| ------------------------------------------------------------------------------ |
| -- -- |
| -- GNAT COMPILER COMPONENTS -- |
| -- -- |
| -- S C N -- |
| -- -- |
| -- B o d y -- |
| -- -- |
| -- Copyright (C) 1992-2013, 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 Atree; use Atree; |
| with Csets; use Csets; |
| with Namet; use Namet; |
| with Opt; use Opt; |
| with Restrict; use Restrict; |
| with Rident; use Rident; |
| with Scans; use Scans; |
| with Sinfo; use Sinfo; |
| with Sinput; use Sinput; |
| with Uintp; use Uintp; |
| |
| package body Scn is |
| |
| use ASCII; |
| |
| Used_As_Identifier : array (Token_Type) of Boolean; |
| -- Flags set True if a given keyword is used as an identifier (used to |
| -- make sure that we only post an error message for incorrect use of a |
| -- keyword as an identifier once for a given keyword). |
| |
| function Determine_License return License_Type; |
| -- Scan header of file and check that it has an appropriate GNAT-style |
| -- header with a proper license statement. Returns GPL, Unrestricted, |
| -- or Modified_GPL depending on header. If none of these, returns Unknown. |
| |
| ----------------------- |
| -- Determine_License -- |
| ----------------------- |
| |
| function Determine_License return License_Type is |
| GPL_Found : Boolean := False; |
| Result : License_Type; |
| |
| function Contains (S : String) return Boolean; |
| -- See if current comment contains successive non-blank characters |
| -- matching the contents of S. If so leave Scan_Ptr unchanged and |
| -- return True, otherwise leave Scan_Ptr unchanged and return False. |
| |
| procedure Skip_EOL; |
| -- Skip to line terminator character |
| |
| -------------- |
| -- Contains -- |
| -------------- |
| |
| function Contains (S : String) return Boolean is |
| CP : Natural; |
| SP : Source_Ptr; |
| SS : Source_Ptr; |
| |
| begin |
| -- Loop to check characters. This loop is terminated by end of |
| -- line, and also we need to check for the EOF case, to take |
| -- care of files containing only comments. |
| |
| SP := Scan_Ptr; |
| while Source (SP) /= CR and then |
| Source (SP) /= LF and then |
| Source (SP) /= EOF |
| loop |
| if Source (SP) = S (S'First) then |
| SS := SP; |
| CP := S'First; |
| |
| loop |
| SS := SS + 1; |
| CP := CP + 1; |
| |
| if CP > S'Last then |
| return True; |
| end if; |
| |
| while Source (SS) = ' ' loop |
| SS := SS + 1; |
| end loop; |
| |
| exit when Source (SS) /= S (CP); |
| end loop; |
| end if; |
| |
| SP := SP + 1; |
| end loop; |
| |
| return False; |
| end Contains; |
| |
| -------------- |
| -- Skip_EOL -- |
| -------------- |
| |
| procedure Skip_EOL is |
| begin |
| while Source (Scan_Ptr) /= CR |
| and then Source (Scan_Ptr) /= LF |
| and then Source (Scan_Ptr) /= EOF |
| loop |
| Scan_Ptr := Scan_Ptr + 1; |
| end loop; |
| end Skip_EOL; |
| |
| -- Start of processing for Determine_License |
| |
| begin |
| loop |
| if Source (Scan_Ptr) /= '-' |
| or else Source (Scan_Ptr + 1) /= '-' |
| then |
| if GPL_Found then |
| Result := GPL; |
| exit; |
| else |
| Result := Unknown; |
| exit; |
| end if; |
| |
| elsif Contains ("Asaspecialexception") then |
| if GPL_Found then |
| Result := Modified_GPL; |
| exit; |
| end if; |
| |
| elsif Contains ("GNUGeneralPublicLicense") then |
| GPL_Found := True; |
| |
| elsif |
| Contains |
| ("ThisspecificationisadaptedfromtheAdaSemanticInterface") |
| or else |
| Contains |
| ("ThisspecificationisderivedfromtheAdaReferenceManual") |
| then |
| Result := Unrestricted; |
| exit; |
| end if; |
| |
| Skip_EOL; |
| |
| Scanner.Check_End_Of_Line; |
| |
| if Source (Scan_Ptr) /= EOF then |
| |
