Std_Package;
 with Flags; use Flags;
 with PSL.Nodes;
-with Sem_Inst;
 
 package body Iirs_Utils is
    -- Transform the current token into an iir literal.
@@ -937,20 +936,6 @@ package body Iirs_Utils is
       return Iir_Predefined_Functions'Image (Func);
    end Get_Predefined_Function_Name;
 
-   procedure Mark_Subprogram_Used (Subprg : Iir)
-   is
-      N : Iir;
-   begin
-      N := Subprg;
-      loop
-         exit when Get_Use_Flag (N);
-         Set_Use_Flag (N, True);
-         N := Sem_Inst.Get_Origin (N);
-         --  The origin may also be an instance.
-         exit when N = Null_Iir;
-      end loop;
-   end Mark_Subprogram_Used;
-
    function Get_Callees_List_Holder (Subprg : Iir) return Iir is
    begin
       case Get_Kind (Subprg) is
diff --git a/src/vhdl/iirs_utils.ads b/src/vhdl/iirs_utils.ads
index 1aabea149..ad1a58f84 100644
--- a/src/vhdl/iirs_utils.ads
+++ b/src/vhdl/iirs_utils.ads
@@ -144,10 +144,6 @@ package Iirs_Utils is
    function Get_Predefined_Function_Name (Func : Iir_Predefined_Functions)
      return String;
 
-   --  Mark SUBPRG as used.  If SUBPRG is an instance, its generic is also
-   --  marked.
-   procedure Mark_Subprogram_Used (Subprg : Iir);
-
    --  Create the range_constraint node for an enumeration type.
    procedure Create_Range_Constraint_For_Enumeration_Type
      (Def : Iir_Enumeration_Type_Definition);
diff --git a/src/vhdl/sem.adb b/src/vhdl/sem.adb
index 83308a74c..7408d05e7 100644
--- a/src/vhdl/sem.adb
+++ b/src/vhdl/sem.adb
@@ -15,7 +15,6 @@
 --  along with GHDL; see the file COPYING.  If not, write to the Free
 --  Software Foundation, 59 Temple Place - Suite 330, Boston, MA
 --  02111-1307, USA.
-with Ada.Unchecked_Conversion;
 with Errorout; use Errorout;
 with Std_Package; use Std_Package;
 with Ieee.Std_Logic_1164;
@@ -28,6 +27,7 @@ with Sem_Specs; use Sem_Specs;
 with Sem_Decls; use Sem_Decls;
 with Sem_Assocs; use Sem_Assocs;
 with Sem_Inst;
+with Sem_Lib; use Sem_Lib;
 with Iirs_Utils; use Iirs_Utils;
 with Flags; use Flags;
 with Str_Table;
@@ -110,7 +110,7 @@ package body Sem is
          --  architecture body is in the declarative region of its entity,
          --  the entity name is directly visible.  But we cannot really use
          --  that rule as is, as we don't know which is the entity.
-         Entity := Libraries.Load_Primary_Unit
+         Entity := Load_Primary_Unit
            (Library, Get_Identifier (Name), Library_Unit);
          if Entity = Null_Iir then
             Error_Msg_Sem (+Library_Unit, "entity %n was not analysed", +Name);
@@ -930,7 +930,7 @@ package body Sem is
                --  declaration: at the place of the block specification in a
                --  block configuration for an external block whose interface
                --  is defined by that entity declaration.
-               Design := Libraries.Load_Secondary_Unit
+               Design := Load_Secondary_Unit
                  (Get_Design_Unit (Get_Entity (Father)),
                   Get_Identifier (Block_Spec),
                   Block_Conf);
@@ -995,10 +995,9 @@ package body Sem is
                   return;
                end if;
 
