Change library format: now store file checksum instead of file time stamp.

For ticket 48.

13 files changed, 197 insertions, 133 deletions

diff --git a/src/files_map.adb b/src/files_map.adb
index ece6e125c..1b45d51d6 100644
--- a/src/files_map.adb
+++ b/src/files_map.adb
@@ -22,6 +22,7 @@ with Ada.Text_IO; use Ada.Text_IO;
 with Ada.Unchecked_Deallocation;
 with GNAT.Table;
 with GNAT.OS_Lib;
+with GNAT.SHA1;
 with GNAT.Directory_Operations;
 with Name_Table; use Name_Table;
 with Str_Table;
@@ -55,7 +56,7 @@ package body Files_Map is
       -- Length of the file, which is also the length of the buffer.
       File_Length: Natural;
 
-      Time_Stamp: Time_Stamp_Id;
+      Checksum : File_Checksum_Id;
 
       --  Current number of line in Lines_Table.
       Nbr_Lines: Natural;
@@ -425,51 +426,6 @@ package body Files_Map is
       return Character'Val (Character'Pos ('0') + Val mod 10);
    end Digit_To_Char;
 
-   -- Format: YYYYMMDDHHmmsscc
-   -- Y: year, M: month, D: day, H: hour, m: minute, s: second, cc:100th sec
-   function Os_Time_To_Time_Stamp_Id (Time: GNAT.OS_Lib.OS_Time)
-     return Time_Stamp_Id
-   is
-      use GNAT.OS_Lib;
-      use Str_Table;
-      Res: Time_Stamp_Id;
-      Year: Year_Type;
-      Month: Month_Type;
-      Day: Day_Type;
-      Hour: Hour_Type;
-      Minute: Minute_Type;
-      Second: Second_Type;
-   begin
-      GM_Split (Time, Year, Month, Day, Hour, Minute, Second);
-      Res := Time_Stamp_Id (Create_String8);
-      Append_String8_Char (Digit_To_Char (Year / 1000));
-      Append_String8_Char (Digit_To_Char (Year / 100));
-      Append_String8_Char (Digit_To_Char (Year / 10));
-      Append_String8_Char (Digit_To_Char (Year / 1));
-      Append_String8_Char (Digit_To_Char (Month / 10));
-      Append_String8_Char (Digit_To_Char (Month / 1));
-      Append_String8_Char (Digit_To_Char (Day / 10));
-      Append_String8_Char (Digit_To_Char (Day / 1));
-      Append_String8_Char (Digit_To_Char (Hour / 10));
-      Append_String8_Char (Digit_To_Char (Hour / 1));
-      Append_String8_Char (Digit_To_Char (Minute / 10));
-      Append_String8_Char (Digit_To_Char (Minute / 1));
-      Append_String8_Char (Digit_To_Char (Second / 10));
-      Append_String8_Char (Digit_To_Char (Second / 1));
-      Append_String8_Char ('.');
-      Append_String8_Char ('0');
-      Append_String8_Char ('0');
-      Append_String8_Char ('0');
-      return Res;
-   end Os_Time_To_Time_Stamp_Id;
-
-   function Get_File_Time_Stamp (FD : GNAT.OS_Lib.File_Descriptor)
-                                return Time_Stamp_Id
-   is
-   begin
-      return Os_Time_To_Time_Stamp_Id (GNAT.OS_Lib.File_Time_Stamp (FD));
-   end Get_File_Time_Stamp;
-
    function Get_Os_Time_Stamp return Time_Stamp_Id
    is
       use Ada.Calendar;
@@ -579,7 +535,7 @@ package body Files_Map is
                                    Last_Location => Next_Location,
                                    File_Name => Name,
                                    Directory => Directory,
-                                   Time_Stamp => Null_Time_Stamp,
+                                   Checksum => No_File_Checksum_Id,
                                    Source => null,
                                    File_Length => 0,
                                    Nbr_Lines => 0,
@@ -650,7 +606,7 @@ package body Files_Map is
       declare
          Filename : String := Get_Pathname (Directory, Name, True);
       begin
-         if not Is_Regular_File(Filename) then
+         if not Is_Regular_File (Filename) then
             return No_Source_File_Entry;
          end if;
          Fd := Open_Read (Filename'Address, Binary);
@@ -661,8 +617,6 @@ package body Files_Map is
 
       Res := Create_Source_File_Entry (Directory, Name);
 
-      Source_Files.Table (Res).Time_Stamp := Get_File_Time_Stamp (Fd);
-
       Length := Source_Ptr (File_Length (Fd));
 
