Autohotkey: how to declare global variable after #ifwinactive - if-statement

When I declare a global variable after #ifwinactive, an error message pop up showing that the variable is not declared.
I have a long script where there are many #ifwinactive ahk_exe xxx. Below those codes, I want to declare a global variable. But that doesn't work. Whenever I run the script, it warns me the global variable is not declared. Here's a brief of my script.
On the top of the script I have these environment settings:
#NoEnv
#Warn
SendMode Input
SetWorkingDir %A_ScriptDir%
SetTitleMatchMode, 2
Then I have many window-specific hotkeys:
#ifwinactive ahk_exe Explorer.EXE
;some hotkeys
#ifwinactive ahk_exe WINWORD.EXE
;some extra hotkeys
;etc.
At the bottom, I try to declare a global variable and this is where the error occurs:
#ifwinactive
a := 1
^p::
if (a != 1){
a := 1
} else {
a := 0
}
return
#if winactive("- YouTube -") and a != 1
p::msgbox,Yes
#if a = 1 and winactive("- YouTube -")
p::msgbox,no
#if

You're declaring the variable a outside of the auto-execute section.
Code execution never actually reaches a := 1, it's stopped when your first hotkey definition is met.
Also, it's not an error, just a warning. Due to how forgiving AHK is, it doesn't actually matter if you don't declare the variable before use. It'll start off with the default value of nothing, which works for your a != 1 check.
Also, after you run the ^p hotkey at least once, it'll behave as intended.
But anyway, to get rid of warning, you'd declare the variable in the auto-execute section of your script (at the top).
And an extra thing to consider:
Don't use #If unless you actually need it. It can cause trouble (as the documentation states), depending on what sort of a script you have.
If a win active check, and a toggle is all you need to check for, I don't think it really warrants usage of #If.

Related

Change variable value of the already running program

I think it is impossible, but I should try.
I have a program, that is doing a physical simulation and recording frames to files. It is recording until the breakup value is not achieved, like:
int counter=0; //global variable
void SomeFunction()
{
...
if(counter == 400) //written exactly by this way, i.e. 400 is not a variable, just a number
PostQuitMessage(0);
else
MakeScreenshot();
counter++;
...
}
The problem is that I forgot to change if(counter == 400) to if(counter == 1000) and now program will be finished with 400 frames, although I need exactly 1000.
I can’t just recompile the program because calculations are very heavy and the program is already running for 2 days, I can’t wait.
It is very important for me, is there any way to change the if statement, or exactly the variable value during the program running?
The only hope I have, is, as far as I remember there was programs that could like change money/health/another stuff in games, and there user exactly could search a variable by value, and change it
Currently it is on about 200-300 frame, I have so little time to fix it.
You can use the Windows functions ReadProcessMemory and WriteProcessMemory.
But you need to determine the position of the value 400. Looking for the value in the running program can be done with the above functions. Depending on the size of the constant, it should be either a USHORT or an UINT.
So you can use the following steps:
Look for the value in a second instance
Isolate the surrounding OpCode sequence.
For example, a cmp xxx, 400
Look for this OpCode sequence in the running executable to find the unique location and replace the crucial value by 1000.
This can be called "hot-patch". It's how simple in-memory cheats do work and requires root privileges.
I downloaded Cheat engine and found address of the counter variable by its value. Through all addresses, the address I need was colored in green.
I changed the value stored at that address to 401, and now all is ok.

Scilab compilation "cannot allocate this quantity of memory"

