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Diffstat (limited to 'src/vhdl/scanner.adb')
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diff --git a/src/vhdl/scanner.adb b/src/vhdl/scanner.adb new file mode 100644 index 0000000..260bd7c --- /dev/null +++ b/src/vhdl/scanner.adb @@ -0,0 +1,1621 @@ +-- 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 Ada.Characters.Handling; +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 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, + Upper_Case_Letter, + Digit, + Special_Character, + Space_Character, + Lower_Case_Letter, + 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 is 191 graphic character. + subtype Graphic_Character is + Character_Kind_Type range Upper_Case_Letter .. Other_Special_Character; + + -- 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; + 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 + Quotation | '#' | '&' | ''' | '(' | ')' | '+' | ',' | '-' | '.' | '/' + | ':' | ';' | '<' | '=' | '>' | '[' | ']' + | '_' | '|' | '*' => Special_Character, + + -- 4. the space characters + ' ' | No_Break_Space => 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; + Pos: Source_Ptr; + Token_Pos: Source_Ptr; + File_Len: Source_Ptr; + File_Name: Name_Id; + Token: Token_Type; + Prev_Token: Token_Type; + Str_Id : String_Id; + Str_Len : Nat32; + Identifier: Name_Id; + Int64: Iir_Int64; + Fp64: Iir_Fp64; + end record; + + -- 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, + Token_Pos => 0, + File_Len => 0, + File_Name => Null_Identifier, + Token => Tok_Invalid, + Prev_Token => Tok_Invalid, + Identifier => Null_Identifier, + Str_Id => Null_String, + 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 String_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 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_File return Name_Id is + begin + return Current_Context.File_Name; + end Get_Current_File; + + 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_Column return Natural + is + Col : Natural; + Name : Name_Id; + begin + Coord_To_Position + (Current_Context.Source_File, + Current_Context.Line_Pos, + Integer (Current_Context.Pos - Current_Context.Line_Pos), + Name, Col); + return Col; + end Get_Current_Column; + + function Get_Token_Column return Natural + is + Col : Natural; + Name : Name_Id; + begin + Coord_To_Position + (Current_Context.Source_File, + Current_Context.Line_Pos, + Integer (Current_Context.Token_Pos - Current_Context.Line_Pos), + Name, Col); + return Col; + end Get_Token_Column; + + 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; + + procedure Set_File (Source_File : Source_File_Entry) + is + N_Source: File_Buffer_Acc; + begin + if Current_Context.Source /= null then + raise Internal_Error; + end if; + if Source_File = No_Source_File_Entry then + raise Internal_Error; + end if; + N_Source := Get_File_Source (Source_File); + Current_Context := + (Source => N_Source, + Source_File => Source_File, + Line_Number => 1, + Line_Pos => 0, + Pos => N_Source'First, + Token_Pos => 0, -- should be invalid, + File_Len => Get_File_Length (Source_File), + File_Name => Get_File_Name (Source_File), + Token => Tok_Invalid, + Prev_Token => Tok_Invalid, + Identifier => Null_Identifier, + Str_Id => Null_String, + Str_Len => 0, + Int64 => -1, + Fp64 => 0.0); + Current_Token := Tok_Invalid; + end Set_File; + + procedure Set_Current_Position (Position: Source_Ptr) + is + Loc : Location_Type; + Offset: Natural; + File_Entry : Source_File_Entry; + begin + if Current_Context.Source = null then + raise Internal_Error; + end if; + 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 + -- 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 + Mark := Source (Pos); + if Mark /= Quotation and then Mark /= '%' then + raise Internal_Error; + end if; + Pos := Pos + 1; + Length := 0; + Current_Context.Str_Id := Str_Table.Start; + 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 => + Error_Msg_Scan ("format effector not allowed in a string"); + exit; + when Invalid => + 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 = Quotation 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 (C); + Pos := Pos + 1; + end loop; + + Str_Table.Finish; + + 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 + is + -- The base specifier. + Base_Len : Nat32 range 1 .. 