-               Design := Libraries.Load_Secondary_Unit
-                 (Get_Design_Unit (Entity),
-                  Get_Identifier (Block_Spec),
-                  Block_Conf);
+               Design := Load_Secondary_Unit (Get_Design_Unit (Entity),
+                                              Get_Identifier (Block_Spec),
+                                              Block_Conf);
                if Design = Null_Iir then
                   Error_Msg_Sem
                     (+Block_Conf, "no architecture %i", +Block_Spec);
@@ -2704,7 +2703,7 @@ package body Sem is
          declare
             Design_Unit: Iir_Design_Unit;
          begin
-            Design_Unit := Libraries.Load_Primary_Unit
+            Design_Unit := Load_Primary_Unit
               (Get_Library (Get_Design_File (Get_Current_Design_Unit)),
                Package_Ident, Decl);
             if Design_Unit = Null_Iir then
@@ -2840,7 +2839,7 @@ package body Sem is
       if Get_Need_Body (Pkg) and then not Is_Nested_Package (Pkg) then
          Bod := Get_Package_Body (Pkg);
          if Is_Null (Bod) then
-            Bod := Libraries.Load_Secondary_Unit
+            Bod := Load_Secondary_Unit
               (Get_Design_Unit (Pkg), Null_Identifier, Decl);
          else
             Bod := Get_Design_Unit (Bod);
diff --git a/src/vhdl/sem_assocs.adb b/src/vhdl/sem_assocs.adb
index 299242a2f..098d21e20 100644
--- a/src/vhdl/sem_assocs.adb
+++ b/src/vhdl/sem_assocs.adb
@@ -24,6 +24,7 @@ with Parse;
 with Std_Names;
 with Sem_Names; use Sem_Names;
 with Sem_Types;
+with Sem_Decls;
 with Std_Package;
 with Sem_Scopes;
 with Iir_Chains; use Iir_Chains;
@@ -1776,7 +1777,7 @@ package body Sem_Assocs is
 
       Set_Named_Entity (Actual, Res);
       Xrefs.Xref_Name (Actual);
-      Mark_Subprogram_Used (Res);
+      Sem_Decls.Mark_Subprogram_Used (Res);
    end Sem_Association_Subprogram;
 
    --  Associate ASSOC with interface INTERFACE
diff --git a/src/vhdl/sem_decls.adb b/src/vhdl/sem_decls.adb
index 408ee21fd..d26b880eb 100644
--- a/src/vhdl/sem_decls.adb
+++ b/src/vhdl/sem_decls.adb
@@ -21,8 +21,6 @@ with Std_Names;
 with Tokens;
 with Flags; use Flags;
 with Std_Package; use Std_Package;
-with Ieee.Std_Logic_1164;
-with Iir_Chains;
 with Evaluation; use Evaluation;
 with Iirs_Utils; use Iirs_Utils;
 with Sem; use Sem;
@@ -35,7 +33,6 @@ with Sem_Types; use Sem_Types;
 with Sem_Psl;
 with Sem_Inst;
 with Xrefs; use Xrefs;
-use Iir_Chains;
 
 package body Sem_Decls is
    --  Region that can declare signals.  Used to add implicit declarations.
@@ -145,6 +142,20 @@ package body Sem_Decls is
       end if;
    end End_Of_Declarations_For_Implicit_Declarations;
 
+   procedure Mark_Subprogram_Used (Subprg : Iir)
+   is
+      N : Iir;
+   begin
+      N := Subprg;
+      loop
+         exit when Get_Use_Flag (N);
+         Set_Use_Flag (N, True);
+         N := Sem_Inst.Get_Origin (N);
+         --  The origin may also be an instance.
+         exit when N = Null_Iir;
+      end loop;
+   end Mark_Subprogram_Used;
+
    --  Emit an error if the type of DECL is a file type, access type,
    --  protected type or if a subelement of DECL is an access type.
    procedure Check_Signal_Type (Decl : Iir)
diff --git a/src/vhdl/sem_decls.ads b/src/vhdl/sem_decls.ads
index b6ab949ec..4362a34fd 100644
--- a/src/vhdl/sem_decls.ads
+++ b/src/vhdl/sem_decls.ads
@@ -52,6 +52,10 @@ package Sem_Decls is
    --  discrete ranges.
    procedure Sem_Object_Type_From_Value (Decl : Iir; Value : Iir);
 
