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Diffstat (limited to 'src/vhdl/vhdl-scanner.adb')
-rw-r--r-- | src/vhdl/vhdl-scanner.adb | 2332 |
1 files changed, 2332 insertions, 0 deletions
diff --git a/src/vhdl/vhdl-scanner.adb b/src/vhdl/vhdl-scanner.adb new file mode 100644 index 000000000..734b0c7ce --- /dev/null +++ b/src/vhdl/vhdl-scanner.adb @@ -0,0 +1,2332 @@ +-- VHDL lexical scanner. +-- Copyright (C) 2002 - 2014 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 +-- Software Foundation; either version 2, or (at your option) any later +-- version. +-- +-- GHDL is distributed in the hope that it will be useful, but WITHOUT 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 +-- 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.Characters.Latin_1; use Ada.Characters.Latin_1; +with Errorout; use Errorout; +with Name_Table; +with Files_Map; use Files_Map; +with Std_Names; +with Str_Table; +with Flags; use Flags; + +package body Vhdl.Scanner is + + -- This classification is a simplification of the categories of LRM93 13.1 + -- LRM93 13.1 + -- The only characters allowed in the text of a VHDL description are the + -- graphic characters and format effector. + + type Character_Kind_Type is + ( + -- Neither a format effector nor a graphic character. + Invalid, + Format_Effector, + Lower_Case_Letter, + Upper_Case_Letter, + Digit, + Special_Character, + Space_Character, + Other_Special_Character + ); + + -- LRM93 13.1 + -- basic_graphic_character ::= + -- upper_case_letter | digit | special_character | space_character + -- + --subtype Basic_Graphic_Character is + -- Character_Kind_Type range Upper_Case_Letter .. Space_Character; + + -- LRM93 13.1 + -- graphic_character ::= + -- basic_graphic_character | lower_case_letter | other_special_character + -- + -- Note: There are 191 graphic characters. + subtype Graphic_Character is + Character_Kind_Type range Lower_Case_Letter .. Other_Special_Character; + + -- letter ::= upper_case_letter | lower_case_letter + subtype Letter is + Character_Kind_Type range Lower_Case_Letter .. Upper_Case_Letter; + + -- LRM93 13.1 + -- The characters included in each of the categories of basic graphic + -- characters are defined as follows: + type Character_Array is array (Character) of Character_Kind_Type; + pragma Suppress_Initialization (Character_Array); + Characters_Kind : constant Character_Array := + (NUL .. BS => Invalid, + + -- Format effectors are the ISO (and ASCII) characters called horizontal + -- tabulation, vertical tabulation, carriage return, line feed, and form + -- feed. + HT | LF | VT | FF | CR => Format_Effector, + + SO .. US => Invalid, + + -- 1. upper case letters + 'A' .. 'Z' | UC_A_Grave .. UC_O_Diaeresis | + UC_O_Oblique_Stroke .. UC_Icelandic_Thorn => Upper_Case_Letter, + + -- 2. digits + '0' .. '9' => Digit, + + -- 3. special characters + '"' | '#' | '&' | ''' | '(' | ')' | '+' | ',' | '-' | '.' | '/' + | ':' | ';' | '<' | '=' | '>' | '[' | ']' + | '_' | '|' | '*' => Special_Character, + + -- 4. the space characters + ' ' | NBSP => Space_Character, + + -- 5. lower case letters + 'a' .. 'z' | LC_German_Sharp_S .. LC_O_Diaeresis | + LC_O_Oblique_Stroke .. LC_Y_Diaeresis => Lower_Case_Letter, + + -- 6. other special characters + '!' | '$' | '%' | '@' | '?' | '\' | '^' | '`' | '{' | '}' | '~' + | Inverted_Exclamation .. Inverted_Question | Multiplication_Sign | + Division_Sign => Other_Special_Character, + + -- '¡' -- INVERTED EXCLAMATION MARK + -- '¢' -- CENT SIGN + -- '£' -- POUND SIGN + -- '¤' -- CURRENCY SIGN + -- '¥' -- YEN SIGN + -- '¦' -- BROKEN BAR + -- '§' -- SECTION SIGN + -- '¨' -- DIAERESIS + -- '©' -- COPYRIGHT SIGN + -- 'ª' -- FEMININE ORDINAL INDICATOR + -- '«' -- LEFT-POINTING DOUBLE ANGLE QUOTATION MARK + -- '¬' -- NOT SIGN + -- '' -- SOFT HYPHEN + -- '®' -- REGISTERED SIGN + -- '¯' -- MACRON + -- '°' -- DEGREE SIGN + -- '±' -- PLUS-MINUS SIGN + -- '²' -- SUPERSCRIPT TWO + -- '³' -- SUPERSCRIPT THREE + -- '´' -- ACUTE ACCENT + -- 'µ' -- MICRO SIGN + -- '¶' -- PILCROW SIGN + -- '·' -- MIDDLE DOT + -- '¸' -- CEDILLA + -- '¹' -- SUPERSCRIPT ONE + -- 'º' -- MASCULINE ORDINAL INDICATOR + -- '»' -- RIGHT-POINTING DOUBLE ANGLE QUOTATION MARK + -- '¼' -- VULGAR FRACTION ONE QUARTER + -- '½' -- VULGAR FRACTION ONE HALF + -- '¾' -- VULGAR FRACTION THREE QUARTERS + -- '¿' -- INVERTED QUESTION MARK + -- '×' -- MULTIPLICATION SIGN + -- '÷' -- DIVISION SIGN + + DEL .. APC => Invalid); + + -- The context contains the whole internal state of the scanner, ie + -- it can be used to push/pop a lexical analysis, to restart the + -- scanner from a context marking a previous point. + type Scan_Context is record + Source : File_Buffer_Acc; + Source_File : Source_File_Entry; + Line_Number : Natural; + Line_Pos : Source_Ptr; + Prev_Pos : Source_Ptr; + Token_Pos : Source_Ptr; + Pos : Source_Ptr; + File_Len : Source_Ptr; + Token : Token_Type; + Prev_Token : Token_Type; + + -- Additional values for the current token. + Bit_Str_Base : Character; + Bit_Str_Sign : Character; + Str_Id : String8_Id; + Str_Len : Nat32; + Identifier: Name_Id; + Int64 : Iir_Int64; + Fp64 : Iir_Fp64; + end record; + pragma Suppress_Initialization (Scan_Context); + + -- Disp a message during scan. + -- The current location is automatically displayed before the message. + -- Disp a message during scan. + procedure Error_Msg_Scan (Msg: String) is + begin + Report_Msg (Msgid_Error, Scan, No_Location, Msg); + end Error_Msg_Scan; + + procedure Error_Msg_Scan (Loc : Location_Type; Msg: String) is + begin + Report_Msg (Msgid_Error, Scan, Loc, Msg); + end Error_Msg_Scan; + + procedure Error_Msg_Scan (Msg: String; Arg1 : Earg_Type) is + begin + Report_Msg (Msgid_Error, Scan, No_Location, Msg, (1 => Arg1)); + end Error_Msg_Scan; + + -- Disp a message during scan. + procedure Warning_Msg_Scan (Id : Msgid_Warnings; Msg: String) is + begin + Report_Msg (Id, Scan, No_Location, Msg); + end Warning_Msg_Scan; + + procedure Warning_Msg_Scan (Id : Msgid_Warnings; + Msg: String; + Arg1 : Earg_Type; + Cont : Boolean := False) is + begin + Report_Msg (Id, Scan, No_Location, Msg, (1 => Arg1), Cont); + end Warning_Msg_Scan; + + -- The current context. + -- Default value is an invalid context. + Current_Context: Scan_Context := (Source => null, + Source_File => No_Source_File_Entry, + Line_Number => 0, + Line_Pos => 0, + Pos => 0, + Prev_Pos => 0, + Token_Pos => 0, + File_Len => 0, + Token => Tok_Invalid, + Prev_Token => Tok_Invalid, + Identifier => Null_Identifier, + Bit_Str_Base => ' ', + Bit_Str_Sign => ' ', + Str_Id => Null_String8, + Str_Len => 0, + Int64 => 0, + Fp64 => 0.0); + + Source: File_Buffer_Acc renames Current_Context.Source; + Pos: Source_Ptr renames Current_Context.Pos; + + -- When CURRENT_TOKEN is an identifier, its name_id is stored into + -- this global variable. + -- Function current_text can be used to convert it into an iir. + function Current_Identifier return Name_Id is + begin + return Current_Context.Identifier; + end Current_Identifier; + + procedure Invalidate_Current_Identifier is + begin + Current_Context.Identifier := Null_Identifier; + end Invalidate_Current_Identifier; + + procedure Invalidate_Current_Token is + begin + if Current_Token /= Tok_Invalid then + Current_Context.Prev_Token := Current_Token; + Current_Token := Tok_Invalid; + end if; + end Invalidate_Current_Token; + + function Current_String_Id return String8_Id is + begin + return Current_Context.Str_Id; + end Current_String_Id; + + function Current_String_Length return Nat32 is + begin + return Current_Context.Str_Len; + end Current_String_Length; + + function Get_Bit_String_Base return Character is + begin + return Current_Context.Bit_Str_Base; + end