1 ------------------------------------------------------------------------------
3 -- GNU ADA RUN-TIME LIBRARY (GNARL) COMPONENTS --
5 -- S Y S T E M - S T A C K _ U S A G E --
9 -- Copyright (C) 2004-2007, Free Software Foundation, Inc. --
11 -- GNARL 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. GNARL 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 GNARL; see file COPYING. If not, write --
19 -- to the Free Software Foundation, 51 Franklin Street, Fifth Floor, --
20 -- Boston, MA 02110-1301, 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 -- GNARL was developed by the GNARL team at Florida State University. --
30 -- Extensive contributions were provided by Ada Core Technologies, Inc. --
32 ------------------------------------------------------------------------------
34 with System
.Parameters
;
38 package body System
.Stack_Usage
is
39 use System
.Storage_Elements
;
48 -- Stackl_Slots is an internal data type to represent a sequence of real
49 -- stack slots initialized with a provided pattern, with operations to
50 -- abstract away the target call stack growth direction.
52 type Stack_Slots
is array (Integer range <>) of Pattern_Type
;
53 for Stack_Slots
'Component_Size use Pattern_Type
'Object_Size;
55 -- We will carefully handle the initializations ourselves and might want
56 -- to remap an initialized overlay later on with an address clause.
58 pragma Suppress_Initialization
(Stack_Slots
);
60 -- The abstract Stack_Slots operations all operate over the simple array
63 -- memory addresses increasing ---->
65 -- Slots('First) Slots('Last)
68 -- +------------------------------------------------------------------+
70 -- +------------------------------------------------------------------+
72 -- What we call Top or Bottom always denotes call chain leaves or entry
73 -- points respectively, and their relative positions in the stack array
74 -- depends on the target stack growth direction:
78 -- <----- calls push frames towards decreasing addresses
80 -- Top(most) Slot Bottom(most) Slot
83 -- +------------------------------------------------------------------+
84 -- |####| | leaf frame | ... | entry frame |
85 -- +------------------------------------------------------------------+
89 -- calls push frames towards increasing addresses ----->
91 -- Bottom(most) Slot Top(most) Slot
94 -- +------------------------------------------------------------------+
95 -- | entry frame | ... | leaf frame | |####|
96 -- +------------------------------------------------------------------+
98 function Top_Slot_Index_In
(Stack
: Stack_Slots
) return Integer;
99 -- Index of the stack Top slot in the Slots array, denoting the latest
100 -- possible slot available to call chain leaves.
102 function Bottom_Slot_Index_In
(Stack
: Stack_Slots
) return Integer;
103 -- Index of the stack Bottom slot in the Slots array, denoting the first
104 -- possible slot available to call chain entry points.
106 function Push_Index_Step_For
(Stack
: Stack_Slots
) return Integer;
107 -- By how much do we need to update a Slots index to Push a single slot on
110 function Pop_Index_Step_For
(Stack
: Stack_Slots
) return Integer;
111 -- By how much do we need to update a Slots index to Pop a single slot off
114 pragma Inline_Always
(Top_Slot_Index_In
);
115 pragma Inline_Always
(Bottom_Slot_Index_In
);
116 pragma Inline_Always
(Push_Index_Step_For
);
117 pragma Inline_Always
(Pop_Index_Step_For
);
119 -----------------------
120 -- Top_Slot_Index_In --
121 -----------------------
123 function Top_Slot_Index_In
(Stack
: Stack_Slots
) return Integer is
125 if System
.Parameters
.Stack_Grows_Down
then
130 end Top_Slot_Index_In
;
132 ----------------------------
133 -- Bottom_Slot_Index_In --
134 ----------------------------
136 function Bottom_Slot_Index_In
(Stack
: Stack_Slots
) return Integer is
138 if System
.Parameters
.Stack_Grows_Down
then
143 end Bottom_Slot_Index_In
;
145 -------------------------
146 -- Push_Index_Step_For --
147 -------------------------
149 function Push_Index_Step_For
(Stack
: Stack_Slots
) return Integer is
150 pragma Unreferenced
(Stack
);
152 if System
.Parameters
.Stack_Grows_Down
then
157 end Push_Index_Step_For
;
159 ------------------------
160 -- Pop_Index_Step_For --
161 ------------------------
163 function Pop_Index_Step_For
(Stack
: Stack_Slots
) return Integer is
165 return -Push_Index_Step_For
(Stack
);
166 end Pop_Index_Step_For
;
172 -- Now the implementation of the services offered by this unit, on top of
173 -- the Stack_Slots abstraction above.
