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------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- P P R I N T --
-- --
-- B o d y --
-- --
-- Copyright (C) 2008-2014, Free Software Foundation, Inc. --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
-- ware Foundation; either version 3, or (at your option) any later ver- --
-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
-- for more details. You should have received a copy of the GNU General --
-- Public License distributed with GNAT; see file COPYING3. If not, go to --
-- http://www.gnu.org/licenses for a complete copy of the license. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
------------------------------------------------------------------------------
with Atree; use Atree;
with Einfo; use Einfo;
with Namet; use Namet;
with Nlists; use Nlists;
with Opt; use Opt;
with Sinfo; use Sinfo;
with Sinput; use Sinput;
with Snames; use Snames;
with Uintp; use Uintp;
package body Pprint is
List_Name_Count : Integer := 0;
-- Counter used to prevent infinite recursion while computing name of
-- complex expressions.
----------------------
-- Expression_Image --
----------------------
function Expression_Image (Expr : Node_Id; Default : String)
return String is
Left : Node_Id := Original_Node (Expr);
Right : Node_Id := Original_Node (Expr);
From_Source : constant Boolean :=
Comes_From_Source (Expr) and then not Opt.Debug_Generated_Code;
Append_Paren : Boolean := False;
function Expr_Name
(Expr : Node_Id;
Take_Prefix : Boolean := True;
Expand_Type : Boolean := True) return String;
-- Return string corresponding to Expr. If no string can be extracted,
-- return "...". If Take_Prefix is True, go back to prefix when needed,
-- otherwise only consider the right-hand side of an expression. If
-- Expand_Type is True and Expr is a type, try to expand Expr (an
-- internally generated type) into a user understandable name.
Max_List : constant := 3;
-- Limit number of list elements to dump
Max_Expr_Elements : constant := 24;
-- Limit number of elements in an expression for use by Expr_Name
Num_Elements : Natural := 0;
-- Current number of elements processed by Expr_Name
function List_Name
(List : Node_Id;
Add_Space : Boolean := True;
Add_Paren : Boolean := True) return String;
-- Return a string corresponding to List
function List_Name
(List : Node_Id;
Add_Space : Boolean := True;
Add_Paren : Boolean := True) return String
is
function Internal_List_Name
(List : Node_Id;
First : Boolean := True;
Add_Space : Boolean := True;
Add_Paren : Boolean := True;
Num : Natural := 1) return String;
------------------------
-- Internal_List_Name --
------------------------
function Internal_List_Name
(List : Node_Id;
First : Boolean := True;
Add_Space : Boolean := True;
Add_Paren : Boolean := True;
Num : Natural := 1) return String
is
function Prepend (S : String) return String;
-------------
-- Prepend --
-------------
function Prepend (S : String) return String is
begin
if Add_Space then
if Add_Paren then
return " (" & S;
else
return ' ' & S;
end if;
elsif Add_Paren then
return '(' & S;
else
return S;
end if;
end Prepend;
-- Start of processing for Internal_List_Name
begin
if not Present (List) then
if First or else not Add_Paren then
return "";
else
return ")";
end if;
elsif Num > Max_List then
if Add_Paren then
return ", ...)";
else
return ", ...";
end if;
end if;
if First then
return Prepend
(Expr_Name (List)
& Internal_List_Name (Next (List),
First => False,
Add_Paren => Add_Paren,
Num => Num + 1));
else
return ", " & Expr_Name (List) &
Internal_List_Name
(Next (List),
First => False,
Add_Paren => Add_Paren,
Num => Num + 1);
end if;
end Internal_List_Name;
-- Start of processing for List_Name
begin
-- Prevent infinite recursion by limiting depth to 3
if List_Name_Count > 3 then
return "...";
end if;
List_Name_Count := List_Name_Count + 1;
declare
Result : constant String :=
Internal_List_Name
(List, Add_Space => Add_Space, Add_Paren => Add_Paren);
begin
List_Name_Count := List_Name_Count - 1;
return Result;
end;
end List_Name;
---------------
-- Expr_Name --
---------------
function Expr_Name
(Expr : Node_Id;
Take_Prefix : Boolean := True;
Expand_Type : Boolean := True) return String
is
begin
Num_Elements := Num_Elements + 1;
if Num_Elements > Max_Expr_Elements then
return "...";
end if;
case Nkind (Expr) is
when N_Defining_Identifier | N_Identifier =>
return Ident_Image (Expr, Expression_Image.Expr, Expand_Type);
when N_Character_Literal =>
declare
Char : constant Int :=
UI_To_Int (Char_Literal_Value (Expr));
begin
if Char in 32 .. 127 then
return "'" & Character'Val (Char) & "'";
else
UI_Image (Char_Literal_Value (Expr));
return "'\" & UI_Image_Buffer (1 .. UI_Image_Length)
& "'";
end if;
end;
when N_Integer_Literal =>
UI_Image (Intval (Expr));
return UI_Image_Buffer (1 .. UI_Image_Length);
when N_Real_Literal =>
return Real_Image (Realval (Expr));
when N_String_Literal =>
return String_Image (Strval (Expr));
when N_Allocator =>
return "new " & Expr_Name (Expression (Expr));
when N_Aggregate =>
if Present (Sinfo.Expressions (Expr)) then
return List_Name
(First (Sinfo.Expressions (Expr)), Add_Space => False);
-- Do not return empty string for (others => <>) aggregate
-- of a componentless record type. At least one caller (the
-- recursive call below in the N_Qualified_Expression case)
-- is not prepared to deal with a zero-length result.
