1 ------------------------------------------------------------------------------
3 -- GNAT RUN-TIME COMPONENTS --
5 -- S Y S T E M . M E M O R Y --
9 -- Copyright (C) 2001-2014, 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:
64 -- NOTE FOR FUTURE PLATFORMS SUPPORT: It is assumed that type Duration is
65 -- 64 bit. If the need arises to support architectures where this assumption
66 -- is incorrect, it will require changing the way timestamps of allocation
67 -- events are recorded.
69 pragma Source_File_Name (System.Memory, Body_File_Name => "memtrack.adb");
72 with System.Soft_Links;
73 with System.Traceback;
74 with System.Traceback_Entries;
76 with System.OS_Primitives;
78 package body System.Memory is
81 use System.Soft_Links;
83 use System.Traceback_Entries;
86 function c_malloc (Size : size_t) return System.Address;
87 pragma Import (C, c_malloc, "malloc");
89 procedure c_free (Ptr : System.Address);
90 pragma Import (C, c_free, "free");
93 (Ptr : System.Address; Size : size_t) return System.Address;
94 pragma Import (C, c_realloc, "realloc");
96 subtype File_Ptr is System.Address;
98 function fopen (Path : String; Mode : String) return File_Ptr;
99 pragma Import (C, fopen);
101 procedure OS_Exit (Status : Integer);
102 pragma Import (C, OS_Exit, "__gnat_os_exit");
103 pragma No_Return (OS_Exit);
106 (Ptr : System.Address;
116 pragma Import (C, fwrite);
118 procedure fputc (C : Integer; Stream : File_Ptr);
119 pragma Import (C, fputc);
121 procedure fclose (Stream : File_Ptr);
122 pragma Import (C, fclose);
125 pragma Export (C, Finalize, "__gnat_finalize");
126 -- Replace the default __gnat_finalize to properly close the log file
128 Address_Size : constant := System.Address'Max_Size_In_Storage_Elements;
129 -- Size in bytes of a pointer
131 Max_Call_Stack : constant := 200;
132 -- Maximum number of frames supported
134 Tracebk : Tracebacks_Array (1 .. Max_Call_Stack);
135 Num_Calls : aliased Integer := 0;
137 Gmemfname : constant String := "gmem.out" & ASCII.NUL;
138 -- Allocation log of a program is saved in a file gmem.out
139 -- ??? What about Ada.Command_Line.Command_Name & ".out" instead of static
143 -- Global C file pointer to the allocation log
145 Needs_Init : Boolean := True;
146 -- Reset after first call to Gmem_Initialize
148 procedure Gmem_Initialize;
149 -- Initialization routine; opens the file and writes a header string. This
150 -- header string is used as a magic-tag to know if the .out file is to be
151 -- handled by GDB or by the GMEM (instrumented malloc/free) implementation.
153 First_Call : Boolean := True;
154 -- Depending on implementation, some of the traceback routines may
155 -- themselves do dynamic allocation. We use First_Call flag to avoid
156 -- infinite recursion
162 function Alloc (Size : size_t) return System.Address is
163 Result : aliased System.Address;
164 Actual_Size : aliased size_t := Size;
165 Timestamp : aliased Duration;
168 if Size = size_t'Last then
169 Raise_Exception (Storage_Error'Identity, "object too large");
172 -- Change size from zero to non-zero. We still want a proper pointer
173 -- for the zero case because pointers to zero length objects have to
174 -- be distinct, but we can't just go ahead and allocate zero bytes,
175 -- since some malloc's return zero for a zero argument.
