[19/77] Add a smallest_int_mode_for_size helper function

[official-gcc.git] / gcc / ada / switch-b.adb

------------------------------------------------------------------------------
--                                                                          --
--                         GNAT COMPILER COMPONENTS                         --
--                                                                          --
--                             S W I T C H - B                              --
--                                                                          --
--                                 B o d y                                  --
--                                                                          --
--          Copyright (C) 2001-2017, Free Software Foundation, Inc.         --
--                                                                          --
-- GNAT is free software;  you can  redistribute it  and/or modify it under --
-- terms of the  GNU General Public License as published  by the Free Soft- --
-- ware  Foundation;  either version 3,  or (at your option) any later ver- --
-- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
-- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --
-- for  more details.  You should have  received  a copy of the GNU General --
-- Public License  distributed with GNAT; see file COPYING3.  If not, go to --
-- http://www.gnu.org/licenses for a complete copy of the license.          --
--                                                                          --
-- GNAT was originally developed  by the GNAT team at  New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc.      --
--                                                                          --
------------------------------------------------------------------------------

with Bindgen;
with Debug;  use Debug;
with Osint;  use Osint;
with Opt;    use Opt;

with System.OS_Lib;  use System.OS_Lib;
with System.WCh_Con; use System.WCh_Con;

package body Switch.B is

   --------------------------
   -- Scan_Binder_Switches --
   --------------------------

   procedure Scan_Binder_Switches (Switch_Chars : String) is
      Max : constant Integer := Switch_Chars'Last;
      Ptr : Integer          := Switch_Chars'First;
      C   : Character        := ' ';

      function Get_Optional_Filename return String_Ptr;
      --  If current character is '=', return a newly allocated string that
      --  contains the remainder of the current switch (after the '='), else
      --  return null.

      function Get_Stack_Size (S : Character) return Int;
      --  Used for -d and -D to scan stack size including handling k/m. S is
      --  set to 'd' or 'D' to indicate the switch being scanned.

      ---------------------------
      -- Get_Optional_Filename --
      ---------------------------

      function Get_Optional_Filename return String_Ptr is
         Result : String_Ptr;

      begin
         if Ptr <= Max and then Switch_Chars (Ptr) = '=' then
            if Ptr = Max then
               Bad_Switch (Switch_Chars);
            else
               Result := new String'(Switch_Chars (Ptr + 1 .. Max));
               Ptr := Max + 1;
               return Result;
            end if;
         end if;

         return null;
      end Get_Optional_Filename;

      --------------------
      -- Get_Stack_Size --
      --------------------

      function Get_Stack_Size (S : Character) return Int is
         Result : Int;

      begin
         Scan_Pos (Switch_Chars, Max, Ptr, Result, S);

         --  In the following code, we enable overflow checking since the
         --  multiplication by K or M may cause overflow, which is an error.

         declare
            pragma Unsuppress (Overflow_Check);

         begin
            --  Check for additional character 'k' (for kilobytes) or 'm' (for
            --  Megabytes), but only if we have not reached the end of the
            --  switch string. Note that if this appears before the end of the
            --  string we will get an error when we test to make sure that the
            --  string is exhausted (at the end of the case).

            if Ptr <= Max then
               if Switch_Chars (Ptr) = 'k' then
                  Result := Result * 1024;
                  Ptr := Ptr + 1;

               elsif Switch_Chars (Ptr) = 'm' then
                  Result := Result * (1024 * 1024);
                  Ptr := Ptr + 1;
               end if;
            end if;

         exception
            when Constraint_Error =>
               Osint.Fail ("numeric value out of range for switch: " & S);
         end;

         return Result;
      end Get_Stack_Size;

   --  Start of processing for Scan_Binder_Switches

   begin
      --  Skip past the initial character (must be the switch character)

      if Ptr = Max then
         Bad_Switch (Switch_Chars);
      else
         Ptr := Ptr + 1;
      end if;

      --  A little check, "gnat" at the start of a switch is not allowed except
      --  for the compiler

      if Max >= Ptr + 3
        and then Switch_Chars (Ptr .. Ptr + 3) = "gnat"
      then
         Osint.Fail ("invalid switch: """ & Switch_Chars & """"
                     & " (gnat not needed here)");
      end if;