175 Index_Str
: constant String := "Index";
176 Task_Name_Str
: constant String := "Task Name";
177 Stack_Size_Str
: constant String := "Stack Size";
178 Actual_Size_Str
: constant String := "Stack usage [min - max]";
180 function Get_Usage_Range
(Result
: Task_Result
) return String;
181 -- Return string representing the range of possible result of stack usage
183 procedure Output_Result
184 (Result_Id
: Natural;
185 Result
: Task_Result
;
186 Max_Stack_Size_Len
: Natural;
187 Max_Actual_Use_Len
: Natural);
188 -- Prints the result on the standard output. Result Id is the number of
189 -- the result in the array, and Result the contents of the actual result.
190 -- Max_Stack_Size_Len and Max_Actual_Use_Len are used for displaying the
191 -- proper layout. They hold the maximum length of the string representing
192 -- the Stack_Size and Actual_Use values.
198 procedure Initialize
(Buffer_Size
: Natural) is
199 Bottom_Of_Stack
: aliased Integer;
200 Stack_Size_Chars
: System
.Address
;
203 -- Initialize the buffered result array
205 Result_Array
:= new Result_Array_Type
(1 .. Buffer_Size
);
208 (Task_Name
=> (others => ASCII
.NUL
),
211 Overflow_Guard
=> 0));
213 -- Set the Is_Enabled flag to true, so that the task wrapper knows that
214 -- it has to handle dynamic stack analysis
218 Stack_Size_Chars
:= System
.CRTL
.getenv
("GNAT_STACK_LIMIT" & ASCII
.NUL
);
220 -- If variable GNAT_STACK_LIMIT is set, then we will take care of the
221 -- environment task, using GNAT_STASK_LIMIT as the size of the stack.
222 -- It doens't make sens to process the stack when no bound is set (e.g.
223 -- limit is typically up to 4 GB).
225 if Stack_Size_Chars
/= Null_Address
then
227 Stack_Size
: Integer;
230 Stack_Size
:= System
.CRTL
.atoi
(Stack_Size_Chars
) * 1024;
233 (Environment_Task_Analyzer
,
237 System
.Storage_Elements
.To_Integer
(Bottom_Of_Stack
'Address));
239 Fill_Stack
(Environment_Task_Analyzer
);
241 Compute_Environment_Task
:= True;
244 -- GNAT_STACK_LIMIT not set
247 Compute_Environment_Task
:= False;
255 procedure Fill_Stack
(Analyzer
: in out Stack_Analyzer
) is
257 -- Change the local variables and parameters of this function with
258 -- super-extra care. The more the stack frame size of this function is
259 -- big, the more an "instrumentation threshold at writing" error is
262 Stack
: aliased Stack_Slots
(1 .. Analyzer
.Size
/ Bytes_Per_Pattern
);
265 Stack
:= (others => Analyzer
.Pattern
);
267 Analyzer
.Stack_Overlay_Address
:= Stack
'Address;
269 Analyzer
.Bottom_Pattern_Mark
:=
270 To_Stack_Address
(Stack
(Bottom_Slot_Index_In
(Stack
))'Address);
271 Analyzer
.Top_Pattern_Mark
:=
272 To_Stack_Address
(Stack
(Top_Slot_Index_In
(Stack
))'Address);
274 -- If Arr has been packed, the following assertion must be true (we add
275 -- the size of the element whose address is:
276 -- Min (Analyzer.Inner_Pattern_Mark, Analyzer.Outer_Pattern_Mark)):
281 (Analyzer
.Top_Pattern_Mark
, Analyzer
.Bottom_Pattern_Mark
));
284 -------------------------
285 -- Initialize_Analyzer --
286 -------------------------
288 procedure Initialize_Analyzer
289 (Analyzer
: in out Stack_Analyzer
;
292 Overflow_Guard
: Natural;
293 Bottom
: Stack_Address
;
294 Pattern
: Unsigned_32
:= 16#DEAD_BEEF#
)
297 -- Initialize the analyzer fields
299 Analyzer
.Bottom_Of_Stack
:= Bottom
;
300 Analyzer
.Size
:= Size
;
301 Analyzer
.Pattern
:= Pattern
;
302 Analyzer
.Result_Id
:= Next_Id
;
304 Analyzer
.Task_Name
:= (others => ' ');
306 -- Compute the task name, and truncate it if it's bigger than
309 if Task_Name
'Length <= Task_Name_Length
then
310 Analyzer
.Task_Name
(1 .. Task_Name
'Length) := Task_Name
;
312 Analyzer
.Task_Name
:=
313 Task_Name
(Task_Name
'First ..
