summaryrefslogtreecommitdiff
path: root/gcc/ada/s-mastop-vms.adb
blob: 08773343ca6559a9f42fb31f1e4845621c10e2dc (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
------------------------------------------------------------------------------
--                                                                          --
--                         GNAT COMPILER COMPONENTS                         --
--                                                                          --
--                     SYSTEM.MACHINE_STATE_OPERATIONS                      --
--                                                                          --
--                                 B o d y                                  --
--                         (Version for Alpha/VMS)                          --
--                                                                          --
--                     Copyright (C) 2001-2007, AdaCore                     --
--                                                                          --
-- 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.                                              --
--                                                                          --
-- As a special exception,  if other files  instantiate  generics from this --
-- unit, or you link  this unit with other files  to produce an executable, --
-- this  unit  does not  by itself cause  the resulting  executable  to  be --
-- covered  by the  GNU  General  Public  License.  This exception does not --
-- however invalidate  any other reasons why  the executable file  might be --
-- covered by the  GNU Public License.                                      --
--                                                                          --
-- GNAT was originally developed  by the GNAT team at  New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc.      --
--                                                                          --
------------------------------------------------------------------------------

--  This version of System.Machine_State_Operations is for use on
--  Alpha systems running VMS.

with System.Memory;
with System.Aux_DEC; use System.Aux_DEC;
with Ada.Unchecked_Conversion;

package body System.Machine_State_Operations is

   subtype Cond_Value_Type is Unsigned_Longword;

   --  Record layouts copied from Starlet

   type ICB_Fflags_Bits_Type is record
      Exception_Frame : Boolean;
      Ast_Frame       : Boolean;
      Bottom_Of_Stack : Boolean;
      Base_Frame      : Boolean;
      Filler_1        : Unsigned_20;
   end record;

   for ICB_Fflags_Bits_Type use record
      Exception_Frame at 0 range 0 .. 0;
      Ast_Frame       at 0 range 1 .. 1;
      Bottom_Of_Stack at 0 range 2 .. 2;
      Base_Frame      at 0 range 3 .. 3;
      Filler_1        at 0 range 4 .. 23;
   end record;
   for ICB_Fflags_Bits_Type'Size use 24;

   type ICB_Hdr_Quad_Type is record
      Context_Length : Unsigned_Longword;
      Fflags_Bits    : ICB_Fflags_Bits_Type;
      Block_Version  : Unsigned_Byte;
   end record;

   for ICB_Hdr_Quad_Type use record
      Context_Length at 0 range 0 .. 31;
      Fflags_Bits    at 4 range 0 .. 23;
      Block_Version  at 7 range 0 .. 7;
   end record;
   for ICB_Hdr_Quad_Type'Size use 64;

   type Invo_Context_Blk_Type is record

      Hdr_Quad : ICB_Hdr_Quad_Type;
      --  The first quadword contains:
      --    o  The length of the structure in bytes (a longword field)
      --    o  The frame flags (a 3 byte field of bits)
      --    o  The version number (a 1 byte field)

      Procedure_Descriptor : Unsigned_Quadword;
      --  The address of the procedure descriptor for the procedure

      Program_Counter : Integer_64;
      --  The current PC of a given procedure invocation

      Processor_Status : Integer_64;
      --  The current PS of a given procedure invocation

      Ireg : Unsigned_Quadword_Array (0 .. 30);
      Freg : Unsigned_Quadword_Array (0 .. 30);
      --  The register contents areas. 31 for scalars, 31 for float

      System_Defined : Unsigned_Quadword_Array (0 .. 1);
      --  The following is an "internal" area that's reserved for use by
      --  the operating system. It's size may vary over time.

      --  Chfctx_Addr : Unsigned_Quadword;
      --  Defined as a comment since it overlaps other fields

      Filler_1             : String (1 .. 0);
      --  Align to octaword
   end record;

   for Invo_Context_Blk_Type use record
      Hdr_Quad             at   0 range 0 .. 63;
      Procedure_Descriptor at   8 range 0 .. 63;
      Program_Counter      at  16 range 0 .. 63;
      Processor_Status     at  24 range 0 .. 63;
      Ireg                 at  32 range 0 .. 1983;
      Freg                 at 280 range 0 .. 1983;
      System_Defined       at 528 range 0 .. 127;

      --  Component representation spec(s) below are defined as
      --  comments since they overlap other fields

      --  Chfctx_Addr at 528 range 0 .. 63;

      Filler_1 at 544 range 0 .. -1;
   end record;
   for Invo_Context_Blk_Type'Size use 4352;

   subtype Invo_Handle_Type is Unsigned_Longword;

   type Invo_Handle_Access_Type is access all Invo_Handle_Type;

   function Fetch is new Fetch_From_Address (Code_Loc);

   function To_Invo_Handle_Access is new Ada.Unchecked_Conversion
     (Machine_State, Invo_Handle_Access_Type);

   function To_Machine_State is new Ada.Unchecked_Conversion
     (System.Address, Machine_State);