      --  Loop to scan through switches given in switch string

      Check_Switch : begin
         C := Switch_Chars (Ptr);

         case C is

         --  Processing for a switch

         when 'a' =>
            Ptr := Ptr + 1;
            Use_Pragma_Linker_Constructor := True;

         --  Processing for A switch

         when 'A' =>
            Ptr := Ptr + 1;
            Output_ALI_List := True;
            ALI_List_Filename := Get_Optional_Filename;

         --  Processing for b switch

         when 'b' =>
            Ptr := Ptr + 1;
            Brief_Output := True;

         --  Processing for c switch

         when 'c' =>
            Ptr := Ptr + 1;
            Check_Only := True;

         --  Processing for d switch

         when 'd' =>

            if Ptr = Max then
               Bad_Switch (Switch_Chars);
            end if;

            Ptr := Ptr + 1;
            C := Switch_Chars (Ptr);

            --  Case where character after -d is a digit (default stack size)

            if C in '0' .. '9' then

               --  In this case, we process the default primary stack size

               Default_Stack_Size := Get_Stack_Size ('d');

            --  Case where character after -d is not digit (debug flags)

            else
               --  Note: for the debug switch, the remaining characters in this
               --  switch field must all be debug flags, since all valid switch
               --  characters are also valid debug characters. This switch is
               --  not documented on purpose because it is only used by the
               --  implementors.

               --  Loop to scan out debug flags

               loop
                  C := Switch_Chars (Ptr);

                  if C in 'a' .. 'z' or else C in 'A' .. 'Z' then
                     Set_Debug_Flag (C);
                  else
                     Bad_Switch (Switch_Chars);
                  end if;

                  Ptr := Ptr + 1;
                  exit when Ptr > Max;
               end loop;
            end if;

         --  Processing for D switch

         when 'D' =>
            if Ptr = Max then
               Bad_Switch (Switch_Chars);
            end if;

            Ptr := Ptr + 1;
            Default_Sec_Stack_Size := Get_Stack_Size ('D');

         --  Processing for e switch

         when 'e' =>
            Ptr := Ptr + 1;
            Elab_Dependency_Output := True;

         --  Processing for E switch

         when 'E' =>

            --  -E is equivalent to -Ea (see below)

            Exception_Tracebacks := True;
            Ptr := Ptr + 1;

            if Ptr <= Max then
               case Switch_Chars (Ptr) is

                  --  -Ea sets Exception_Tracebacks

                  when 'a' => null;

                  --  -Es sets both Exception_Tracebacks and
                  --  Exception_Tracebacks_Symbolic.

                  when 's' => Exception_Tracebacks_Symbolic := True;
                  when others => Bad_Switch (Switch_Chars);
               end case;

               Ptr := Ptr + 1;
            end if;

         --  Processing for f switch

         when 'f' =>
            if Ptr = Max then
               Bad_Switch (Switch_Chars);
            end if;

            Force_Elab_Order_File :=
              new String'(Switch_Chars (Ptr + 1 .. Max));

            Ptr := Max + 1;

            if not Is_Read_Accessible_File (Force_Elab_Order_File.all) then
               Osint.Fail (Force_Elab_Order_File.all & ": file not found");
            end if;

         --  Processing for F switch

         when 'F' =>
            Ptr := Ptr + 1;
            Force_Checking_Of_Elaboration_Flags := True;

         --  Processing for g switch

         when 'g' =>
            Ptr := Ptr + 1;

            if Ptr <= Max then
               C := Switch_Chars (Ptr);

               if C in '0' .. '3' then
                  Debugger_Level :=
                    Character'Pos
                      (Switch_Chars (Ptr)) - Character'Pos ('0');
                  Ptr := Ptr + 1;
               end if;

            else
               Debugger_Level := 2;
            end if;

         --  Processing for h switch

         when 'h' =>
            Ptr := Ptr + 1;
            Usage_Requested := True;

         --  Processing for i switch

         when 'i' =>
            if Ptr = Max then
               Bad_Switch (Switch_Chars);
            end if;

