--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/ada/repinfo.ads	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,329 @@
+------------------------------------------------------------------------------
+--                                                                          --
+--                         GNAT COMPILER COMPONENTS                         --
+--                                                                          --
+--                              R E P I N F O                               --
+--                                                                          --
+--                                 S p e c                                  --
+--                                                                          --
+--          Copyright (C) 1999-2017, 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.                                     --
+--                                                                          --
+-- As a special exception under Section 7 of GPL version 3, you are granted --
+-- additional permissions described in the GCC Runtime Library Exception,   --
+-- version 3.1, as published by the Free Software Foundation.               --
+--                                                                          --
+-- You should have received a copy of the GNU General Public License and    --
+-- a copy of the GCC Runtime Library Exception along with this program;     --
+-- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
+-- <http://www.gnu.org/licenses/>.                                          --
+--                                                                          --
+-- GNAT was originally developed  by the GNAT team at  New York University. --
+-- Extensive contributions were provided by Ada Core Technologies Inc.      --
+--                                                                          --
+------------------------------------------------------------------------------
+
+--  This package contains the routines to handle back annotation of the
+--  tree to fill in representation information, and also the routine used
+--  by -gnatR to print this information. This unit is used both in the
+--  compiler and in ASIS (it is used in ASIS as part of the implementation
+--  of the data decomposition annex).
+
+with Types; use Types;
+with Uintp; use Uintp;
+
+package Repinfo is
+
+   --------------------------------
+   -- Representation Information --
+   --------------------------------
+
+   --  The representation information of interest here is size and
+   --  component information for arrays and records. For primitive
+   --  types, the front end computes the Esize and RM_Size fields of
+   --  the corresponding entities as constant non-negative integers,
+   --  and the Uint values are stored directly in these fields.
+
+   --  For composite types, there are three cases:
+
+   --    1. In some cases the front end knows the values statically,
+   --       for example in the case where representation clauses or
+   --       pragmas specify the values.
+
+   --    2. If Backend_Layout is True, then the backend is responsible
+   --       for layout of all types and objects not laid out by the
+   --       front end. This includes all dynamic values, and also
+   --       static values (e.g. record sizes) when not set by the
+   --       front end.
+
+   --    3. If Backend_Layout is False, then the front end lays out
+   --       all data, according to target dependent size and alignment
+   --       information, creating dynamic inlinable functions where
+   --       needed in the case of sizes not known till runtime.
+
+   -----------------------------
+   -- Back-Annotation by Gigi --
+   -----------------------------
+
+   --  The following interface is used by gigi if Backend_Layout is True
+
+   --  As part of the processing in gigi, the types are laid out and
+   --  appropriate values computed for the sizes and component positions
+   --  and sizes of records and arrays.
+
+   --  The back-annotation circuit in gigi is responsible for updating the
+   --  relevant fields in the tree to reflect these computations, as follows:
+
+   --    For E_Array_Type entities, the Component_Size field
+
+   --    For all record and array types and subtypes, the Esize field,
+   --    which contains the Size (more accurately the Object_Size) value
+   --    for the type or subtype.
+
+   --    For E_Component and E_Discriminant entities, the Esize (size
+   --    of component) and Component_Bit_Offset fields. Note that gigi
+   --    does not back annotate Normalized_Position/First_Bit.
+
+   --  There are three cases to consider:
+
+   --    1. The value is constant. In this case, the back annotation works
+   --       by simply storing the non-negative universal integer value in
+   --       the appropriate field corresponding to this constant size.
+
+   --    2. The value depends on the discriminant values for the current
+   --       record. In this case, gigi back annotates the field with a
+   --       representation of the expression for computing the value in
+   --       terms of the discriminants. A negative Uint value is used to
+   --       represent the value of such an expression, as explained in
+   --       the following section.
+
+   --    3. The value depends on variables other than discriminants of the
+   --       current record. In this case, gigi also back annotates the field
+   --       with a representation of the expression for computing the value
+   --       in terms of the variables represented symbolically.
+
+   --  Note: the extended back annotation for the dynamic case is needed only
+   --  for -gnatR3 output, and for proper operation of the ASIS DDA. Since it
+   --  can be expensive to do this back annotation (for discriminated records
+   --  with many variable length arrays), we only do the full back annotation
+   --  in -gnatR3 mode, or ASIS mode. In any other mode, the back-end just sets
+   --  the value to Uint_Minus_1, indicating that the value of the attribute
+   --  depends on discriminant information, but not giving further details.
+
+   --  GCC expressions are represented with a Uint value that is negative.
+   --  See the body of this package for details on the representation used.
+
+   --  One other case in which gigi back annotates GCC expressions is in
+   --  the Present_Expr field of an N_Variant node. This expression which
+   --  will always depend on discriminants, and hence always be represented
+   --  as a negative Uint value, provides an expression which, when evaluated
+   --  with a given set of discriminant values, indicates whether the variant
+   --  is present for that set of values (result is True, i.e. non-zero) or
+   --  not present (result is False, i.e. zero). Again, the full annotation of
+   --  this field is done only in -gnatR3 mode or in ASIS mode, and in other
+   --  modes, the value is set to Uint_Minus_1.