314 Task_Name
'First + Task_Name_Length
- 1);
317 Analyzer
.Overflow_Guard
:= Overflow_Guard
;
319 Next_Id
:= Next_Id
+ 1;
320 end Initialize_Analyzer
;
327 (SP_Low
: Stack_Address
;
328 SP_High
: Stack_Address
) return Natural
331 if SP_Low
> SP_High
then
332 return Natural (SP_Low
- SP_High
+ 4);
334 return Natural (SP_High
- SP_Low
+ 4);
342 procedure Compute_Result
(Analyzer
: in out Stack_Analyzer
) is
344 -- Change the local variables and parameters of this function with
345 -- super-extra care. The larger the stack frame size of this function
346 -- is, the more an "instrumentation threshold at reading" error is
349 Stack
: Stack_Slots
(1 .. Analyzer
.Size
/ Bytes_Per_Pattern
);
350 for Stack
'Address use Analyzer
.Stack_Overlay_Address
;
353 Analyzer
.Topmost_Touched_Mark
:= Analyzer
.Bottom_Pattern_Mark
;
355 -- Look backward from the topmost possible end of the marked stack to
356 -- the bottom of it. The first index not equals to the patterns marks
357 -- the beginning of the used stack.
360 Top_Index
: constant Integer := Top_Slot_Index_In
(Stack
);
361 Bottom_Index
: constant Integer := Bottom_Slot_Index_In
(Stack
);
362 Step
: constant Integer := Pop_Index_Step_For
(Stack
);
368 if Stack
(J
) /= Analyzer
.Pattern
then
369 Analyzer
.Topmost_Touched_Mark
370 := To_Stack_Address
(Stack
(J
)'Address);
374 exit when J
= Bottom_Index
;
380 ---------------------
381 -- Get_Usage_Range --
382 ---------------------
384 function Get_Usage_Range
(Result
: Task_Result
) return String is
385 Min_Used_Str
: constant String :=
386 Natural'Image (Result
.Measure
);
387 Max_Used_Str
: constant String :=
388 Natural'Image (Result
.Measure
+ Result
.Overflow_Guard
);
390 return "[" & Min_Used_Str
(2 .. Min_Used_Str
'Last) & " -"
391 & Max_Used_Str
& "]";
394 ---------------------
396 ---------------------
398 procedure Output_Result
399 (Result_Id
: Natural;
400 Result
: Task_Result
;
401 Max_Stack_Size_Len
: Natural;
402 Max_Actual_Use_Len
: Natural)
404 Result_Id_Str
: constant String := Natural'Image (Result_Id
);
405 Stack_Size_Str
: constant String := Natural'Image (Result
.Max_Size
);
406 Actual_Use_Str
: constant String := Get_Usage_Range
(Result
);
408 Result_Id_Blanks
: constant
409 String (1 .. Index_Str
'Length - Result_Id_Str
'Length) :=
412 Stack_Size_Blanks
: constant
413 String (1 .. Max_Stack_Size_Len
- Stack_Size_Str
'Length) :=
416 Actual_Use_Blanks
: constant
417 String (1 .. Max_Actual_Use_Len
- Actual_Use_Str
'Length) :=
421 Set_Output
(Standard_Error
);
422 Put
(Result_Id_Blanks
& Natural'Image (Result_Id
));
424 Put
(Result
.Task_Name
);
426 Put
(Stack_Size_Blanks
& Stack_Size_Str
);
428 Put
(Actual_Use_Blanks
& Actual_Use_Str
);
432 ---------------------
434 ---------------------
436 procedure Output_Results
is
437 Max_Stack_Size
: Natural := 0;
438 Max_Actual_Use_Result_Id
: Natural := Result_Array
'First;
439 Max_Stack_Size_Len
, Max_Actual_Use_Len
: Natural := 0;
441 Task_Name_Blanks
: constant
442 String (1 .. Task_Name_Length
- Task_Name_Str
'Length) :=
446 Set_Output
(Standard_Error
);
448 if Compute_Environment_Task
then
449 Compute_Result
(Environment_Task_Analyzer
);
450 Report_Result
(Environment_Task_Analyzer
);
453 if Result_Array
'Length > 0 then
455 -- Computes the size of the largest strings that will get displayed,
456 -- in order to do correct column alignment.
