1------------------------------------------------------------------------------ 2-- -- 3-- GNAT COMPILER COMPONENTS -- 4-- -- 5-- S C N -- 6-- -- 7-- B o d y -- 8-- -- 9-- Copyright (C) 1992-2020, Free Software Foundation, Inc. -- 10-- -- 11-- GNAT is free software; you can redistribute it and/or modify it under -- 12-- terms of the GNU General Public License as published by the Free Soft- -- 13-- ware Foundation; either version 3, or (at your option) any later ver- -- 14-- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- 15-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- 16-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- 17-- for more details. You should have received a copy of the GNU General -- 18-- Public License distributed with GNAT; see file COPYING3. If not, go to -- 19-- http://www.gnu.org/licenses for a complete copy of the license. -- 20-- -- 21-- GNAT was originally developed by the GNAT team at New York University. -- 22-- Extensive contributions were provided by Ada Core Technologies Inc. -- 23-- -- 24------------------------------------------------------------------------------ 25 26with Atree; use Atree; 27with Csets; use Csets; 28with Namet; use Namet; 29with Opt; use Opt; 30with Restrict; use Restrict; 31with Rident; use Rident; 32with Scans; use Scans; 33with Sinfo; use Sinfo; 34with Sinput; use Sinput; 35with Uintp; use Uintp; 36 37package body Scn is 38 39 Used_As_Identifier : array (Token_Type) of Boolean; 40 -- Flags set True if a given keyword is used as an identifier (used to 41 -- make sure that we only post an error message for incorrect use of a 42 -- keyword as an identifier once for a given keyword). 43 44 ---------------------------- 45 -- Determine_Token_Casing -- 46 ---------------------------- 47 48 function Determine_Token_Casing return Casing_Type is 49 begin 50 return Scanner.Determine_Token_Casing; 51 end Determine_Token_Casing; 52 53 ------------------------ 54 -- Initialize_Scanner -- 55 ------------------------ 56 57 procedure Initialize_Scanner 58 (Unit : Unit_Number_Type; 59 Index : Source_File_Index) is 60 begin 61 Scanner.Initialize_Scanner (Index); 62 Set_Unit (Index, Unit); 63 64 Current_Source_Unit := Unit; 65 66 -- Set default for Comes_From_Source. All nodes built now until we 67 -- reenter the analyzer will have Comes_From_Source set to True 68 69 Set_Comes_From_Source_Default (True); 70 71 Check_For_BOM; 72 73 -- Because of the License stuff above, Scng.Initialize_Scanner cannot 74 -- call Scan. Scan initial token (note this initializes Prev_Token, 75 -- Prev_Token_Ptr). 76 77 Scan; 78 79 -- Clear flags for reserved words used as identifiers 80 81 Used_As_Identifier := (others => False); 82 end Initialize_Scanner; 83 84 --------------- 85 -- Post_Scan -- 86 --------------- 87 88 procedure Post_Scan is 89 procedure Check_Obsolescent_Features_Restriction (S : Source_Ptr); 90 -- This checks for Obsolescent_Features restriction being active, and 91 -- if so, flags the restriction as occurring at the given scan location. 92 93 procedure Check_Obsolete_Base_Char; 94 -- Check for numeric literal using ':' instead of '#' for based case 95 96 -------------------------------------------- 97 -- Check_Obsolescent_Features_Restriction -- 98 -------------------------------------------- 99 100 procedure Check_Obsolescent_Features_Restriction (S : Source_Ptr) is 101 begin 102 -- Normally we have a node handy for posting restrictions. We don't 103 -- have such a node here, so construct a dummy one with the right 104 -- scan pointer. This is only used to get the Sloc value anyway. 