+   --  Mark SUBPRG as used.  If SUBPRG is an instance, its generic is also
+   --  marked.
+   procedure Mark_Subprogram_Used (Subprg : Iir);
+
    --  The attribute signals ('stable, 'quiet and 'transaction) are
    --  implicitely declared.
    --  Note: guard signals are also implicitly declared but with a guard
diff --git a/src/vhdl/sem_expr.adb b/src/vhdl/sem_expr.adb
index e08fc5940..c75a78823 100644
--- a/src/vhdl/sem_expr.adb
+++ b/src/vhdl/sem_expr.adb
@@ -31,6 +31,7 @@ with Iir_Chains; use Iir_Chains;
 with Sem_Types;
 with Sem_Stmts; use Sem_Stmts;
 with Sem_Assocs; use Sem_Assocs;
+with Sem_Decls;
 with Xrefs; use Xrefs;
 
 package body Sem_Expr is
@@ -1173,7 +1174,7 @@ package body Sem_Expr is
       Subprg : constant Iir := Get_Current_Subprogram;
    begin
       Set_Function_Call_Staticness (Expr, Imp);
-      Mark_Subprogram_Used (Imp);
+      Sem_Decls.Mark_Subprogram_Used (Imp);
 
       --  Check purity/wait/passive.
 
diff --git a/src/vhdl/sem_inst.adb b/src/vhdl/sem_inst.adb
index c32ccebf9..b4673efeb 100644
--- a/src/vhdl/sem_inst.adb
+++ b/src/vhdl/sem_inst.adb
@@ -21,7 +21,6 @@ with Types; use Types;
 with Files_Map;
 with Iirs_Utils; use Iirs_Utils;
 with Errorout; use Errorout;
-with Sem;
 with Sem_Utils;
 