Get_Bit_String_Base; + + function Get_Bit_String_Sign return Character is + begin + return Current_Context.Bit_Str_Sign; + end Get_Bit_String_Sign; + + function Current_Iir_Int64 return Iir_Int64 is + begin + return Current_Context.Int64; + end Current_Iir_Int64; + + function Current_Iir_Fp64 return Iir_Fp64 is + begin + return Current_Context.Fp64; + end Current_Iir_Fp64; + + function Get_Current_Source_File return Source_File_Entry is + begin + return Current_Context.Source_File; + end Get_Current_Source_File; + + function Get_Current_Line return Natural is + begin + return Current_Context.Line_Number; + end Get_Current_Line; + + function Get_Current_Offset return Natural is + begin + return Natural (Current_Context.Pos - Current_Context.Line_Pos); + end Get_Current_Offset; + + function Get_Token_Offset return Natural is + begin + return Natural (Current_Context.Token_Pos - Current_Context.Line_Pos); + end Get_Token_Offset; + + function Get_Token_Position return Source_Ptr is + begin + return Current_Context.Token_Pos; + end Get_Token_Position; + + function Get_Position return Source_Ptr is + begin + return Current_Context.Pos; + end Get_Position; + + function Get_Token_Location return Location_Type is + begin + return File_Pos_To_Location + (Current_Context.Source_File, Current_Context.Token_Pos); + end Get_Token_Location; + + function Get_Prev_Location return Location_Type is + begin + return File_Pos_To_Location + (Current_Context.Source_File, Current_Context.Prev_Pos); + end Get_Prev_Location; + + procedure Set_File (Source_File : Source_File_Entry) + is + N_Source: File_Buffer_Acc; + begin + pragma Assert (Current_Context.Source = null); + pragma Assert (Source_File /= No_Source_File_Entry); + N_Source := Get_File_Source (Source_File); + Current_Context := (Source => N_Source, + Source_File => Source_File, + Line_Number => 1, + Line_Pos => 0, + Prev_Pos => N_Source'First, + Pos => N_Source'First, + Token_Pos => 0, -- should be invalid, + File_Len => Get_File_Length (Source_File), + Token => Tok_Invalid, + Prev_Token => Tok_Invalid, + Identifier => Null_Identifier, + Bit_Str_Base => ' ', + Bit_Str_Sign => ' ', + Str_Id => Null_String8, + Str_Len => 0, + Int64 => -1, + Fp64 => 0.0); + Current_Token := Tok_Invalid; + end Set_File; + + function Detect_Encoding_Errors return Boolean + is + C : constant Character := Source (Pos); + begin + -- No need to check further if first character is plain ASCII-7 + if C >= ' ' and C < Character'Val (127) then + return False; + end if; + + -- UTF-8 BOM is EF BB BF + if Source (Pos + 0) = Character'Val (16#ef#) + and then Source (Pos + 1) = Character'Val (16#bb#) + and then Source (Pos + 2) = Character'Val (16#bf#) + then + Error_Msg_Scan + ("source encoding must be latin-1 (UTF-8 BOM detected)"); + return True; + end if; + + -- UTF-16 BE BOM is FE FF + if Source (Pos + 0) = Character'Val (16#fe#) + and then Source (Pos + 1) = Character'Val (16#ff#) + then + Error_Msg_Scan + ("source encoding must be latin-1 (UTF-16 BE BOM detected)"); + return True; + end if; + + -- UTF-16 LE BOM is FF FE + if Source (Pos + 0) = Character'Val (16#ff#) + and then Source (Pos + 1) = Character'Val (16#fe#) + then + Error_Msg_Scan + ("source encoding must be latin-1 (UTF-16 LE BOM detected)"); + return True; + end if; + + -- Certainly weird, but scanner/parser will catch it. + return False; + end Detect_Encoding_Errors; + + procedure Set_Current_Position (Position: Source_Ptr) + is + Loc : Location_Type; + Offset: Natural; + File_Entry : Source_File_Entry; + begin + -- Scanner must have been initialized. + pragma Assert (Current_Context.Source /= null); + + Current_Token := Tok_Invalid; + Current_Context.Pos := Position; + Loc := File_Pos_To_Location (Current_Context.Source_File, + Current_Context.Pos); + Location_To_Coord (Loc, + File_Entry, Current_Context.Line_Pos, + Current_Context.Line_Number, Offset); + end Set_Current_Position; + + procedure Close_File is + begin + Current_Context.Source := null; + end Close_File; + + -- Emit an error when a character above 128 was found. + -- This must be called only in vhdl87. + procedure Error_8bit is + begin + Error_Msg_Scan ("8 bits characters not allowed in vhdl87"); + end Error_8bit; + + -- Emit an error when a separator is expected. + procedure Error_Separator is + begin + Error_Msg_Scan ("a separator is required here"); + end Error_Separator; + + -- scan a decimal literal or a based literal. + -- + -- LRM93 13.4.1 + -- DECIMAL_LITERAL ::= INTEGER [ . INTEGER ] [ EXPONENT ] + -- EXPONENT ::= E [ + ] INTEGER | E - INTEGER + -- + -- LRM93 13.4.2 + -- BASED_LITERAL ::= BASE # BASED_INTEGER [ . BASED_INTEGER ] # EXPONENT + -- BASE ::= INTEGER + procedure Scan_Literal is separate; + + -- Scan a string literal. + -- + -- LRM93 13.6 / LRM08 15.7 + -- A string literal is formed by a sequence of graphic characters + -- (possibly none) enclosed between two quotation marks used as string + -- brackets. + -- STRING_LITERAL ::= " { GRAPHIC_CHARACTER } " + -- + -- IN: for a string, at the call of this procedure, the current character + -- must be either '"' or '%'. + procedure Scan_String + is + -- The quotation character (can be " or %). + Mark: Character; + -- Current character. + C : Character; + -- Current length. + Length : Nat32; + begin + -- String delimiter. + Mark := Source (Pos); + pragma Assert (Mark = '"' or else Mark = '%'); + + Pos := Pos + 1; + Length := 0; + Current_Context.Str_Id := Str_Table.Create_String8; + loop + C := Source (Pos); + if C = Mark then + -- LRM93 13.6 + -- If a quotation mark value is to be represented in the sequence + -- of character values, then a pair of adjacent quoatation + -- characters marks must be written at the corresponding place + -- within the string literal. + -- LRM93 13.10 + -- Any pourcent sign within the sequence of characters must then + -- be doubled, and each such doubled percent sign is interpreted + -- as a single percent sign value. + -- The same replacement is allowed for a bit string literal, + -- provieded that both bit string brackets are replaced. + Pos := Pos + 1; + exit when Source (Pos) /= Mark; + end if; + + case Characters_Kind (C) is + when Format_Effector => + if Mark = '%' then + -- No matching '%' has been found. Consider '%' was used + -- as the remainder operator, instead of 'rem'. This will + -- improve the error message. + Error_Msg_Scan + (Get_Token_Location, + "'%%' is not a vhdl operator, use 'rem'"); + Current_Token := Tok_Rem; + Pos := Current_Context.Token_Pos + 1; + return; + end if; + if C = CR or C = LF then + Error_Msg_Scan + ("string cannot be multi-line, use concatenation"); + else + Error_Msg_Scan ("format effector not allowed in a string"); + end if; + exit; + when Invalid => + if C = Files_Map.EOT + and then Pos >= Current_Context.File_Len + then + Error_Msg_Scan ("string not terminated at end of file"); + exit; + end if; + + Error_Msg_Scan + ("invalid character not allowed, even in a string"); + when Graphic_Character => + if Vhdl_Std = Vhdl_87 and then C > Character'Val (127) then + Error_8bit; + end if; + end case; + + if C = '"' and Mark = '%' then + -- LRM93 13.10 + -- The quotation marks (") used as string brackets at both ends of + -- a string literal can be replaced by percent signs (%), provided + -- that the enclosed sequence of characters constains no quotation + -- marks, and provided that both string brackets are replaced. + Error_Msg_Scan + ("'""' cannot be used in a string delimited with '%%'"); + end if; + + Length := Length + 1; + Str_Table.Append_String8 (Character'Pos (C)); + Pos := Pos + 1; + end loop; + + Current_Token := Tok_String; + Current_Context.Str_Len := Length; + end Scan_String; + + -- Scan a bit string literal. + -- + -- LRM93 13.7 + -- A bit string literal is formed by a sequence of extended digits + -- (possibly none) enclosed between two quotations used as bit string + -- brackets, preceded by a base specifier. + -- BIT_STRING_LITERAL ::= BASE_SPECIFIER " [ BIT_VALUE ] " + -- BIT_VALUE ::= EXTENDED_DIGIT { [ UNDERLINE ] EXTENDED_DIGIT } + -- + -- The current character must be a base specifier, followed by '"' or '%'. + -- The base must be valid. + procedure Scan_Bit_String (Base_Log : Nat32) + is + -- Position of character '0'. + Pos_0 : constant Nat8 := Character'Pos ('0'); + + -- Used for the base. + subtype Nat4 is Natural range 1 .. 