gcc/ada/sinput-c.adb

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT COMPILER COMPONENTS                         --
   4 --                                                                          --
   5 --                             S I N P U T . C                              --
   6 --                                                                          --
   7 --                                 B o d y                                  --
   8 --                                                                          --
   9 --          Copyright (C) 1992-2007, Free Software Foundation, Inc.         --
  10 --                                                                          --
  11 -- GNAT is free software;  you can  redistribute it  and/or modify it under --
  12 -- terms of the  GNU General Public License as published  by the Free Soft- --
  13 -- ware  Foundation;  either version 3,  or (at your option) any later ver- --
  14 -- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
  15 -- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
  16 -- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --
  17 -- for  more details.  You should have  received  a copy of the GNU General --
  18 -- Public License  distributed with GNAT; see file COPYING3.  If not, go to --
  19 -- http://www.gnu.org/licenses for a complete copy of the license.          --
  20 --                                                                          --
  21 -- GNAT was originally developed  by the GNAT team at  New York University. --
  22 -- Extensive contributions were provided by Ada Core Technologies Inc.      --
  23 --                                                                          --
  24 ------------------------------------------------------------------------------
  25
  26 with Opt;    use Opt;
  27 with System; use System;
  28
  29 with Ada.Unchecked_Conversion;
  30
  31 with System.OS_Lib; use System.OS_Lib;
  32
  33 package body Sinput.C is
  34
  35    ---------------
  36    -- Load_File --
  37    ---------------
  38
  39    function Load_File (Path : String) return Source_File_Index is
  40       Src  : Source_Buffer_Ptr;
  41       X    : Source_File_Index;
  42       Lo   : Source_Ptr;
  43       Hi   : Source_Ptr;
  44
  45       Source_File_FD : File_Descriptor;
  46       --  The file descriptor for the current source file. A negative value
  47       --  indicates failure to open the specified source file.
  48
  49       Len : Integer;
  50       --  Length of file. Assume no more than 2 gigabytes of source!
  51
  52       Actual_Len : Integer;
  53
  54       Path_Id : File_Name_Type;
  55       File_Id : File_Name_Type;
  56
  57    begin
  58       if Path = "" then
  59          return No_Source_File;
  60       end if;
  61
  62       Source_File.Increment_Last;
  63       X := Source_File.Last;
  64
  65       if X = Source_File.First then
  66          Lo := First_Source_Ptr;
  67       else
  68          Lo := Source_File.Table (X - 1).Source_Last + 1;
  69       end if;
  70
  71       Name_Len := Path'Length;
  72       Name_Buffer (1 .. Name_Len) := Path;
  73       Path_Id := Name_Find;
  74       Name_Buffer (Name_Len + 1) := ASCII.NUL;
  75
  76       --  Open the source FD, note that we open in binary mode, because as
  77       --  documented in the spec, the caller is expected to handle either
  78       --  DOS or Unix mode files, and there is no point in wasting time on
  79       --  text translation when it is not required.
  80
  81       Source_File_FD := Open_Read (Name_Buffer'Address, Binary);
  82
  83       if Source_File_FD = Invalid_FD then
  84          Source_File.Decrement_Last;
  85          return No_Source_File;
  86
  87       end if;
  88
  89       Len := Integer (File_Length (Source_File_FD));
  90
  91       --  Set Hi so that length is one more than the physical length,
  92       --  allowing for the extra EOF character at the end of the buffer
  93
  94       Hi := Lo + Source_Ptr (Len);
  95
  96       --  Do the actual read operation
  97
  98       declare
  99          subtype Actual_Source_Buffer is Source_Buffer (Lo .. Hi);
 100          --  Physical buffer allocated
 101
 102          type Actual_Source_Ptr is access Actual_Source_Buffer;
 103          --  This is the pointer type for the physical buffer allocated
 104
 105          Actual_Ptr : constant Actual_Source_Ptr := new Actual_Source_Buffer;
 106          --  And this is the actual physical buffer
 107
 108       begin
 109          --  Allocate source buffer, allowing extra character at end for EOF
 110
 111          --  Some systems (e.g. VMS) have file types that require one
 112          --  read per line, so read until we get the Len bytes or until
 113          --  there are no more characters.
 114
 115          Hi := Lo;
 116          loop
 117             Actual_Len := Read (Source_File_FD, Actual_Ptr (Hi)'Address, Len);
 118             Hi := Hi + Source_Ptr (Actual_Len);
 119             exit when Actual_Len = Len or Actual_Len <= 0;
 120          end loop;
 121
 122          Actual_Ptr (Hi) := EOF;
 123
 124          --  Now we need to work out the proper virtual origin pointer to
 125          --  return. This is exactly Actual_Ptr (0)'Address, but we have
 126          --  to be careful to suppress checks to compute this address.
 127
 128          declare
 129             pragma Suppress (All_Checks);
 130
 131             pragma Warnings (Off);
 132             --  The following unchecked conversion is aliased safe, since it
 133             --  is not used to create improperly aliased pointer values.
 134
 135             function To_Source_Buffer_Ptr is new
 136               Ada.Unchecked_Conversion (Address, Source_Buffer_Ptr);
 137
 138             pragma Warnings (On);
 139
 140          begin
 141             Src := To_Source_Buffer_Ptr (Actual_Ptr (0)'Address);
 142          end;
 143       end;
 144
 145       --  Read is complete, close the file and we are done (no need to test
 146       --  status from close, since we have successfully read the file!)
 147
 148       Close (Source_File_FD);
 149
 150       --  Get the file name, without path information
 151
 152       declare
 153          Index : Positive := Path'Last;
 154
 155       begin
 156          while Index > Path'First loop
 157             exit when Path (Index - 1) = '/';
 158             exit when Path (Index - 1) = Directory_Separator;
 159             Index := Index - 1;
 160          end loop;
 161
 162          Name_Len := Path'Last - Index + 1;
 163          Name_Buffer (1 .. Name_Len) := Path (Index .. Path'Last);
 164          File_Id := Name_Find;
 165       end;
 166
 167       declare
 168          S : Source_File_Record renames Source_File.Table (X);
 169
 170       begin
 171          S := (Debug_Source_Name   => File_Id,
 172                File_Name           => File_Id,
 173                File_Type           => Config,
 174                First_Mapped_Line   => No_Line_Number,
 175                Full_Debug_Name     => Path_Id,
 176                Full_File_Name      => Path_Id,
 177                Full_Ref_Name       => Path_Id,
 178                Identifier_Casing   => Unknown,
 179                Inlined_Body        => False,
 180                Instantiation       => No_Location,
 181                Keyword_Casing      => Unknown,
 182                Last_Source_Line    => 1,
 183                License             => Unknown,
 184                Lines_Table         => null,
 185                Lines_Table_Max     => 1,
 186                Logical_Lines_Table => null,
 187                Num_SRef_Pragmas    => 0,
 188                Reference_Name      => File_Id,
 189                Sloc_Adjust         => 0,
 190                Source_Checksum     => 0,
 191                Source_First        => Lo,
 192                Source_Last         => Hi,
 193                Source_Text         => Src,
 194                Template            => No_Source_File,
 195                Unit                => No_Unit,
 196                Time_Stamp          => Empty_Time_Stamp);
 197
 198          Alloc_Line_Tables (S, Opt.Table_Factor * Alloc.Lines_Initial);
 199          S.Lines_Table (1) := Lo;
 200       end;
 201
 202       Set_Source_File_Index_Table (X);
 203       return X;
 204    end Load_File;
 205
 206 end Sinput.C;