 package body Sem_Inst is
diff --git a/src/vhdl/sem_lib.adb b/src/vhdl/sem_lib.adb
new file mode 100644
index 000000000..cf32ea7f1
--- /dev/null
+++ b/src/vhdl/sem_lib.adb
@@ -0,0 +1,388 @@
+with Flags;
+with Name_Table;
+with Files_Map;
+with Iirs_Utils; use Iirs_Utils;
+with Errorout; use Errorout;
+with Libraries; use Libraries;
+with Scanner;
+with Parse;
+with Disp_Tree;
+with Disp_Vhdl;
+with Sem;
+with Post_Sems;
+with Canon;
+with Nodes_GC;
+
+package body Sem_Lib is
+   procedure Error_Lib_Msg (Msg : String; Arg1 : Earg_Type) is
+   begin
+      Report_Msg (Msgid_Error, Library, No_Location, Msg, (1 => Arg1));
+   end Error_Lib_Msg;
+
+   function Load_File (File : Source_File_Entry) return Iir_Design_File
+   is
+      Res : Iir_Design_File;
+   begin
+      Scanner.Set_File (File);
+      if Scanner.Detect_Encoding_Errors then
+         --  Don't even try to parse such a file.  The BOM will be interpreted
+         --  as an identifier, which is not valid at the beginning of a file.
+         Res := Null_Iir;
+      else
+         Res := Parse.Parse_Design_File;
+      end if;
+      Scanner.Close_File;
+
+      if Res /= Null_Iir then
+         Set_Parent (Res, Work_Library);
+         Set_Design_File_Filename (Res, Files_Map.Get_File_Name (File));
+      end if;
+      return Res;
+   end Load_File;
+
+   -- parse a file.
+   -- Return a design_file without putting it into the library
+   -- (because it was not analyzed).
+   function Load_File (File_Name: Name_Id) return Iir_Design_File
+   is
+      Fe : Source_File_Entry;
+   begin
+      Fe := Files_Map.Read_Source_File (Local_Directory, File_Name);
+      if Fe = No_Source_File_Entry then
+         Error_Msg_Option ("cannot open " & Name_Table.Image (File_Name));
+         return Null_Iir;
+      end if;
+      return Load_File (Fe);
+   end Load_File;
+
+   procedure Finish_Compilation
+     (Unit : Iir_Design_Unit; Main : Boolean := False)
+   is
+      Lib_Unit : Iir;
+   begin
+      Lib_Unit := Get_Library_Unit (Unit);
+      if (Main or Flags.Dump_All) and then Flags.Dump_Parse then
+         Disp_Tree.Disp_Tree (Unit);
+      end if;
+
+      if Flags.Check_Ast_Level > 0 then
+         Nodes_GC.Check_Tree (Unit);
+      end if;
+
+      if Flags.Verbose then
+         Report_Msg (Msgid_Note, Semantic, +Lib_Unit,
+                     "analyze %n", (1 => +Lib_Unit));
+      end if;
+
+      Sem.Semantic (Unit);
+
+      if (Main or Flags.Dump_All) and then Flags.Dump_Sem then
+         Disp_Tree.Disp_Tree (Unit);
+      end if;
+
+      if Errorout.Nbr_Errors > 0 then
+         raise Compilation_Error;
+      end if;
+
+      if (Main or Flags.List_All) and then Flags.List_Sem then
+         Disp_Vhdl.Disp_Vhdl (Unit);
+      end if;
+
+      if Flags.Check_Ast_Level > 0 then
+         Nodes_GC.Check_Tree (Unit);
+      end if;
+
+      --  Post checks
+      ----------------
+
+      Post_Sems.Post_Sem_Checks (Unit);
+
+      if Errorout.Nbr_Errors > 0 then
+         raise Compilation_Error;
+      end if;
+
+      --  Canonalisation.
+      ------------------
+
+      if Flags.Verbose then
+         Report_Msg (Msgid_Note, Semantic, +Lib_Unit,
+                     "canonicalize %n", (1 => +Lib_Unit));
+      end if;
+
+      Canon.Canonicalize (Unit);
+
+      if (Main or Flags.Dump_All) and then Flags.Dump_Canon then
+         Disp_Tree.Disp_Tree (Unit);
+      end if;
+
+      if Errorout.Nbr_Errors > 0 then
+         raise Compilation_Error;
+      end if;
+
+      if (Main or Flags.List_All) and then Flags.List_Canon then
+         Disp_Vhdl.Disp_Vhdl (Unit);
+      end if;
+
+      if Flags.Check_Ast_Level > 0 then
+         Nodes_GC.Check_Tree (Unit);
+      end if;
+   end Finish_Compilation;
+
+   procedure Free_Dependence_List (Design : Iir_Design_Unit)
+   is
+      List : Iir_List;
+   begin
+      List := Get_Dependence_List (Design);
+      if List /= Null_Iir_List then
+         Free_Recursive_List (List);
+         Destroy_Iir_List (List);
+      end if;
+   end Free_Dependence_List;
+
+   procedure Load_Parse_Design_Unit (Design_Unit: Iir_Design_Unit; Loc : Iir)
+   is
+      use Scanner;
+      Line, Off: Natural;
+      Pos: Source_Ptr;
+      Res: Iir;
+      Design_File : Iir_Design_File;
+      Fe : Source_File_Entry;
+   begin
+      --  The unit must not be loaded.
+      pragma Assert (Get_Date_State (Design_Unit) = Date_Disk);
+
+      --  Load the file in memory.
+      Design_File := Get_Design_File (Design_Unit);
+      Fe := Files_Map.Read_Source_File
+        (Get_Design_File_Directory (Design_File),
+         Get_Design_File_Filename (Design_File));
+      if Fe = No_Source_File_Entry then
+         Error_Lib_Msg ("cannot load %n", +Get_Library_Unit (Design_Unit));
+         raise Compilation_Error;
+      end if;
+      Set_File (Fe);
+
+      --  Check if the file has changed.
+      if not Files_Map.Is_Eq
+        (Files_Map.Get_File_Checksum (Get_Current_Source_File),
+         Get_File_Checksum (Design_File))
+      then
+         Error_Msg_Sem (+Loc, "file %i has changed and must be reanalysed",
+                        +Get_Design_File_Filename (Design_File));
+         raise Compilation_Error;
+      elsif Get_Date (Design_Unit) = Date_Obsolete then
+         Error_Msg_Sem (+Design_Unit, "%n has been obsoleted",
+                        +Get_Library_Unit (Design_Unit));
+         raise Compilation_Error;
+      end if;
+
+      --  Set the position of the lexer
+      Pos := Get_Design_Unit_Source_Pos (Design_Unit);
+      Line := Natural (Get_Design_Unit_Source_Line (Design_Unit));
+      Off := Natural (Get_Design_Unit_Source_Col (Design_Unit));
