1 ------------------------------------------------------------------------------
3 -- GNAT RUN-TIME COMPONENTS --
5 -- S Y S T E M . M E M O R Y --
9 -- Copyright (C) 2001 Free Software Foundation, Inc. --
11 -- This specification is derived from the Ada Reference Manual for use with --
12 -- GNAT. The copyright notice above, and the license provisions that follow --
13 -- apply solely to the contents of the part following the private keyword. --
15 -- GNAT is free software; you can redistribute it and/or modify it under --
16 -- terms of the GNU General Public License as published by the Free Soft- --
17 -- ware Foundation; either version 2, or (at your option) any later ver- --
18 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
19 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
20 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
21 -- for more details. You should have received a copy of the GNU General --
22 -- Public License distributed with GNAT; see file COPYING. If not, write --
23 -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
24 -- MA 02111-1307, USA. --
26 -- As a special exception, if other files instantiate generics from this --
27 -- unit, or you link this unit with other files to produce an executable, --
28 -- this unit does not by itself cause the resulting executable to be --
29 -- covered by the GNU General Public License. This exception does not --
30 -- however invalidate any other reasons why the executable file might be --
31 -- covered by the GNU Public License. --
33 -- GNAT was originally developed by the GNAT team at New York University. --
34 -- Extensive contributions were provided by Ada Core Technologies Inc. --
36 ------------------------------------------------------------------------------
38 -- This version contains allocation tracking capability.
39 -- The object file corresponding to this instrumented version is to be found
41 -- When enabled, the subsystem logs all the calls to __gnat_malloc and
42 -- __gnat_free. This log can then be processed by gnatmem to detect
43 -- dynamic memory leaks.
45 -- To use this functionality, you must compile your application with -g
46 -- and then link with this object file:
48 -- gnatmake -g program -largs -lgmem
50 -- After compilation, you may use your program as usual except that upon
51 -- completion, it will generate in the current directory the file gmem.out.
53 -- You can then investigate for possible memory leaks and mismatch by calling
54 -- gnatmem with this file as an input:
56 -- gnatmem -i gmem.out program
58 -- See gnatmem section in the GNAT User's Guide for more details.
60 -- NOTE: This capability is currently supported on the following targets:
69 pragma Source_File_Name (System.Memory, Body_File_Name => "memtrack.adb");
72 with System.Soft_Links;
73 with System.Traceback;
75 package body System.Memory is
78 use System.Soft_Links;
81 function c_malloc (Size : size_t) return System.Address;
82 pragma Import (C, c_malloc, "malloc");
84 procedure c_free (Ptr : System.Address);
85 pragma Import (C, c_free, "free");
88 (Ptr : System.Address; Size : size_t) return System.Address;
89 pragma Import (C, c_realloc, "realloc");
91 type File_Ptr is new System.Address;
93 function fopen (Path : String; Mode : String) return File_Ptr;
94 pragma Import (C, fopen);
97 (Ptr : System.Address;
107 pragma Import (C, fwrite);
109 procedure fputc (C : Integer; Stream : File_Ptr);
110 pragma Import (C, fputc);
112 procedure fclose (Stream : File_Ptr);
113 pragma Import (C, fclose);
116 -- Replace the default __gnat_finalize to properly close the log file.
117 pragma Export (C, Finalize, "__gnat_finalize");
119 Address_Size : constant := System.Address'Max_Size_In_Storage_Elements;
120 -- Size in bytes of a pointer
122 Max_Call_Stack : constant := 200;
123 -- Maximum number of frames supported
125 Skip_Frame : constant := 1;
126 -- Number of frames to remove from the call stack to hide functions from
129 Tracebk : aliased array (0 .. Max_Call_Stack) of System.Address;
130 Num_Calls : aliased Integer := 0;
131 -- Store the current call stack from Alloc and Free
133 Gmemfname : constant String := "gmem.out" & ASCII.NUL;
134 -- Allocation log of a program is saved in a file gmem.out
135 -- ??? What about Ada.Command_Line.Command_Name & ".out" instead of static
139 -- Global C file pointer to the allocation log
141 procedure Gmem_Initialize;
142 -- Initialization routine; opens the file and writes a header string. This
143 -- header string is used as a magic-tag to know if the .out file is to be
144 -- handled by GDB or by the GMEM (instrumented malloc/free) implementation.
150 function Alloc (Size : size_t) return System.Address is
151 Result : aliased System.Address;
152 Actual_Size : aliased size_t := Size;
155 if Size = size_t'Last then
156 Raise_Exception (Storage_Error'Identity, "object too large");
159 -- Change size from zero to non-zero. We still want a proper pointer
160 -- for the zero case because pointers to zero length objects have to
161 -- be distinct, but we can't just go ahead and allocate zero bytes,
162 -- since some malloc's return zero for a zero argument.
170 Result := c_malloc (Actual_Size);
172 -- Logs allocation call
174 -- 'A' <mem addr> <size chunk> <len backtrace> <addr1> ... <addrn>
177 Call_Chain (Tracebk'Address, Max_Call_Stack, Num_Calls);
178 Num_Calls := Num_Calls - Skip_Frame;
179 fputc (Character'Pos ('A'), Gmemfile);
180 fwrite (Result'Address, Address_Size, 1, Gmemfile);
181 fwrite (Actual_Size'Address, size_t'Max_Size_In_Storage_Elements, 1,
183 fwrite (Num_Calls'Address, Integer'Max_Size_In_Storage_Elements, 1,
185 fwrite (Tracebk (Skip_Frame)'Address, Address_Size, size_t (Num_Calls),
190 if Result = System.Null_Address then
191 Raise_Exception (Storage_Error'Identity, "heap exhausted");
201 Needs_Init : Boolean := True;
202 -- Reset after first call to Gmem_Initialize
204 procedure Finalize is
206 if not Needs_Init then
215 procedure Free (Ptr : System.Address) is
216 Addr : aliased constant System.Address := Ptr;
220 -- Logs deallocation call
222 -- 'D' <mem addr> <len backtrace> <addr1> ... <addrn>
225 Call_Chain (Tracebk'Address, Max_Call_Stack, Num_Calls);
226 Num_Calls := Num_Calls - Skip_Frame;
227 fputc (Character'Pos ('D'), Gmemfile);
228 fwrite (Addr'Address, Address_Size, 1, Gmemfile);
229 fwrite (Num_Calls'Address, Integer'Max_Size_In_Storage_Elements, 1,
231 fwrite (Tracebk (Skip_Frame)'Address, Address_Size, size_t (Num_Calls),
239 ---------------------
240 -- Gmem_Initialize --
241 ---------------------
243 procedure Gmem_Initialize is
247 Gmemfile := fopen (Gmemfname, "wb" & ASCII.NUL);
248 fwrite ("GMEM DUMP" & ASCII.LF, 10, 1, Gmemfile);
257 (Ptr : System.Address; Size : size_t) return System.Address
259 Result : System.Address;
261 if Size = size_t'Last then
262 Raise_Exception (Storage_Error'Identity, "object too large");
266 Result := c_realloc (Ptr, Size);
269 if Result = System.Null_Address then
270 Raise_Exception (Storage_Error'Identity, "heap exhausted");