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) 1992-2012, 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 pragma Warnings (Off);
  32 --  This package is used also by gnatcoll
  33 with System.OS_Lib; use System.OS_Lib;
  34 pragma Warnings (On);
  35
  36 package body Sinput.C is
  37
  38    ---------------
  39    -- Load_File --
  40    ---------------
  41
  42    function Load_File (Path : String) return Source_File_Index is
  43       Src  : Source_Buffer_Ptr;
  44       X    : Source_File_Index;
  45       Lo   : Source_Ptr;
  46       Hi   : Source_Ptr;
  47
  48       Source_File_FD : File_Descriptor;
  49       --  The file descriptor for the current source file. A negative value
  50       --  indicates failure to open the specified source file.
  51
  52       Len : Integer;
  53       --  Length of file. Assume no more than 2 gigabytes of source!
  54
  55       Actual_Len : Integer;
  56
  57       Path_Id : File_Name_Type;
  58       File_Id : File_Name_Type;
  59
  60    begin
  61       if Path = "" then
  62          return No_Source_File;
  63       end if;
  64
  65       Source_File.Increment_Last;
  66       X := Source_File.Last;
  67
  68       if X = Source_File.First then
  69          Lo := First_Source_Ptr;
  70       else
  71          Lo := Source_File.Table (X - 1).Source_Last + 1;
  72       end if;
  73
  74       Name_Len := Path'Length;
  75       Name_Buffer (1 .. Name_Len) := Path;
  76       Path_Id := Name_Find;
  77       Name_Buffer (Name_Len + 1) := ASCII.NUL;
  78
  79       --  Open the source FD, note that we open in binary mode, because as
  80       --  documented in the spec, the caller is expected to handle either
  81       --  DOS or Unix mode files, and there is no point in wasting time on
  82       --  text translation when it is not required.
  83
  84       Source_File_FD := Open_Read (Name_Buffer'Address, Binary);
  85
  86       if Source_File_FD = Invalid_FD then
  87          Source_File.Decrement_Last;
  88          return No_Source_File;
  89
  90       end if;
  91
  92       Len := Integer (File_Length (Source_File_FD));
  93
  94       --  Set Hi so that length is one more than the physical length,
  95       --  allowing for the extra EOF character at the end of the buffer
  96
  97       Hi := Lo + Source_Ptr (Len);
  98
  99       --  Do the actual read operation
 100
 101       declare
 102          subtype Actual_Source_Buffer is Source_Buffer (Lo .. Hi);
 103          --  Physical buffer allocated
 104
 105          type Actual_Source_Ptr is access Actual_Source_Buffer;
 106          --  This is the pointer type for the physical buffer allocated
 107
 108          Actual_Ptr : constant Actual_Source_Ptr := new Actual_Source_Buffer;
 109          --  And this is the actual physical buffer
 110
 111       begin
 112          --  Allocate source buffer, allowing extra character at end for EOF
 113
 114          --  Some systems (e.g. VMS) have file types that require one
 115          --  read per line, so read until we get the Len bytes or until
 116          --  there are no more characters.
 117
 118          Hi := Lo;
 119          loop
 120             Actual_Len := Read (Source_File_FD, Actual_Ptr (Hi)'Address, Len);
 121             Hi := Hi + Source_Ptr (Actual_Len);
 122             exit when Actual_Len = Len or else Actual_Len <= 0;
 123          end loop;
 124
 125          Actual_Ptr (Hi) := EOF;
 126
 127          --  Now we need to work out the proper virtual origin pointer to
 128          --  return. This is exactly Actual_Ptr (0)'Address, but we have
 129          --  to be careful to suppress checks to compute this address.
 130
 131          declare
 132             pragma Suppress (All_Checks);
 133
 134             pragma Warnings (Off);
 135             --  The following unchecked conversion is aliased safe, since it
 136             --  is not used to create improperly aliased pointer values.
 137
 138             function To_Source_Buffer_Ptr is new
 139               Ada.Unchecked_Conversion (Address, Source_Buffer_Ptr);
 140
 141             pragma Warnings (On);
 142
 143          begin
 144             Src := To_Source_Buffer_Ptr (Actual_Ptr (0)'Address);
 145          end;
 146       end;
 147
 148       --  Read is complete, close the file and we are done (no need to test
 149       --  status from close, since we have successfully read the file!)
 150
 151       Close (Source_File_FD);
 152
 153       --  Get the file name, without path information
 154
 155       declare
 156          Index : Positive := Path'Last;
 157
 158       begin
 159          while Index > Path'First loop
 160             exit when Path (Index - 1) = '/';
 161             exit when Path (Index - 1) = Directory_Separator;
 162             Index := Index - 1;
 163          end loop;
 164
 165          Name_Len := Path'Last - Index + 1;
 166          Name_Buffer (1 .. Name_Len) := Path (Index .. Path'Last);
 167          File_Id := Name_Find;
 168       end;
 169
 170       declare
 171          S : Source_File_Record renames Source_File.Table (X);
 172
 173       begin
 174          S := (Debug_Source_Name   => File_Id,
 175                File_Name           => File_Id,
 176                File_Type           => Config,
 177                First_Mapped_Line   => No_Line_Number,
 178                Full_Debug_Name     => Path_Id,
 179                Full_File_Name      => Path_Id,
 180                Full_Ref_Name       => Path_Id,
 181                Instance            => No_Instance_Id,
 182                Identifier_Casing   => Unknown,
 183                Inlined_Call        => No_Location,
 184                Inlined_Body        => False,
 185                Keyword_Casing      => Unknown,
 186                Last_Source_Line    => 1,
 187                License             => Unknown,
 188                Lines_Table         => null,
 189                Lines_Table_Max     => 1,
 190                Logical_Lines_Table => null,
 191                Num_SRef_Pragmas    => 0,
 192                Reference_Name      => File_Id,
 193                Sloc_Adjust         => 0,
 194                Source_Checksum     => 0,
 195                Source_First        => Lo,
 196                Source_Last         => Hi,
 197                Source_Text         => Src,
 198                Template            => No_Source_File,
 199                Unit                => No_Unit,
 200                Time_Stamp          => Empty_Time_Stamp);
 201
 202          Alloc_Line_Tables (S, Opt.Table_Factor * Alloc.Lines_Initial);
 203          S.Lines_Table (1) := Lo;
 204       end;
 205
 206       Set_Source_File_Index_Table (X);
 207       return X;
 208    end Load_File;
 209
 210 end Sinput.C;