File : back_end.ads


   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT COMPILER COMPONENTS                         --
   4 --                                                                          --
   5 --                             B A C K _ E N D                              --
   6 --                                                                          --
   7 --                                 S p e c                                  --
   8 --                                                                          --
   9 --          Copyright (C) 1992-2015, 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 --  Call the back end with all the information needed
  27 
  28 --  Note: there are multiple bodies/variants of this package, so do not
  29 --  modify this spec without coordination.
  30 
  31 package Back_End is
  32 
  33    type Back_End_Mode_Type is (
  34       Generate_Object,
  35       --  Full back end operation with object file generation
  36 
  37       Declarations_Only,
  38       --  Partial back end operation with no object file generation. In this
  39       --  mode the only useful action performed by gigi is to process all
  40       --  declarations issuing any error messages (in particular those to
  41       --  do with rep clauses), and to back annotate representation info.
  42 
  43       Skip);
  44       --  Back end call is skipped (syntax only, or errors found)
  45 
  46    pragma Convention (C, Back_End_Mode_Type);
  47    for Back_End_Mode_Type use (0, 1, 2);
  48 
  49    procedure Call_Back_End (Mode : Back_End_Mode_Type);
  50    --  Call back end, i.e. make call to driver traversing the tree and
  51    --  outputting code. This call is made with all tables locked. The back
  52    --  end is responsible for unlocking any tables it may need to change,
  53    --  and locking them again before returning.
  54 
  55    procedure Scan_Compiler_Arguments;
  56    --  Acquires command-line parameters passed to the compiler and processes
  57    --  them. Calls Scan_Front_End_Switches for any front-end switches found.
  58    --
  59    --  The processing of arguments is private to the back end, since the way
  60    --  of acquiring the arguments as well as the set of allowable back end
  61    --  switches is different depending on the particular back end being used.
  62    --
  63    --  Any processed switches that influence the result of a compilation must
  64    --  be added to the Compilation_Arguments table.
  65    --
  66    --  This routine is expected to set the following to True if necessary (the
  67    --  default for all of these in Opt is False).
  68    --
  69    --    Opt.Disable_FE_Inline
  70    --    Opt.Disable_FE_Inline_Always
  71    --    Opt.Suppress_Control_Float_Optimizations
  72    --    Opt.Generate_SCO
  73    --    Opt.Generate_SCO_Instance_Table
  74    --    Opt.Stack_Checking_Enabled
  75    --    Opt.No_Stdinc
  76    --    Opt.No_Stdlib
  77 
  78    procedure Gen_Or_Update_Object_File;
  79    --  Is used to generate the object file (if generated directly by gnat1), or
  80    --  update it if it has already been generated by the call to Call_Back_End,
  81    --  so that its timestamp is updated by the call.
  82    --
  83    --  This is a no-op with the gcc back-end (the object file is generated by
  84    --  the assembler afterwards), but is needed for back-ends that directly
  85    --  generate the final object file so that the object file's timestamp is
  86    --  correct when compared with the corresponding ali file by gnatmake.
  87 
  88 end Back_End;