183 Result := c_malloc (Actual_Size);
187 -- Logs allocation call
189 -- 'A' <mem addr> <size chunk> <len backtrace> <addr1> ... <addrn>
197 Timestamp := System.OS_Primitives.Clock;
199 (Tracebk, Max_Call_Stack, Num_Calls, Skip_Frames => 2);
200 fputc (Character'Pos ('A'), Gmemfile);
201 fwrite (Result'Address, Address_Size, 1, Gmemfile);
202 fwrite (Actual_Size'Address, size_t'Max_Size_In_Storage_Elements, 1,
204 fwrite (Timestamp'Address, Duration'Max_Size_In_Storage_Elements, 1,
206 fwrite (Num_Calls'Address, Integer'Max_Size_In_Storage_Elements, 1,
209 for J in Tracebk'First .. Tracebk'First + Num_Calls - 1 loop
211 Ptr : System.Address := PC_For (Tracebk (J));
213 fwrite (Ptr'Address, Address_Size, 1, Gmemfile);
223 if Result = System.Null_Address then
224 Raise_Exception (Storage_Error'Identity, "heap exhausted");
234 procedure Finalize is
236 if not Needs_Init then
245 procedure Free (Ptr : System.Address) is
246 Addr : aliased constant System.Address := Ptr;
247 Timestamp : aliased Duration;
254 -- Logs deallocation call
256 -- 'D' <mem addr> <len backtrace> <addr1> ... <addrn>
265 (Tracebk, Max_Call_Stack, Num_Calls, Skip_Frames => 2);
266 Timestamp := System.OS_Primitives.Clock;
267 fputc (Character'Pos ('D'), Gmemfile);
268 fwrite (Addr'Address, Address_Size, 1, Gmemfile);
269 fwrite (Timestamp'Address, Duration'Max_Size_In_Storage_Elements, 1,
271 fwrite (Num_Calls'Address, Integer'Max_Size_In_Storage_Elements, 1,
274 for J in Tracebk'First .. Tracebk'First + Num_Calls - 1 loop
276 Ptr : System.Address := PC_For (Tracebk (J));
278 fwrite (Ptr'Address, Address_Size, 1, Gmemfile);
290 ---------------------
291 -- Gmem_Initialize --
292 ---------------------
294 procedure Gmem_Initialize is
295 Timestamp : aliased Duration;
300 System.OS_Primitives.Initialize;
301 Timestamp := System.OS_Primitives.Clock;
302 Gmemfile := fopen (Gmemfname, "wb" & ASCII.NUL);
304 if Gmemfile = System.Null_Address then
305 Put_Line ("Couldn't open gnatmem log file for writing");
309 fwrite ("GMEM DUMP" & ASCII.LF, 10, 1, Gmemfile);
310 fwrite (Timestamp'Address, Duration'Max_Size_In_Storage_Elements, 1,
320 (Ptr : System.Address;
321 Size : size_t) return System.Address
323 Addr : aliased constant System.Address := Ptr;
324 Result : aliased System.Address;
325 Timestamp : aliased Duration;
328 -- For the purposes of allocations logging, we treat realloc as a free
329 -- followed by malloc. This is not exactly accurate, but is a good way
330 -- to fit it into malloc/free-centered reports.
332 if Size = size_t'Last then
333 Raise_Exception (Storage_Error'Identity, "object too large");
342 -- We first log deallocation call
348 (Tracebk, Max_Call_Stack, Num_Calls, Skip_Frames => 2);
349 Timestamp := System.OS_Primitives.Clock;
350 fputc (Character'Pos ('D'), Gmemfile);
351 fwrite (Addr'Address, Address_Size, 1, Gmemfile);
352 fwrite (Timestamp'Address, Duration'Max_Size_In_Storage_Elements, 1,
354 fwrite (Num_Calls'Address, Integer'Max_Size_In_Storage_Elements, 1,
357 for J in Tracebk'First .. Tracebk'First + Num_Calls - 1 loop
359 Ptr : System.Address := PC_For (Tracebk (J));
361 fwrite (Ptr'Address, Address_Size, 1, Gmemfile);
365 -- Now perform actual realloc
367 Result := c_realloc (Ptr, Size);
369 -- Log allocation call using the same backtrace
371 fputc (Character'Pos ('A'), Gmemfile);
372 fwrite (Result'Address, Address_Size, 1, Gmemfile);
373 fwrite (Size'Address, size_t'Max_Size_In_Storage_Elements, 1,
375 fwrite (Timestamp'Address, Duration'Max_Size_In_Storage_Elements, 1,
377 fwrite (Num_Calls'Address, Integer'Max_Size_In_Storage_Elements, 1,
380 for J in Tracebk'First .. Tracebk'First + Num_Calls - 1 loop
382 Ptr : System.Address := PC_For (Tracebk (J));
384 fwrite (Ptr'Address, Address_Size, 1, Gmemfile);
394 if Result = System.Null_Address then
395 Raise_Exception (Storage_Error'Identity, "heap exhausted");