       Buffer :=
@@ -674,14 +628,30 @@ package body Files_Map is
          Close (Fd);
          raise Internal_Error;
       end if;
-      Buffer (Length) := EOT;
-      Buffer (Length + 1) := EOT;
+      Buffer (Source_Ptr_Org + Length) := EOT;
+      Buffer (Source_Ptr_Org + Length + 1) := EOT;
 
       if Source_Files.Table (Res).First_Location /= Next_Location then
          --  Load_Source_File call must follow its Create_Source_File.
          raise Internal_Error;
       end if;
 
+      declare
+         use GNAT.SHA1;
+         use Str_Table;
+
+         subtype Buffer_String is String (1 .. Buffer'Length - 2);
+         Buffer_Digest : constant Message_Digest :=
+           Digest (Buffer_String
+                     (Buffer (Source_Ptr_Org .. Source_Ptr_Org + Length - 1)));
+      begin
+         Source_Files.Table (Res).Checksum :=
+           File_Checksum_Id (Create_String8);
+         for I in Buffer_Digest'Range loop
+            Append_String8_Char (Buffer_Digest (I));
+         end loop;
+      end;
+
       Source_Files.Table (Res).Last_Location :=
         Next_Location + Location_Type (Length) + 1;
       Next_Location := Source_Files.Table (Res).Last_Location + 1;
@@ -724,13 +694,12 @@ package body Files_Map is
       return Source_Files.Table (File).File_Name;
    end Get_File_Name;
 
-   -- Return the date of the file (last modification date) as a string.
-   function Get_File_Time_Stamp (File: Source_File_Entry)
-     return Time_Stamp_Id is
+   function Get_File_Checksum (File : Source_File_Entry)
+                              return File_Checksum_Id is
    begin
       Check_File (File);
-      return Source_Files.Table (File).Time_Stamp;
-   end Get_File_Time_Stamp;
+      return Source_Files.Table (File).Checksum;
+   end Get_File_Checksum;
 
    function Get_Source_File_Directory (File : Source_File_Entry)
                                        return Name_Id is
@@ -765,6 +734,21 @@ package body Files_Map is
       return True;
    end Is_Eq;
 
+   function Is_Eq (L, R : File_Checksum_Id) return Boolean
+   is
+      use Str_Table;
+      L_Str : constant String8_Id := String8_Id (L);
+      R_Str : constant String8_Id := String8_Id (R);
+   begin
+      for I in 1 .. Nat32 (File_Checksum_String'Length) loop
+         if Element_String8 (L_Str, I) /= Element_String8 (R_Str, I) then
+            return False;
+         end if;
+      end loop;
+      return True;
+   end Is_Eq;
+
+
    function Is_Gt (L : Time_Stamp_Id; R : Time_Stamp_Id) return Boolean
    is
       use Str_Table;
@@ -792,6 +776,17 @@ package body Files_Map is
       end if;
    end Get_Time_Stamp_String;
 
+   function Get_File_Checksum_String (Checksum : File_Checksum_Id)
+                                     return String is
+   begin
+      if Checksum = No_File_Checksum_Id then
+         return "NO_CHECKSUM";
+      else
+         return Str_Table.String_String8
+           (String8_Id (Checksum), File_Checksum_String'Length);
+      end if;
+   end Get_File_Checksum_String;
+
    function Image (Loc : Location_Type; Filename : Boolean := True)
                   return string
    is
@@ -848,8 +843,8 @@ package body Files_Map is
             Put (" dir:" & Image (F.Directory));
             Put (" length:" & Natural'Image (F.File_Length));
             New_Line;
-            if F.Time_Stamp /= Null_Time_Stamp then
-               Put (" time_stamp: " & Get_Time_Stamp_String (F.Time_Stamp));
+            if F.Checksum /= No_File_Checksum_Id then
+               Put (" checksum: " & Get_File_Checksum_String (F.Checksum));
             end if;
             Put (" nbr lines:" & Natural'Image (F.Nbr_Lines));
             Put (" lines_table_max:" & Natural'Image (F.Lines_Table_Max));
diff --git a/src/files_map.ads b/src/files_map.ads
index c48aebd28..265e3d04d 100644
--- a/src/files_map.ads
+++ b/src/files_map.ads
@@ -63,9 +63,16 @@ package Files_Map is
    function Is_Gt (L : Time_Stamp_Id; R : Time_Stamp_Id) return Boolean;
    function Get_Time_Stamp_String (Ts : Time_Stamp_Id) return String;
 