4; + -- The quotation character (can be " or %). + Mark: Character; + -- Current character. + C : Character; + -- Current length. + Length : Nat32; + -- Digit value. + V : Natural; + begin + case Source (Pos) is + when 'x' | 'X' => + Base_Len := 4; + when 'o' | 'O' => + Base_Len := 3; + when 'b' | 'B' => + Base_Len := 1; + when others => + raise Internal_Error; + end case; + Pos := Pos + 1; + Mark := Source (Pos); + if Mark /= Quotation and then Mark /= '%' then + raise Internal_Error; + end if; + Pos := Pos + 1; + Length := 0; + Current_Context.Str_Id := Str_Table.Start; + 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' => + 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 => + Error_Msg_Scan ("bit string not terminated"); + Pos := Pos - 1; + exit; + end case; + + case Base_Len is + when 1 => + if V > 1 then + Error_Msg_Scan ("invalid character in a binary bit string"); + end if; + Str_Table.Append (C); + when 2 => + raise Internal_Error; + when 3 => + if V > 7 then + Error_Msg_Scan ("invalid character in a octal bit string"); + end if; + for I in 1 .. 3 loop + if (V / 4) = 1 then + Str_Table.Append ('1'); + else + Str_Table.Append ('0'); + end if; + V := (V mod 4) * 2; + end loop; + when 4 => + for I in 1 .. 4 loop + if (V / 8) = 1 then + Str_Table.Append ('1'); + else + Str_Table.Append ('0'); + end if; + V := (V mod 8) * 2; + end loop; + end case; + Length := Length + Base_Len; + end loop; + + Str_Table.Finish; + + if Length = 0 then + Error_Msg_Scan ("empty bit string is not allowed"); + end if; + Current_Token := Tok_Bit_String; + Current_Context.Int64 := Iir_Int64 (Base_Len); + Current_Context.Str_Len := Length; + end Scan_Bit_String; + + -- 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 + is + use Name_Table; + 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. + -- This is achieved by converting all upper case letters into + -- equivalent lower case letters. + -- The opposite (converting in lower case letters) is not possible, + -- because two characters have no upper-case equivalent. + C := Source (Pos); + case Characters_Kind (C) is + when Upper_Case_Letter => + if Vhdl_Std = Vhdl_87 and C > 'Z' then + Error_8bit; + end if; + Len := Len + 1; + Name_Buffer (Len) := Ada.Characters.Handling.To_Lower (C); + when Lower_Case_Letter | Digit => + if Vhdl_Std = Vhdl_87 and C > 'z' then + Error_8bit; + end if; + Len := Len + 1; + Name_Buffer (Len) := C; + when Special_Character => + -- The current character is legal in an identifier. + if C = '_' then + if Source (Pos + 1) = '_' then + Error_Msg_Scan ("two underscores can't be consecutive"); + end if; + Len := Len + 1; + Name_Buffer (Len) := C; + else + exit; + end if; + when others => + exit; + end case; + Pos := Pos + 1; + end loop; + + if Source (Pos - 1) = '_' then + if not Flag_Psl then + -- Some PSL reserved words finish with '_'. This case is handled + -- later. + Error_Msg_Scan ("identifier cannot finish with '_'"); + end if; + Pos := Pos - 1; + Len := Len - 1; + C := '_'; + 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 => + if Vhdl_Std /= Vhdl_87 and then C = '\' then + Error_Separator; + end if; + when Invalid + | Format_Effector + | Space_Character + | Special_Character => + null; + end case; + Name_Length := Len; + + -- Hash it. + Current_Context.Identifier := Name_Table.Get_Identifier; + 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 Flags.Warn_Reserved_Word then + Warning_Msg_Scan + ("using """ & Name_Buffer (1 .. Name_Length) + & """ AMS-VHDL reserved word as an identifier"); + end if; + Current_Token := Tok_Identifier; + end if; + when Std_Names.Name_Id_Vhdl00_Reserved_Words => + if Vhdl_Std < Vhdl_00 then + if Flags.Warn_Reserved_Word then + Warning_Msg_Scan + ("using """ & Name_Buffer (1 .. Name_Length) + & """ vhdl00 reserved word as an identifier"); + end if; + Current_Token := Tok_Identifier; + end if; + when Std_Names.Name_Id_Vhdl93_Reserved_Words => + if Vhdl_Std = Vhdl_87 then + if Flags.Warn_Reserved_Word then + Warning_Msg_Scan + ("using """ & Name_Buffer (1 .. Name_Length) + & """ vhdl93 reserved word as a vhdl87 identifier"); + Warning_Msg_Scan + ("(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_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 