4; + Base : constant Nat32 := 2 ** Nat4 (Base_Log); + + -- The quotation character (can be " or %). + Orig_Pos : constant Source_Ptr := Pos; + Mark : constant Character := Source (Orig_Pos); + -- Current character. + C : Character; + -- Current length. + Length : Nat32; + -- Digit value. + V, D : Nat8; + -- True if invalid character already found, to avoid duplicate message. + Has_Invalid : Boolean; + begin + pragma Assert (Mark = '"' or else Mark = '%'); + Pos := Pos + 1; + Length := 0; + Has_Invalid := False; + Current_Context.Str_Id := Str_Table.Create_String8; + loop + << Again >> null; + C := Source (Pos); + Pos := Pos + 1; + exit when C = Mark; + + -- LRM93 13.7 + -- If the base specifier is 'B', the extended digits in the bit + -- value are restricted to 0 and 1. + -- If the base specifier is 'O', the extended digits int the bit + -- value are restricted to legal digits in the octal number + -- system, ie, the digits 0 through 7. + -- If the base specifier is 'X', the extended digits are all digits + -- together with the letters A through F. + case C is + when '0' .. '9' => + V := Character'Pos (C) - Character'Pos ('0'); + when 'A' .. 'F' => + V := Character'Pos (C) - Character'Pos ('A') + 10; + when 'a' .. 'f' => + -- LRM93 13.7 + -- A letter in a bit string literal (...) can be written either + -- in lowercase or in upper case, with the same meaning. + V := Character'Pos (C) - Character'Pos ('a') + 10; + when '_' => + if Source (Pos) = '_' then + Error_Msg_Scan + ("double underscore not allowed in a bit string"); + end if; + if Source (Pos - 2) = Mark then + Error_Msg_Scan + ("underscore not allowed at the start of a bit string"); + elsif Source (Pos) = Mark then + Error_Msg_Scan + ("underscore not allowed at the end of a bit string"); + end if; + goto Again; + when '"' => + pragma Assert (Mark = '%'); + Error_Msg_Scan + ("'""' cannot close a bit string opened by '%%'"); + exit; + when '%' => + pragma Assert (Mark = '"'); + Error_Msg_Scan + ("'%%' cannot close a bit string opened by '""'"); + exit; + when others => + if Characters_Kind (C) in Graphic_Character then + if Vhdl_Std >= Vhdl_08 then + V := Nat8'Last; + else + if not Has_Invalid then + Error_Msg_Scan ("invalid character in bit string"); + Has_Invalid := True; + end if; + -- Continue the bit string + V := 0; + end if; + else + if Mark = '%' then + Error_Msg_Scan + (File_Pos_To_Location + (Current_Context.Source_File, Orig_Pos), + "'%%' is not a vhdl operator, use 'rem'"); + Current_Token := Tok_Rem; + Pos := Orig_Pos + 1; + return; + else + Error_Msg_Scan ("bit string not terminated"); + Pos := Pos - 1; + end if; + exit; + end if; + end case; + + -- Expand bit value. + if Vhdl_Std >= Vhdl_08 and V > Base then + -- Expand as graphic character. + for I in 1 .. Base_Log loop + Str_Table.Append_String8_Char (C); + end loop; + else + -- Expand as extended digits. + case Base_Log is + when 1 => + if V > 1 then + Error_Msg_Scan + ("invalid character in a binary bit string"); + V := 1; + end if; + Str_Table.Append_String8 (Pos_0 + V); + when 3 => + if V > 7 then + Error_Msg_Scan + ("invalid character in a octal bit string"); + V := 7; + end if; + for I in 1 .. 3 loop + D := V / 4; + Str_Table.Append_String8 (Pos_0 + D); + V := (V - 4 * D) * 2; + end loop; + when 4 => + for I in 1 .. 4 loop + D := V / 8; + Str_Table.Append_String8 (Pos_0 + D); + V := (V - 8 * D) * 2; + end loop; + when others => + raise Internal_Error; + end case; + end if; + + Length := Length + Base_Log; + end loop; + + -- Note: the length of the bit string may be 0. + + Current_Token := Tok_Bit_String; + Current_Context.Str_Len := Length; + end Scan_Bit_String; + + -- Scan a decimal bit string literal. For base specifier D the algorithm + -- is rather different: all the graphic characters shall be digits, and we + -- need to use a (not very efficient) arbitrary precision multiplication. + procedure Scan_Dec_Bit_String + is + use Str_Table; + + Id : String8_Id; + + -- Position of character '0'. + Pos_0 : constant Nat8 := Character'Pos ('0'); + + -- Current character. + C : Character; + -- Current length. + Length : Nat32; + -- Digit value. + V, D : Nat8; + + type Carries_Type is array (0 .. 3) of Nat8; + Carries : Carries_Type; + No_Carries : constant Carries_Type := (others => Pos_0); + + -- Shift right carries. Note the Carries (0) is the LSB. + procedure Shr_Carries is + begin + Carries := (Carries (1), Carries (2), Carries (3), Pos_0); + end Shr_Carries; + + procedure Append_Carries is + begin + -- Expand the bit string. Note that position 1 of the string8 is + -- the MSB. + while Carries /= No_Carries loop + Append_String8 (Pos_0); + Length := Length + 1; + for I in reverse 2 .. Length loop + Set_Element_String8 (Id, I, Element_String8 (Id, I - 1)); + end loop; + Set_Element_String8 (Id, 1, Carries (0)); + Shr_Carries; + end loop; + end Append_Carries; + + -- Add 1 to Carries. Overflow is not allowed and should be prevented by + -- construction. + procedure Add_One_To_Carries is + begin + for I in Carries'Range loop + if Carries (I) = Pos_0 then + Carries (I) := Pos_0 + 1; + -- End of propagation. + exit; + else + Carries (I) := Pos_0; + -- Continue propagation. + pragma Assert (I < Carries'Last); + end if; + end loop; + end Add_One_To_Carries; + begin + pragma Assert (Source (Pos) = '"'); + Pos := Pos + 1; + Length := 0; + Id := Create_String8; + Current_Context.Str_Id := Id; + loop + << Again >> null; + C := Source (Pos); + Pos := Pos + 1; + exit when C = '"'; + + if C in '0' .. '9' then + V := Character'Pos (C) - Character'Pos ('0'); + elsif C = '_' then + if Source (Pos) = '_' then + Error_Msg_Scan + ("double underscore not allowed in a bit string"); + end if; + if Source (Pos - 2) = '"' then + Error_Msg_Scan + ("underscore not allowed at the start of a bit string"); + elsif Source (Pos) = '"' then + Error_Msg_Scan + ("underscore not allowed at the end of a bit string"); + end if; + goto Again; + else + if Characters_Kind (C) in Graphic_Character then + Error_Msg_Scan + ("graphic character not allowed in decimal bit string"); + -- Continue the bit string + V := 0; + else + Error_Msg_Scan ("bit string not terminated"); + Pos := Pos - 1; + exit; + end if; + end if; + + -- Multiply by 10. + Carries := (others => Pos_0); + for I in reverse 1 .. Length loop + -- Shift by 1 (*2). + D := Element_String8 (Id, I); + Set_Element_String8 (Id, I, Carries (0)); + Shr_Carries; + -- Add D and D * 4. + if D /= Pos_0 then + Add_One_To_Carries; + -- Add_Four_To_Carries: + for I in 2 .. 