1 ------------------------------------------------------------------------------
3 -- GNAT RUN-TIME COMPONENTS --
5 -- S Y S T E M . M E M O R Y --
11 -- Copyright (C) 2001 Free Software Foundation, Inc. --
13 -- This specification is derived from the Ada Reference Manual for use with --
14 -- GNAT. The copyright notice above, and the license provisions that follow --
15 -- apply solely to the contents of the part following the private keyword. --
17 -- GNAT is free software; you can redistribute it and/or modify it under --
18 -- terms of the GNU General Public License as published by the Free Soft- --
19 -- ware Foundation; either version 2, or (at your option) any later ver- --
20 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
21 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
22 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
23 -- for more details. You should have received a copy of the GNU General --
24 -- Public License distributed with GNAT; see file COPYING. If not, write --
25 -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
26 -- MA 02111-1307, USA. --
28 -- As a special exception, if other files instantiate generics from this --
29 -- unit, or you link this unit with other files to produce an executable, --
30 -- this unit does not by itself cause the resulting executable to be --
31 -- covered by the GNU General Public License. This exception does not --
32 -- however invalidate any other reasons why the executable file might be --
33 -- covered by the GNU Public License. --
35 -- GNAT was originally developed by the GNAT team at New York University. --
36 -- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). --
38 ------------------------------------------------------------------------------
40 -- This version contains allocation tracking capability.
41 -- The object file corresponding to this instrumented version is to be found
43 -- When enabled, the subsystem logs all the calls to __gnat_malloc and
44 -- __gnat_free. This log can then be processed by gnatmem to detect
45 -- dynamic memory leaks.
47 -- To use this functionality, you must compile your application with -g
48 -- and then link with this object file:
50 -- gnatmake -g program -largs -lgmem
52 -- After compilation, you may use your program as usual except that upon
53 -- completion, it will generate in the current directory the file gmem.out.
55 -- You can then investigate for possible memory leaks and mismatch by calling
56 -- gnatmem with this file as an input:
58 -- gnatmem -i gmem.out program
60 -- See gnatmem section in the GNAT User's Guide for more details.
62 -- NOTE: This capability is currently supported on the following targets:
71 pragma Source_File_Name (System.Memory, Body_File_Name => "memtrack.adb");
74 with System.Soft_Links;
75 with System.Traceback;
77 package body System.Memory is
80 use System.Soft_Links;
83 function c_malloc (Size : size_t) return System.Address;
84 pragma Import (C, c_malloc, "malloc");
86 procedure c_free (Ptr : System.Address);
87 pragma Import (C, c_free, "free");
90 (Ptr : System.Address; Size : size_t) return System.Address;
91 pragma Import (C, c_realloc, "realloc");
93 type File_Ptr is new System.Address;
95 function fopen (Path : String; Mode : String) return File_Ptr;
96 pragma Import (C, fopen);
99 (Ptr : System.Address;
109 pragma Import (C, fwrite);
111 procedure fputc (C : Integer; Stream : File_Ptr);
112 pragma Import (C, fputc);
114 procedure fclose (Stream : File_Ptr);
115 pragma Import (C, fclose);
118 -- Replace the default __gnat_finalize to properly close the log file.
119 pragma Export (C, Finalize, "__gnat_finalize");
121 Address_Size : constant := System.Address'Max_Size_In_Storage_Elements;
122 -- Size in bytes of a pointer
124 Max_Call_Stack : constant := 200;
125 -- Maximum number of frames supported
127 Skip_Frame : constant := 1;
128 -- Number of frames to remove from the call stack to hide functions from
131 Tracebk : aliased array (0 .. Max_Call_Stack) of System.Address;
132 Num_Calls : aliased Integer := 0;
133 -- Store the current call stack from Alloc and Free
135 Gmemfname : constant String := "gmem.out" & ASCII.NUL;
136 -- Allocation log of a program is saved in a file gmem.out
137 -- ??? What about Ada.Command_Line.Command_Name & ".out" instead of static
141 -- Global C file pointer to the allocation log
143 procedure Gmem_Initialize;
144 -- Initialization routine; opens the file and writes a header string. This
145 -- header string is used as a magic-tag to know if the .out file is to be
146 -- handled by GDB or by the GMEM (instrumented malloc/free) implementation.
152 function Alloc (Size : size_t) return System.Address is
153 Result : aliased System.Address;
154 Actual_Size : aliased size_t := Size;
157 if Size = size_t'Last then
158 Raise_Exception (Storage_Error'Identity, "object too large");
161 -- Change size from zero to non-zero. We still want a proper pointer
162 -- for the zero case because pointers to zero length objects have to
163 -- be distinct, but we can't just go ahead and allocate zero bytes,
164 -- since some malloc's return zero for a zero argument.
172 Result := c_malloc (Actual_Size);
174 -- Logs allocation call
176 -- 'A' <mem addr> <size chunk> <len backtrace> <addr1> ... <addrn>
179 Call_Chain (Tracebk'Address, Max_Call_Stack, Num_Calls);
180 Num_Calls := Num_Calls - Skip_Frame;
181 fputc (Character'Pos ('A'), Gmemfile);
182 fwrite (Result'Address, Address_Size, 1, Gmemfile);
183 fwrite (Actual_Size'Address, size_t'Max_Size_In_Storage_Elements, 1,
185 fwrite (Num_Calls'Address, Integer'Max_Size_In_Storage_Elements, 1,
187 fwrite (Tracebk (Skip_Frame)'Address, Address_Size, size_t (Num_Calls),
192 if Result = System.Null_Address then
193 Raise_Exception (Storage_Error'Identity, "heap exhausted");
203 Needs_Init : Boolean := True;
204 -- Reset after first call to Gmem_Initialize
206 procedure Finalize is
208 if not Needs_Init then
217 procedure Free (Ptr : System.Address) is
218 Addr : aliased constant System.Address := Ptr;
222 -- Logs deallocation call
224 -- 'D' <mem addr> <len backtrace> <addr1> ... <addrn>
227 Call_Chain (Tracebk'Address, Max_Call_Stack, Num_Calls);
228 Num_Calls := Num_Calls - Skip_Frame;
229 fputc (Character'Pos ('D'), Gmemfile);
230 fwrite (Addr'Address, Address_Size, 1, Gmemfile);
231 fwrite (Num_Calls'Address, Integer'Max_Size_In_Storage_Elements, 1,
233 fwrite (Tracebk (Skip_Frame)'Address, Address_Size, size_t (Num_Calls),
241 ---------------------
242 -- Gmem_Initialize --
243 ---------------------
245 procedure Gmem_Initialize is
249 Gmemfile := fopen (Gmemfname, "wb" & ASCII.NUL);
250 fwrite ("GMEM DUMP" & ASCII.LF, 10, 1, Gmemfile);
259 (Ptr : System.Address; Size : size_t) return System.Address
261 Result : System.Address;
263 if Size = size_t'Last then
264 Raise_Exception (Storage_Error'Identity, "object too large");
268 Result := c_realloc (Ptr, Size);
271 if Result = System.Null_Address then
272 Raise_Exception (Storage_Error'Identity, "heap exhausted");