I am facing issues with memory allocation in Scilab after compiling.
I am compiling on a Red Hat on ppc64 (POWER8). Stack limits are already set to unlimited (ulimit -s unlimited). The ./configure script (with several options I am not showing here) runs successfully, but the make all fails and stops. When it stops, it is stuck at the Scilab command prompt with this message:
./bin/scilab-cli -ns -noatomsautoload -f modules/functions/scripts/buildmacros/buildmacros.sce
stacksize(5000000);
!--error 10001
stacksize: Cannot allocate memory.
%s: Cannot allocate this quantity of memory.
at line 27 of exec file called by :
exec('modules/functions/scripts/buildmacros/buildmacros.sce',-1)
-->
I have investigated a bit, and that error message seems to be called of course at line 00027 in buildmatros.sce, where the function stacksize(5000000) is called.
This function is defined in:
scilab-5.5.1/modules/core/sci_gateway/c/sci_stacksize.c
I found a version of the file at this page: http://doxygen.scilab.org/master_wg/d5/dfb/sci__stacksize_8c_source.html.
The condition that is FALSE and that triggers the message seems to me to show up at line 00295.
Inside that file, you see that error is displayed whenever the stacksize given as input is LARGER than what is returned by the method get_max_memory_for_scilab_stack() from the class:
scilab-5.5.1/modules/core/src/c/stackinfo.c
Again I found a version online at the following page:
http://doxygen.scilab.org/master_wg/dd/dfb/stackinfo_8h.html#afbd65a57df45bed9445a7393a4558395
The Method is declared from line 109.
It seems to invoke a variable called MAXLONG, which is however NEVER explicitly declared! As you see, it is declared several times (line 00019, 00035, 00043, 00050), but all lines are commented! [correction: the lines are NOT commented, it was my false understanding of # being a comment sign, but it's not]
So my guess is: MAXLONG is not declared, so the function does not return a value (or it returns 0) and therefore the error message is triggered because the stacksize given as input is higher than 0 or NULL or N/A.
My questions are then:
Why are all lines commented where MAXLONG is defined?
Where does MAXLONG originate from? Is it something passed from the kernel?
How can I solve the problem?
Thanks!
PS - I tried to uncomment the line in buildmacros, and it compiled and installed without issues. However, when I started scilab-cli, it displayed the same message again.
Edit after further investigation:
After further investigation, I found out that what I thought were the comments are indeed instructions for the compiler... but I kept those errors of mine, so that the answer to my question is understandable.
Here are my new points.
In Scilab I noticed that by giving an input stacksize out of bounds, the same method get_max_memory_for_scilab_stack() is invoked, to get the upper bound. The lower bound I've seen it's defined by default.
-->stacksize(1)
!--error 1504
stacksize: Out of bounds value. Not in [180000,268435454].
Also the stacksize used seems fine:
-->stacksize()
ans =
7999994. 332.
However, when trying to give such value an input inbetween, it fails.
-->stacksize(1)
!--error 1504
stacksize: Out of bounds value. Not in [180000,268435454].
It seems to invoke a variable called MAXLONG
It's not a variable, but a pre-processor macro.
Why are all lines commented where MAXLONG is defined?
You should ask that from the person who commented the lines. They're not commented in scilab-5.5.1 that's online.
Where does MAXLONG originate from? Is it something passed from the kernel?
It's defined in the file scilab-5.5.1/modules/core/src/c/stackinfo.c. It's defined to the same value as LONG_MAX which is defined by the standard c library (<limits.h> header). If the macro is not supplied by the standard library, then it's defined to some other, platform specific value.
How can I solve the problem?
If your problem originates from the lack of definition for MAXLONG, then you must define it. One way going about it is to uncomment the lines that define it. Or re-download the original sources since yours don't appear to match with the official ones.

How do I use GDB to edit a python 2.7 global variable?

I've got a script that's been running for days and is about halfway done. It's got a stupid bug in it which is going to cause it to crash before it finishes if a certain counter gets too high (the counter is otherwise unused; I don't mind mangling it to keep the script going). I did not have the foresight to import a module or write a backdoor to let me change state in any way; I've been told I can still get at the counter using gdb.
For simplicity, imagine instead I'm talking about this script below, which I have run from the command line as "python foo.py"
from time import sleep
i = 0
while(True):
i += 1
if (i > 100):
raise Exception("Explosion")
sleep(10)
What exactly would I need to type in gdb from time to time to change the value of the variable i to 0, and avoid the explosion? (If it matters, my python binary is 2.7.3).
Went ahead and powered through on my own. This worked for me (not shown - 'file' to load the python binary, 'attach'; 'detach' from process):
"bt" - see the stack trace
"frame foo" - where foo is the first frame mentioning "globals" as arguments to a Py* function
"print globals" (or, print *(PyDictObject*)globals) - confirm that your
variable is there
"down" - move just below the frame you're interested in.
"finish" - (maybe unnecessary?) - let python complete whatever it was doing and release any locks or etc. that might interfere with interfacing with the globals object.
"call PyDict_SetItemString(globals, "i", PyLong_FromLong(0))" - hope it doesn't segfault. Change "i" to whatever your variable is.
"continue" - if you're lucky, the counter should now have been reset to 0.
However, for this to succeed, I think python2.7-gdb has to be installed/setup BEFORE you begin running the python process - can't do it after the fact, or gdb sees a garbled stack.