+
+   subtype Node_Ref is Uint;
+   --  Subtype used for negative Uint values used to represent nodes
+
+   subtype Node_Ref_Or_Val is Uint;
+   --  Subtype used for values that can either be a Node_Ref (negative)
+   --  or a value (non-negative)
+
+   type TCode is range 0 .. 29;
+   --  Type used on Ada side to represent DEFTREECODE values defined in
+   --  tree.def. Only a subset of these tree codes can actually appear.
+   --  The names are the names from tree.def in Ada casing.
+
+   --  name                             code   description           operands
+
+   Cond_Expr        : constant TCode :=  1; -- conditional              3
+   Plus_Expr        : constant TCode :=  2; -- addition                 2
+   Minus_Expr       : constant TCode :=  3; -- subtraction              2
+   Mult_Expr        : constant TCode :=  4; -- multiplication           2
+   Trunc_Div_Expr   : constant TCode :=  5; -- truncating division      2
+   Ceil_Div_Expr    : constant TCode :=  6; -- division rounding up     2
+   Floor_Div_Expr   : constant TCode :=  7; -- division rounding down   2
+   Trunc_Mod_Expr   : constant TCode :=  8; -- mod for trunc_div        2
+   Ceil_Mod_Expr    : constant TCode :=  9; -- mod for ceil_div         2
+   Floor_Mod_Expr   : constant TCode := 10; -- mod for floor_div        2
+   Exact_Div_Expr   : constant TCode := 11; -- exact div                2
+   Negate_Expr      : constant TCode := 12; -- negation                 1
+   Min_Expr         : constant TCode := 13; -- minimum                  2
+   Max_Expr         : constant TCode := 14; -- maximum                  2
+   Abs_Expr         : constant TCode := 15; -- absolute value           1
+   Truth_Andif_Expr : constant TCode := 16; -- Boolean and then         2
+   Truth_Orif_Expr  : constant TCode := 17; -- Boolean or else          2
+   Truth_And_Expr   : constant TCode := 18; -- Boolean and              2
+   Truth_Or_Expr    : constant TCode := 19; -- Boolean or               2
+   Truth_Xor_Expr   : constant TCode := 20; -- Boolean xor              2
+   Truth_Not_Expr   : constant TCode := 21; -- Boolean not              1
+   Lt_Expr          : constant TCode := 22; -- comparison <             2
+   Le_Expr          : constant TCode := 23; -- comparison <=            2
+   Gt_Expr          : constant TCode := 24; -- comparison >             2
+   Ge_Expr          : constant TCode := 25; -- comparison >=            2
+   Eq_Expr          : constant TCode := 26; -- comparison =             2
+   Ne_Expr          : constant TCode := 27; -- comparison /=            2
+   Bit_And_Expr     : constant TCode := 28; -- Binary and               2
+
+   --  The following entry is used to represent a discriminant value in
+   --  the tree. It has a special tree code that does not correspond
+   --  directly to a GCC node. The single operand is the index number
+   --  of the discriminant in the record (1 = first discriminant).
+
+   Discrim_Val      : constant TCode :=  0;  -- discriminant value      1
+
+   --  The following entry is used to represent a value not known at
+   --  compile time in the tree, other than a discriminant value. It
+   --  has a special tree code that does not correspond directly to
+   --  a GCC node. The single operand is an arbitrary index number.
+
+   Dynamic_Val      : constant TCode := 29;  -- dynamic value           1
+
+   ------------------------
+   -- The gigi Interface --
+   ------------------------
+
+   --  The following declarations are for use by gigi for back annotation
+
+   function Create_Node
+     (Expr : TCode;
+      Op1  : Node_Ref_Or_Val;
+      Op2  : Node_Ref_Or_Val := No_Uint;
+      Op3  : Node_Ref_Or_Val := No_Uint) return Node_Ref;
+   --  Creates a node using the tree code defined by Expr and from one to three
+   --  operands as required (unused operands set as shown to No_Uint) Note that
+   --  this call can be used to create a discriminant reference by using (Expr
+   --  => Discrim_Val, Op1 => discriminant_number).
+
+   function Create_Discrim_Ref (Discr : Entity_Id) return Node_Ref;
+   --  Creates a reference to the discriminant whose entity is Discr
+
+   --------------------------------------------------------
+   -- Front-End Interface for Dynamic Size/Offset Values --
+   --------------------------------------------------------
+
+   --  If Backend_Layout is False, then the front-end deals with all
+   --  dynamic size and offset fields. There are two cases:
+
+   --    1. The value can be computed at the time of type freezing, and
+   --       is stored in a run-time constant. In this case, the field
+   --       contains a reference to this entity. In the case of sizes
+   --       the value stored is the size in storage units, since dynamic
+   --       sizes are always a multiple of storage units.