-   -- Return the date of the file (last modification date) as a string.
-   function Get_File_Time_Stamp (File : Source_File_Entry)
-                                return Time_Stamp_Id;
+   --  Return the checksum of the content of FILE.
+   function Get_File_Checksum (File : Source_File_Entry)
+                              return File_Checksum_Id;
+
+   --  True if two file checksums are identical.
+   function Is_Eq (L, R : File_Checksum_Id) return Boolean;
+
+   --  String image of CHECKSUM.
+   function Get_File_Checksum_String (Checksum : File_Checksum_Id)
+                                     return String;
 
    -- Return the current date of the system.
    function Get_Os_Time_Stamp return Time_Stamp_Id;
diff --git a/src/ghdldrv/ghdllocal.adb b/src/ghdldrv/ghdllocal.adb
index 6b2a53e7c..8e2eceb94 100644
--- a/src/ghdldrv/ghdllocal.adb
+++ b/src/ghdldrv/ghdllocal.adb
@@ -1155,8 +1155,8 @@ package body Ghdllocal is
             if Fe = No_Source_File_Entry then
                --  FIXME: should remove all the design file from the library.
                null;
-            elsif Is_Eq (Get_File_Time_Stamp (Fe),
-                         Get_File_Time_Stamp (File))
+            elsif Is_Eq (Get_File_Checksum (Fe),
+                         Get_File_Checksum (File))
             then
                --  File has not been modified.
                --  Extract libraries.
@@ -1283,8 +1283,8 @@ package body Ghdllocal is
                   --  the library.
                   null;
                else
-                  if not Is_Eq (Get_File_Time_Stamp (Fe),
-                                Get_File_Time_Stamp (File))
+                  if not Is_Eq (Get_File_Checksum (Fe),
+                                Get_File_Checksum (File))
                   then
                      --  FILE has been modified.
                      Design_File := Libraries.Load_File (Fe);
@@ -1359,8 +1359,8 @@ package body Ghdllocal is
       --  2) file has been modified.
       Fe := Load_Source_File (Get_Design_File_Directory (File),
                               Get_Design_File_Filename (File));
-      if not Is_Eq (Get_File_Time_Stamp (Fe),
-                    Get_File_Time_Stamp (File))
+      if not Is_Eq (Get_File_Checksum (Fe),
+                    Get_File_Checksum (File))
       then
          if Flag_Verbose then
             Put_Line ("file " & Name_Table.Image (Get_File_Name (Fe))
diff --git a/src/libraries.adb b/src/libraries.adb
index 39e50395f..c620c0035 100644
--- a/src/libraries.adb
+++ b/src/libraries.adb
@@ -272,10 +272,15 @@ package body Libraries is
 
       File : Source_File_Entry;
 
+      --  Report an error message and abort.
+      procedure Bad_Library_Format;
+      pragma No_Return (Bad_Library_Format);
+
       procedure Bad_Library_Format is
       begin
          Error_Msg (Image (Files_Map.Get_File_Name (File)) &
-                    ": bad library format");
+                      ": bad library format");
+         raise Compilation_Error;
       end Bad_Library_Format;
 
       procedure Scan_Expect (Tok: Token_Type) is
@@ -283,7 +288,6 @@ package body Libraries is
          Scan;
          if Current_Token /= Tok then
             Bad_Library_Format;
-            raise Compilation_Error;
          end if;
       end Scan_Expect;
 
@@ -291,7 +295,6 @@ package body Libraries is
       begin
          if Current_String_Length /= Time_Stamp_String'Length then
             Bad_Library_Format;
-            raise Compilation_Error;
          end if;
          return Time_Stamp_Id (Current_String_Id);
       end Current_Time_Stamp;
@@ -388,12 +391,10 @@ package body Libraries is
         or else Nam_Length /= 1 or else Nam_Buffer (1) /= 'v'
       then
          Bad_Library_Format;
-         raise Compilation_Error;
       end if;
       Scan_Expect (Tok_Integer);
-      if Current_Iir_Int64 not in 1 .. 3 then
+      if Current_Iir_Int64 /= 4 then
          Bad_Library_Format;
-         raise Compilation_Error;
       end if;
       Scan;
 