+      Files_Map.File_Add_Line_Number (Get_Current_Source_File, Line, Pos);
+      Set_Current_Position (Pos + Source_Ptr (Off));
+
+      --  Parse
+      Res := Parse.Parse_Design_Unit;
+      Close_File;
+      if Res = Null_Iir then
+         raise Compilation_Error;
+      end if;
+
+      Set_Date_State (Design_Unit, Date_Parse);
+
+      --  FIXME: check the library unit read is the one expected.
+
+      --  Move the unit in the library: keep the design_unit of the library,
+      --  but replace the library_unit by the one that has been parsed.  Do
+      --  not forget to relocate parents.
+      Iirs_Utils.Free_Recursive (Get_Library_Unit (Design_Unit));
+      Set_Library_Unit (Design_Unit, Get_Library_Unit (Res));
+      Set_Design_Unit (Get_Library_Unit (Res), Design_Unit);
+      Set_Parent (Get_Library_Unit (Res), Design_Unit);
+      declare
+         Item : Iir;
+      begin
+         Item := Get_Context_Items (Res);
+         Set_Context_Items (Design_Unit, Item);
+         while Is_Valid (Item) loop
+            Set_Parent (Item, Design_Unit);
+            Item := Get_Chain (Item);
+         end loop;
+      end;
+      Location_Copy (Design_Unit, Res);
+      Free_Dependence_List (Design_Unit);
+      Set_Dependence_List (Design_Unit, Get_Dependence_List (Res));
+      Set_Dependence_List (Res, Null_Iir_List);
+      Free_Iir (Res);
+   end Load_Parse_Design_Unit;
+
+   procedure Error_Obsolete (Loc : Iir; Msg : String; Args : Earg_Arr) is
+   begin
+      if not Flags.Flag_Elaborate_With_Outdated then
+         if Loc = Null_Iir then
+            Error_Msg_Sem (Command_Line_Location, Msg, Args);
+         else
+            Error_Msg_Sem (+Loc, Msg, Args);
+         end if;
+      end if;
+   end Error_Obsolete;
+
+   --  Check if one of its dependency makes this unit obsolete.
+   function Check_Obsolete_Dependence (Design_Unit : Iir; Loc : Iir)
+                                      return Boolean
+   is
+      List : constant Iir_List := Get_Dependence_List (Design_Unit);
+      Du_Ts : constant Time_Stamp_Id :=
+        Get_Analysis_Time_Stamp (Get_Design_File (Design_Unit));
+      U_Ts : Time_Stamp_Id;
+      El : Iir;
+      It : List_Iterator;
+   begin
+      if List = Null_Iir_List then
+         return False;
+      end if;
+
+      It := List_Iterate (List);
+      while Is_Valid (It) loop
+         El := Get_Element (It);
+         if Get_Kind (El) = Iir_Kind_Design_Unit then
+            U_Ts := Get_Analysis_Time_Stamp (Get_Design_File (El));
+            if Files_Map.Is_Gt (U_Ts, Du_Ts) then
+               Error_Obsolete
+                 (Loc, "%n is obsoleted by %n", (+Design_Unit, +El));
+               return True;
+            end if;
+         end if;
+         Next (It);
+      end loop;
+
+      return False;
+   end Check_Obsolete_Dependence;
+
+   procedure Explain_Obsolete (Design_Unit : Iir_Design_Unit; Loc : Iir)
+   is
+      List : Iir_List;
+      It : List_Iterator;
+      El : Iir;
+   begin
+      pragma Assert (Get_Date_State (Design_Unit) = Date_Analyze);
+      pragma Assert (Get_Date (Design_Unit) = Date_Obsolete);
+
+      List := Get_Dependence_List (Design_Unit);
+      if List = Null_Iir_List then
+         --  Argh, we don't know why.
+         Error_Obsolete (Loc, "%n is obsolete", (1 => +Design_Unit));
+         return;
+      end if;
+
+      It := List_Iterate (List);
+      while Is_Valid (It) loop
+         El := Get_Element (It);
+         if Get_Date (El) = Date_Obsolete then
+            Error_Obsolete (Loc, "%n is obsoleted by %n", (+Design_Unit, +El));
+            return;
+         end if;
+         Next (It);
+      end loop;
+   end Explain_Obsolete;
+
+   -- Load, parse, analyze, back-end a design_unit if necessary.
+   procedure Load_Design_Unit (Design_Unit : Iir_Design_Unit; Loc : Iir)
+   is
+      Warnings : Warnings_Setting;
+   begin
+      if Get_Date (Design_Unit) = Date_Replacing then
+         Error_Msg_Sem (+Loc, "circular reference of %n", +Design_Unit);
+         return;
+      end if;
+
+      if Get_Date_State (Design_Unit) = Date_Disk then
+         Load_Parse_Design_Unit (Design_Unit, Loc);
+      end if;
+
+      if Get_Date_State (Design_Unit) = Date_Parse then
+         --  Analyze the design unit.
+
+         if Get_Date (Design_Unit) = Date_Analyzed then
+            --  Work-around for an internal check in sem.
+            --  FIXME: to be removed ?
+            Set_Date (Design_Unit, Date_Parsed);
+         end if;
+
+         --  Avoid infinite recursion, if the unit is self-referenced.
+         Set_Date_State (Design_Unit, Date_Analyze);
+
+         --  Disable all warnings.  Warnings are emitted only when the unit
+         --  is analyzed.
+         Save_Warnings_Setting (Warnings);
+         Disable_All_Warnings;
+
+         --  Analyze unit.
+         Finish_Compilation (Design_Unit);
+
+         --  Restore warnings.
+         Restore_Warnings_Setting (Warnings);
+
+         --  Check if one of its dependency makes this unit obsolete.
+         --  FIXME: to do when the dependency is added ?
+         if not Flags.Flag_Elaborate_With_Outdated
+           and then Check_Obsolete_Dependence (Design_Unit, Loc)
+         then
+            Set_Date (Design_Unit, Date_Obsolete);
+            return;
+         end if;
+      end if;
+
+      case Get_Date (Design_Unit) is
+         when Date_Parsed =>
+            raise Internal_Error;
+         when Date_Analyzing =>
+            --  Self-referenced unit.
+            return;
+         when Date_Analyzed =>
+            --  FIXME: Accept it silently ?
+            --  Note: this is used when Flag_Elaborate_With_Outdated is set.
