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");