@@ -415,16 +416,9 @@ package body Libraries is
                --  The filename is an absolute file.
                File_Dir := Null_Identifier;
             elsif Current_Token = Tok_String then
-               --  Be compatible with version 1: an empty directory for
-               --  an absolute filename.
-               if Current_String_Length = 0 then
-                  File_Dir := Null_Identifier;
-               else
-                  File_Dir := String_To_Name_Id;
-               end if;
+               File_Dir := String_To_Name_Id;
             else
                Bad_Library_Format;
-               raise Compilation_Error;
             end if;
 
             Set_Design_File_Directory (Design_File, File_Dir);
@@ -441,7 +435,11 @@ package body Libraries is
             Set_Design_File_Chain (Library, Design_File);
 
             Scan_Expect (Tok_String);
-            Set_File_Time_Stamp (Design_File, Current_Time_Stamp);
+            if Current_String_Length /= File_Checksum_String'Length then
+               Bad_Library_Format;
+            end if;
+            Set_File_Checksum
+              (Design_File, File_Checksum_Id (Current_String_Id));
 
             Scan_Expect (Tok_String);
             Set_Analysis_Time_Stamp (Design_File, Current_Time_Stamp);
@@ -861,7 +859,7 @@ package body Libraries is
       New_Library_Unit: Iir;
       Unit_Id : Name_Id;
       Date: Date_Type;
-      New_Lib_Time_Stamp : Time_Stamp_Id;
+      New_Lib_Checksum : File_Checksum_Id;
       Id : Hash_Id;
 
       --  File name and dir name of DECL.
@@ -901,7 +899,7 @@ package body Libraries is
       begin
          Files_Map.Location_To_File_Pos (Get_Location (New_Library_Unit),
                                          File, Pos);
-         New_Lib_Time_Stamp := Files_Map.Get_File_Time_Stamp (File);
+         New_Lib_Checksum := Files_Map.Get_File_Checksum (File);
          File_Name := Files_Map.Get_File_Name (File);
          Image (File_Name);
          if GNAT.OS_Lib.Is_Absolute_Path (Nam_Buffer (1 .. Nam_Length)) then
@@ -1024,15 +1022,15 @@ package body Libraries is
       end if;
 
       if Design_File /= Null_Iir
-        and then not Files_Map.Is_Eq (New_Lib_Time_Stamp,
-                                      Get_File_Time_Stamp (Design_File))
+        and then not Files_Map.Is_Eq (New_Lib_Checksum,
+                                      Get_File_Checksum (Design_File))
       then
          -- FIXME: this test is not enough: what about reanalyzing
          --  unmodified files (this works only because the order is not
          --  changed).
          -- Design file is updated.
          -- Outdate all other units, overwrite the design_file.
-         Set_File_Time_Stamp (Design_File, New_Lib_Time_Stamp);
+         Set_File_Checksum (Design_File, New_Lib_Checksum);
          Design_Unit := Get_First_Design_Unit (Design_File);
          while Design_Unit /= Null_Iir loop
             if Design_Unit /= Unit then
@@ -1060,7 +1058,7 @@ package body Libraries is
          Set_Design_File_Filename (Design_File, File_Name);
          Set_Design_File_Directory (Design_File, Dir_Name);
 
-         Set_File_Time_Stamp (Design_File, New_Lib_Time_Stamp);
+         Set_File_Checksum (Design_File, New_Lib_Checksum);
          Set_Parent (Design_File, Work_Library);
          Set_Chain (Design_File, Get_Design_File_Chain (Work_Library));
          Set_Design_File_Chain (Work_Library, Design_File);
@@ -1166,7 +1164,7 @@ package body Libraries is
       end if;
 
       --  Header: version.
-      WR ("v 3");
+      WR ("v 4");
       WR_LF;
 
       Design_File := Get_Design_File_Chain (Library);
@@ -1199,8 +1197,8 @@ package body Libraries is
             Image (Get_Design_File_Filename (Design_File));
             WR (Nam_Buffer (1 .. Nam_Length));
             WR (""" """);
-            WR (Files_Map.Get_Time_Stamp_String
-                  (Get_File_Time_Stamp (Design_File)));
+            WR (Files_Map.Get_File_Checksum_String
+                  (Get_File_Checksum (Design_File)));
             WR (""" """);
             WR (Files_Map.Get_Time_Stamp_String
                   (Get_Analysis_Time_Stamp (Design_File)));
@@ -1488,8 +1486,8 @@ package body Libraries is
       Set_File (Fe);
 