105 106 Check_Restriction (No_Obsolescent_Features, New_Node (N_Empty, S)); 107 end Check_Obsolescent_Features_Restriction; 108 109 ------------------------------ 110 -- Check_Obsolete_Base_Char -- 111 ------------------------------ 112 113 procedure Check_Obsolete_Base_Char is 114 S : Source_Ptr; 115 116 begin 117 if Based_Literal_Uses_Colon then 118 119 -- Find the : for the restriction or warning message 120 121 S := Token_Ptr; 122 while Source (S) /= ':' loop 123 S := S + 1; 124 end loop; 125 126 Check_Obsolescent_Features_Restriction (S); 127 128 if Warn_On_Obsolescent_Feature then 129 Error_Msg 130 ("?j?use of "":"" is an obsolescent feature (RM J.2(3))", S); 131 Error_Msg 132 ("\?j?use ""'#"" instead", S); 133 end if; 134 end if; 135 end Check_Obsolete_Base_Char; 136 137 -- Start of processing for Post_Scan 138 139 begin 140 case Token is 141 when Tok_Char_Literal => 142 Token_Node := New_Node (N_Character_Literal, Token_Ptr); 143 Set_Char_Literal_Value (Token_Node, UI_From_CC (Character_Code)); 144 Set_Chars (Token_Node, Token_Name); 145 146 when Tok_Identifier => 147 Token_Node := New_Node (N_Identifier, Token_Ptr); 148 Set_Chars (Token_Node, Token_Name); 149 150 when Tok_Real_Literal => 151 Token_Node := New_Node (N_Real_Literal, Token_Ptr); 152 Set_Realval (Token_Node, Real_Literal_Value); 153 Check_Obsolete_Base_Char; 154 155 when Tok_Integer_Literal => 156 Token_Node := New_Node (N_Integer_Literal, Token_Ptr); 157 Set_Intval (Token_Node, Int_Literal_Value); 158 Check_Obsolete_Base_Char; 159 160 when Tok_String_Literal => 161 Token_Node := New_Node (N_String_Literal, Token_Ptr); 162 Set_Has_Wide_Character 163 (Token_Node, Wide_Character_Found); 164 Set_Has_Wide_Wide_Character 165 (Token_Node, Wide_Wide_Character_Found); 166 Set_Strval (Token_Node, String_Literal_Id); 167 168 if Source (Token_Ptr) = '%' then 169 Check_Obsolescent_Features_Restriction (Token_Ptr); 170 171 if Warn_On_Obsolescent_Feature then 172 Error_Msg_SC 173 ("?j?use of ""'%"" is an obsolescent feature (RM J.2(4))"); 174 Error_Msg_SC ("\?j?use """""" instead"); 175 end if; 176 end if; 177 178 when Tok_Operator_Symbol => 179 Token_Node := New_Node (N_Operator_Symbol, Token_Ptr); 180 Set_Chars (Token_Node, Token_Name); 181 Set_Strval (Token_Node, String_Literal_Id); 182 183 when Tok_Vertical_Bar => 184 if Source (Token_Ptr) = '!' then 185 Check_Obsolescent_Features_Restriction (Token_Ptr); 186 187 if Warn_On_Obsolescent_Feature then 188 Error_Msg_SC 189 ("?j?use of ""'!"" is an obsolescent feature (RM J.2(2))"); 190 Error_Msg_SC ("\?j?use ""'|"" instead"); 191 end if; 192 end if; 193 194 when others => 195 null; 196 end case; 197 end Post_Scan; 198 199 ------------------------------ 200 -- Scan_Reserved_Identifier -- 201 ------------------------------ 202 203 procedure Scan_Reserved_Identifier (Force_Msg : Boolean) is 204 Token_Chars : String := Token_Type'Image (Token); 205 Len : Natural := 0; 206 207 begin 208 -- AI12-0125 : '@' denotes the target_name, i.e. serves as an 209 -- abbreviation for the LHS of an assignment. 210 211 if Token = Tok_At_Sign then 212 Token_Node := New_Node (N_Target_Name, Token_Ptr); 213 return; 214 end if; 215 216 -- We have in Token_Chars the image of the Token name, i.e. Tok_xxx. 217 -- This code extracts the xxx and makes an identifier out of it. 218 219 for J in 5 .. Token_Chars'Length loop 220 Len := Len + 1; 221 Token_Chars (Len) := Fold_Lower (Token_Chars (J)); 222 end loop; 223 224 Token_Name := Name_Find (Token_Chars (1 .. Len)); 225 226 -- If Inside_Pragma is True, we don't give an error. This is to allow 227 -- things like "pragma Ignore_Pragma (Interface)", where "Interface" is 228 -- a reserved word. There is no danger of missing errors, because any 229 -- misuse must have been preceded by an illegal declaration. For 230 -- example, in "pragma Pack (Begin);", either Begin is not declared, 231 -- which is an error, or it is declared, which will be an error on that 232 -- declaration. 233 234 if (not Used_As_Identifier (Token) or else Force_Msg) 235 and then not Inside_Pragma 236 then 237 Error_Msg_Name_1 := Token_Name; 238 Error_Msg_SC ("reserved word* cannot be used as identifier!"); 239 Used_As_Identifier (Token) := True; 240 end if; 241 242 Token := Tok_Identifier; 243 Token_Node := New_Node (N_Identifier, Token_Ptr); 244 Set_Chars (Token_Node, Token_Name); 245 end Scan_Reserved_Identifier; 246 247end Scn; 248