elsif Null_Record_Present (Expr)
or else not Present (First (Component_Associations (Expr)))
then
return ("(null record)");
else
return List_Name
(First (Component_Associations (Expr)),
Add_Space => False, Add_Paren => False);
end if;
when N_Extension_Aggregate =>
return "(" & Expr_Name (Ancestor_Part (Expr)) &
" with " &
List_Name (First (Sinfo.Expressions (Expr)),
Add_Space => False, Add_Paren => False) &
")";
when N_Attribute_Reference =>
if Take_Prefix then
declare
Str : constant String := Expr_Name (Prefix (Expr))
& "'" & Get_Name_String (Attribute_Name (Expr));
Id : constant Attribute_Id :=
Get_Attribute_Id (Attribute_Name (Expr));
Ranges : List_Id;
N : Node_Id;
begin
if (Id = Attribute_First or else Id = Attribute_Last)
and then Str (Str'First) = '$'
then
N := Associated_Node_For_Itype (Etype (Prefix (Expr)));
if Present (N) then
if Nkind (N) = N_Full_Type_Declaration then
N := Type_Definition (N);
end if;
if Nkind (N) = N_Subtype_Declaration then
Ranges := Constraints (Constraint
(Subtype_Indication (N)));
if List_Length (Ranges) = 1
and then Nkind_In
(First (Ranges),
N_Range,
N_Real_Range_Specification,
N_Signed_Integer_Type_Definition)
then
if Id = Attribute_First then
return Expression_Image
(Low_Bound (First (Ranges)), Str);
else
return Expression_Image
(High_Bound (First (Ranges)), Str);
end if;
end if;
end if;
end if;
end if;
return Str;
end;
else
return "'" & Get_Name_String (Attribute_Name (Expr));
end if;
when N_Explicit_Dereference =>
if Take_Prefix then
return Expr_Name (Prefix (Expr)) & ".all";
else
return ".all";
end if;
when N_Expanded_Name | N_Selected_Component =>
if Take_Prefix then
return Expr_Name (Prefix (Expr))
& "." & Expr_Name (Selector_Name (Expr));
else
return "." & Expr_Name (Selector_Name (Expr));
end if;
when N_Component_Association =>
return "("
& List_Name (First (Choices (Expr)),
Add_Space => False, Add_Paren => False)
& " => " & Expr_Name (Expression (Expr)) & ")";
when N_If_Expression =>
declare
N : constant Node_Id := First (Sinfo.Expressions (Expr));
begin
return "if " & Expr_Name (N) & " then " &
Expr_Name (Next (N)) & " else " &
Expr_Name (Next (Next (N)));
end;
when N_Qualified_Expression =>
declare
Mark : constant String :=
Expr_Name (Subtype_Mark (Expr), Expand_Type => False);
Str : constant String := Expr_Name (Expression (Expr));
begin
if Str (Str'First) = '(' and then Str (Str'Last) = ')' then
return Mark & "'" & Str;
else
return Mark & "'(" & Str & ")";
end if;
end;
when N_Unchecked_Expression | N_Expression_With_Actions =>
return Expr_Name (Expression (Expr));
when N_Raise_Constraint_Error =>
if Present (Condition (Expr)) then
return "[constraint_error when " &
Expr_Name (Condition (Expr)) & "]";
else
return "[constraint_error]";
end if;
when N_Raise_Program_Error =>
if Present (Condition (Expr)) then
return "[program_error when " &
Expr_Name (Condition (Expr)) & "]";
else
return "[program_error]";
end if;
when N_Range =>
return Expr_Name (Low_Bound (Expr)) & ".." &
Expr_Name (High_Bound (Expr));
when N_Slice =>
return Expr_Name (Prefix (Expr)) & " (" &
Expr_Name (Discrete_Range (Expr)) & ")";
when N_And_Then =>
return Expr_Name (Left_Opnd (Expr)) & " and then " &