            Ptr := Ptr + 1;
            C := Switch_Chars (Ptr);

            if C in '1' .. '5'
              or else C = '8'
              or else C = 'p'
              or else C = 'f'
              or else C = 'n'
              or else C = 'w'
            then
               Identifier_Character_Set := C;
               Ptr := Ptr + 1;
            else
               Bad_Switch (Switch_Chars);
            end if;

         --  Processing for K switch

         when 'K' =>
            Ptr := Ptr + 1;
            Output_Linker_Option_List := True;

         --  Processing for l switch

         when 'l' =>
            Ptr := Ptr + 1;
            Elab_Order_Output := True;

         --  Processing for m switch

         when 'm' =>
            if Ptr = Max then
               Bad_Switch (Switch_Chars);
            end if;

            Ptr := Ptr + 1;
            Scan_Pos (Switch_Chars, Max, Ptr, Maximum_Messages, C);

         --  Processing for n switch

         when 'n' =>
            Ptr := Ptr + 1;
            Bind_Main_Program := False;

            --  Note: The -L option of the binder also implies -n, so
            --  any change here must also be reflected in the processing
            --  for -L that is found in Gnatbind.Scan_Bind_Arg.

         --  Processing for o switch

         when 'o' =>
            Ptr := Ptr + 1;

            if Output_File_Name_Present then
               Osint.Fail ("duplicate -o switch");
            else
               Output_File_Name_Present := True;
            end if;

         --  Processing for O switch

         when 'O' =>
            Ptr := Ptr + 1;
            Output_Object_List := True;
            Object_List_Filename := Get_Optional_Filename;

         --  Processing for p switch

         when 'p' =>
            Ptr := Ptr + 1;
            Pessimistic_Elab_Order := True;

         --  Processing for P switch

         when 'P' =>
            Ptr := Ptr + 1;
            CodePeer_Mode := True;

         --  Processing for q switch

         when 'q' =>
            Ptr := Ptr + 1;
            Quiet_Output := True;

         --  Processing for r switch

         when 'r' =>
            Ptr := Ptr + 1;
            List_Restrictions := True;

         --  Processing for R switch

         when 'R' =>
            Ptr := Ptr + 1;
            List_Closure := True;

            if Ptr <= Max and then Switch_Chars (Ptr) = 'a' then
               Ptr := Ptr + 1;
               List_Closure_All := True;
            end if;

         --  Processing for s switch

         when 's' =>
            Ptr := Ptr + 1;
            All_Sources := True;
            Check_Source_Files := True;

         --  Processing for t switch

         when 't' =>
            Ptr := Ptr + 1;
            Tolerate_Consistency_Errors := True;

         --  Processing for T switch

         when 'T' =>
            if Ptr = Max then
               Bad_Switch (Switch_Chars);
            end if;

            Ptr := Ptr + 1;
            Time_Slice_Set := True;
            Scan_Nat (Switch_Chars, Max, Ptr, Time_Slice_Value, C);
            Time_Slice_Value := Time_Slice_Value * 1_000;

         --  Processing for u switch

         when 'u' =>
            if Ptr = Max then
               Bad_Switch (Switch_Chars);
            end if;

            Ptr := Ptr + 1;
            Dynamic_Stack_Measurement := True;
            Scan_Nat
              (Switch_Chars,
               Max,
               Ptr,
               Dynamic_Stack_Measurement_Array_Size,
               C);

         --  Processing for v switch

         when 'v' =>
            Ptr := Ptr + 1;
            Verbose_Mode := True;

         --  Processing for V switch

         when 'V' =>
            declare
               Eq : Integer;
            begin
               Ptr := Ptr + 1;
               Eq := Ptr;
               while Eq <= Max and then Switch_Chars (Eq) /= '=' loop
                  Eq := Eq + 1;
               end loop;
               if Eq = Ptr or else Eq = Max then
                  Bad_Switch (Switch_Chars);
               end if;
               Bindgen.Set_Bind_Env
                 (Key   => Switch_Chars (Ptr .. Eq - 1),
                  Value => Switch_Chars (Eq + 1 .. Max));
               Ptr := Max + 1;
            end;