       if not Files_Map.Is_Eq
-        (Files_Map.Get_File_Time_Stamp (Get_Current_Source_File),
-         Get_File_Time_Stamp (Design_File))
+        (Files_Map.Get_File_Checksum (Get_Current_Source_File),
+         Get_File_Checksum (Design_File))
       then
          Error_Msg_Sem
            ("file " & Image (Get_Design_File_Filename (Design_File))
diff --git a/src/types.ads b/src/types.ads
index e15d00ebc..7717e5fcd 100644
--- a/src/types.ads
+++ b/src/types.ads
@@ -1,5 +1,5 @@
 --  Common types.
---  Copyright (C) 2002, 2003, 2004, 2005 Tristan Gingold
+--  Copyright (C) 2002 - 2015 Tristan Gingold
 --
 --  GHDL is free software; you can redistribute it and/or modify it under
 --  the terms of the GNU General Public License as published by the Free
@@ -48,26 +48,34 @@ package Types is
    --  iir_index32 is aimed at containing an array index.
    type Iir_Index32 is new Nat32;
 
-   -- Useful type.
+   --  Useful types.
    type String_Acc is access String;
    type String_Cst is access constant String;
    type String_Acc_Array is array (Natural range <>) of String_Acc;
 
-   -- Type of a name table element.
-   -- The name table is defined in the name_table package.
+   --  The name table is defined in Name_Table package.  This is an hash table
+   --  that associate a uniq Name_Id to a string.  Name_Id are allocated in
+   --  increasing numbers, so it is possible to create a parallel table
+   --  indexed on Name_Id to associate additional data to the names.
    type Name_Id is new Nat32;
 
-   -- null entry in the name table.
-   -- It is sure that this entry is never allocated.
+   --  Null entry in the name table.
+   --  It is sure that this entry is never allocated.
    Null_Identifier: constant Name_Id := 0;
 
+   --  A String8_Id represents a string stored in a dedicated table.  Contrary
+   --  to Name_Id, String8 aren't uniq: two different String8_Id can correspond
+   --  to a same String.  The purpose of an integer number for string is to
+   --  have a 32 bit type to represent a string (contrary to pointers that
+   --  could be 32 or 64 bit - in general - or to an access type which can be
+   --  even wider in Ada).
    type String8_Id is new Nat32;
    for String8_Id'Size use 32;
 
    Null_String8 : constant String8_Id := 0;
 
-   -- Index type is the source file table.
-   -- This table is defined in the files_map package.
+   --  Index type is the source file table.
+   --  This table is defined in the files_map package.
    type Source_File_Entry is new Nat32;
    No_Source_File_Entry: constant Source_File_Entry := 0;
 
@@ -92,7 +100,7 @@ package Types is
    for Location_Type'Size use 32;
    Location_Nil : constant Location_Type := 0;
 
-   -- Type of a file buffer.
+   --  Type of a file buffer.
    type File_Buffer is array (Source_Ptr range <>) of Character;
    type File_Buffer_Acc is access File_Buffer;
 
@@ -102,8 +110,8 @@ package Types is
    --  PSL NFA
    type PSL_NFA is new Int32;
 
-   -- Indentation.
-   -- This is used by all packages that display vhdl code or informations.
+   --  Indentation.
+   --  This is used by all packages that display vhdl code or informations.
    Indentation : constant := 2;
 
    --  String representing a date/time (format is YYYYMMDDHHmmSS.sss).
@@ -111,6 +119,16 @@ package Types is
    type Time_Stamp_Id is new String8_Id;
    Null_Time_Stamp : constant Time_Stamp_Id := 0;
 
+   --  In order to detect file changes, a checksum of the content is computed.
+   --  Currently SHA1 is used, but the cryptographic aspect is not a strong
+   --  requirement.
+   type File_Checksum_Id is new String8_Id;
+   No_File_Checksum_Id : constant File_Checksum_Id := 0;
+
+   --  String image of a File_Hash_Id.  SHA1 digests are 5 * 32 bytes long, so
+   --  the hexadecimal image is 40 characters.
+   subtype File_Checksum_String is String (1 .. 40);
+
    --  Self-explaining: raised when an internal error (such as consistency)
    --  is detected.
    Internal_Error: exception;
diff --git a/src/vhdl/disp_tree.adb b/src/vhdl/disp_tree.adb
index 62fc3c4bf..34f31fe6d 100644
--- a/src/vhdl/disp_tree.adb
+++ b/src/vhdl/disp_tree.adb
@@ -289,6 +289,9 @@ package body Disp_Tree is
    function Image_Time_Stamp_Id (Id : Time_Stamp_Id) return String
      renames Files_Map.Get_Time_Stamp_String;
 