3 loop + if Carries (I) = Pos_0 then + Carries (I) := Pos_0 + 1; + -- End of propagation. + exit; + else + Carries (I) := Pos_0; + -- Continue propagation. + end if; + end loop; + end if; + end loop; + Append_Carries; + + -- Add V. + for I in Carries'Range loop + D := V / 2; + Carries (I) := Pos_0 + (V - 2 * D); + V := D; + end loop; + for I in reverse 1 .. Length loop + D := Element_String8 (Id, I); + if D /= Pos_0 then + Add_One_To_Carries; + end if; + Set_Element_String8 (Id, I, Carries (0)); + Shr_Carries; + exit when Carries = No_Carries; + end loop; + Append_Carries; + end loop; + + Current_Token := Tok_Bit_String; + Current_Context.Str_Len := Length; + end Scan_Dec_Bit_String; + + -- LRM08 15.2 Character set + -- For each uppercase letter, there is a corresponding lowercase letter; + -- and for each lowercase letter except [y diaeresis] and [german sharp s], + -- there is a corresponding uppercase letter. + type Character_Map is array (Character) of Character; + To_Lower_Map : constant Character_Map := + ( + -- Uppercase ASCII letters. + 'A' => 'a', + 'B' => 'b', + 'C' => 'c', + 'D' => 'd', + 'E' => 'e', + 'F' => 'f', + 'G' => 'g', + 'H' => 'h', + 'I' => 'i', + 'J' => 'j', + 'K' => 'k', + 'L' => 'l', + 'M' => 'm', + 'N' => 'n', + 'O' => 'o', + 'P' => 'p', + 'Q' => 'q', + 'R' => 'r', + 'S' => 's', + 'T' => 't', + 'U' => 'u', + 'V' => 'v', + 'W' => 'w', + 'X' => 'x', + 'Y' => 'y', + 'Z' => 'z', + + -- Lowercase ASCII letters. + 'a' => 'a', + 'b' => 'b', + 'c' => 'c', + 'd' => 'd', + 'e' => 'e', + 'f' => 'f', + 'g' => 'g', + 'h' => 'h', + 'i' => 'i', + 'j' => 'j', + 'k' => 'k', + 'l' => 'l', + 'm' => 'm', + 'n' => 'n', + 'o' => 'o', + 'p' => 'p', + 'q' => 'q', + 'r' => 'r', + 's' => 's', + 't' => 't', + 'u' => 'u', + 'v' => 'v', + 'w' => 'w', + 'x' => 'x', + 'y' => 'y', + 'z' => 'z', + + -- Uppercase Latin-1 letters. + UC_A_Grave => LC_A_Grave, + UC_A_Acute => LC_A_Acute, + UC_A_Circumflex => LC_A_Circumflex, + UC_A_Tilde => LC_A_Tilde, + UC_A_Diaeresis => LC_A_Diaeresis, + UC_A_Ring => LC_A_Ring, + UC_AE_Diphthong => LC_AE_Diphthong, + UC_C_Cedilla => LC_C_Cedilla, + UC_E_Grave => LC_E_Grave, + UC_E_Acute => LC_E_Acute, + UC_E_Circumflex => LC_E_Circumflex, + UC_E_Diaeresis => LC_E_Diaeresis, + UC_I_Grave => LC_I_Grave, + UC_I_Acute => LC_I_Acute, + UC_I_Circumflex => LC_I_Circumflex, + UC_I_Diaeresis => LC_I_Diaeresis, + UC_Icelandic_Eth => LC_Icelandic_Eth, + UC_N_Tilde => LC_N_Tilde, + UC_O_Grave => LC_O_Grave, + UC_O_Acute => LC_O_Acute, + UC_O_Circumflex => LC_O_Circumflex, + UC_O_Tilde => LC_O_Tilde, + UC_O_Diaeresis => LC_O_Diaeresis, + UC_O_Oblique_Stroke => LC_O_Oblique_Stroke, + UC_U_Grave => LC_U_Grave, + UC_U_Acute => LC_U_Acute, + UC_U_Circumflex => LC_U_Circumflex, + UC_U_Diaeresis => LC_U_Diaeresis, + UC_Y_Acute => LC_Y_Acute, + UC_Icelandic_Thorn => LC_Icelandic_Thorn, + + -- Lowercase Latin-1 letters. + LC_A_Grave => LC_A_Grave, + LC_A_Acute => LC_A_Acute, + LC_A_Circumflex => LC_A_Circumflex, + LC_A_Tilde => LC_A_Tilde, + LC_A_Diaeresis => LC_A_Diaeresis, + LC_A_Ring => LC_A_Ring, + LC_AE_Diphthong => LC_AE_Diphthong, + LC_C_Cedilla => LC_C_Cedilla, + LC_E_Grave => LC_E_Grave, + LC_E_Acute => LC_E_Acute, + LC_E_Circumflex => LC_E_Circumflex, + LC_E_Diaeresis => LC_E_Diaeresis, + LC_I_Grave => LC_I_Grave, + LC_I_Acute => LC_I_Acute, + LC_I_Circumflex => LC_I_Circumflex, + LC_I_Diaeresis => LC_I_Diaeresis, + LC_Icelandic_Eth => LC_Icelandic_Eth, + LC_N_Tilde => LC_N_Tilde, + LC_O_Grave => LC_O_Grave, + LC_O_Acute => LC_O_Acute, + LC_O_Circumflex => LC_O_Circumflex, + LC_O_Tilde => LC_O_Tilde, + LC_O_Diaeresis => LC_O_Diaeresis, + LC_O_Oblique_Stroke => LC_O_Oblique_Stroke, + LC_U_Grave => LC_U_Grave, + LC_U_Acute => LC_U_Acute, + LC_U_Circumflex => LC_U_Circumflex, + LC_U_Diaeresis => LC_U_Diaeresis, + LC_Y_Acute => LC_Y_Acute, + LC_Icelandic_Thorn => LC_Icelandic_Thorn, + + -- Lowercase latin-1 characters without corresponding uppercase one. + LC_Y_Diaeresis => LC_Y_Diaeresis, + LC_German_Sharp_S => LC_German_Sharp_S, + + -- Not a letter. + others => NUL); + + procedure Error_Too_Long is + begin + Error_Msg_Scan ("identifier is too long (>" + & Natural'Image (Max_Name_Length - 1) & ")"); + end Error_Too_Long; + + -- LRM93 13.3.1 + -- Basic Identifiers + -- A basic identifier consists only of letters, digits, and underlines. + -- BASIC_IDENTIFIER ::= LETTER { [ UNDERLINE ] LETTER_OR_DIGIT } + -- LETTER_OR_DIGIT ::= LETTER | DIGIT + -- LETTER ::= UPPER_CASE_LETTER | LOWER_CASE_LETTER + -- + -- NB: At the call of this procedure, the current character must be a legal + -- character for a basic identifier. + procedure Scan_Identifier (Allow_PSL : Boolean) + is + use Name_Table; + Buffer : String (1 .. Max_Name_Length); + C : Character; + Len : Natural; + begin + -- This is an identifier or a key word. + Len := 0; + loop + -- Source (pos) is correct. + -- LRM93 13.3.1 + -- All characters if a basic identifier are signifiant, including + -- any underline character inserted between a letter or digit and + -- an adjacent letter or digit. + -- Basic identifiers differing only in the use of the corresponding + -- upper and lower case letters are considered as the same. + -- + -- GHDL: This is achieved by converting all upper case letters into + -- equivalent lower case letters. + -- The opposite (converting to upper lower case letters) is not + -- possible because two characters have no upper-case equivalent. + C := Source (Pos); + case C is + when 'A' .. 'Z' => + C := Character'Val + (Character'Pos (C) + + Character'Pos ('a') - Character'Pos ('A')); + when 'a' .. 'z' | '0' .. '9' => + null; + when '_' => + if Source (Pos + 1) = '_' then + Error_Msg_Scan ("two underscores can't be consecutive"); + end if; + when ' ' | ')' | '.' | ';' | ':' => + exit; + when others => + -- Non common case. + case Characters_Kind (C) is + when Upper_Case_Letter | Lower_Case_Letter => + if Vhdl_Std = Vhdl_87 then + Error_8bit; + end if; + C := To_Lower_Map (C); + pragma Assert (C /= NUL); + when Digit => + raise Internal_Error; + when others => + exit; + end case; + end case; + + -- Put character in name buffer. FIXME: compute the hash at the same + -- time ? + if Len >= Max_Name_Length - 1 then + if Len = Max_Name_Length -1 then + Error_Msg_Scan ("identifier is too long (>" + & Natural'Image (Max_Name_Length - 1) & ")"); + -- Accept this last one character, so that no error for the + -- following characters. + Len := Len + 1; + Buffer (Len) := C; + end if; + else + Len := Len + 1; + Buffer (Len) := C; + end if; + + -- Next character. + Pos := Pos + 1; + end loop; + + if Source (Pos - 1) = '_' then + if Allow_PSL then + -- Some PSL reserved words finish with '_'. This case is handled + -- later by Scan_Underscore and Scan_Exclam_Mark. + Pos := Pos - 1; + Len := Len - 1; + C := '_'; + else + -- Eat the trailing underscore. + Error_Msg_Scan ("an identifier cannot finish with '_'"); + end if; + end if; + + -- LRM93 13.2 + -- At least one separator is required between an identifier or an + -- abstract literal and an adjacent identifier or abstract literal. + case Characters_Kind (C) is + when Digit + | Upper_Case_Letter + | Lower_Case_Letter => + raise Internal_Error; + when Other_Special_Character | Special_Character => + if (C = '"' or C = '%') and then Len <= 2 then + if C = '%' and Vhdl_Std >= Vhdl_08 then + Error_Msg_Scan ("'%%' not allowed in vhdl 2008 " + & "(was replacement character)"); + -- Continue as a bit string. + end if; + + -- Good candidate for bit string. + + -- LRM93 13.7 + -- BASE_SPECIFIER ::= B | O | X + -- + -- A letter in a bit string literal (either an extended digit + -- or the base specifier) can be written either in lower case + -- or in upper case, with the same meaning. + -- + -- LRM08 15.8 Bit string literals + -- BASE_SPECICIER ::= + -- B | O | X | UB | UO | UX | SB | SO | SX | D + -- + -- An extended digit and the base specifier in a bit string + -- literal can be written either in lowercase or in uppercase, + -- with the same meaning. + declare + Base : Nat32; + Cl : constant Character := Buffer (Len); + Cf : constant Character := Buffer (1); + begin + Current_Context.Bit_Str_Base := Cl; + if Cl = 'b' then + Base := 1; + elsif Cl = 'o' then + Base := 