         --  Processing for w switch

         when 'w' =>
            if Ptr = Max then
               Bad_Switch (Switch_Chars);
            end if;

            --  For the binder we only allow suppress/error cases

            Ptr := Ptr + 1;

            case Switch_Chars (Ptr) is
               when 'e' =>
                  Warning_Mode := Treat_As_Error;

               when 'E' =>
                  Warning_Mode := Treat_Run_Time_Warnings_As_Errors;

               when 's' =>
                  Warning_Mode := Suppress;

               when others =>
                  Bad_Switch (Switch_Chars);
            end case;

            Ptr := Ptr + 1;

         --  Processing for W switch

         when 'W' =>
            Ptr := Ptr + 1;

            if Ptr > Max then
               Bad_Switch (Switch_Chars);
            end if;

            begin
               Wide_Character_Encoding_Method :=
                 Get_WC_Encoding_Method (Switch_Chars (Ptr));
            exception
               when Constraint_Error =>
                  Bad_Switch (Switch_Chars);
            end;

            Wide_Character_Encoding_Method_Specified := True;

            Upper_Half_Encoding :=
              Wide_Character_Encoding_Method in WC_Upper_Half_Encoding_Method;

            Ptr := Ptr + 1;

         --  Processing for x switch

         when 'x' =>
            Ptr := Ptr + 1;
            All_Sources := False;
            Check_Source_Files := False;

         --  Processing for X switch

         when 'X' =>
            if Ptr = Max then
               Bad_Switch (Switch_Chars);
            end if;

            Ptr := Ptr + 1;
            Scan_Pos (Switch_Chars, Max, Ptr, Default_Exit_Status, C);

         --  Processing for y switch

         when 'y' =>
            Ptr := Ptr + 1;
            Leap_Seconds_Support := True;

         --  Processing for z switch

         when 'z' =>
            Ptr := Ptr + 1;
            No_Main_Subprogram := True;

         --  Processing for Z switch

         when 'Z' =>
            Ptr := Ptr + 1;
            Zero_Formatting := True;

         --  Processing for --RTS

         when '-' =>

            if Ptr + 4 <= Max and then
              Switch_Chars (Ptr + 1 .. Ptr + 3) = "RTS"
            then
               Ptr := Ptr + 4;

               if Switch_Chars (Ptr) /= '=' or else Ptr = Max then
                  Osint.Fail ("missing path for --RTS");

               else
                  --  Valid --RTS switch

                  Opt.No_Stdinc := True;
                  Opt.RTS_Switch := True;

                  declare
                     Src_Path_Name : constant String_Ptr :=
                                       Get_RTS_Search_Dir
                                         (Switch_Chars (Ptr + 1 .. Max),
                                          Include);
                     Lib_Path_Name : constant String_Ptr :=
                                       Get_RTS_Search_Dir
                                         (Switch_Chars (Ptr + 1 .. Max),
                                          Objects);

                  begin
                     if Src_Path_Name /= null and then
                       Lib_Path_Name /= null
                     then
                        --  Set the RTS_*_Path_Name variables, so that the
                        --  correct directories will be set when a subsequent
                        --  call Osint.Add_Default_Search_Dirs is made.

                        RTS_Src_Path_Name := Src_Path_Name;
                        RTS_Lib_Path_Name := Lib_Path_Name;

                        Ptr := Max + 1;

                     elsif Src_Path_Name = null
                       and then Lib_Path_Name = null
                     then
                        Osint.Fail
                          ("RTS path not valid: missing adainclude and "
                           & "adalib directories");
                     elsif Src_Path_Name = null then
                        Osint.Fail
                          ("RTS path not valid: missing adainclude directory");
                     elsif Lib_Path_Name = null then
                        Osint.Fail
                          ("RTS path not valid: missing adalib directory");
                     end if;
                  end;
               end if;

            else
               Bad_Switch (Switch_Chars);
            end if;

         --  Anything else is an error (illegal switch character)

         when others =>
            Bad_Switch (Switch_Chars);
         end case;

         if Ptr <= Max then
            Bad_Switch (Switch_Chars);
         end if;
      end Check_Switch;
   end Scan_Binder_Switches;

end Switch.B;