+            --  This is also used by anonymous configuration declaration.
+            null;
+         when Date_Uptodate =>
+            return;
+         when Date_Valid =>
+            null;
+         when Date_Obsolete =>
+            if not Flags.Flag_Elaborate_With_Outdated then
+               Explain_Obsolete (Design_Unit, Loc);
+            end if;
+         when others =>
+            raise Internal_Error;
+      end case;
+   end Load_Design_Unit;
+
+   function Load_Primary_Unit
+     (Library: Iir_Library_Declaration; Name: Name_Id; Loc : Iir)
+      return Iir_Design_Unit
+   is
+      Design_Unit: Iir_Design_Unit;
+   begin
+      Design_Unit := Find_Primary_Unit (Library, Name);
+      if Design_Unit /= Null_Iir then
+         Load_Design_Unit (Design_Unit, Loc);
+      end if;
+      return Design_Unit;
+   end Load_Primary_Unit;
+
+   -- Load an secondary unit and analyse it.
+   function Load_Secondary_Unit
+     (Primary: Iir_Design_Unit; Name: Name_Id; Loc : Iir)
+     return Iir_Design_Unit
+   is
+      Design_Unit: Iir_Design_Unit;
+   begin
+      Design_Unit := Find_Secondary_Unit (Primary, Name);
+      if Design_Unit /= Null_Iir then
+         Load_Design_Unit (Design_Unit, Loc);
+      end if;
+      return Design_Unit;
+   end Load_Secondary_Unit;
+end Sem_Lib;
diff --git a/src/vhdl/sem_lib.ads b/src/vhdl/sem_lib.ads
new file mode 100644
index 000000000..7fb168a8c
--- /dev/null
+++ b/src/vhdl/sem_lib.ads
@@ -0,0 +1,41 @@
+with Types; use Types;
+with Iirs; use Iirs;
+
+package Sem_Lib is
+   --  Start the analyse a file (ie load and parse it).
+   --  The file is read from the current directory (unless FILE_NAME is an
+   --    absolute path).
+   --  Emit an error if the file cannot be opened.
+   --  Return NULL_IIR in case of parse error.
+   function Load_File (File_Name: Name_Id) return Iir_Design_File;
+   function Load_File (File : Source_File_Entry) return Iir_Design_File;
+
+   --  Load, parse, analyze, back-end a design_unit if necessary.
+   --  Check Design_Unit is not obsolete.
+   --  LOC is the location where the design unit was needed, in case of error.
+   procedure Load_Design_Unit (Design_Unit: Iir_Design_Unit; Loc : Iir);
+
+   --  Load and parse DESIGN_UNIT.
+   --  Contrary to Load_Design_Unit, the design_unit is not analyzed.
+   --  Also, the design_unit must not have been already loaded.
+   --  Used almost only by Load_Design_Unit.
+   procedure Load_Parse_Design_Unit (Design_Unit: Iir_Design_Unit; Loc : Iir);
+
+      -- Load an already analyzed primary unit NAME from library LIBRARY
+   -- and compile it.
+   -- Return NULL_IIR if not found (ie, NAME does not correspond to a
+   --   library unit identifier).
+   function Load_Primary_Unit
+     (Library: Iir_Library_Declaration; Name: Name_Id; Loc : Iir)
+      return Iir_Design_Unit;
+
+   -- Load an secondary unit of primary unit PRIMARY and analyse it.
+   -- NAME must be set only for an architecture.
+   function Load_Secondary_Unit
+     (Primary: Iir_Design_Unit; Name: Name_Id; Loc : Iir)
+     return Iir_Design_Unit;
+
+   --  Analyze UNIT.
+   procedure Finish_Compilation
+     (Unit : Iir_Design_Unit; Main : Boolean := False);
+end Sem_Lib;
diff --git a/src/vhdl/sem_names.adb b/src/vhdl/sem_names.adb
index 033762bd5..09d99d8d5 100644
--- a/src/vhdl/sem_names.adb
+++ b/src/vhdl/sem_names.adb
@@ -17,7 +17,6 @@
 --  02111-1307, USA.
 with Evaluation; use Evaluation;
 with Iirs_Utils; use Iirs_Utils;
-with Libraries;
 with Errorout; use Errorout;
 with Flags; use Flags;
 with Name_Table;
@@ -26,6 +25,7 @@ with Types; use Types;
 with Iir_Chains; use Iir_Chains;
 with Std_Names;
 with Sem;
+with Sem_Lib; use Sem_Lib;
 with Sem_Scopes; use Sem_Scopes;
 with Sem_Expr; use Sem_Expr;
 with Sem_Stmts; use Sem_Stmts;
@@ -1849,7 +1849,7 @@ package body Sem_Names is
          --  For a design unit, return the library unit
          if Get_Kind (Res) = Iir_Kind_Design_Unit then
             --  FIXME: should replace interpretation ?
-            Libraries.Load_Design_Unit (Res, Name);
+            Load_Design_Unit (Res, Name);
             Sem.Add_Dependence (Res);
             Res := Get_Library_Unit (Res);
          end if;
@@ -2150,7 +2150,7 @@ package body Sem_Names is
             --  An expanded name is not allowed for a secondary unit,
             --  particularly for an architecture body.
             --  GHDL: FIXME: error message more explicit
-            Res := Libraries.Load_Primary_Unit (Prefix, Suffix, Name);
+            Res := Load_Primary_Unit (Prefix, Suffix, Name);
             if Res /= Null_Iir then
                Sem.Add_Dependence (Res);
                Res := Get_Library_Unit (Res);
@@ -2178,7 +2178,7 @@ package body Sem_Names is
             --  literal, or operator symbol of an named entity whose
             --  declaration occurs immediatly within that construct.
             if Get_Kind (Prefix) = Iir_Kind_Design_Unit then
-               Libraries.Load_Design_Unit (Prefix, Name);
+               Load_Design_Unit (Prefix, Name);
                Sem.Add_Dependence (Prefix);
                Prefix := Get_Library_Unit (Prefix);
                --  Modified only for xrefs, since a design_unit points to
diff --git a/src/vhdl/sem_specs.adb b/src/vhdl/sem_specs.adb
index 6e28c5b39..7f91d38b1 100644
--- a/src/vhdl/sem_specs.adb
+++ b/src/vhdl/sem_specs.adb
@@ -22,6 +22,7 @@ with Evaluation; use Evaluation;
 with Std_Package; use Std_Package;
 with Errorout; use Errorout;
 with Sem; use Sem;
+with Sem_Lib; use Sem_Lib;
 with Sem_Scopes; use Sem_Scopes;
 with Sem_Assocs; use Sem_Assocs;
 with Libraries;
@@ -1539,7 +1540,7 @@ package body Sem_Specs is
          null;
       end if;
 