3; + elsif Cl = 'x' then + Base := 4; + elsif Vhdl_Std >= Vhdl_08 and Len = 1 and Cf = 'd' then + Current_Context.Bit_Str_Sign := ' '; + Scan_Dec_Bit_String; + return; + else + Base := 0; + end if; + if Base > 0 then + if Len = 1 then + Current_Context.Bit_Str_Sign := ' '; + Scan_Bit_String (Base); + return; + elsif Vhdl_Std >= Vhdl_08 + and then (Cf = 's' or Cf = 'u') + then + Current_Context.Bit_Str_Sign := Cf; + Scan_Bit_String (Base); + return; + end if; + end if; + end; + elsif Vhdl_Std > Vhdl_87 and then C = '\' then + -- Start of extended identifier. Cannot follow an identifier. + Error_Separator; + end if; + + when Invalid => + -- Improve error message for use of UTF-8 quote marks. + -- It's possible because in the sequence of UTF-8 bytes for the + -- quote marks, there are invalid character (in the 128-160 + -- range). + if C = Character'Val (16#80#) + and then Buffer (Len) = Character'Val (16#e2#) + and then (Source (Pos + 1) = Character'Val (16#98#) + or else Source (Pos + 1) = Character'Val (16#99#)) + then + -- UTF-8 left or right single quote mark. + if Len > 1 then + -- The first byte (0xe2) is part of the identifier. An + -- error will be detected as the next byte (0x80) is + -- invalid. Remove the first byte from the identifier, and + -- let's catch the error later. + Len := Len - 1; + Pos := Pos - 1; + else + Error_Msg_Scan ("invalid use of UTF8 character for '"); + Pos := Pos + 2; + + -- Distinguish between character literal and tick. Don't + -- care about possible invalid character literal, as in any + -- case we have already emitted an error message. + if Current_Context.Prev_Token /= Tok_Identifier + and then Current_Context.Prev_Token /= Tok_Character + and then + (Source (Pos + 1) = ''' + or else + (Source (Pos + 1) = Character'Val (16#e2#) + and then Source (Pos + 2) = Character'Val (16#80#) + and then Source (Pos + 3) = Character'Val (16#99#))) + then + Current_Token := Tok_Character; + Current_Context.Identifier := + Name_Table.Get_Identifier (Source (Pos)); + if Source (Pos + 1) = ''' then + Pos := Pos + 2; + else + Pos := Pos + 4; + end if; + else + Current_Token := Tok_Tick; + end if; + return; + end if; + end if; + when Format_Effector + | Space_Character => + null; + end case; + + -- Hash it. + Current_Context.Identifier := Get_Identifier (Buffer (1 .. Len)); + Current_Token := Tok_Identifier; + end Scan_Identifier; + + procedure Identifier_To_Token is + begin + if Current_Identifier in Std_Names.Name_Id_Keywords then + -- LRM93 13.9 + -- The identifiers listed below are called reserved words and are + -- reserved for signifiances in the language. + -- IN: this is also achieved in packages std_names and tokens. + Current_Token := Token_Type'Val + (Token_Type'Pos (Tok_First_Keyword) + + Current_Identifier - Std_Names.Name_First_Keyword); + case Current_Identifier is + when Std_Names.Name_Id_AMS_Reserved_Words => + if not AMS_Vhdl then + if Is_Warning_Enabled (Warnid_Reserved_Word) then + Warning_Msg_Scan + (Warnid_Reserved_Word, + "using %i AMS-VHDL reserved word as an identifier", + +Current_Identifier); + end if; + Current_Token := Tok_Identifier; + end if; + when Std_Names.Name_Id_Vhdl08_Reserved_Words => + if Vhdl_Std < Vhdl_08 then + if Is_Warning_Enabled (Warnid_Reserved_Word) then + Warning_Msg_Scan + (Warnid_Reserved_Word, + "using %i vhdl-2008 reserved word as an identifier", + +Current_Identifier); + end if; + Current_Token := Tok_Identifier; + end if; + when Std_Names.Name_Id_Vhdl00_Reserved_Words => + if Vhdl_Std < Vhdl_00 then + if Is_Warning_Enabled (Warnid_Reserved_Word) then + Warning_Msg_Scan + (Warnid_Reserved_Word, + "using %i vhdl-2000 reserved word as an identifier", + +Current_Identifier); + end if; + Current_Token := Tok_Identifier; + end if; + when Std_Names.Name_Id_Vhdl93_Reserved_Words => + if Vhdl_Std = Vhdl_87 then + if Is_Warning_Enabled (Warnid_Reserved_Word) then + Warning_Msg_Scan + (Warnid_Reserved_Word, + "using %i vhdl93 reserved word as a vhdl87 identifier", + +Current_Identifier, True); + Warning_Msg_Scan + (Warnid_Reserved_Word, + "(use option --std=93 to compile as vhdl93)"); + end if; + Current_Token := Tok_Identifier; + end if; + when Std_Names.Name_Id_Vhdl87_Reserved_Words => + null; + when others => + raise Program_Error; + end case; + elsif Flag_Psl then + case Current_Identifier is + when Std_Names.Name_Clock => + Current_Token := Tok_Psl_Clock; + when Std_Names.Name_Const => + Current_Token := Tok_Psl_Const; + when Std_Names.Name_Boolean => + Current_Token := Tok_Psl_Boolean; + when Std_Names.Name_Sequence => + Current_Token := Tok_Psl_Sequence; + when Std_Names.Name_Property => + Current_Token := Tok_Psl_Property; + when Std_Names.Name_Endpoint => + Current_Token := Tok_Psl_Endpoint; + when Std_Names.Name_Cover => + Current_Token := Tok_Psl_Cover; + when Std_Names.Name_Default => + Current_Token := Tok_Psl_Default; + when Std_Names.Name_Inf => + Current_Token := Tok_Inf; + when Std_Names.Name_Within => + Current_Token := Tok_Within; + when Std_Names.Name_Abort => + Current_Token := Tok_Abort; + when Std_Names.Name_Before => + Current_Token := Tok_Before; + when Std_Names.Name_Always => + Current_Token := Tok_Always; + when Std_Names.Name_Never => + Current_Token := Tok_Never; + when Std_Names.Name_Eventually => + Current_Token := Tok_Eventually; + when Std_Names.Name_Next_A => + Current_Token := Tok_Next_A; + when Std_Names.Name_Next_E => + Current_Token := Tok_Next_E; + when Std_Names.Name_Next_Event => + Current_Token := Tok_Next_Event; + when Std_Names.Name_Next_Event_A => + Current_Token := Tok_Next_Event_A; + when Std_Names.Name_Next_Event_E => + Current_Token := Tok_Next_Event_E; + when Std_Names.Name_Until => + Current_Token := Tok_Until; + when others => + Current_Token := Tok_Identifier; + if Source (Pos - 1) = '_' then + Error_Msg_Scan ("identifiers cannot finish with '_'"); + end if; + end case; + end if; + end Identifier_To_Token; + + -- LRM93 13.3.2 + -- EXTENDED_IDENTIFIER ::= \ GRAPHIC_CHARACTER { GRAPHIC_CHARACTER } \ + -- + -- Create an (extended) indentifier. + -- Extended identifiers are stored as they appear (leading and tailing + -- backslashes, doubling backslashes inside). + procedure Scan_Extended_Identifier + is + use Name_Table; + Buffer : String (1 .. Max_Name_Length); + Len : Natural; + C : Character; + begin + -- LRM93 13.3.2 + -- Moreover, every extended identifiers is distinct from any basic + -- identifier. + -- GHDL: This is satisfied by storing '\' in the name table. + Len := 1; + Buffer (1) := '\'; + loop + -- Next character. + Pos := Pos + 1; + C := Source (Pos); + + if C = '\' then + -- LRM93 13.3.2 + -- If a backslash is to be used as one of the graphic characters + -- of an extended literal, it must be doubled. + -- LRM93 13.3.2 + -- (a doubled backslash couting as one character) + if Len >= Max_Name_Length - 1 then + if Len = Max_Name_Length - 1 then + Error_Too_Long; + -- Accept this last one. + Len := Len + 1; + Buffer (Len) := C; + end if; + else + Len := Len + 1; + Buffer (Len) := C; + end if; + + Pos := Pos + 1; + C := Source (Pos); + + exit when C /= '\'; + end if; + + case Characters_Kind (C) is + when Format_Effector => + Error_Msg_Scan ("format effector in extended identifier"); + exit; + when Graphic_Character => + null; + when Invalid => + if C = Files_Map.EOT + and then Pos >= Current_Context.File_Len + then + Error_Msg_Scan + ("extended identifier not terminated at end of file"); + elsif C = LF or C = CR then + Error_Msg_Scan + ("extended identifier not terminated at end of line"); + else + Error_Msg_Scan ("invalid character in extended identifier"); + end if; + exit; + end case; + + -- LRM93 13.3.2 + -- Extended identifiers differing