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diff --git a/gcc-4.2.1/gcc/ada/sem_mech.ads b/gcc-4.2.1/gcc/ada/sem_mech.ads deleted file mode 100644 index f3600d3f7..000000000 --- a/gcc-4.2.1/gcc/ada/sem_mech.ads +++ /dev/null @@ -1,171 +0,0 @@ ------------------------------------------------------------------------------- --- -- --- GNAT COMPILER COMPONENTS -- --- -- --- S E M _ M E C H -- --- -- --- S p e c -- --- -- --- Copyright (C) 1996-1997 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 2, 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 COPYING. If not, write -- --- to the Free Software Foundation, 51 Franklin Street, Fifth Floor, -- --- Boston, MA 02110-1301, USA. -- --- -- --- 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 routine used to establish calling mechanisms --- The reason we separate this off into its own package is that it is --- entirely possible that it may need some target specific specialization. - -with Types; use Types; - -package Sem_Mech is - - ------------------------------------------------- - -- Definitions for Parameter Mechanism Control -- - ------------------------------------------------- - - -- For parameters passed to subprograms, and for function return values, - -- as passing mechanism is defined. The entity attribute Mechanism returns - -- an indication of the mechanism, and Set_Mechanism can be used to set - -- the mechanism. At the program level, there are three ways to explicitly - -- set the mechanism: - - -- An Import_xxx or Export_xxx pragma (where xxx is Function, Procedure, - -- or Valued_Procedure) can explicitly set the mechanism for either a - -- parameter or a function return value. A mechanism explicitly set by - -- such a pragma overrides the effect of C_Pass_By_Copy described below. - - -- If convention C_Pass_By_Copy is set for a record, and the record type - -- is used as the formal type of a subprogram with a foreign convention, - -- then the mechanism is set to By_Copy. - - -- If a pragma C_Pass_By_Copy applies, and a record type has Convention - -- C, and the record type is used as the formal type of a subprogram - -- with a foreign convention, then the mechanism is set to use By_Copy - -- if the size of the record is sufficiently small (as determined by - -- the value of the parameter to pragma C_Pass_By_Copy). - - -- The subtype Mechanism_Type (declared in Types) is used to describe - -- the mechanism to be used. The following special values of this type - -- specify the mechanism, as follows. - - Default_Mechanism : constant Mechanism_Type := 0; - -- The default setting indicates that the backend will choose the proper - -- default mechanism. This depends on the convention of the subprogram - -- involved, and is generally target dependent. In the compiler, the - -- backend chooses the mechanism in this case in accordance with any - -- requirements imposed by the ABI. Note that Default is never used for - -- record types on foreign convention subprograms, since By_Reference - -- is forced for such types unless one of the above described approaches - -- is used to explicitly force By_Copy. - - By_Copy : constant Mechanism_Type := -1; - -- Passing by copy is forced. The exact meaning of By_Copy (e.g. whether - -- at a low level the value is passed in registers, or the value is copied - -- and a pointer is passed), is determined by the backend in accordance - -- with requirements imposed by the ABI. Note that in the extended import - -- and export pragma mechanisms, this is called Value, rather than Copy. - - By_Reference : constant Mechanism_Type := -2; - -- Passing by reference is forced. This is always equivalent to passing - -- a simple pointer in the case of subprograms with a foreign convention. - -- For unconstrained arrays passed to foreign convention subprograms, the - -- address of the first element of the array is passed. For convention - -- Ada, the result is logically to pass a reference, but the precise - -- mechanism (e.g. to pass bounds of unconstrained types and other needed - -- special information) is determined by the backend in accordance with - -- requirements imposed by the ABI as interpreted for Ada. - - By_Descriptor : constant Mechanism_Type := -3; - By_Descriptor_UBS : constant Mechanism_Type := -4; - By_Descriptor_UBSB : constant Mechanism_Type := -5; - By_Descriptor_UBA : constant Mechanism_Type := -6; - By_Descriptor_S : constant Mechanism_Type := -7; - By_Descriptor_SB : constant Mechanism_Type := -8; - By_Descriptor_A : constant Mechanism_Type := -9; - By_Descriptor_NCA : constant Mechanism_Type := -10; - -- These values are used only in OpenVMS ports of GNAT. Pass by descriptor - -- is forced, as described in the OpenVMS ABI. The suffix indicates the - -- descriptor type: - -- - -- UBS unaligned bit string - -- UBSB aligned bit string with arbitrary bounds - -- UBA unaligned bit array - -- S string, also a scalar or access type parameter - -- SB string with arbitrary bounds - -- A contiguous array - -- NCA non-contiguous array - -- - -- Note: the form with no suffix is used if the Import/Export pragma - -- uses the simple form of the mechanism name where no descriptor - -- type is supplied. In this case the back end assigns a descriptor - -- type based on the Ada type in accordance with the OpenVMS ABI. - - subtype Descriptor_Codes is Mechanism_Type - range By_Descriptor_NCA .. By_Descriptor; - -- Subtype including all descriptor mechanisms - - -- All the above special values are non-positive. Positive values for - -- Mechanism_Type values have a special meaning. They are used only in - -- the case of records, as a result of the use of the C_Pass_By_Copy - -- pragma, and the meaning is that if the size of the record is known - -- at compile time and does not exceed the mechanism type value, then - -- By_Copy passing is forced, otherwise By_Reference is forced. - - ---------------------- - -- Global Variables -- - ---------------------- - - Default_C_Record_Mechanism : Mechanism_Type := By_Reference; - -- This value is the default mechanism used for C convention records - -- in foreign-convention subprograms if no mechanism is otherwise - -- specified. This value is modified appropriately by the occurrence - -- of a C_Pass_By_Copy configuration pragma. - - ----------------- - -- Subprograms -- - ----------------- - - procedure Set_Mechanisms (E : Entity_Id); - -- E is a subprogram or subprogram type that has been frozen, so the - -- convention of the subprogram and all its formal types and result - -- type in the case of a function are established. The function of - -- this call is to set mechanism values for formals and for the - -- function return if they have not already been explicitly set by - -- a use of an extended Import or Export pragma. The idea is to set - -- mechanism values whereever the semantics is dictated by either - -- requirements or implementation advice in the RM, and to leave - -- the mechanism set to Default if there is no requirement, so that - -- the back-end is free to choose the most efficient method. - - procedure Set_Mechanism_Value (Ent : Entity_Id; Mech_Name : Node_Id); - -- Mech is a parameter passing mechanism (see Import_Function syntax - -- for MECHANISM_NAME). This routine checks that the mechanism argument - -- has the right form, and if not issues an error message. If the - -- argument has the right form then the Mechanism field of Ent is - -- set appropriately. It also performs some error checks. Note that - -- the mechanism name has not been analyzed (and cannot indeed be - -- analyzed, since it is semantic nonsense), so we get it in the - -- exact form created by the parser. - - procedure Set_Mechanism_With_Checks - (Ent : Entity_Id; - Mech : Mechanism_Type; - Enod : Node_Id); - -- Sets the mechanism of Ent to the given Mech value, after first checking - -- that the request makes sense. If it does not make sense, a warning is - -- posted on node Enod, and the Mechanism of Ent is unchanged. - -end Sem_Mech; |