| -- We have to take into account a degenerate case when the source |
| -- file contains only comments and no Ada code. |
| |
| declare |
| Physical : Boolean; |
| |
| begin |
| Skip_Line_Terminators (Scan_Ptr, Physical); |
| |
| -- If we are at start of physical line, update scan pointers |
| -- to reflect the start of the new line. |
| |
| if Physical then |
| Current_Line_Start := Scan_Ptr; |
| Start_Column := Scanner.Set_Start_Column; |
| First_Non_Blank_Location := Scan_Ptr; |
| end if; |
| end; |
| end if; |
| end loop; |
| |
| return Result; |
| end Determine_License; |
| |
| ---------------------------- |
| -- Determine_Token_Casing -- |
| ---------------------------- |
| |
| function Determine_Token_Casing return Casing_Type is |
| begin |
| return Scanner.Determine_Token_Casing; |
| end Determine_Token_Casing; |
| |
| ------------------------ |
| -- Initialize_Scanner -- |
| ------------------------ |
| |
| procedure Initialize_Scanner |
| (Unit : Unit_Number_Type; |
| Index : Source_File_Index) |
| is |
| GNAT_Hedr : constant Text_Buffer (1 .. 78) := (others => '-'); |
| |
| begin |
| Scanner.Initialize_Scanner (Index); |
| |
| if Index /= Internal_Source_File then |
| Set_Unit (Index, Unit); |
| end if; |
| |
| Current_Source_Unit := Unit; |
| |
| -- Set default for Comes_From_Source (except if we are going to process |
| -- an artificial string internally created within the compiler and |
| -- placed into internal source duffer). All nodes built now until we |
| -- reenter the analyzer will have Comes_From_Source set to True |
| |
| if Index /= Internal_Source_File then |
| Set_Comes_From_Source_Default (True); |
| end if; |
| |
| -- Check license if GNAT type header possibly present |
| |
| if Source_Last (Index) - Scan_Ptr > 80 |
| and then Source (Scan_Ptr .. Scan_Ptr + 77) = GNAT_Hedr |
| then |
| Set_License (Current_Source_File, Determine_License); |
| end if; |
| |
| Check_For_BOM; |
| |
| -- Because of the License stuff above, Scng.Initialize_Scanner cannot |
| -- call Scan. Scan initial token (note this initializes Prev_Token, |
| -- Prev_Token_Ptr). |
| |
| -- There are two reasons not to do the Scan step in case if we |
| -- initialize the scanner for the internal source buffer: |
| |
| -- - The artificial string may not be created by the compiler in this |
| -- buffer when we call Initialize_Scanner |
| |
| -- - For these artificial strings a special way of scanning is used, so |
| -- the standard step of the scanner may just break the algorithm of |
| -- processing these strings. |
| |
| if Index /= Internal_Source_File then |
| Scan; |
| end if; |
| |
| -- Clear flags for reserved words used as identifiers |
| |
| for J in Token_Type loop |
| Used_As_Identifier (J) := False; |
| end loop; |
| end Initialize_Scanner; |
| |
| --------------- |
| -- Post_Scan -- |
| --------------- |
| |
| procedure Post_Scan is |
| procedure Check_Obsolescent_Features_Restriction (S : Source_Ptr); |
| -- This checks for Obsolescent_Features restriction being active, and |
| -- if so, flags the restriction as occurring at the given scan location. |
| |
| procedure Check_Obsolete_Base_Char; |
| -- Check for numeric literal using ':' instead of '#' for based case |
| |
| -------------------------------------------- |
| -- Check_Obsolescent_Features_Restriction -- |
| -------------------------------------------- |
| |
| procedure Check_Obsolescent_Features_Restriction (S : Source_Ptr) is |
| begin |
| -- Normally we have a node handy for posting restrictions. We don't |
| -- have such a node here, so construct a dummy one with the right |
| -- scan pointer. This is only used to get the Sloc value anyway. |
| |