only in the use of corresponding + -- upper and lower case letters are distinct. + if Len >= Max_Name_Length - 1 then + if Len = Max_Name_Length - 1 then + Error_Too_Long; + -- Accept this last one. + Len := Len + 1; + Buffer (Len) := C; + end if; + else + Len := Len + 1; + Buffer (Len) := C; + end if; + end loop; + + if Len <= 2 then + Error_Msg_Scan ("empty extended identifier is not allowed"); + end if; + + -- LRM93 13.2 + -- At least one separator is required between an identifier or an + -- abstract literal and an adjacent identifier or abstract literal. + case Characters_Kind (C) is + when Digit + | Upper_Case_Letter + | Lower_Case_Letter => + Error_Separator; + when Invalid + | Format_Effector + | Space_Character + | Special_Character + | Other_Special_Character => + null; + end case; + + -- Hash it. + Current_Context.Identifier := Get_Identifier (Buffer (1 .. Len)); + Current_Token := Tok_Identifier; + end Scan_Extended_Identifier; + + procedure Convert_Identifier (Str : in out String) + is + procedure Error_Bad is + begin + Error_Msg_Option ("bad character in identifier"); + end Error_Bad; + + procedure Error_8bit is + begin + Error_Msg_Option ("8 bits characters not allowed in vhdl87"); + end Error_8bit; + + C : Character; + subtype Id_Subtype is String (1 .. Str'Length); + Id : Id_Subtype renames Str; + begin + if Id'Length = 0 then + Error_Msg_Option ("identifier required"); + return; + end if; + + if Id (1) = '\' then + -- Extended identifier. + if Vhdl_Std = Vhdl_87 then + Error_Msg_Option ("extended identifiers not allowed in vhdl87"); + return; + end if; + + if Id'Length < 3 then + Error_Msg_Option ("extended identifier is too short"); + return; + end if; + if Id (Id'Last) /= '\' then + Error_Msg_Option ("extended identifier must finish with a '\'"); + return; + end if; + for I in 2 .. Id'Last - 1 loop + C := Id (I); + case Characters_Kind (C) is + when Format_Effector => + Error_Msg_Option ("format effector in extended identifier"); + return; + when Graphic_Character => + if C = '\' then + if Id (I + 1) /= '\' + or else I = Id'Last - 1 + then + Error_Msg_Option ("anti-slash must be doubled " + & "in extended identifier"); + return; + end if; + end if; + when Invalid => + Error_Bad; + end case; + end loop; + else + -- Identifier + for I in 1 .. Id'Length loop + C := Id (I); + case Characters_Kind (C) is + when Upper_Case_Letter => + if Vhdl_Std = Vhdl_87 and C > 'Z' then + Error_8bit; + end if; + Id (I) := To_Lower_Map (C); + when Lower_Case_Letter | Digit => + if Vhdl_Std = Vhdl_87 and C > 'z' then + Error_8bit; + end if; + when Special_Character => + -- The current character is legal in an identifier. + if C = '_' then + if I = 1 then + Error_Msg_Option + ("an identifier cannot start with an underscore"); + return; + end if; + if Id (I - 1) = '_' then + Error_Msg_Option + ("two underscores can't be consecutive"); + return; + end if; + if I = Id'Last then + Error_Msg_Option + ("an identifier cannot finish with an underscore"); + return; + end if; + else + Error_Bad; + end if; + when others => + Error_Bad; + end case; + end loop; + end if; + end Convert_Identifier; + + -- Internal scanner function: return True if C must be considered as a line + -- terminator. This also includes EOT (which terminates the file or is + -- invalid). + function Is_EOL (C : Character) return Boolean is + begin + case C is + when CR | LF | VT | FF | Files_Map.EOT => + return True; + when others => + return False; + end case; + end Is_EOL; + + -- Advance scanner till the first non-space character. + procedure Skip_Spaces is + begin + while Source (Pos) = ' ' or Source (Pos) = HT loop + Pos := Pos + 1; + end loop; + end Skip_Spaces; + + -- Eat all characters until end-of-line (not included). + procedure Skip_Until_EOL is + begin + while not Is_EOL (Source (Pos)) loop + -- Don't warn about invalid character, it's somewhat out of the + -- scope. + Pos := Pos + 1; + end loop; + end Skip_Until_EOL; + + -- Scan an identifier within a comment. Only lower case letters are + -- allowed. + procedure Scan_Comment_Identifier (Id : out Name_Id) + is + use Name_Table; + Buffer : String (1 .. Max_Name_Length); + Len : Natural; + C : Character; + begin + Id := Null_Identifier; + Skip_Spaces; + + -- The identifier shall start with a lower case letter. + if Source (Pos) not in 'a' .. 'z' then + return; + end if; + + -- Scan the identifier (in lower cases). + Len := 0; + loop + C := Source (Pos); + exit when C not in 'a' .. 'z' and C /= '_'; + Len := Len + 1; + Buffer (Len) := C; + Pos := Pos + 1; + end loop; + + -- Shall be followed by a space or a new line. + if not (C = ' ' or else C = HT or else Is_EOL (C)) then + return; + end if; + + Id := Get_Identifier (Buffer (1 .. Len)); + end Scan_Comment_Identifier; + + package Directive_Protect is + -- Called to scan a protect tool directive. + procedure Scan_Protect_Directive; + end Directive_Protect; + + -- Body is put in a separate file to avoid pollution. + package body Directive_Protect is separate; + + -- Called to scan a tool directive. + procedure Scan_Tool_Directive + is + procedure Error_Missing_Directive is + begin + Error_Msg_Scan ("tool directive required after '`'"); + Skip_Until_EOL; + end Error_Missing_Directive; + + C : Character; + begin + -- The current character is '`'. + Pos := Pos + 1; + Skip_Spaces; + + -- Check and scan identifier. + C := Source (Pos); + if Characters_Kind (C) not in Letter then + Error_Missing_Directive; + return; + end if; + + Scan_Identifier (False); + + if Current_Token /= Tok_Identifier then + Error_Missing_Directive; + return; + end if; + + Skip_Spaces; + + -- Dispatch according to the identifier. + if Current_Identifier = Std_Names.Name_Protect then + Directive_Protect.Scan_Protect_Directive; + else + Error_Msg_Scan + ("unknown tool directive %i ignored", +Current_Identifier); + Skip_Until_EOL; + end if; + end Scan_Tool_Directive; + + -- Scan tokens within a comment. Return TRUE if Current_Token was set, + -- return FALSE to discard the comment (ie treat it like a real comment). + function Scan_Comment return Boolean + is + use Std_Names; + Id : Name_Id; + begin + Scan_Comment_Identifier (Id); + + if Id = Null_Identifier then + return False; + end if; + + case Id is + when Name_Psl => + -- Accept tokens after '-- psl'. + if Flag_Psl_Comment then + Flag_Psl := True; + Flag_Scan_In_Comment := True; + return True; + end if; + when others => + null; + end case; + return False; + end Scan_Comment; + + function Scan_Exclam_Mark return Boolean is + begin + if Source (Pos) = '!' then + Pos := Pos + 1; + return True; + else + return False; + end if; + end Scan_Exclam_Mark; + + function Scan_Underscore return Boolean is + begin + if Source (Pos) = '_' then + Pos := Pos + 1; + return True; + else + return False; + end if; + end Scan_Underscore; + + -- The Scan_Next_Line procedure must be called after each end-of-line to + -- register to next line number. This is called by Scan_CR_Newline and + -- Scan_LF_Newline. + procedure Scan_Next_Line is + begin + Files_Map.Skip_Gap (Current_Context.Source_File, Pos); + Current_Context.Line_Number := Current_Context.Line_Number + 1; + Current_Context.Line_Pos := Pos; + File_Add_Line_Number + (Current_Context.Source_File, Current_Context.Line_Number, Pos); + end Scan_Next_Line; + + -- Scan a CR end-of-line. + procedure Scan_CR_Newline is + begin + -- Accept CR or CR+LF as line separator. + if Source (Pos + 1) = LF then + Pos := Pos + 2; + else + Pos := Pos + 1; + end if; + Scan_Next_Line; + end Scan_CR_Newline; + + -- Scan a LF end-of-line. + procedure Scan_LF_Newline is + begin + -- Accept LF or LF+CR as line separator. + if Source (Pos + 1) = CR then + Pos := Pos + 