1 ------------------------------------------------------------------------------
3 -- GNAT RUN-TIME COMPONENTS --
5 -- S Y S T E M . M E M O R Y --
9 -- Copyright (C) 2001-2009, 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 3, 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. --
18 -- As a special exception under Section 7 of GPL version 3, you are granted --
19 -- additional permissions described in the GCC Runtime Library Exception, --
20 -- version 3.1, as published by the Free Software Foundation. --
22 -- You should have received a copy of the GNU General Public License and --
23 -- a copy of the GCC Runtime Library Exception along with this program; --
24 -- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
25 -- <http://www.gnu.org/licenses/>. --
27 -- GNAT was originally developed by the GNAT team at New York University. --
28 -- Extensive contributions were provided by Ada Core Technologies Inc. --
30 ------------------------------------------------------------------------------
32 -- This version contains allocation tracking capability
34 -- The object file corresponding to this instrumented version is to be found
37 -- When enabled, the subsystem logs all the calls to __gnat_malloc and
38 -- __gnat_free. This log can then be processed by gnatmem to detect
39 -- dynamic memory leaks.
41 -- To use this functionality, you must compile your application with -g
42 -- and then link with this object file:
44 -- gnatmake -g program -largs -lgmem
46 -- After compilation, you may use your program as usual except that upon
47 -- completion, it will generate in the current directory the file gmem.out.
49 -- You can then investigate for possible memory leaks and mismatch by calling
50 -- gnatmem with this file as an input:
52 -- gnatmem -i gmem.out program
54 -- See gnatmem section in the GNAT User's Guide for more details
56 -- NOTE: This capability is currently supported on the following targets:
67 -- NOTE FOR FUTURE PLATFORMS SUPPORT: It is assumed that type Duration is
68 -- 64 bit. If the need arises to support architectures where this assumption
69 -- is incorrect, it will require changing the way timestamps of allocation
70 -- events are recorded.
72 pragma Source_File_Name (System.Memory, Body_File_Name => "memtrack.adb");
75 with System.Soft_Links;
76 with System.Traceback;
77 with System.Traceback_Entries;
79 with System.OS_Primitives;
81 package body System.Memory is
84 use System.Soft_Links;
86 use System.Traceback_Entries;
89 function c_malloc (Size : size_t) return System.Address;
90 pragma Import (C, c_malloc, "malloc");
92 procedure c_free (Ptr : System.Address);
93 pragma Import (C, c_free, "free");
96 (Ptr : System.Address; Size : size_t) return System.Address;
97 pragma Import (C, c_realloc, "realloc");
99 subtype File_Ptr is System.Address;
101 function fopen (Path : String; Mode : String) return File_Ptr;
102 pragma Import (C, fopen);
104 procedure OS_Exit (Status : Integer);
105 pragma Import (C, OS_Exit, "__gnat_os_exit");
106 pragma No_Return (OS_Exit);
109 (Ptr : System.Address;
119 pragma Import (C, fwrite);
121 procedure fputc (C : Integer; Stream : File_Ptr);
122 pragma Import (C, fputc);
124 procedure fclose (Stream : File_Ptr);
125 pragma Import (C, fclose);
128 pragma Export (C, Finalize, "__gnat_finalize");
129 -- Replace the default __gnat_finalize to properly close the log file
131 Address_Size : constant := System.Address'Max_Size_In_Storage_Elements;
132 -- Size in bytes of a pointer
134 Max_Call_Stack : constant := 200;
135 -- Maximum number of frames supported
137 Tracebk : aliased array (0 .. Max_Call_Stack) of Traceback_Entry;
138 Num_Calls : aliased Integer := 0;
140 Gmemfname : constant String := "gmem.out" & ASCII.NUL;
141 -- Allocation log of a program is saved in a file gmem.out
142 -- ??? What about Ada.Command_Line.Command_Name & ".out" instead of static
146 -- Global C file pointer to the allocation log
148 Needs_Init : Boolean := True;
149 -- Reset after first call to Gmem_Initialize
151 procedure Gmem_Initialize;
152 -- Initialization routine; opens the file and writes a header string. This
153 -- header string is used as a magic-tag to know if the .out file is to be
154 -- handled by GDB or by the GMEM (instrumented malloc/free) implementation.
156 First_Call : Boolean := True;
157 -- Depending on implementation, some of the traceback routines may
158 -- themselves do dynamic allocation. We use First_Call flag to avoid
159 -- infinite recursion
165 function Alloc (Size : size_t) return System.Address is
166 Result : aliased System.Address;
167 Actual_Size : aliased size_t := Size;
168 Timestamp : aliased Duration;
171 if Size = size_t'Last then
172 Raise_Exception (Storage_Error'Identity, "object too large");
175 -- Change size from zero to non-zero. We still want a proper pointer
176 -- for the zero case because pointers to zero length objects have to
177 -- be distinct, but we can't just go ahead and allocate zero bytes,
178 -- since some malloc's return zero for a zero argument.
