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Diffstat (limited to 'gcc-4.8.3/gcc/ada/s-mastop.ads')
| -rw-r--r-- | gcc-4.8.3/gcc/ada/s-mastop.ads | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/gcc-4.8.3/gcc/ada/s-mastop.ads b/gcc-4.8.3/gcc/ada/s-mastop.ads new file mode 100644 index 000000000..74ff217c6 --- /dev/null +++ b/gcc-4.8.3/gcc/ada/s-mastop.ads @@ -0,0 +1,107 @@ +------------------------------------------------------------------------------ +-- -- +-- GNAT COMPILER COMPONENTS -- +-- -- +-- SYSTEM.MACHINE_STATE_OPERATIONS -- +-- -- +-- S p e c -- +-- -- +-- Copyright (C) 1999-2009, 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. -- +-- -- +------------------------------------------------------------------------------ + +pragma Compiler_Unit; + +pragma Polling (Off); +-- We must turn polling off for this unit, because otherwise we get +-- elaboration circularities with System.Exception_Tables. + +with System.Storage_Elements; + +package System.Machine_State_Operations is + + subtype Code_Loc is System.Address; + -- Code location used in building exception tables and for call + -- addresses when propagating an exception (also traceback table) + -- Values of this type are created by using Label'Address or + -- extracted from machine states using Get_Code_Loc. + + type Machine_State is new System.Address; + -- The table based exception handling approach (see a-except.adb) isolates + -- the target dependent aspects using an abstract data type interface + -- to the type Machine_State, which is represented as a System.Address + -- value (presumably implemented as a pointer to an appropriate record + -- structure). + + function Machine_State_Length return System.Storage_Elements.Storage_Offset; + -- Function to determine the length of the Storage_Array needed to hold + -- a machine state. The machine state will always be maximally aligned. + -- The value returned is a constant that will be used to allocate space + -- for a machine state value. + + function Allocate_Machine_State return Machine_State; + -- Allocate the required space for a Machine_State + + procedure Free_Machine_State (M : in out Machine_State); + -- Free the dynamic memory taken by Machine_State + + -- The initial value of type Machine_State is created by the low level + -- routine that actually raises an exception using the special builtin + -- _builtin_machine_state. This value will typically encode the value + -- of the program counter, and relevant registers. The following + -- operations are defined on Machine_State values: + + function Get_Code_Loc (M : Machine_State) return Code_Loc; + -- This function extracts the program counter value from a machine + -- state, which the caller uses for searching the exception tables, + -- and also for recording entries in the traceback table. The call + -- returns a value of Null_Loc if the machine state represents the + -- outer level, or some other frame for which no information can be + -- provided. + + procedure Pop_Frame (M : Machine_State); + -- This procedure pops the machine state M so that it represents the + -- call point, as though the current subprogram had returned. It + -- changes only the value referenced by M, and does not affect + -- the current stack environment. + + function Fetch_Code (Loc : Code_Loc) return Code_Loc; + -- Some architectures (notably VMS) use a descriptor to describe + -- a subprogram address. This function computes the actual starting + -- address of the code from Loc. + -- + -- ??? This function will go away when 'Code_Address is fixed on VMS. + -- + -- Do not add pragma Inline to this function: there is a curious + -- interaction between rtsfind and front-end inlining. The exception + -- declaration in s-auxdec calls rtsfind, which forces several other system + -- packages to be compiled. Some of those have a pragma Inline, and we + -- compile the corresponding bodies so that inlining can take place. One + -- of these packages is s-mastop, which depends on s-auxdec, which is still + -- being compiled: we have not seen all the declarations in it yet, so we + -- get confused semantic errors. + + procedure Set_Machine_State (M : Machine_State); + -- This routine sets M from the current machine state. It is called + -- when an exception is initially signalled to initialize the state. + +end System.Machine_State_Operations; |