C = '_' then + Error_Msg_Scan ("identifiers cannot finish with '_'"); + end if; + end case; + else + Current_Token := Tok_Identifier; + end if; + end Scan_Identifier; + + -- 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; + begin + -- LRM93 13.3.2 + -- Moreover, every extended identifiers is distinct from any basic + -- identifier. + -- This is satisfied by storing '\' in the name table. + Name_Length := 1; + Name_Buffer (1) := '\'; + loop + -- Next character. + Pos := Pos + 1; + + if Source (Pos) = '\' 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) + Name_Length := Name_Length + 1; + Name_Buffer (Name_Length) := '\'; + + Pos := Pos + 1; + + exit when Source (Pos) /= '\'; + end if; + + -- source (pos) is correct. + case Characters_Kind (Source (Pos)) is + when Format_Effector => + Error_Msg_Scan ("format effector in extended identifier"); + exit; + when Graphic_Character => + null; + when Invalid => + Error_Msg_Scan ("invalid character in extended identifier"); + end case; + Name_Length := Name_Length + 1; + -- LRM93 13.3.2 + -- Extended identifiers differing only in the use of corresponding + -- upper and lower case letters are distinct. + Name_Buffer (Name_Length) := Source (Pos); + end loop; + + if Name_Length <= 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 (Source (Pos)) 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 := Name_Table.Get_Identifier; + Current_Token := Tok_Identifier; + end Scan_Extended_Identifier; + + procedure Convert_Identifier + 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; + + use Name_Table; + C : Character; + begin + if Name_Length = 0 then + Error_Msg_Option ("identifier required"); + return; + end if; + + if Name_Buffer (1) = '\' then + -- Extended identifier. + if Vhdl_Std = Vhdl_87 then + Error_Msg_Option ("extended identifiers not allowed in vhdl87"); + return; + end if; + + if Name_Length < 3 then + Error_Msg_Option ("extended identifier is too short"); + return; + end if; + if Name_Buffer (Name_Length) /= '\' then + Error_Msg_Option ("extended identifier must finish with a '\'"); + return; + end if; + for I in 2 .. Name_Length - 1 loop + C := Name_Buffer (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 Name_Buffer (I + 1) /= '\' + or else I = Name_Length - 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 .. Name_Length loop + C := Name_Buffer (I); + case Characters_Kind (C) is + when Upper_Case_Letter => + if Vhdl_Std = Vhdl_87 and C > 'Z' then + Error_8bit; + end if; + Name_Buffer (I) := Ada.Characters.Handling.To_Lower (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 + ("identifier cannot start with an underscore"); + return; + end if; + if Name_Buffer (I - 1) = '_' then + Error_Msg_Option + ("two underscores can't be consecutive"); + return; + end if; + if I = Name_Length then + Error_Msg_Option + ("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; + + -- Scan an identifier within a comment. Only lower case letters are + -- allowed. + function Scan_Comment_Identifier return Boolean + is + use Name_Table; + Len : Natural; + C : Character; + begin + -- Skip spaces. + while Source (Pos) = ' ' or Source (Pos) = HT loop + Pos := Pos + 1; + end loop; + + -- The identifier shall start with a lower case letter. + if Source (Pos) not in 'a' .. 'z' then + return False; + 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; + Name_Buffer (Len) := C; + Pos := Pos + 1; + end loop; + + -- Shall be followed by a space or a new line. + case C is + when ' ' | HT | LF | CR => + null; + when others => + return False; + end case; + + Name_Length := Len; + return True; + end Scan_Comment_Identifier; + + -- 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 + if not Scan_Comment_Identifier then + return False; + end if; + + -- Hash it. + Id := Name_Table.Get_Identifier; + + case Id is + when Name_Psl => + -- Scan first identifier after '-- psl'. + if not Scan_Comment_Identifier then + return False; + end if; + Id := Name_Table.Get_Identifier; + case Id is + when Name_Property => + Current_Token := Tok_Psl_Property; + when Name_Sequence => + Current_Token := Tok_Psl_Sequence; + when Name_Endpoint => + Current_Token := Tok_Psl_Endpoint; + when Name_Assert => + Current_Token := Tok_Psl_Assert; + when Name_Cover => + Current_Token := Tok_Psl_Cover; + when Name_Default => + Current_Token := Tok_Psl_Default; + when others => + return False; + end case; + Flag_Scan_In_Comment := True; + return True; + when others => + return False; + end case; + 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 + 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; + + -- Get a new token. + procedure Scan is + begin + if Current_Token /= Tok_Invalid then + Current_Context.Prev_Token := Current_Token; + end if; + + << Again >> null; + + -- Skip commonly used separators. + 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 + -- wether 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 + return; + 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 Source (Pos) /= CR and Source (Pos) /= LF and + Source (Pos) /= VT and Source (Pos) /= FF and + Source (Pos) /= Files_Map.EOT + loop + if not Flags.Mb_Comment + 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 + ("'/*' 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 + ("block comment not terminated at end of file", + File_Pos_To_Location + (Current_Context.Source_File, + Current_Context.Token_Pos)); + 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 + -- LRM93 13.10 + -- A vertical line (|) can be replaced by an exclamation + -- mark (!) where used as a delimiter. + Current_Token := Tok_Bar; + 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 '<' => + if Source (Pos + 1) = '=' then + Current_Token := Tok_Less_Equal; + Pos := Pos + 2; + elsif Source (Pos + 1) = '>' then + Current_Token := Tok_Box; + Pos := Pos + 2; + else + Current_Token := Tok_Less; + Pos := Pos + 1; + end if; + return; + when '>' => + if Source (Pos + 1) = '=' then + Current_Token := Tok_Greater_Equal; + Pos := Pos + 2; + else + Current_Token := Tok_Greater; + Pos := Pos + 1; + end if; + 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; + + -- LRM 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 => + raise Internal_Error; + 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). + Error_Msg_Scan + ("space is required between number and unit name"); + when Other_Special_Character => + if Vhdl_Std /= Vhdl_87 and then Source (Pos) = '\' then + 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"); + -- Cannot easily continue. + raise Compilation_Error; + when Quotation | '%' => + 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 '^' => + Error_Msg_Scan ("'^' is not a VHDL operator, use 'xor'"); + Pos := Pos + 1; + Current_Token := Tok_Xor; + 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_Msg_Scan ("'?' can only be used in strings or comments"); + 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 '$' | '`' + | Inverted_Exclamation .. Inverted_Question + | Multiplication_Sign | Division_Sign => + Error_Msg_Scan ("character """ & Source (Pos) + & """ can only be used in strings or comments"); + Pos := Pos + 1; + goto Again; + when '@' => + if Flag_Psl then + Current_Token := Tok_Arobase; + Pos := Pos + 1; + return; + else + Error_Msg_Scan + ("character """ & Source (Pos) + & """ can only be used in strings or comments"); + Pos := Pos + 1; + goto Again; + end if; + when '_' => + Error_Msg_Scan ("an identifier can't start with '_'"); + Pos := Pos + 1; + goto Again; + when 'B' | 'b' | 'O' | 'o' | 'X' | 'x' => + if Source (Pos + 1) = Quotation or else Source (Pos + 1) = '%' then + -- 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. + Scan_Bit_String; + else + Scan_Identifier; + end if; + return; + when 'A' | 'C' .. 'N' | 'P' .. 'W' | 'Y'| 'Z' + | 'a' | 'c' .. 'n' | 'p' .. 'w' | 'y'| 'z' => + Scan_Identifier; + return; + when UC_A_Grave .. UC_O_Diaeresis + | UC_O_Oblique_Stroke .. UC_Icelandic_Thorn => + if Vhdl_Std = Vhdl_87 then + Error_Msg_Scan + ("upper case letters above 128 are not allowed in vhdl87"); + end if; + Scan_Identifier; + return; + when LC_German_Sharp_S .. LC_O_Diaeresis + | LC_O_Oblique_Stroke .. LC_Y_Diaeresis => + if Vhdl_Std = Vhdl_87 then + Error_Msg_Scan + ("lower case letters above 128 are not allowed in vhdl87"); + end if; + Scan_Identifier; + 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; + end Scan; + + 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; +end Scanner; |