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430 | with Ada.Strings;
with Ada.Strings.Fixed;
with Ada.Characters.Handling; use Ada.Characters.Handling;
with SPDX.Licenses;
with SPDX.Exceptions;
package body SPDX is
function Token_Str (This : Expression; Loc : Location) return String;
function Is_Custom_Id (Str : String) return Boolean;
procedure Parse_License (This : in out Expression);
procedure Parse_Compound_Expression (This : in out Expression);
procedure Parse_Simple_Expression (This : in out Expression);
procedure Parse_Exception (This : in out Expression);
---------------
-- Token_Str --
---------------
function Token_Str (This : Expression; Loc : Location) return String is
begin
if Loc.From not in This.Str'Range
or else
Loc.To not in This.Str'Range
then
return "";
else
return This.Str (Loc.From .. Loc.To);
end if;
end Token_Str;
------------------
-- Is_Custom_Id --
------------------
function Is_Custom_Id (Str : String) return Boolean is
Lower : constant String := To_Lower (Str);
Prefix : constant String := "custom-";
begin
return Lower'Length > Prefix'Length
and then
Lower (Lower'First .. Lower'First + Prefix'Length - 1) = Prefix;
end Is_Custom_Id;
-------------------
-- Parse_License --
-------------------
procedure Parse_License (This : in out Expression) is
begin
Parse_Compound_Expression (This);
if This.Error /= None then
return;
end if;
if not This.Tokens.Is_Empty then
This.Error := Unexpected_Token;
This.Err_Loc := This.Tokens.First_Element.Loc;
end if;
end Parse_License;
-------------------------------
-- Parse_Compound_Expression --
-------------------------------
procedure Parse_Compound_Expression (This : in out Expression) is
begin
-- compound = ( compound )
-- | simple
-- | simple AND compound
-- | simple OR compound
if This.Tokens.Is_Empty then
This.Error := Empty_Expression;
This.Err_Loc := (This.Str'Last, This.Str'Last);
return;
end if;
case This.Tokens.First_Element.Kind is
when Paren_Open =>
This.Tokens.Delete_First;
Parse_Compound_Expression (This);
if This.Error /= None then
return;
end if;
if This.Tokens.Is_Empty then
This.Error := Paren_Close_Expected;
This.Err_Loc := (This.Str'Last, This.Str'Last);
return;
end if;
if This.Tokens.First_Element.Kind /= Paren_Close then
This.Error := Paren_Close_Expected;
This.Err_Loc := This.Tokens.First_Element.Loc;
return;
end if;
-- Delete the Paren_Close
This.Tokens.Delete_First;
when Id_Str =>
Parse_Simple_Expression (This);
if This.Error /= None then
return;
end if;
when others =>
This.Error := Unexpected_Token;
This.Err_Loc := This.Tokens.First_Element.Loc;
return;
end case;
if This.Tokens.Is_Empty then
-- End of expression
return;
end if;
if This.Tokens.First_Element.Kind in Op_And | Op_Or then
-- Just skip operator as we do not build the AST
This.Tokens.Delete_First;
Parse_Compound_Expression (This);
end if;
end Parse_Compound_Expression;
-----------------------------
-- Parse_Simple_Expression --
-----------------------------
procedure Parse_Simple_Expression (This : in out Expression) is
begin
-- simple = id
-- | id+
-- | id exception
-- | id+ exception
if This.Tokens.Is_Empty then
This.Error := License_Id_Expected;
This.Err_Loc := (This.Str'Last, This.Str'Last);
return;
end if;
if This.Tokens.First_Element.Kind /= Id_Str then
This.Error := License_Id_Expected;
This.Err_Loc := This.Tokens.First_Element.Loc;
return;
end if;
declare
License_Id : constant String :=
Token_Str (This, This.Tokens.First_Element.Loc);
begin
if This.Allow_Custom and then Is_Custom_Id (License_Id) then
This.Has_Custom_Id := True;
elsif not SPDX.Licenses.Valid_Id (License_Id) then
This.Error := Invalid_License_Id;
This.Err_Loc := This.Tokens.First_Element.Loc;
end if;
This.Tokens.Delete_First;
if This.Tokens.Is_Empty then
return;
end if;
-- + operator
if This.Tokens.First_Element.Kind = Op_Or_Later then
This.Tokens.Delete_First;
end if;
if This.Tokens.Is_Empty then
return;
end if;
Parse_Exception (This);
end;
end Parse_Simple_Expression;
---------------------
-- Parse_Exception --
---------------------
procedure Parse_Exception (This : in out Expression) is
begin
-- exception = <nothing>
-- | WITH id
if This.Tokens.First_Element.Kind = Op_With then
This.Tokens.Delete_First;
if This.Tokens.Is_Empty then
This.Error := Exception_Id_Expected;
This.Err_Loc := (This.Str'Last, This.Str'Last);
return;