-      Design_Unit := Libraries.Load_Primary_Unit
+      Design_Unit := Load_Primary_Unit
         (Get_Library (Get_Design_File (Entity_Unit)),
          Get_Identifier (Get_Library_Unit (Entity_Unit)),
          Parent);
diff --git a/src/vhdl/sem_types.adb b/src/vhdl/sem_types.adb
index d57d7d5fc..5f9438a8f 100644
--- a/src/vhdl/sem_types.adb
+++ b/src/vhdl/sem_types.adb
@@ -20,7 +20,6 @@ with Flags; use Flags;
 with Types; use Types;
 with Errorout; use Errorout;
 with Evaluation; use Evaluation;
-with Sem;
 with Sem_Utils;
 with Sem_Expr; use Sem_Expr;
 with Sem_Scopes; use Sem_Scopes;
@@ -1383,7 +1382,7 @@ package body Sem_Types is
            (+Atype, "no matching resolution function for %n", +Name);
       else
          Name1 := Finish_Sem_Name (Name);
-         Mark_Subprogram_Used (Res);
+         Sem_Decls.Mark_Subprogram_Used (Res);
          Set_Resolved_Flag (Atype, True);
          Set_Resolution_Indication (Atype, Name1);
       end if;
diff --git a/src/vhdl/std_package.adb b/src/vhdl/std_package.adb
index 5700bdf70..02f604936 100644
--- a/src/vhdl/std_package.adb
+++ b/src/vhdl/std_package.adb
@@ -23,7 +23,6 @@ with Std_Names; use Std_Names;
 with Flags; use Flags;
 with Iirs_Utils;
 with Sem_Utils;
-with Sem_Decls;
 with Iir_Chains;
 