Expr_Name (Right_Opnd (Expr));
when N_In =>
return Expr_Name (Left_Opnd (Expr)) & " in " &
Expr_Name (Right_Opnd (Expr));
when N_Not_In =>
return Expr_Name (Left_Opnd (Expr)) & " not in " &
Expr_Name (Right_Opnd (Expr));
when N_Or_Else =>
return Expr_Name (Left_Opnd (Expr)) & " or else " &
Expr_Name (Right_Opnd (Expr));
when N_Op_And =>
return Expr_Name (Left_Opnd (Expr)) & " and " &
Expr_Name (Right_Opnd (Expr));
when N_Op_Or =>
return Expr_Name (Left_Opnd (Expr)) & " or " &
Expr_Name (Right_Opnd (Expr));
when N_Op_Xor =>
return Expr_Name (Left_Opnd (Expr)) & " xor " &
Expr_Name (Right_Opnd (Expr));
when N_Op_Eq =>
return Expr_Name (Left_Opnd (Expr)) & " = " &
Expr_Name (Right_Opnd (Expr));
when N_Op_Ne =>
return Expr_Name (Left_Opnd (Expr)) & " /= " &
Expr_Name (Right_Opnd (Expr));
when N_Op_Lt =>
return Expr_Name (Left_Opnd (Expr)) & " < " &
Expr_Name (Right_Opnd (Expr));
when N_Op_Le =>
return Expr_Name (Left_Opnd (Expr)) & " <= " &
Expr_Name (Right_Opnd (Expr));
when N_Op_Gt =>
return Expr_Name (Left_Opnd (Expr)) & " > " &
Expr_Name (Right_Opnd (Expr));
when N_Op_Ge =>
return Expr_Name (Left_Opnd (Expr)) & " >= " &
Expr_Name (Right_Opnd (Expr));
when N_Op_Add =>
return Expr_Name (Left_Opnd (Expr)) & " + " &
Expr_Name (Right_Opnd (Expr));
when N_Op_Subtract =>
return Expr_Name (Left_Opnd (Expr)) & " - " &
Expr_Name (Right_Opnd (Expr));
when N_Op_Multiply =>
return Expr_Name (Left_Opnd (Expr)) & " * " &
Expr_Name (Right_Opnd (Expr));
when N_Op_Divide =>
return Expr_Name (Left_Opnd (Expr)) & " / " &
Expr_Name (Right_Opnd (Expr));
when N_Op_Mod =>
return Expr_Name (Left_Opnd (Expr)) & " mod " &
Expr_Name (Right_Opnd (Expr));
when N_Op_Rem =>
return Expr_Name (Left_Opnd (Expr)) & " rem " &
Expr_Name (Right_Opnd (Expr));
when N_Op_Expon =>
return Expr_Name (Left_Opnd (Expr)) & " ** " &
Expr_Name (Right_Opnd (Expr));
when N_Op_Shift_Left =>
return Expr_Name (Left_Opnd (Expr)) & " << " &
Expr_Name (Right_Opnd (Expr));
when N_Op_Shift_Right | N_Op_Shift_Right_Arithmetic =>
return Expr_Name (Left_Opnd (Expr)) & " >> " &
Expr_Name (Right_Opnd (Expr));
when N_Op_Concat =>
return Expr_Name (Left_Opnd (Expr)) & " & " &
Expr_Name (Right_Opnd (Expr));
when N_Op_Plus =>
return "+" & Expr_Name (Right_Opnd (Expr));
when N_Op_Minus =>
return "-" & Expr_Name (Right_Opnd (Expr));
when N_Op_Abs =>
return "abs " & Expr_Name (Right_Opnd (Expr));
when N_Op_Not =>
return "not (" & Expr_Name (Right_Opnd (Expr)) & ")";
when N_Parameter_Association =>
return Expr_Name (Explicit_Actual_Parameter (Expr));
when N_Type_Conversion | N_Unchecked_Type_Conversion =>
-- Most conversions are not very interesting (used inside
-- expanded checks to convert to larger ranges), so skip them.
return Expr_Name (Expression (Expr));
when N_Indexed_Component =>
if Take_Prefix then
return Expr_Name (Prefix (Expr)) &
List_Name (First (Sinfo.Expressions (Expr)));
else
return List_Name (First (Sinfo.Expressions (Expr)));
end if;
when N_Function_Call =>
-- If Default = "", it means we're expanding the name of
-- a gnat temporary (and not really a function call), so add
-- parentheses around function call to mark it specially.