2; + else + Pos := Pos + 1; + end if; + Scan_Next_Line; + end Scan_LF_Newline; + + -- Emit an error message for an invalid character. + procedure Error_Bad_Character is + begin + -- Technically character literals, string literals, extended + -- identifiers and comments. + Error_Msg_Scan ("character %c can only be used in strings or comments", + +Source (Pos)); + end Error_Bad_Character; + + -- Get a new token. + procedure Scan is + begin + if Current_Token /= Tok_Invalid then + Current_Context.Prev_Token := Current_Token; + end if; + + Current_Context.Prev_Pos := Pos; + + << Again >> null; + + -- Skip commonly used separators. + -- (Like Skip_Spaces but manually inlined for speed). + while Source (Pos) = ' ' or Source (Pos) = HT loop + Pos := Pos + 1; + end loop; + + Current_Context.Token_Pos := Pos; + Current_Context.Identifier := Null_Identifier; + + case Source (Pos) is + when HT | ' ' => + -- Must have already been skipped just above. + raise Internal_Error; + when NBSP => + if Vhdl_Std = Vhdl_87 then + Error_Msg_Scan ("NBSP character not allowed in vhdl87"); + end if; + Pos := Pos + 1; + goto Again; + when VT | FF => + Pos := Pos + 1; + goto Again; + when LF => + Scan_LF_Newline; + if Flag_Newline then + Current_Token := Tok_Newline; + return; + end if; + goto Again; + when CR => + Scan_CR_Newline; + if Flag_Newline then + Current_Token := Tok_Newline; + return; + end if; + goto Again; + when '-' => + if Source (Pos + 1) = '-' then + -- This is a comment. + -- LRM93 13.8 + -- A comment starts with two adjacent hyphens and extends up + -- to the end of the line. + -- A comment can appear on any line line of a VHDL + -- description. + -- The presence or absence of comments has no influence on + -- whether a description is legal or illegal. + -- Futhermore, comments do not influence the execution of a + -- simulation module; their sole purpose is the enlightenment + -- of the human reader. + -- GHDL note: As a consequence, an obfruscating comment + -- is out of purpose, and a warning could be reported :-) + Pos := Pos + 2; + + -- Scan inside a comment. So we just ignore the two dashes. + if Flag_Scan_In_Comment then + goto Again; + end if; + + -- Handle keywords in comment (PSL). + if Flag_Comment_Keyword and then Scan_Comment then + goto Again; + end if; + + -- LRM93 13.2 + -- In any case, a sequence of one or more format + -- effectors other than horizontal tabulation must + -- cause at least one end of line. + while not Is_EOL (Source (Pos)) loop + -- LRM93 13.1 + -- The only characters allowed in the text of a VHDL + -- description are the graphic characters and the format + -- effectors. + + -- LRM02 13.1 Character set + -- The only characters allowed in the text of a VHDL + -- description (except within comments -- see 13.8) [...] + -- + -- LRM02 13.8 Comments + -- A comment [...] may contain any character except the + -- format effectors vertical tab, carriage return, line + -- feed and form feed. + if not (Flags.Mb_Comment or Vhdl_Std >= Vhdl_02) + and then Characters_Kind (Source (Pos)) = Invalid + then + Error_Msg_Scan ("invalid character, even in a comment"); + end if; + Pos := Pos + 1; + end loop; + if Flag_Comment then + Current_Token := Tok_Comment; + return; + end if; + goto Again; + elsif Flag_Psl and then Source (Pos + 1) = '>' then + Current_Token := Tok_Minus_Greater; + Pos := Pos + 2; + return; + else + Current_Token := Tok_Minus; + Pos := Pos + 1; + return; + end if; + when '+' => + Current_Token := Tok_Plus; + Pos := Pos + 1; + return; + when '*' => + if Source (Pos + 1) = '*' then + Current_Token := Tok_Double_Star; + Pos := Pos + 2; + else + Current_Token := Tok_Star; + Pos := Pos + 1; + end if; + return; + when '/' => + if Source (Pos + 1) = '=' then + Current_Token := Tok_Not_Equal; + Pos := Pos + 2; + elsif Source (Pos + 1) = '*' then + -- LRM08 15.9 Comments + -- A delimited comment start with a solidus (slash) character + -- immediately followed by an asterisk character and extends up + -- to the first subsequent occurrence of an asterisk character + -- immediately followed by a solidus character. + if Vhdl_Std < Vhdl_08 then + Error_Msg_Scan + ("block comment are not allowed before vhdl 2008"); + end if; + + -- Skip '/*'. + Pos := Pos + 2; + + loop + case Source (Pos) is + when '/' => + -- LRM08 15.9 + -- Moreover, an occurrence of a solidus character + -- immediately followed by an asterisk character + -- within a delimited comment is not interpreted as + -- the start of a nested delimited comment. + if Source (Pos + 1) = '*' then + Warning_Msg_Scan + (Warnid_Nested_Comment, + "'/*' found within a block comment"); + end if; + Pos := Pos + 1; + when '*' => + if Source (Pos + 1) = '/' then + Pos := Pos + 2; + exit; + else + Pos := Pos + 1; + end if; + when CR => + Scan_CR_Newline; + when LF => + Scan_LF_Newline; + when Files_Map.EOT => + if Pos >= Current_Context.File_Len then + -- Point at the start of the comment. + Error_Msg_Scan + (Get_Token_Location, + "block comment not terminated at end of file"); + exit; + end if; + Pos := Pos + 1; + when others => + Pos := Pos + 1; + end case; + end loop; + if Flag_Comment then + Current_Token := Tok_Comment; + return; + end if; + goto Again; + else + Current_Token := Tok_Slash; + Pos := Pos + 1; + end if; + return; + when '(' => + Current_Token := Tok_Left_Paren; + Pos := Pos + 1; + return; + when ')' => + Current_Token := Tok_Right_Paren; + Pos := Pos + 1; + return; + when '|' => + if Flag_Psl then + if Source (Pos + 1) = '|' then + Current_Token := Tok_Bar_Bar; + Pos := Pos + 2; + elsif Source (Pos + 1) = '-' + and then Source (Pos + 2) = '>' + then + Current_Token := Tok_Bar_Arrow; + Pos := Pos + 3; + elsif Source (Pos + 1) = '=' + and then Source (Pos + 2) = '>' + then + Current_Token := Tok_Bar_Double_Arrow; + Pos := Pos + 3; + else + Current_Token := Tok_Bar; + Pos := Pos + 1; + end if; + else + Current_Token := Tok_Bar; + Pos := Pos + 1; + end if; + return; + when '!' => + if Flag_Psl then + Current_Token := Tok_Exclam_Mark; + else + if Source (Pos + 1) = '=' then + -- != is not allowed in VHDL, but be friendly with C users. + Error_Msg_Scan + (Get_Token_Location, "Use '/=' for inequality in vhdl"); + Current_Token := Tok_Not_Equal; + Pos := Pos + 1; + else + -- LRM93 13.10 + -- A vertical line (|) can be replaced by an exclamation + -- mark (!) where used as a delimiter. + Current_Token := Tok_Bar; + end if; + end if; + Pos := Pos + 1; + return; + when ':' => + if Source (Pos + 1) = '=' then + Current_Token := Tok_Assign; + Pos := Pos + 2; + else + Current_Token := Tok_Colon; + Pos := Pos + 1; + end if; + return; + when ';' => + Current_Token := Tok_Semi_Colon; + Pos := Pos + 1; + return; + when ',' => + Current_Token := Tok_Comma; + Pos := Pos + 1; + return; + when '.' => + if Source (Pos + 1) = '.' then + -- Be Ada friendly... + Error_Msg_Scan ("'..' is invalid in vhdl, replaced by 'to'"); + Current_Token := Tok_To; + Pos := Pos + 2; + return; + end if; + Current_Token := Tok_Dot; + Pos := Pos + 1; + return; + when '&' => + if Flag_Psl and then Source (Pos + 1) = '&' then + Current_Token := Tok_And_And; + Pos := Pos + 2; + else + Current_Token := Tok_Ampersand; + Pos := Pos + 1; + end if; + return; + when '<' => + case Source (Pos + 1) is + when '=' => + Current_Token := Tok_Less_Equal; + Pos := Pos + 2; + when '>' => + Current_Token := Tok_Box; + Pos := Pos + 2; + when '<' => + Current_Token := Tok_Double_Less; + Pos := Pos + 2; + when others => + Current_Token := Tok_Less; + Pos := Pos + 1; + end case; + return; + when '>' => + case Source (Pos + 1) is + when '=' => + Current_Token := Tok_Greater_Equal; + Pos := Pos + 2; + when '>' => + Current_Token := Tok_Double_Greater; + Pos := Pos + 2; + when others => + Current_Token := Tok_Greater; + Pos := Pos + 1; + end case; + return; + when '=' => + if Source (Pos + 1) = '=' then + if AMS_Vhdl then + Current_Token := Tok_Equal_Equal; + else + Error_Msg_Scan + ("'==' is not the vhdl equality, replaced by '='"); + Current_Token := Tok_Equal; + end if; + Pos := Pos + 2; + elsif Source (Pos + 1) = '>' then + Current_Token := Tok_Double_Arrow; + Pos := Pos + 2; + else + Current_Token := Tok_Equal; + Pos := Pos + 1; + end if; + return; + when ''' => + -- Handle cases such as character'('a') + -- FIXME: what about f ()'length ? or .all'length + if Current_Context.Prev_Token /= Tok_Identifier + and then Current_Context.Prev_Token /= Tok_Character + and then Source (Pos + 2) = ''' + then + -- LRM93 13.5 + -- A character literal is formed by enclosing one of the 191 + -- graphic character (...) between two apostrophe characters. + -- CHARACTER_LITERAL ::= ' GRAPHIC_CHARACTER ' + if Characters_Kind (Source (Pos + 1)) not in Graphic_Character + then + Error_Msg_Scan + ("a character literal can only be a graphic character"); + elsif Vhdl_Std = Vhdl_87 + and then Source (Pos + 1) > Character'Val (127) + then + Error_8bit; + end if; + Current_Token := Tok_Character; + Current_Context.Identifier := + Name_Table.Get_Identifier (Source (Pos + 1)); + Pos := Pos + 3; + return; + else + Current_Token := Tok_Tick; + Pos := Pos + 1; + end if; + return; + when '0' .. '9' => + Scan_Literal; + + -- LRM93 13.2 + -- At least one separator is required between an identifier or + -- an abstract literal and an adjacent identifier or abstract + -- literal. + case Characters_Kind (Source (Pos)) is + when Digit => + -- Happen if d#ddd# is followed by a number. + Error_Msg_Scan ("space is required between numbers"); + when Upper_Case_Letter + | Lower_Case_Letter => + -- Could call Error_Separator, but use a clearer message + -- for this common case. + -- Note: the term "unit name" is not correct here, since + -- it can be any identifier or even a keyword; however it + -- is probably the most common case (eg 10ns). + if Vhdl_Std >= Vhdl_08 and then Current_Token = Tok_Integer + then + Current_Token := Tok_Integer_Letter; + else + Error_Msg_Scan + ("space is required between number and unit name"); + end if; + when Other_Special_Character => + if Vhdl_Std > Vhdl_87 and then Source (Pos) = '\' then + -- Start of extended identifier. + Error_Separator; + end if; + when Invalid + | Format_Effector + | Space_Character + | Special_Character => + null; + end case; + return; + when '#' => + Error_Msg_Scan ("'#' is used for based literals and " + & "must be preceded by a base"); + -- Skip. + Pos := Pos + 1; + goto Again; + when '"' => + Scan_String; + return; + when '%' => + if Vhdl_Std >= Vhdl_08 then + Error_Msg_Scan + ("'%%' not allowed in vhdl 2008 (was replacement character)"); + -- Continue as a string. + end if; + Scan_String; + return; + when '[' => + if Flag_Psl then + if Source (Pos + 1) = '*' then + Current_Token := Tok_Brack_Star; + Pos := Pos + 2; + elsif Source (Pos + 1) = '+' + and then Source (Pos + 2) = ']' + then + Current_Token := Tok_Brack_Plus_Brack; + Pos := Pos + 3; + elsif Source (Pos + 1) = '-' + and then Source (Pos + 2) = '>' + then + Current_Token := Tok_Brack_Arrow; + Pos := Pos + 3; + elsif Source (Pos + 1) = '=' then + Current_Token := Tok_Brack_Equal; + Pos := Pos + 2; + else + Current_Token := Tok_Left_Bracket; + Pos := Pos + 1; + end if; + else + if Vhdl_Std = Vhdl_87 then + Error_Msg_Scan + ("'[' is an invalid character in vhdl87, replaced by '('"); + Current_Token := Tok_Left_Paren; + else + Current_Token := Tok_Left_Bracket; + end if; + Pos := Pos + 1; + end if; + return; + when ']' => + if Vhdl_Std = Vhdl_87 and not Flag_Psl then + Error_Msg_Scan + ("']' is an invalid character in vhdl87, replaced by ')'"); + Current_Token := Tok_Right_Paren; + else + Current_Token := Tok_Right_Bracket; + end if; + Pos := Pos + 1; + return; + when '{' => + if Flag_Psl then + Current_Token := Tok_Left_Curly; + else + Error_Msg_Scan ("'{' is an invalid character, replaced by '('"); + Current_Token := Tok_Left_Paren; + end if; + Pos := Pos + 1; + return; + when '}' => + if Flag_Psl then + Current_Token := Tok_Right_Curly; + else + Error_Msg_Scan ("'}' is an invalid character, replaced by ')'"); + Current_Token := Tok_Right_Paren; + end if; + Pos := Pos + 1; + return; + when '\' => + if Vhdl_Std = Vhdl_87 then + Error_Msg_Scan + ("extended identifiers are not allowed in vhdl87"); + end if; + Scan_Extended_Identifier; + return; + when '^' => + if Vhdl_Std >= Vhdl_08 then + Current_Token := Tok_Caret; + else + Current_Token := Tok_Xor; + Error_Msg_Scan ("'^' is not a VHDL operator, use 'xor'"); + end if; + Pos := Pos + 1; + return; + when '~' => + Error_Msg_Scan ("'~' is not a VHDL operator, use 'not'"); + Pos := Pos + 1; + Current_Token := Tok_Not; + return; + when '?' => + if Vhdl_Std < Vhdl_08 then + Error_Bad_Character; + Pos := Pos + 1; + goto Again; + else + if Source (Pos + 1) = '<' then + if Source (Pos + 2) = '=' then + Current_Token := Tok_Match_Less_Equal; + Pos := Pos + 3; + else + Current_Token := Tok_Match_Less; + Pos := Pos + 2; + end if; + elsif Source (Pos + 1) = '>' then + if Source (Pos + 2) = '=' then + Current_Token := Tok_Match_Greater_Equal; + Pos := Pos + 3; + else + Current_Token := Tok_Match_Greater; + Pos := Pos + 2; + end if; + elsif Source (Pos + 1) = '?' then + Current_Token := Tok_Condition; + Pos := Pos + 2; + elsif Source (Pos + 1) = '=' then + Current_Token := Tok_Match_Equal; + Pos := Pos + 2; + elsif Source (Pos + 1) = '/' + and then Source (Pos + 2) = '=' + then + Current_Token := Tok_Match_Not_Equal; + Pos := Pos + 3; + else + Error_Msg_Scan ("unknown matching operator"); + Pos := Pos + 1; + goto Again; + end if; + end if; + return; + when '`' => + if Vhdl_Std >= Vhdl_08 then + Scan_Tool_Directive; + else + Error_Bad_Character; + Skip_Until_EOL; + end if; + goto Again; + when '$' + | Inverted_Exclamation .. Inverted_Question + | Multiplication_Sign | Division_Sign => + Error_Bad_Character; + Pos := Pos + 1; + goto Again; + when '@' => + if Vhdl_Std >= Vhdl_08 or Flag_Psl then + Current_Token := Tok_Arobase; + Pos := Pos + 1; + return; + else + Error_Bad_Character; + Pos := Pos + 1; + goto Again; + end if; + when '_' => + Error_Msg_Scan ("an identifier can't start with '_'"); + Scan_Identifier (Flag_Psl); + -- Cannot be a reserved word. + return; + when 'A' .. 'Z' | 'a' .. 'z' => + Scan_Identifier (Flag_Psl); + Identifier_To_Token; + return; + when UC_A_Grave .. UC_O_Diaeresis + | UC_O_Oblique_Stroke .. UC_Icelandic_Thorn + | LC_German_Sharp_S .. LC_O_Diaeresis + | LC_O_Oblique_Stroke .. LC_Y_Diaeresis => + if Vhdl_Std = Vhdl_87 then + Error_Msg_Scan + ("non 7-bit latin-1 letters are not allowed in vhdl87"); + end if; + Scan_Identifier (False); + -- Not a reserved word. + return; + when NUL .. ETX | ENQ .. BS | SO .. US | DEL .. APC => + Error_Msg_Scan + ("control character that is not CR, LF, FF, HT or VT " & + "is not allowed"); + Pos := Pos + 1; + goto Again; + when Files_Map.EOT => + if Pos >= Current_Context.File_Len then + -- FIXME: should conditionnaly emit a warning if the file + -- is not terminated by an end of line. + Current_Token := Tok_Eof; + else + Error_Msg_Scan ("EOT is not allowed inside the file"); + Pos := Pos + 1; + goto Again; + end if; + return; + end case; + -- Not reachable: all case should use goto Again or return. + end Scan; + + function Is_Whitespace (C : Character) return Boolean is + begin + if C = ' ' then + return True; + elsif Vhdl_Std > Vhdl_87 and C = NBSP then + return True; + else + return False; + end if; + end Is_Whitespace; +end Vhdl.Scanner; |