 package body Std_Package is
diff --git a/src/vhdl/translate/ortho_front.adb b/src/vhdl/translate/ortho_front.adb
index 8e0532738..d7dee0015 100644
--- a/src/vhdl/translate/ortho_front.adb
+++ b/src/vhdl/translate/ortho_front.adb
@@ -25,6 +25,7 @@ with Flags;
 with Configuration;
 with Translation;
 with Sem;
+with Sem_Lib; use Sem_Lib;
 with Errorout; use Errorout;
 with GNAT.OS_Lib;
 with Bug;
@@ -268,7 +269,7 @@ package body Ortho_Front is
       Flags.Flag_Elaborate := False;
 
       --  Read and parse the file.
-      Res := Libraries.Load_File (Vhdl_File);
+      Res := Load_File (Vhdl_File);
       if Errorout.Nbr_Errors > 0 then
          raise Compilation_Error;
       end if;
@@ -279,7 +280,7 @@ package body Ortho_Front is
       Design := Get_First_Design_Unit (Res);
       while Is_Valid (Design) loop
          --  Analyze and canon a design unit.
-         Libraries.Finish_Compilation (Design, True);
+         Finish_Compilation (Design, True);
 
          Next_Design := Get_Chain (Design);
          if Errorout.Nbr_Errors = 0 then
@@ -449,7 +450,7 @@ package body Ortho_Front is
                begin
                   L := Anaelab_Files;
                   while L /= null loop
-                     Res := Libraries.Load_File (L.Id);
+                     Res := Load_File (L.Id);
                      if Errorout.Nbr_Errors > 0 then
                         raise Compilation_Error;
                      end if;
diff --git a/src/vhdl/translate/trans-chap12.adb b/src/vhdl/translate/trans-chap12.adb
index dfd50856c..2f8884841 100644
--- a/src/vhdl/translate/trans-chap12.adb
+++ b/src/vhdl/translate/trans-chap12.adb
@@ -26,6 +26,7 @@ with Name_Table;
 with Libraries;
 with Flags;
 with Sem;
+with Sem_Lib; use Sem_Lib;
 with Trans.Chap1;
 with Trans.Chap2;
 with Trans.Chap6;
@@ -360,7 +361,7 @@ package body Trans.Chap12 is
 
       Decl : Iir;
    begin
-      Libraries.Load_Design_Unit (Unit, Null_Iir);
+      Load_Design_Unit (Unit, Null_Iir);
       Pkg := Get_Library_Unit (Unit);
       Reset_Identifier_Prefix;
       Lib := Get_Library (Get_Design_File (Get_Design_Unit (Pkg)));
@@ -434,7 +435,7 @@ package body Trans.Chap12 is
          Lib_Unit : Iir;
       begin
          --  Load the unit in memory to compute the dependence list.
-         Libraries.Load_Design_Unit (Unit, Null_Iir);
+         Load_Design_Unit (Unit, Null_Iir);
          Update_Node_Infos;
 
          Set_Elab_Flag (Unit, True);