end if;
if This.Tokens.First_Element.Kind /= Id_Str then
This.Error := Exception_Id_Expected;
This.Err_Loc := This.Tokens.First_Element.Loc;
return;
end if;
declare
Exception_Id : constant String :=
Token_Str (This, This.Tokens.First_Element.Loc);
begin
if not SPDX.Exceptions.Valid_Id (Exception_Id) then
This.Error := Invalid_Exception_Id;
This.Err_Loc := This.Tokens.First_Element.Loc;
end if;
This.Tokens.Delete_First;
end;
end if;
end Parse_Exception;
-----------
-- Parse --
-----------
function Parse (Str : String;
Allow_Custom : Boolean := False)
return Expression
is
Exp : Expression (Str'Length);
begin
Exp.Str := Str;
Exp.Allow_Custom := Allow_Custom;
Tokenize (Exp);
if Exp.Error /= None then
return Exp;
end if;
Parse_License (Exp);
return Exp;
end Parse;
-----------
-- Error --
-----------
function Error (This : Expression) return String is
function Img (N : Natural) return String;
function Img (Loc : Location) return String;
---------
-- Img --
---------
function Img (N : Natural) return String
is (Ada.Strings.Fixed.Trim (N'Img, Ada.Strings.Left));
---------
-- Img --
---------
function Img (Loc : Location) return String
is ((Img (Loc.From) & ":" & Img (Loc.To)));
begin
case This.Error is
when None =>
return "";
when Or_Later_Misplaced =>
return "+ operator must follow and indentifier without " &
"whitespace (" & Img (This.Err_Loc) & ")";
when Invalid_Char =>
return "Invalid character at " & Img (This.Err_Loc.From);
when Operator_Lowcase =>
return "Operator must be uppercase at (" & Img (This.Err_Loc) & ")";
when Unexpected_Token =>
return "Unexpected token at (" & Img (This.Err_Loc) & ")";
when Paren_Close_Expected =>
return "Missing closing parentheses ')' at (" &
Img (This.Err_Loc) & ")";
when License_Id_Expected =>
return "License id expected at (" & Img (This.Err_Loc) & ")";
when Invalid_License_Id =>
return "Invalid license ID: '" &
Token_Str (This, This.Err_Loc) & "' (" & Img (This.Err_Loc) & ")";
when Exception_Id_Expected =>
return "License exception id expected at (" &
Img (This.Err_Loc) & ")";
when Invalid_Exception_Id =>
return "Invalid license exception ID: '" &
Token_Str (This, This.Err_Loc) &
"' (" & Img (This.Err_Loc) & ")";
when Empty_Expression =>
return "Empty license expression at (" & Img (This.Err_Loc) & ")";
end case;
end Error;
-----------
-- Valid --
-----------
function Valid (This : Expression) return Boolean is
begin
return This.Error = None;
end Valid;
---------
-- Img --
---------
function Img (This : Expression) return String is
begin
return This.Str;
end Img;
----------------
-- Has_Custom --
----------------
function Has_Custom (This : Expression) return Boolean
is (This.Has_Custom_Id);
--------------
-- Tokenize --
--------------
procedure Tokenize (This : in out Expression) is
Tokens : Token_Vector.Vector renames This.Tokens;
Str : String renames This.Str;
Index : Natural := Str'First;
begin
while Index in Str'Range loop
if Str (Index) in Whitespace_Characters then
Index := Index + 1; -- Skip whitespace
elsif Str (Index) = '(' then
Tokens.Append ((Paren_Open, (Index, Index)));
Index := Index + 1;
elsif Str (Index) = ')' then
Tokens.Append ((Paren_Close, (Index, Index)));
Index := Index + 1;
elsif Str (Index) = '+' then
This.Error := Or_Later_Misplaced;
This.Err_Loc := (Index, Index);
return;
elsif Str (Index) in Id_Characters then
-- Operator or identifier
declare
From : constant Natural := Index;
begin
while Index in Str'Range
and then Str (Index) in Id_Characters | '+'
loop
Index := Index + 1;
end loop;
declare
To : constant Natural := Index - 1;
Substr : constant String := Str (From .. To);
begin
if Substr = "WITH" then
Tokens.Append ((Op_With, (From, To)));
elsif Substr = "OR" then
Tokens.Append ((Op_Or, (From, To)));
elsif Substr = "AND" then
Tokens.Append ((Op_And, (From, To)));
elsif To_Lower (Substr) = "with"
or else To_Lower (Substr) = "or"
or else To_Lower (Substr) = "and"
then
This.Error := Operator_Lowcase;
This.Err_Loc := (From, To);
return;
else
if Str (To) = '+' then
-- + operator can be found after and id (without
-- whitespace).
Tokens.Append ((Id_Str, (From, To - 1)));
Tokens.Append ((Op_Or_Later, (To, To)));
else
Tokens.Append ((Id_Str, (From, To)));
end if;
end if;
end;
end;
else
This.Error := Invalid_Char;
This.Err_Loc := (Index, Index);
return;
end if;
end loop;
end Tokenize;
end SPDX;
|