| Check_Restriction (No_Obsolescent_Features, New_Node (N_Empty, S)); |
| end Check_Obsolescent_Features_Restriction; |
| |
| ------------------------------ |
| -- Check_Obsolete_Base_Char -- |
| ------------------------------ |
| |
| procedure Check_Obsolete_Base_Char is |
| S : Source_Ptr; |
| |
| begin |
| if Based_Literal_Uses_Colon then |
| |
| -- Find the : for the restriction or warning message |
| |
| S := Token_Ptr; |
| while Source (S) /= ':' loop |
| S := S + 1; |
| end loop; |
| |
| Check_Obsolescent_Features_Restriction (S); |
| |
| if Warn_On_Obsolescent_Feature then |
| Error_Msg |
| ("?j?use of "":"" is an obsolescent feature (RM J.2(3))", S); |
| Error_Msg |
| ("\?j?use ""'#"" instead", S); |
| end if; |
| end if; |
| end Check_Obsolete_Base_Char; |
| |
| -- Start of processing for Post_Scan |
| |
| begin |
| case Token is |
| when Tok_Char_Literal => |
| Token_Node := New_Node (N_Character_Literal, Token_Ptr); |
| Set_Char_Literal_Value (Token_Node, UI_From_CC (Character_Code)); |
| Set_Chars (Token_Node, Token_Name); |
| |
| when Tok_Identifier => |
| Token_Node := New_Node (N_Identifier, Token_Ptr); |
| Set_Chars (Token_Node, Token_Name); |
| |
| when Tok_Real_Literal => |
| Token_Node := New_Node (N_Real_Literal, Token_Ptr); |
| Set_Realval (Token_Node, Real_Literal_Value); |
| Check_Obsolete_Base_Char; |
| |
| when Tok_Integer_Literal => |
| Token_Node := New_Node (N_Integer_Literal, Token_Ptr); |
| Set_Intval (Token_Node, Int_Literal_Value); |
| Check_Obsolete_Base_Char; |
| |
| when Tok_String_Literal => |
| Token_Node := New_Node (N_String_Literal, Token_Ptr); |
| Set_Has_Wide_Character |
| (Token_Node, Wide_Character_Found); |
| Set_Has_Wide_Wide_Character |
| (Token_Node, Wide_Wide_Character_Found); |
| Set_Strval (Token_Node, String_Literal_Id); |
| |
| if Source (Token_Ptr) = '%' then |
| Check_Obsolescent_Features_Restriction (Token_Ptr); |
| |
| if Warn_On_Obsolescent_Feature then |
| Error_Msg_SC |
| ("?j?use of ""'%"" is an obsolescent feature (RM J.2(4))"); |
| Error_Msg_SC ("\?j?use """""" instead"); |
| end if; |
| end if; |
| |
| when Tok_Operator_Symbol => |
| Token_Node := New_Node (N_Operator_Symbol, Token_Ptr); |
| Set_Chars (Token_Node, Token_Name); |
| Set_Strval (Token_Node, String_Literal_Id); |
| |
| when Tok_Vertical_Bar => |
| if Source (Token_Ptr) = '!' then |
| Check_Obsolescent_Features_Restriction (Token_Ptr); |
| |
| if Warn_On_Obsolescent_Feature then |
| Error_Msg_SC |
| ("?j?use of ""'!"" is an obsolescent feature (RM J.2(2))"); |
| Error_Msg_SC ("\?j?use ""'|"" instead"); |
| end if; |
| end if; |
| |
| when others => |
| null; |
| end case; |
| end Post_Scan; |
| |
| ------------------------------ |
| -- Scan_Reserved_Identifier -- |
| ------------------------------ |
| |
| procedure Scan_Reserved_Identifier (Force_Msg : Boolean) is |
| Token_Chars : constant String := Token_Type'Image (Token); |
| |
| begin |
| -- We have in Token_Chars the image of the Token name, i.e. Tok_xxx. |
| -- This code extracts the xxx and makes an identifier out of it. |
| |
| Name_Len := 0; |
| |
| for J in 5 .. Token_Chars'Length loop |
| Name_Len := Name_Len + 1; |
| Name_Buffer (Name_Len) := Fold_Lower (Token_Chars (J)); |
| end loop; |
| |
| Token_Name := Name_Find; |
| |
| if not Used_As_Identifier (Token) or else Force_Msg then |
| Error_Msg_Name_1 := Token_Name; |
| Error_Msg_SC ("reserved word* cannot be used as identifier!"); |
| Used_As_Identifier (Token) := True; |
| end if; |
| |
| Token := Tok_Identifier; |
| Token_Node := New_Node (N_Identifier, Token_Ptr); |
| Set_Chars (Token_Node, Token_Name); |
| end Scan_Reserved_Identifier; |
| |
| end Scn; |