+
+   --    2. The size/offset depends on the value of discriminants at
+   --       run-time. In this case, the front end builds a function to
+   --       compute the value. This function has a single parameter
+   --       which is the discriminated record object in question. Any
+   --       references to discriminant values are simply references to
+   --       the appropriate discriminant in this single argument, and
+   --       to compute the required size/offset value at run time, the
+   --       code generator simply constructs a call to the function
+   --       with the appropriate argument. The size/offset field in
+   --       this case contains a reference to the function entity.
+   --       Note that as for case 1, if such a function is used to
+   --       return a size, then the size in storage units is returned,
+   --       not the size in bits.
+
+   --  The interface here allows these created entities to be referenced
+   --  using negative Unit values, so that they can be stored in the
+   --  appropriate size and offset fields in the tree.
+
+   --  In the case of components, if the location of the component is static,
+   --  then all four fields (Component_Bit_Offset, Normalized_Position, Esize,
+   --  and Normalized_First_Bit) are set to appropriate values. In the case of
+   --  a non-static component location, Component_Bit_Offset is not used and
+   --  is left set to Unknown. Normalized_Position and Normalized_First_Bit
+   --  are set appropriately.
+
+   subtype SO_Ref is Uint;
+   --  Type used to represent a Uint value that represents a static or
+   --  dynamic size/offset value (non-negative if static, negative if
+   --  the size value is dynamic).
+
+   subtype Dynamic_SO_Ref is Uint;
+   --  Type used to represent a negative Uint value used to store
+   --  a dynamic size/offset value.
+
+   function Is_Dynamic_SO_Ref (U : SO_Ref) return Boolean;
+   pragma Inline (Is_Dynamic_SO_Ref);
+   --  Given a SO_Ref (Uint) value, returns True iff the SO_Ref value
+   --  represents a dynamic Size/Offset value (i.e. it is negative).
+
+   function Is_Static_SO_Ref (U : SO_Ref) return Boolean;
+   pragma Inline (Is_Static_SO_Ref);
+   --  Given a SO_Ref (Uint) value, returns True iff the SO_Ref value
+   --  represents a static Size/Offset value (i.e. it is non-negative).
+
+   function Create_Dynamic_SO_Ref (E : Entity_Id) return Dynamic_SO_Ref;
+   --  Given the Entity_Id for a constant (case 1), the Node_Id for an
+   --  expression (case 2), or the Entity_Id for a function (case 3),
+   --  this function returns a (negative) Uint value that can be used
+   --  to retrieve the entity or expression for later use.
+
+   function Get_Dynamic_SO_Entity (U : Dynamic_SO_Ref) return Entity_Id;
+   --  Retrieve the Node_Id or Entity_Id stored by a previous call to
+   --  Create_Dynamic_SO_Ref. The approach is that the front end makes
+   --  the necessary Create_Dynamic_SO_Ref calls to associate the node
+   --  and entity id values and the back end makes Get_Dynamic_SO_Ref
+   --  calls to retrieve them.
+
+   --------------------
+   -- ASIS_Interface --
+   --------------------
+
+   type Discrim_List is array (Pos range <>) of Uint;
+   --  Type used to represent list of discriminant values
+
+   function Rep_Value
+     (Val : Node_Ref_Or_Val;
+      D   : Discrim_List) return Uint;
+   --  Given the contents of a First_Bit_Position or Esize field containing
+   --  a node reference (i.e. a negative Uint value) and D, the list of
+   --  discriminant values, returns the interpreted value of this field.
+   --  For convenience, Rep_Value will take a non-negative Uint value
+   --  as an argument value, and return it unmodified. A No_Uint value is
+   --  also returned unmodified.
+
+   procedure Tree_Read;
+   --  Initializes internal tables from current tree file using the relevant
+   --  Table.Tree_Read routines.
+
+   ------------------------
+   -- Compiler Interface --
+   ------------------------
+
+   procedure List_Rep_Info (Bytes_Big_Endian : Boolean);
+   --  Procedure to list representation information. Bytes_Big_Endian is the
+   --  value from Ttypes (Repinfo cannot have a dependency on Ttypes).
+
+   procedure Tree_Write;
+   --  Writes out internal tables to current tree file using the relevant
+   --  Table.Tree_Write routines.
+
+   --------------------------
+   -- Debugging Procedures --
+   --------------------------
+
+   procedure List_GCC_Expression (U : Node_Ref_Or_Val);
+   --  Prints out given expression in symbolic form. Constants are listed
+   --  in decimal numeric form, Discriminants are listed with a # followed
+   --  by the discriminant number, and operators are output in appropriate
+   --  symbolic form No_Uint displays as two question marks. The output is
+   --  on a single line but has no line return after it. This procedure is
+   --  useful only if operating in backend layout mode.
+
+   procedure lgx (U : Node_Ref_Or_Val);
+   --  In backend layout mode, this is like List_GCC_Expression, but
+   --  includes a line return at the end. If operating in front end
+   --  layout mode, then the name of the entity for the size (either
+   --  a function of a variable) is listed followed by a line return.
+
+end Repinfo;