+   function Image_File_Checksum_Id (Id : File_Checksum_Id) return String
+     renames Files_Map.Get_File_Checksum_String;
+
    function Image_Iir_Predefined_Functions (F : Iir_Predefined_Functions)
                                            return String is
    begin
@@ -467,6 +470,9 @@ package body Disp_Tree is
                when Type_Time_Stamp_Id =>
                   Put_Line (Image_Time_Stamp_Id
                               (Get_Time_Stamp_Id (N, F)));
+               when Type_File_Checksum_Id =>
+                  Put_Line (Image_File_Checksum_Id
+                              (Get_File_Checksum_Id (N, F)));
                when Type_Token_Type =>
                   Put_Line (Image_Token_Type (Get_Token_Type (N, F)));
                when Type_Name_Id =>
diff --git a/src/vhdl/iirs.adb b/src/vhdl/iirs.adb
index 99b875610..9d056d7c1 100644
--- a/src/vhdl/iirs.adb
+++ b/src/vhdl/iirs.adb
@@ -141,6 +141,12 @@ package body Iirs is
    function Iir_To_Time_Stamp_Id is new Ada.Unchecked_Conversion
      (Source => Iir, Target => Time_Stamp_Id);
 
+   function File_Checksum_Id_To_Iir is new Ada.Unchecked_Conversion
+     (Source => File_Checksum_Id, Target => Iir);
+
+   function Iir_To_File_Checksum_Id is new Ada.Unchecked_Conversion
+     (Source => Iir, Target => File_Checksum_Id);
+
    function Iir_To_Iir_List is new Ada.Unchecked_Conversion
      (Source => Iir, Target => Iir_List);
    function Iir_List_To_Iir is new Ada.Unchecked_Conversion
@@ -536,21 +542,21 @@ package body Iirs is
       Set_Field1 (Design, Library);
    end Set_Library_Declaration;
 
-   function Get_File_Time_Stamp (Design : Iir) return Time_Stamp_Id is
+   function Get_File_Checksum (Design : Iir) return File_Checksum_Id is
    begin
       pragma Assert (Design /= Null_Iir);
-      pragma Assert (Has_File_Time_Stamp (Get_Kind (Design)),
-                     "no field File_Time_Stamp");
-      return Iir_To_Time_Stamp_Id (Get_Field4 (Design));
-   end Get_File_Time_Stamp;
+      pragma Assert (Has_File_Checksum (Get_Kind (Design)),
+                     "no field File_Checksum");
+      return Iir_To_File_Checksum_Id (Get_Field4 (Design));
+   end Get_File_Checksum;
 
-   procedure Set_File_Time_Stamp (Design : Iir; Stamp : Time_Stamp_Id) is
+   procedure Set_File_Checksum (Design : Iir; Checksum : File_Checksum_Id) is
    begin
       pragma Assert (Design /= Null_Iir);
-      pragma Assert (Has_File_Time_Stamp (Get_Kind (Design)),
-                     "no field File_Time_Stamp");
-      Set_Field4 (Design, Time_Stamp_Id_To_Iir (Stamp));
-   end Set_File_Time_Stamp;
+      pragma Assert (Has_File_Checksum (Get_Kind (Design)),
+                     "no field File_Checksum");
+      Set_Field4 (Design, File_Checksum_Id_To_Iir (Checksum));
+   end Set_File_Checksum;
 
    function Get_Analysis_Time_Stamp (Design : Iir) return Time_Stamp_Id is
    begin
diff --git a/src/vhdl/iirs.adb.in b/src/vhdl/iirs.adb.in
index 481a35542..40c9d6802 100644
--- a/src/vhdl/iirs.adb.in
+++ b/src/vhdl/iirs.adb.in
@@ -141,6 +141,12 @@ package body Iirs is
    function Iir_To_Time_Stamp_Id is new Ada.Unchecked_Conversion
      (Source => Iir, Target => Time_Stamp_Id);
 
