1 ------------------------------------------------------------------------------
3 -- GNAT RUN-TIME COMPONENTS --
5 -- S Y S T E M . M E M O R Y --
9 -- Copyright (C) 2001-2004 Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 2, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING. If not, write --
19 -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
20 -- MA 02111-1307, USA. --
22 -- As a special exception, if other files instantiate generics from this --
23 -- unit, or you link this unit with other files to produce an executable, --
24 -- this unit does not by itself cause the resulting executable to be --
25 -- covered by the GNU General Public License. This exception does not --
26 -- however invalidate any other reasons why the executable file might be --
27 -- covered by the GNU Public License. --
29 -- GNAT was originally developed by the GNAT team at New York University. --
30 -- Extensive contributions were provided by Ada Core Technologies Inc. --
32 ------------------------------------------------------------------------------
34 -- This version contains allocation tracking capability
36 -- The object file corresponding to this instrumented version is to be found
39 -- When enabled, the subsystem logs all the calls to __gnat_malloc and
40 -- __gnat_free. This log can then be processed by gnatmem to detect
41 -- dynamic memory leaks.
43 -- To use this functionality, you must compile your application with -g
44 -- and then link with this object file:
46 -- gnatmake -g program -largs -lgmem
48 -- After compilation, you may use your program as usual except that upon
49 -- completion, it will generate in the current directory the file gmem.out.
51 -- You can then investigate for possible memory leaks and mismatch by calling
52 -- gnatmem with this file as an input:
54 -- gnatmem -i gmem.out program
56 -- See gnatmem section in the GNAT User's Guide for more details.
58 -- NOTE: This capability is currently supported on the following targets:
68 pragma Source_File_Name (System.Memory, Body_File_Name => "memtrack.adb");
71 with System.Soft_Links;
72 with System.Traceback;
73 with System.Traceback_Entries;
76 package body System.Memory is
79 use System.Soft_Links;
81 use System.Traceback_Entries;
84 function c_malloc (Size : size_t) return System.Address;
85 pragma Import (C, c_malloc, "malloc");
87 procedure c_free (Ptr : System.Address);
88 pragma Import (C, c_free, "free");
91 (Ptr : System.Address; Size : size_t) return System.Address;
92 pragma Import (C, c_realloc, "realloc");
94 subtype File_Ptr is System.Address;
96 function fopen (Path : String; Mode : String) return File_Ptr;
97 pragma Import (C, fopen);
99 procedure OS_Exit (Status : Integer);
100 pragma Import (C, OS_Exit, "__gnat_os_exit");
101 pragma No_Return (OS_Exit);
104 (Ptr : System.Address;
114 pragma Import (C, fwrite);
116 procedure fputc (C : Integer; Stream : File_Ptr);
117 pragma Import (C, fputc);
119 procedure fclose (Stream : File_Ptr);
120 pragma Import (C, fclose);
123 -- Replace the default __gnat_finalize to properly close the log file.
124 pragma Export (C, Finalize, "__gnat_finalize");
126 Address_Size : constant := System.Address'Max_Size_In_Storage_Elements;
127 -- Size in bytes of a pointer
129 Max_Call_Stack : constant := 200;
130 -- Maximum number of frames supported
132 Tracebk : aliased array (0 .. Max_Call_Stack) of Traceback_Entry;
133 Num_Calls : aliased Integer := 0;
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.
148 First_Call : Boolean := True;
149 -- Depending on implementation, some of the traceback routines may
150 -- themselves do dynamic allocation. We use First_Call flag to avoid
151 -- infinite recursion
157 function Alloc (Size : size_t) return System.Address is
158 Result : aliased System.Address;
159 Actual_Size : aliased size_t := Size;
162 if Size = size_t'Last then
163 Raise_Exception (Storage_Error'Identity, "object too large");
166 -- Change size from zero to non-zero. We still want a proper pointer
167 -- for the zero case because pointers to zero length objects have to
168 -- be distinct, but we can't just go ahead and allocate zero bytes,
169 -- since some malloc's return zero for a zero argument.