186 Result := c_malloc (Actual_Size);
190 -- Logs allocation call
192 -- 'A' <mem addr> <size chunk> <len backtrace> <addr1> ... <addrn>
200 Timestamp := System.OS_Primitives.Clock;
201 Call_Chain (Tracebk'Address, Max_Call_Stack, Num_Calls,
203 fputc (Character'Pos ('A'), Gmemfile);
204 fwrite (Result'Address, Address_Size, 1, Gmemfile);
205 fwrite (Actual_Size'Address, size_t'Max_Size_In_Storage_Elements, 1,
207 fwrite (Timestamp'Address, Duration'Max_Size_In_Storage_Elements, 1,
209 fwrite (Num_Calls'Address, Integer'Max_Size_In_Storage_Elements, 1,
212 for J in Tracebk'First .. Tracebk'First + Num_Calls - 1 loop
214 Ptr : System.Address := PC_For (Tracebk (J));
216 fwrite (Ptr'Address, Address_Size, 1, Gmemfile);
226 if Result = System.Null_Address then
227 Raise_Exception (Storage_Error'Identity, "heap exhausted");
237 procedure Finalize is
239 if not Needs_Init then
248 procedure Free (Ptr : System.Address) is
249 Addr : aliased constant System.Address := Ptr;
250 Timestamp : aliased Duration;
257 -- Logs deallocation call
259 -- 'D' <mem addr> <len backtrace> <addr1> ... <addrn>
267 Call_Chain (Tracebk'Address, Max_Call_Stack, Num_Calls,
269 Timestamp := System.OS_Primitives.Clock;
270 fputc (Character'Pos ('D'), Gmemfile);
271 fwrite (Addr'Address, Address_Size, 1, Gmemfile);
272 fwrite (Timestamp'Address, Duration'Max_Size_In_Storage_Elements, 1,
274 fwrite (Num_Calls'Address, Integer'Max_Size_In_Storage_Elements, 1,
277 for J in Tracebk'First .. Tracebk'First + Num_Calls - 1 loop
279 Ptr : System.Address := PC_For (Tracebk (J));
281 fwrite (Ptr'Address, Address_Size, 1, Gmemfile);
293 ---------------------
294 -- Gmem_Initialize --
295 ---------------------
297 procedure Gmem_Initialize is
298 Timestamp : aliased Duration;
303 System.OS_Primitives.Initialize;
304 Timestamp := System.OS_Primitives.Clock;
305 Gmemfile := fopen (Gmemfname, "wb" & ASCII.NUL);
307 if Gmemfile = System.Null_Address then
308 Put_Line ("Couldn't open gnatmem log file for writing");
312 fwrite ("GMEM DUMP" & ASCII.LF, 10, 1, Gmemfile);
313 fwrite (Timestamp'Address, Duration'Max_Size_In_Storage_Elements, 1,
323 (Ptr : System.Address;
324 Size : size_t) return System.Address
326 Addr : aliased constant System.Address := Ptr;
327 Result : aliased System.Address;
328 Timestamp : aliased Duration;
331 -- For the purposes of allocations logging, we treat realloc as a free
332 -- followed by malloc. This is not exactly accurate, but is a good way
333 -- to fit it into malloc/free-centered reports.
335 if Size = size_t'Last then
336 Raise_Exception (Storage_Error'Identity, "object too large");
345 -- We first log deallocation call
350 Call_Chain (Tracebk'Address, Max_Call_Stack, Num_Calls,
352 Timestamp := System.OS_Primitives.Clock;
353 fputc (Character'Pos ('D'), Gmemfile);
354 fwrite (Addr'Address, Address_Size, 1, Gmemfile);
355 fwrite (Timestamp'Address, Duration'Max_Size_In_Storage_Elements, 1,
357 fwrite (Num_Calls'Address, Integer'Max_Size_In_Storage_Elements, 1,
360 for J in Tracebk'First .. Tracebk'First + Num_Calls - 1 loop
362 Ptr : System.Address := PC_For (Tracebk (J));
364 fwrite (Ptr'Address, Address_Size, 1, Gmemfile);
368 -- Now perform actual realloc
370 Result := c_realloc (Ptr, Size);
372 -- Log allocation call using the same backtrace
374 fputc (Character'Pos ('A'), Gmemfile);
375 fwrite (Result'Address, Address_Size, 1, Gmemfile);
376 fwrite (Size'Address, size_t'Max_Size_In_Storage_Elements, 1,
378 fwrite (Timestamp'Address, Duration'Max_Size_In_Storage_Elements, 1,
380 fwrite (Num_Calls'Address, Integer'Max_Size_In_Storage_Elements, 1,
383 for J in Tracebk'First .. Tracebk'First + Num_Calls - 1 loop
385 Ptr : System.Address := PC_For (Tracebk (J));
387 fwrite (Ptr'Address, Address_Size, 1, Gmemfile);
397 if Result = System.Null_Address then
398 Raise_Exception (Storage_Error'Identity, "heap exhausted");