+   function File_Checksum_Id_To_Iir is new Ada.Unchecked_Conversion
+     (Source => File_Checksum_Id, Target => Iir);
+
+   function Iir_To_File_Checksum_Id is new Ada.Unchecked_Conversion
+     (Source => Iir, Target => File_Checksum_Id);
+
    function Iir_To_Iir_List is new Ada.Unchecked_Conversion
      (Source => Iir, Target => Iir_List);
    function Iir_List_To_Iir is new Ada.Unchecked_Conversion
diff --git a/src/vhdl/iirs.ads b/src/vhdl/iirs.ads
index 75db32235..c8cc0f99c 100644
--- a/src/vhdl/iirs.ads
+++ b/src/vhdl/iirs.ads
@@ -173,7 +173,7 @@ package Iirs is
    --  analysis and detecting obsolete units across libraries.
    --   Get/Set_Analysis_Time_Stamp (Field3)
    --
-   --   Get/Set_File_Time_Stamp (Field4)
+   --   Get/Set_File_Checksum (Field4)
    --
    --  Get the chain of unit contained in the file.  This is a simply linked
    --  chain, but the tail is kept to speed-up appending operation.
@@ -5006,8 +5006,8 @@ package Iirs is
 
    -- File time stamp is the system time of the file last modification.
    --  Field: Field4 (uc)
-   function Get_File_Time_Stamp (Design : Iir) return Time_Stamp_Id;
-   procedure Set_File_Time_Stamp (Design : Iir; Stamp : Time_Stamp_Id);
+   function Get_File_Checksum (Design : Iir) return File_Checksum_Id;
+   procedure Set_File_Checksum (Design : Iir; Checksum : File_Checksum_Id);
 
    -- Time stamp of the last analysis system time.
    --  Field: Field3 (uc)
diff --git a/src/vhdl/nodes_meta.adb b/src/vhdl/nodes_meta.adb
index 13422cbc9..514ed57d5 100644
--- a/src/vhdl/nodes_meta.adb
+++ b/src/vhdl/nodes_meta.adb
@@ -22,7 +22,7 @@ package body Nodes_Meta is
       Field_First_Design_Unit => Type_Iir,
       Field_Last_Design_Unit => Type_Iir,
       Field_Library_Declaration => Type_Iir,
-      Field_File_Time_Stamp => Type_Time_Stamp_Id,
+      Field_File_Checksum => Type_File_Checksum_Id,
       Field_Analysis_Time_Stamp => Type_Time_Stamp_Id,
       Field_Library => Type_Iir,
       Field_File_Dependence_List => Type_Iir_List,
@@ -327,8 +327,8 @@ package body Nodes_Meta is
             return "last_design_unit";
          when Field_Library_Declaration =>
             return "library_declaration";
-         when Field_File_Time_Stamp =>
-            return "file_time_stamp";
+         when Field_File_Checksum =>
+            return "file_checksum";
          when Field_Analysis_Time_Stamp =>
             return "analysis_time_stamp";
          when Field_Library =>
@@ -1407,7 +1407,7 @@ package body Nodes_Meta is
             return Attr_Ref;
          when Field_Library_Declaration =>
             return Attr_Ref;
-         when Field_File_Time_Stamp =>
+         when Field_File_Checksum =>
             return Attr_None;
          when Field_Analysis_Time_Stamp =>
             return Attr_None;
@@ -2004,7 +2004,7 @@ package body Nodes_Meta is
       Field_Design_File_Directory,
       Field_Design_File_Filename,
       Field_Analysis_Time_Stamp,
-      Field_File_Time_Stamp,
+      Field_File_Checksum,
       Field_Elab_Flag,
       Field_File_Dependence_List,
       Field_Chain,
@@ -4415,6 +4415,30 @@ package body Nodes_Meta is
       end case;
    end Set_Date_Type;
 
+   function Get_File_Checksum_Id
+      (N : Iir; F : Fields_Enum) return File_Checksum_Id is
+   begin
+      pragma Assert (Fields_Type (F) = Type_File_Checksum_Id);
+      case F is
+         when Field_File_Checksum =>
+            return Get_File_Checksum (N);
+         when others =>
+            raise Internal_Error;
+      end case;
+   end Get_File_Checksum_Id;
+
+   procedure Set_File_Checksum_Id
+      (N : Iir; F : Fields_Enum; V: File_Checksum_Id) is
+   begin
+      pragma Assert (Fields_Type (F) = Type_File_Checksum_Id);
+      case F is
+         when Field_File_Checksum =>
+            Set_File_Checksum (N, V);
+         when others =>
+            raise Internal_Error;
+      end case;
+   end Set_File_Checksum_Id;
+
    function Get_Iir
       (N : Iir; F : Fields_Enum) return Iir is
    begin
@@ -5804,8 +5828,6 @@ package body Nodes_Meta is
    begin
       pragma Assert (Fields_Type (F) = Type_Time_Stamp_Id);
       case F is
-         when Field_File_Time_Stamp =>
-            return Get_File_Time_Stamp (N);
          when Field_Analysis_Time_Stamp =>
             return Get_Analysis_Time_Stamp (N);
          when others =>
@@ -5818,8 +5840,6 @@ package body Nodes_Meta is
    begin
       pragma Assert (Fields_Type (F) = Type_Time_Stamp_Id);
       case F is
-         when Field_File_Time_Stamp =>
-            Set_File_Time_Stamp (N, V);
          when Field_Analysis_Time_Stamp =>
             Set_Analysis_Time_Stamp (N, V);
          when others =>
@@ -5894,10 +5914,10 @@ package body Nodes_Meta is
       return K = Iir_Kind_Library_Clause;
    end Has_Library_Declaration;
 