177 Result := c_malloc (Actual_Size);
181 -- Logs allocation call
183 -- 'A' <mem addr> <size chunk> <len backtrace> <addr1> ... <addrn>
188 Call_Chain (Tracebk'Address, Max_Call_Stack, Num_Calls,
190 fputc (Character'Pos ('A'), Gmemfile);
191 fwrite (Result'Address, Address_Size, 1, Gmemfile);
192 fwrite (Actual_Size'Address, size_t'Max_Size_In_Storage_Elements, 1,
194 fwrite (Num_Calls'Address, Integer'Max_Size_In_Storage_Elements, 1,
197 for J in Tracebk'First .. Tracebk'First + Num_Calls - 1 loop
199 Ptr : System.Address := PC_For (Tracebk (J));
201 fwrite (Ptr'Address, Address_Size, 1, Gmemfile);
211 if Result = System.Null_Address then
212 Raise_Exception (Storage_Error'Identity, "heap exhausted");
222 Needs_Init : Boolean := True;
223 -- Reset after first call to Gmem_Initialize
225 procedure Finalize is
227 if not Needs_Init then
236 procedure Free (Ptr : System.Address) is
237 Addr : aliased constant System.Address := Ptr;
244 -- Logs deallocation call
246 -- 'D' <mem addr> <len backtrace> <addr1> ... <addrn>
251 Call_Chain (Tracebk'Address, Max_Call_Stack, Num_Calls,
253 fputc (Character'Pos ('D'), Gmemfile);
254 fwrite (Addr'Address, Address_Size, 1, Gmemfile);
255 fwrite (Num_Calls'Address, Integer'Max_Size_In_Storage_Elements, 1,
258 for J in Tracebk'First .. Tracebk'First + Num_Calls - 1 loop
260 Ptr : System.Address := PC_For (Tracebk (J));
262 fwrite (Ptr'Address, Address_Size, 1, Gmemfile);
274 ---------------------
275 -- Gmem_Initialize --
276 ---------------------
278 procedure Gmem_Initialize is
282 Gmemfile := fopen (Gmemfname, "wb" & ASCII.NUL);
284 if Gmemfile = System.Null_Address then
285 Put_Line ("Couldn't open gnatmem log file for writing");
289 fwrite ("GMEM DUMP" & ASCII.LF, 10, 1, Gmemfile);
298 (Ptr : System.Address; Size : size_t) return System.Address
300 Addr : aliased constant System.Address := Ptr;
301 Result : aliased System.Address;
304 -- For the purposes of allocations logging, we treat realloc as a free
305 -- followed by malloc. This is not exactly accurate, but is a good way
306 -- to fit it into malloc/free-centered reports.
308 if Size = size_t'Last then
309 Raise_Exception (Storage_Error'Identity, "object too large");
318 -- We first log deallocation call
321 Call_Chain (Tracebk'Address, Max_Call_Stack, Num_Calls,
323 fputc (Character'Pos ('D'), Gmemfile);
324 fwrite (Addr'Address, Address_Size, 1, Gmemfile);
325 fwrite (Num_Calls'Address, Integer'Max_Size_In_Storage_Elements, 1,
328 for J in Tracebk'First .. Tracebk'First + Num_Calls - 1 loop
330 Ptr : System.Address := PC_For (Tracebk (J));
332 fwrite (Ptr'Address, Address_Size, 1, Gmemfile);
336 -- Now perform actual realloc
338 Result := c_realloc (Ptr, Size);
340 -- Log allocation call using the same backtrace
342 fputc (Character'Pos ('A'), Gmemfile);
343 fwrite (Result'Address, Address_Size, 1, Gmemfile);
344 fwrite (Size'Address, size_t'Max_Size_In_Storage_Elements, 1,
346 fwrite (Num_Calls'Address, Integer'Max_Size_In_Storage_Elements, 1,
349 for J in Tracebk'First .. Tracebk'First + Num_Calls - 1 loop
351 Ptr : System.Address := PC_For (Tracebk (J));
353 fwrite (Ptr'Address, Address_Size, 1, Gmemfile);
363 if Result = System.Null_Address then
364 Raise_Exception (Storage_Error'Identity, "heap exhausted");