if Default = "" then
return '(' & Expr_Name (Name (Expr)) &
List_Name (First (Sinfo.Parameter_Associations (Expr))) &
')';
else
return Expr_Name (Name (Expr)) &
List_Name (First (Sinfo.Parameter_Associations (Expr)));
end if;
when N_Null =>
return "null";
when N_Others_Choice =>
return "others";
when others =>
return "...";
end case;
end Expr_Name;
-- Start of processing for Expression_Name
begin
if not From_Source then
declare
S : constant String := Expr_Name (Expr);
begin
if S = "..." then
return Default;
else
return S;
end if;
end;
end if;
-- Compute left (start) and right (end) slocs for the expression
-- Consider using Sinput.Sloc_Range instead, except that it does not
-- work properly currently???
loop
case Nkind (Left) is
when N_Binary_Op | N_Membership_Test |
N_And_Then | N_Or_Else =>
Left := Original_Node (Left_Opnd (Left));
when N_Attribute_Reference | N_Expanded_Name |
N_Explicit_Dereference | N_Indexed_Component |
N_Reference | N_Selected_Component |
N_Slice =>
Left := Original_Node (Prefix (Left));
when N_Designator | N_Defining_Program_Unit_Name |
N_Function_Call =>
Left := Original_Node (Name (Left));
when N_Range =>
Left := Original_Node (Low_Bound (Left));
when N_Type_Conversion =>
Left := Original_Node (Subtype_Mark (Left));
-- For any other item, quit loop
when others =>
exit;
end case;
end loop;
loop
case Nkind (Right) is
when N_Op | N_Membership_Test |
N_And_Then | N_Or_Else =>
Right := Original_Node (Right_Opnd (Right));
when N_Selected_Component | N_Expanded_Name =>
Right := Original_Node (Selector_Name (Right));
when N_Designator =>
Right := Original_Node (Identifier (Right));
when N_Defining_Program_Unit_Name =>
Right := Original_Node (Defining_Identifier (Right));
when N_Range =>
Right := Original_Node (High_Bound (Right));
when N_Parameter_Association =>
Right := Original_Node (Explicit_Actual_Parameter (Right));
when N_Indexed_Component =>
Right := Original_Node (Last (Sinfo.Expressions (Right)));
Append_Paren := True;
when N_Function_Call =>
if Present (Sinfo.Parameter_Associations (Right)) then
declare
Rover : Node_Id;
Found : Boolean;
begin
-- Avoid source position confusion associated with
-- parameters for which Comes_From_Source is False.
Rover := First (Sinfo.Parameter_Associations (Right));
Found := False;
while Present (Rover) loop
if Comes_From_Source (Original_Node (Rover)) then
Right := Original_Node (Rover);
Append_Paren := True;
Found := True;
end if;
Next (Rover);
end loop;
-- Quit loop if no Comes_From_Source parameters
exit when not Found;
end;
-- Quit loop if no parameters
else
exit;
end if;
when N_Quantified_Expression =>
Right := Original_Node (Condition (Right));
-- For all other items, quit the loop
when others =>
exit;
end case;
end loop;
declare
Scn : Source_Ptr := Original_Location (Sloc (Left));
Src : constant Source_Buffer_Ptr :=
Source_Text (Get_Source_File_Index (Scn));
End_Sloc : constant Source_Ptr :=
Original_Location (Sloc (Right));
begin
if Scn > End_Sloc then
return Default;
end if;
declare
Buffer : String (1 .. Natural (End_Sloc - Scn));
Skipping_Comment : Boolean := False;
Underscore : Boolean := False;
Index : Natural := 0;
begin
if Right /= Expr then
while Scn < End_Sloc loop
case Src (Scn) is
when ' ' | ASCII.HT =>
if not Skipping_Comment and then not Underscore then
Underscore := True;
Index := Index + 1;
Buffer (Index) := ' ';
end if;
-- CR/LF/FF is the end of any comment
when ASCII.LF | ASCII.CR | ASCII.FF =>
Skipping_Comment := False;
when others =>
Underscore := False;
if not Skipping_Comment then
-- Ignore comment
if Src (Scn) = '-' and then Src (Scn + 1) = '-' then
Skipping_Comment := True;
else
Index := Index + 1;
Buffer (Index) := Src (Scn);
end if;
end if;
end case;
Scn := Scn + 1;
end loop;
end if;
if Index < 1 then
declare
S : constant String := Expr_Name (Right);
begin
if S = "..." then
return Default;
else
return S;
end if;
end;
elsif Append_Paren then
return Buffer (1 .. Index) & Expr_Name (Right, False) & ')';
else
return Buffer (1 .. Index) & Expr_Name (Right, False);
end if;
end;
end;
end Expression_Image;
end Pprint;