-   function Has_File_Time_Stamp (K : Iir_Kind) return Boolean is
+   function Has_File_Checksum (K : Iir_Kind) return Boolean is
    begin
       return K = Iir_Kind_Design_File;
-   end Has_File_Time_Stamp;
+   end Has_File_Checksum;
 
    function Has_Analysis_Time_Stamp (K : Iir_Kind) return Boolean is
    begin
diff --git a/src/vhdl/nodes_meta.ads b/src/vhdl/nodes_meta.ads
index f1b874b21..830ca25b5 100644
--- a/src/vhdl/nodes_meta.ads
+++ b/src/vhdl/nodes_meta.ads
@@ -28,6 +28,7 @@ package Nodes_Meta is
       Type_Boolean,
       Type_Date_State_Type,
       Type_Date_Type,
+      Type_File_Checksum_Id,
       Type_Iir,
       Type_Iir_All_Sensitized,
       Type_Iir_Constraint,
@@ -61,7 +62,7 @@ package Nodes_Meta is
       Field_First_Design_Unit,
       Field_Last_Design_Unit,
       Field_Library_Declaration,
-      Field_File_Time_Stamp,
+      Field_File_Checksum,
       Field_Analysis_Time_Stamp,
       Field_Library,
       Field_File_Dependence_List,
@@ -401,6 +402,11 @@ package Nodes_Meta is
    procedure Set_Date_Type
       (N : Iir; F : Fields_Enum; V: Date_Type);
 
+   function Get_File_Checksum_Id
+      (N : Iir; F : Fields_Enum) return File_Checksum_Id;
+   procedure Set_File_Checksum_Id
+      (N : Iir; F : Fields_Enum; V: File_Checksum_Id);
+
    function Get_Iir
       (N : Iir; F : Fields_Enum) return Iir;
    procedure Set_Iir
@@ -529,7 +535,7 @@ package Nodes_Meta is
    function Has_First_Design_Unit (K : Iir_Kind) return Boolean;
    function Has_Last_Design_Unit (K : Iir_Kind) return Boolean;
    function Has_Library_Declaration (K : Iir_Kind) return Boolean;
-   function Has_File_Time_Stamp (K : Iir_Kind) return Boolean;
+   function Has_File_Checksum (K : Iir_Kind) return Boolean;
    function Has_Analysis_Time_Stamp (K : Iir_Kind) return Boolean;
    function Has_Library (K : Iir_Kind) return Boolean;
    function Has_File_Dependence_List (K : Iir_Kind) return Boolean;
diff --git a/src/vhdl/sem_inst.adb b/src/vhdl/sem_inst.adb
index 4993c8347..b60b34b9b 100644
--- a/src/vhdl/sem_inst.adb
+++ b/src/vhdl/sem_inst.adb
@@ -252,7 +252,8 @@ package body Sem_Inst is
             Set_Source_Ptr (Res, F, Get_Source_Ptr (N, F));
          when Type_Date_Type
            | Type_Date_State_Type
-           | Type_Time_Stamp_Id =>
+           | Type_Time_Stamp_Id
+           | Type_File_Checksum_Id =>
             --  Can this happen ?
             raise Internal_Error;
          when Type_Base_Type =>
diff --git a/src/vhdl/translate/trans-chap2.adb b/src/vhdl/translate/trans-chap2.adb
index 875e4a060..69ec3e547 100644
--- a/src/vhdl/translate/trans-chap2.adb
+++ b/src/vhdl/translate/trans-chap2.adb
@@ -1015,7 +1015,8 @@ package body Trans.Chap2 is
                   raise Internal_Error;
                when Type_Date_Type
                   | Type_Date_State_Type
-                  | Type_Time_Stamp_Id =>
+                  | Type_Time_Stamp_Id
+                  | Type_File_Checksum_Id =>
                   --  Can this happen ?
                   raise Internal_Error;
                when Type_String8_Id