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
26with Opt;    use Opt;
27with System; use System;
28
29with Ada.Unchecked_Conversion;
30
31pragma Warnings (Off);
32--  This package is used also by gnatcoll
33with System.OS_Lib; use System.OS_Lib;
34pragma Warnings (On);
35
36package 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
210end Sinput.C;
211