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------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- S Y M B O L S . P R O C E S S I N G --
-- --
-- B o d y --
-- --
-- Copyright (C) 2003-2010, 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. --
-- --
------------------------------------------------------------------------------
-- This is the VMS Alpha version of this package
separate (Symbols)
package body Processing is
type Number is mod 2**16;
-- 16 bits unsigned number for number of characters
EMH : constant Number := 8;
-- Code for the Module Header section
GSD : constant Number := 10;
-- Code for the Global Symbol Definition section
C_SYM : constant Number := 1;
-- Code for a Symbol subsection
V_DEF_Mask : constant Number := 2 ** 1;
V_NORM_Mask : constant Number := 2 ** 6;
-- Comments ???
B : Byte;
Number_Of_Characters : Natural := 0;
-- The number of characters of each section
Native_Format : Boolean;
-- True if records are decoded by the system (like on VMS)
Has_Pad : Boolean;
-- If true, a pad byte must be skipped before reading the next record
-- The following variables are used by procedure Process when reading an
-- object file.
Code : Number := 0;
Length : Natural := 0;
Dummy : Number;
Nchars : Natural := 0;
Flags : Number := 0;
Symbol : String (1 .. 255);
LSymb : Natural;
procedure Get (N : out Number);
-- Read two bytes from the object file LSB first as unsigned 16 bit number
procedure Get (N : out Natural);
-- Read two bytes from the object file, LSByte first, as a Natural
---------
-- Get --
---------
procedure Get (N : out Number) is
C : Byte;
LSByte : Number;
begin
Read (File, C);
LSByte := Byte'Pos (C);
Read (File, C);
N := LSByte + (256 * Byte'Pos (C));
end Get;
procedure Get (N : out Natural) is
Result : Number;
begin
Get (Result);
N := Natural (Result);
end Get;
-------------
-- Process --
-------------
procedure Process
(Object_File : String;
Success : out Boolean)
is
OK : Boolean := True;
begin
-- Open the object file with Byte_IO. Return with Success = False if
-- this fails.
begin
Open (File, In_File, Object_File);
exception
when others =>
Put_Line
("*** Unable to open object file """ & Object_File & """");
Success := False;
return;
end;
-- Assume that the object file has a correct format
Success := True;
-- Check the file format in case of cross-tool
Get (Code);
Get (Number_Of_Characters);
Get (Dummy);
if Code = Dummy and then Number_Of_Characters = Natural (EMH) then
-- Looks like a cross tool
Native_Format := False;
Number_Of_Characters := Natural (Dummy) - 4;
Has_Pad := (Number_Of_Characters mod 2) = 1;
elsif Code = EMH then
Native_Format := True;
Number_Of_Characters := Number_Of_Characters - 6;
Has_Pad := False;
else
Put_Line ("file """ & Object_File & """ is not an object file");
Close (File);
Success := False;
return;
end if;
-- Skip the EMH section
for J in 1 .. Number_Of_Characters loop
Read (File, B);
end loop;
-- Get the different sections one by one from the object file
while not End_Of_File (File) loop
if not Native_Format then
-- Skip pad byte if present
if Has_Pad then
Get (B);
end if;
-- Skip record length
Get (Dummy);
end if;
Get (Code);
Get (Number_Of_Characters);
if not Native_Format then
if Natural (Dummy) /= Number_Of_Characters then
-- Format error
raise Constraint_Error;
end if;
Has_Pad := (Number_Of_Characters mod 2) = 1;
end if;
-- The header is 4 bytes length
Number_Of_Characters := Number_Of_Characters - 4;
-- If this is not a Global Symbol Definition section, skip to the
-- next section.
if Code /= GSD then
for J in 1 .. Number_Of_Characters loop
Read (File, B);
end loop;
else
-- Skip over the next 4 bytes
Get (Dummy);
Get (Dummy);
Number_Of_Characters := Number_Of_Characters - 4;
-- Get each subsection in turn
loop
Get (Code);
Get (Nchars);
Get (Dummy);
Get (Flags);
Number_Of_Characters := Number_Of_Characters - 8;
Nchars := Nchars - 8;
-- If this is a symbol and the V_DEF flag is set, get symbol
if Code = C_SYM and then ((Flags and V_DEF_Mask) /= 0) then
-- First, reach the symbol length
for J in 1 .. 25 loop
Read (File, B);
Nchars := Nchars - 1;
Number_Of_Characters := Number_Of_Characters - 1;
end loop;
Length := Byte'Pos (B);
LSymb := 0;
-- Get the symbol characters
for J in 1 .. Nchars loop
Read (File, B);
Number_Of_Characters := Number_Of_Characters - 1;
if Length > 0 then
LSymb := LSymb + 1;
Symbol (LSymb) := B;
Length := Length - 1;
end if;
end loop;
-- Check if it is a symbol from a generic body
OK := True;
for J in 1 .. LSymb - 2 loop
if Symbol (J) = 'G' and then Symbol (J + 1) = 'P'
and then Symbol (J + 2) in '0' .. '9'
then
OK := False;
exit;
end if;
end loop;
if OK then
-- Create the new Symbol
declare
S_Data : Symbol_Data;
begin
S_Data.Name := new String'(Symbol (1 .. LSymb));
-- The symbol kind (Data or Procedure) depends on the
-- V_NORM flag.
if (Flags and V_NORM_Mask) = 0 then
S_Data.Kind := Data;
else
S_Data.Kind := Proc;
end if;
-- Put the new symbol in the table
Symbol_Table.Append (Complete_Symbols, S_Data);
end;
end if;
else
-- As it is not a symbol subsection, skip to the next
-- subsection.
for J in 1 .. Nchars loop
Read (File, B);
Number_Of_Characters := Number_Of_Characters - 1;
end loop;
end if;
-- Exit the GSD section when number of characters reaches zero
exit when Number_Of_Characters = 0;
end loop;
end if;
end loop;
-- The object file has been processed, close it
Close (File);
exception
-- For any exception, output an error message, close the object file
-- and return with Success = False.
when X : others =>
Put_Line ("unexpected exception raised while processing """
& Object_File & """");
Put_Line (Exception_Information (X));
Close (File);
Success := False;
end Process;
end Processing;
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