   ----------------------------
   -- Allocate_Machine_State --
   ----------------------------

   function Allocate_Machine_State return Machine_State is
   begin
      return To_Machine_State
        (Memory.Alloc (Invo_Handle_Type'Max_Size_In_Storage_Elements));
   end Allocate_Machine_State;

   ----------------
   -- Fetch_Code --
   ----------------

   function Fetch_Code (Loc : Code_Loc) return Code_Loc is
   begin
      --  The starting address is in the second longword pointed to by Loc

      return Fetch (System.Aux_DEC."+" (Loc, 8));
   end Fetch_Code;

   ------------------------
   -- Free_Machine_State --
   ------------------------

   procedure Free_Machine_State (M : in out Machine_State) is
   begin
      Memory.Free (Address (M));
      M := Machine_State (Null_Address);
   end Free_Machine_State;

   ------------------
   -- Get_Code_Loc --
   ------------------

   function Get_Code_Loc (M : Machine_State) return Code_Loc is
      procedure Get_Invo_Context (
         Result       : out Unsigned_Longword; -- return value
         Invo_Handle  : Invo_Handle_Type;
         Invo_Context : out Invo_Context_Blk_Type);

      pragma Interface (External, Get_Invo_Context);

      pragma Import_Valued_Procedure (Get_Invo_Context, "LIB$GET_INVO_CONTEXT",
         (Unsigned_Longword, Invo_Handle_Type, Invo_Context_Blk_Type),
         (Value, Value, Reference));

      Asm_Call_Size : constant := 4;
      --  Under VMS a call
      --  asm instruction takes 4 bytes. So we must remove this amount.

      ICB : Invo_Context_Blk_Type;
      Status : Cond_Value_Type;

   begin
      Get_Invo_Context (Status, To_Invo_Handle_Access (M).all, ICB);

      if (Status and 1) /= 1 then
         return Code_Loc (System.Null_Address);
      end if;

      return Code_Loc (ICB.Program_Counter - Asm_Call_Size);
   end Get_Code_Loc;

   --------------------------
   -- Machine_State_Length --
   --------------------------

   function Machine_State_Length
     return System.Storage_Elements.Storage_Offset
   is
      use System.Storage_Elements;

   begin
      return Invo_Handle_Type'Size / 8;
   end Machine_State_Length;

   ---------------
   -- Pop_Frame --
   ---------------

   procedure Pop_Frame (M : Machine_State) is
      procedure Get_Prev_Invo_Handle (
         Result : out Invo_Handle_Type; -- return value
         ICB    : Invo_Handle_Type);

      pragma Interface (External, Get_Prev_Invo_Handle);

      pragma Import_Valued_Procedure
        (Get_Prev_Invo_Handle, "LIB$GET_PREV_INVO_HANDLE",
         (Invo_Handle_Type, Invo_Handle_Type),
         (Value, Value));

      Prev_Handle : aliased Invo_Handle_Type;

   begin
      Get_Prev_Invo_Handle (Prev_Handle, To_Invo_Handle_Access (M).all);
      To_Invo_Handle_Access (M).all := Prev_Handle;
   end Pop_Frame;

   -----------------------
   -- Set_Machine_State --
   -----------------------

   procedure Set_Machine_State (M : Machine_State) is

      procedure Get_Curr_Invo_Context
        (Invo_Context : out Invo_Context_Blk_Type);

      pragma Interface (External, Get_Curr_Invo_Context);

      pragma Import_Valued_Procedure
        (Get_Curr_Invo_Context, "LIB$GET_CURR_INVO_CONTEXT",
         (Invo_Context_Blk_Type),
         (Reference));

      procedure Get_Invo_Handle (
         Result       : out Invo_Handle_Type; -- return value
         Invo_Context : Invo_Context_Blk_Type);

      pragma Interface (External, Get_Invo_Handle);

      pragma Import_Valued_Procedure (Get_Invo_Handle, "LIB$GET_INVO_HANDLE",
         (Invo_Handle_Type, Invo_Context_Blk_Type),
         (Value, Reference));

      ICB         : Invo_Context_Blk_Type;
      Invo_Handle : aliased Invo_Handle_Type;

   begin
      Get_Curr_Invo_Context (ICB);
      Get_Invo_Handle (Invo_Handle, ICB);
      To_Invo_Handle_Access (M).all := Invo_Handle;
      Pop_Frame (M, System.Null_Address);
   end Set_Machine_State;

end System.Machine_State_Operations;