------------------------------------------------------------------------------ -- -- -- GNAT COMPILER COMPONENTS -- -- -- -- S E T _ T A R G -- -- -- -- S p e c -- -- -- -- Copyright (C) 2013-2020, 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. See the GNU General Public License -- -- for more details. You should have received a copy of the GNU General -- -- Public License distributed with GNAT; see file COPYING3. If not, go to -- -- http://www.gnu.org/licenses for a complete copy of the license. -- -- -- -- GNAT was originally developed by the GNAT team at New York University. -- -- Extensive contributions were provided by Ada Core Technologies Inc. -- -- -- ------------------------------------------------------------------------------ -- This package handles setting target dependent parameters. If the -gnatet -- switch is not set, then these values are taken from the back end (via the -- routines in Get_Targ, and the enumerate_modes routine in misc.c). If the -- switch is set, then the values are read from the target.atp file in the -- current directory (usually written with the Write_Target_Dependent_Values -- procedure defined in this package). -- Note that all these values return sizes of C types with corresponding -- names. This allows GNAT to define the corresponding Ada types to have -- the same representation. There is one exception: the representation -- of Wide_Character_Type uses twice the size of a C char, instead of the -- size of wchar_t, since this corresponds to expected Ada usage. with Einfo; use Einfo; with Stand; use Stand; with Types; use Types; package Set_Targ is ----------------------------- -- Target-Dependent Values -- ----------------------------- -- The following is a table of target dependent values. In normal operation -- these values are set by calling the appropriate C backend routines that -- interface to back end routines that determine target characteristics. -- If the -gnateT switch is used, then any values that are read from the -- file target.atp in the current directory overwrite values set from the -- back end. This is used by tools other than the compiler, e.g. to do -- semantic analysis of programs that will run on some other target than -- the machine on which the tool is run. -- Note: fields marked with a question mark are boolean fields, where a -- value of 0 is False, and a value of 1 is True. Bits_BE : Nat; -- Bits stored big-endian? Bits_Per_Unit : Pos; -- Bits in a storage unit Bits_Per_Word : Pos; -- Bits in a word Bytes_BE : Nat; -- Bytes stored big-endian? Char_Size : Pos; -- Standard.Character'Size Double_Float_Alignment : Nat; -- Alignment of double float Double_Scalar_Alignment : Nat; -- Alignment of double length scalar Double_Size : Pos; -- Standard.Long_Float'Size Float_Size : Pos; -- Standard.Float'Size Float_Words_BE : Nat; -- Float words stored big-endian? Int_Size : Pos; -- Standard.Integer'Size Long_Double_Size : Pos; -- Standard.Long_Long_Float'Size Long_Long_Size : Pos; -- Standard.Long_Long_Integer'Size Long_Size : Pos; -- Standard.Long_Integer'Size Maximum_Alignment : Pos; -- Maximum permitted alignment Max_Unaligned_Field : Pos; -- Maximum size for unaligned bit field Pointer_Size : Pos; -- System.Address'Size Short_Enums : Nat; -- Foreign enums use short size? Short_Size : Pos; -- Standard.Short_Integer'Size Strict_Alignment : Nat; -- Strict alignment? System_Allocator_Alignment : Nat; -- Alignment for malloc calls Wchar_T_Size : Pos; -- Interfaces.C.wchar_t'Size Words_BE : Nat; -- Words stored big-endian? ------------------------------------- -- Registered Floating-Point Types -- ------------------------------------- -- This table contains the list of modes supported by the back-end as -- provided by the back end routine enumerate_modes in misc.c. Note that -- we only store floating-point modes (see Register_Float_Type). type FPT_Mode_Entry is record NAME : String_Ptr; -- Name of mode (no null character at end) DIGS : Natural; -- Digits for floating-point type FLOAT_REP : Float_Rep_Kind; -- Float representation PRECISION : Natural; -- Precision in bits SIZE : Natural; -- Size in bits ALIGNMENT : Natural; -- Alignment in bits end record; FPT_Mode_Table : array (1 .. 1000) of FPT_Mode_Entry; Num_FPT_Modes : Natural := 0; -- Table containing the supported modes and number of entries ----------------- -- Subprograms -- ----------------- subtype S_Float_Types is Standard_Entity_Type range S_Short_Float .. S_Long_Long_Float; function C_Type_For (T : S_Float_Types) return String; -- Return the name of a C type supported by the back-end and suitable as -- a basis to construct the standard Ada floating point type identified by -- T. This is used as a common ground to feed both ttypes values and the -- GNAT tree nodes for the standard floating point types. procedure Write_Target_Dependent_Values; -- This routine writes the file target.atp in the current directory with -- the values of the global target parameters as listed above, and as set -- by prior calls to Initialize/Read_Target_Dependent_Values. The format -- of the target.atp file is as follows -- -- First come the values of the variables defined in this spec: -- -- One line per value -- -- name value -- -- where name is the name of the parameter, spelled out in full, -- and cased as in the above list, and value is an unsigned decimal -- integer. Two or more blanks separates the name from the value. -- -- All the variables must be present, in alphabetical order (i.e. the -- same order as the declarations in this spec). -- -- Then there is a blank line to separate the two parts of the file. Then -- come the lines showing the floating-point types to be registered. -- -- One line per registered mode -- -- name digs float_rep precision alignment -- -- where name is the string name of the type (which can have single -- spaces embedded in the name (e.g. long double). The name is followed -- by at least two blanks. The following fields are as described above -- for a Mode_Entry (where float_rep is I/V/A for IEEE-754-Binary, -- Vax_Native, AAMP), fields are separated by at least one blank, and -- a LF character immediately follows the alignment field. -- -- ??? We do not write the size for backward compatibility reasons, -- which means that target.atp will not be a complete description for -- the very peculiar cases where the size cannot be computed from the -- precision and the alignment by the formula: -- -- size := (precision + alignment - 1) / alignment * alignment end Set_Targ;