How do I set persistent and conditional watchpoints on locally scoped variables?

If I set a watchpoint for a variable local to the current scope, it will be auto deleted when going out of the scope. Is there any way to set it once and keep it auto alive whenever entering the same scope?
Is there anyway to set conditional watchpoint, like watch var1 if var1==0? In my case, the condition does't work. gdb stops whenever var1's value is changed, instead of untill var1 == 0 is true. My gdb is GNU gdb 6.8-debian.
I agree with Dave that a conditional breakpoint is the way to go.
However, to do what you asked, you can use GDB's commands command to set a list of GDB commands to execute whenever a breakpoint is hit. I find this incredibly useful.
I suggest writing your GDB commands into a file so that they are easy to edit and easy to reload with the source command. Or you can specify command files to load on the GDB command line or use .gdbinit to make them load automatically.
An example of a good use of commands:
Suppose that I have a function format that is called by a lot of other functions. I want to break on it, but only after function do_step_3 has been called.
break do_step_3
commands
break format
continue
end
You could use this for your problem with something like:
break func
commands
watch var
continue
end
You can set conditions on watchpoints in the same way that you do with breakpoints. This is in the documentation but admittedly it hardly calls attention to itself.
So watch my_var if my_var > 3 works just fine, as does the condition command.
To recreate the watchpoint if the variable it is watching goes out of scope, have gdb do this automatically using a breakpoint at the start of the function as Zan has described.
You can set a watchpoint that does not go out of scope by setting it to the memory address.
(gdb) p &var1
$1 = (int *) 0x41523c0
(gdb) watch *(int *)0x41523c0
Hardware watchpoint 1: *(int *)0x41523c0
This also works for other data types and pointers.
I'm not sure which language us are using, so the exact answer will vary, but could you change the variable to either be static, global, or dynamically allocated (and don't free it when the function returns?). This way it's raw address won't change, and gdb will be able breakpoint on it.
Instead of watching the value whe it equals a specific value; you should set a conditional break point on the line where you want to check the value of var1. This should effectively have the same effect
e.g.
(gdb) break main.c:123 if (var1 == 0)

Set Visual Studio (conditional) breakpoint on local variable value

I'm trying to debug a method which among other things, adds items to a list which is local to the method.
However, every so often the list size gets set to zero "midstream". I would like to set the debugger to break when the list size becomes zero, but I don't know how to, and would appreciate any pointers on how to do this.
Thanks.
Why not use conditional breakpoints?
http://blogs.msdn.com/saraford/archive/2008/06/17/did-you-know-you-can-set-conditional-breakpoints-239.aspx
in C#
if(theList.Count == 0){
//do something meaningless here .e.g.
int i = 1; // << set your breakpoint here
}
in VB.NET
If theList.Count = 0 Then
'do something meaningless here .e.g.
Dim i = 1; ' << set your breakpoint here
End If
For completeness sake, here's the C++ version:
if(theList->Count == 0){
//do something meaningless here .e.g.
int i = 1; // << set your breakpoint here
}
I can give a partial answer for Visual Studio 2005. If you open the "Breakpoints" window (Alt + F9) you get a list of breakpoints. Right-click on the breakpoint you want, and choose "Condition." Then put in the condition you want.
You have already got both major options suggested:
1. Conditional breakpoints
2. Code to check for the wrong value, and with a breakpoint if so happens
The first option is the easiest and best, but on large loops it is unfortunately really slow! If you loop 100's of thousands iterations the only real option is #2. In option #1 the cpu break into the debugger on each iteration, then it evaluates the condition and if the condition for breaking is false it just continiues execution of the program. This is slow when it happens thousands of times, it is actually slow if you loop just 1000 times (depending on hardware of course)
As I suspect you really want an "global" breakpoint condition that should break the program if a certain condition is met (array size == 0), unfortunately that does not exist to my knowledge. I have made a debugging function that checks the condition, and if it is true it does something meaningless that I have a breakpoint set to (i.e. option 2), then I call that function frequently where I suspect the original fails. When the system breaks you can use the call stack to identify the faulty location.