458 for J
in Result_Array
'Range loop
459 exit when J
>= Next_Id
;
461 if Result_Array
(J
).Measure
462 > Result_Array
(Max_Actual_Use_Result_Id
).Measure
464 Max_Actual_Use_Result_Id
:= J
;
467 if Result_Array
(J
).Max_Size
> Max_Stack_Size
then
468 Max_Stack_Size
:= Result_Array
(J
).Max_Size
;
472 Max_Stack_Size_Len
:= Natural'Image (Max_Stack_Size
)'Length;
474 Max_Actual_Use_Len
:=
475 Get_Usage_Range
(Result_Array
(Max_Actual_Use_Result_Id
))'Length;
477 -- Display the output header. Blanks will be added in front of the
481 Stack_Size_Blanks
: constant
482 String (1 .. Max_Stack_Size_Len
- Stack_Size_Str
'Length) :=
485 Stack_Usage_Blanks
: constant
486 String (1 .. Max_Actual_Use_Len
- Actual_Size_Str
'Length) :=
490 if Stack_Size_Str
'Length > Max_Stack_Size_Len
then
491 Max_Stack_Size_Len
:= Stack_Size_Str
'Length;
494 if Actual_Size_Str
'Length > Max_Actual_Use_Len
then
495 Max_Actual_Use_Len
:= Actual_Size_Str
'Length;
499 (Index_Str
& " | " & Task_Name_Str
& Task_Name_Blanks
& " | "
500 & Stack_Size_Str
& Stack_Size_Blanks
& " | "
501 & Stack_Usage_Blanks
& Actual_Size_Str
);
506 -- Now display the individual results
508 for J
in Result_Array
'Range loop
509 exit when J
>= Next_Id
;
511 (J
, Result_Array
(J
), Max_Stack_Size_Len
, Max_Actual_Use_Len
);
514 -- Case of no result stored, still display the labels
518 (Index_Str
& " | " & Task_Name_Str
& Task_Name_Blanks
& " | "
519 & Stack_Size_Str
& " | " & Actual_Size_Str
);
528 procedure Report_Result
(Analyzer
: Stack_Analyzer
) is
529 Result
: constant Task_Result
:=
530 (Task_Name
=> Analyzer
.Task_Name
,
531 Max_Size
=> Analyzer
.Size
+ Analyzer
.Overflow_Guard
,
532 Measure
=> Stack_Size
533 (Analyzer
.Topmost_Touched_Mark
,
534 Analyzer
.Bottom_Of_Stack
),
535 Overflow_Guard
=> Analyzer
.Overflow_Guard
-
536 Natural (Analyzer
.Bottom_Of_Stack
-
537 Analyzer
.Bottom_Pattern_Mark
));
540 if Analyzer
.Result_Id
in Result_Array
'Range then
542 -- If the result can be stored, then store it in Result_Array
544 Result_Array
(Analyzer
.Result_Id
) := Result
;
547 -- If the result cannot be stored, then we display it right away
550 Result_Str_Len
: constant Natural :=
551 Get_Usage_Range
(Result
)'Length;
552 Size_Str_Len
: constant Natural :=
553 Natural'Image (Analyzer
.Size
)'Length;
555 Max_Stack_Size_Len
: Natural;
556 Max_Actual_Use_Len
: Natural;
559 -- Take either the label size or the number image size for the
560 -- size of the column "Stack Size".
562 if Size_Str_Len
> Stack_Size_Str
'Length then
563 Max_Stack_Size_Len
:= Size_Str_Len
;
565 Max_Stack_Size_Len
:= Stack_Size_Str
'Length;
568 -- Take either the label size or the number image size for the
569 -- size of the column "Stack Usage"
571 if Result_Str_Len
> Actual_Size_Str
'Length then
572 Max_Actual_Use_Len
:= Result_Str_Len
;
574 Max_Actual_Use_Len
:= Actual_Size_Str
'Length;
586 end System
.Stack_Usage
;