I've been using FP 1.0.12 with FPC 3.0.4 (the built in IDE when you install Free Pascal Compiler for Win32, that blue one), usually it worked fine in my old Windows 7. But recently in my new Windows 10 laptop, when I run a program from within the IDE, the console window behave strangely:
when I asked for 3 inputs like "readln(a,b,c);" the console asked me 4 times, with the last one actually is not stored
when I combine writing text explanation and input like this:
write('Please input A ... '); readln(a);
write('Please input B ... '); readln(b);
write('Please input C ... '); readln(c);
all the texts and inputs are in the same place (they are printed overlapping) in the console run window
Anyone got the solution for these strange behaviours? Thank you
Related
Recently I noticed in my current vb.net project that sometimes (depending on the value), if I enter a double value the editor changes my input, for example:
When I type ...
Dim x As Double = 0.6
...after commiting the line by pressing Enter it becomes:
Dim x As Double = 0.59999999999999998
If I directly undo the action, then it gets reverted back to the original value I typed in. Any future edit in that line will again produce the undesired results.
I'm aware that internally 0.6 is calculated as 0.59999999999999998 so it doesn't make a difference for the running application, but it's very annoying and the strange thing is: this hasn't always happened and, if I create a new project, it doesn't happen there either.
So my questions are: How can I prevent VS from doing this? Why does it happen at all? Why isn't it always like this (previously in my current project or in a new one)?
I'm running 64bit-Windows 8.1 on an Intel CPU - if that has anything to do with it.
Has anyone got any ideas?
EDIT: I'm using Visual Studio 2013 Professional (12.0.31101.00 Update 4) and, yes, the project has been migrated from several earlier VS versions. There are no relevant Add-Ins or extensions installed. Disabling "Pretty Listing" does indeed prevent the problem, but of course then the other highly useful aspects of the option are disabled as well :o(
EDIT2: After the tip leading to "Pretty Listing" I found the following SO article, but there also no solution was found: Visual Studio VB pretty listing settings
Several years ago I had a project where this was happening. As you wrote, the reason for the number is that some numbers can't be represented exactly in a binary floating point variable. More on this here.
My project had been upgraded through several versions of Visual Studio. It was also shared with developers using VS Express.
If I ran into this problem again today I would open and check the project-file manually, or just simply create a new project and re-add the files if I could not quickly locate the problem and the project was small enough.
If you have upgraded the project through multiple versions of Visual Studio like I had, it might be dragging some settings along that are no longer visible in the projects options dialog.
Just as an interesting experiment you could also try to turn off Visual Studio's Pretty Listings to see if that is what is actually changing your code.
I'm running GPS on Windows 8.1.
Version info:
GPS 6.0.1 (20140113) hosted on i686-pc-mingw32
GNAT GPL 2014 (20140331)
The output is different when I run my program in the IDE, vs when I run it from the Windows command line.
In the GPS execution window, it doesn't display the prompt until I type something, like this:
Bob
What is your name? Hi there, Bob!
In the command line the same program works properly, like this:
What is your name? Bob
Hi there, Bob!
How do I make the GPS execution window work properly?
Here is my code (Demo_Execution_Window.adb):
with Ada.Text_IO,
Ada.Strings.Unbounded,
Ada.Strings.Unbounded.Text_IO;
use Ada.Text_IO,
Ada.Strings.Unbounded,
Ada.Strings.Unbounded.Text_IO;
procedure Demo_Execution_Window is
Input : Unbounded_String;
begin
New_Line;
Put("What is your name? ");
Get_Line(Input);
Put("Hi there, "); Put(Input); Put_Line("!");
end Demo_Execution_Window;
My guess (I don't use GPS myself) is that your problem simply is that GPS behaves differently from your terminal window. It appears that GPS buffers the output until the program sends a line-feed. If my analysis is correct, you have two options:
Add a line-feed after the question (i.e. change Put to Put_Line).
Fix the GPS output processing, so it doesn't wait for a line-feed before displaying the output from a program.
And of course also the third option, to accept that things look slightly different inside your IDE compared to real life use.
Context
As a university project we want to change the the pharo vm to use an object-table and see what happens.
We use a pharo-vm clone from github and VMMaker. Building the VM works fine.
To get started we added a primitive that returns an incremented Integer:
InterpreterPrimitives>>primitiveIntegerIncrement
"increments an integer"
self pushInteger: self popInteger + 1 .
and modified StackInterpreter class>>initializePrimitiveTable accordingly
MaxPrimitiveIndex := 576.
"... and so on ..."
(575 primitiveFail)
(576 primitiveIntegerIncrement))
And it works.
Problem
When we make changes to the VM we want to test-run already in the SmalltalkImage so we do not need to compile and see it did not work.
Something like:
StackInterpreter test: '1 inc'
And then I can debug if the primitive is wrong or an error occurs. Of course there needs to be done much more but how can I achieve this?
What we tried
category VMMaker-InterpreterSimulation class StackInterpreterSimulator. Trying the code in the comments
DoIt
^ (StackInterpreterSimulator new openOn: Smalltalk imageName) test
errors:
displayForm := 'Display has not yet been installed' asDisplayText form.
the ByteString does not understand asDisplayText
(CogVMSimulator new openOn: Smalltalk imageName) test
(InterpreterSimulator new openOn: Smalltalk imageName) test
error:
PrimitiveFailed: primitive #basicNew: in Array class failed
I also found this screen cast but it only debugs the VM from outside using gbd: http://vimeo.com/22485382#
Our project is hosted here: http://smalltalkhub.com/#!/~kirstin/PharoObjectTable
Current Status
We started implementing an object table. The lookup of attributes can go throught the object table. Full object table support and no usage of direct pointes is very tricky since pointers are expected everywhere. So we use pointers into the object table to identify when a lookup should go through the OT. We also found all object creation primitives and add new objects to the table.
How long is your project and how many people are you ? To me what you try to do is quite some work. Do you have good knowledge about low level behavior ?
To answer your question, the main problem here is that the cog simulator is not maintained in the pharo vm fork. This is because no one in the pharo crew use the simulator. We only use external debugging from gdb. In fact the pharo folks work mostly on VM plugins, the core of the VM is mainly maintained and developed by Eliot Miranda which works on Squeak. Therefore we report to him when there's a bug in the VM core.
For your project you would have to split it in at least 2 steps:
step 1: make the object table work with the stack VM
step 2: make the JIT work with your object table
Note that for step 2 I would recommend not to change the way an object access its header, therefore having a VW-like object table where you have the fixed size header on the one in the the object table, and the fields of the objects (and maybe header extensions) in the heap.
So use the StackVMSimulator and build the StackVM first. When everything will work (including context), you can think about hacking the JIT. Recently Guillermo Polito ported the Stack VM to the build process (see PharoSVMBuilder instead of PharoVMBuilder), a guy reported problems with this builder but you could hack it a bit to make it work.
Now to make the simulator work on Pharo 2.0 (which is the Pharo version of the generator image you have), you have to open the monticello browser and merge from Eliot's branch the Cog package (repo MCHttpRepository location: 'http: //source. squeak. org/VMMaker'), but not the latest Cog, the one at around the same date as the current VMMaker package of pharo-vm because the latest Cog and VMMaker of Eliot's branch are not stable.
The alternative being to start from Eliot's build image and merge things from the pharo branch. Here are infos about how to build the squeak development image (http://www.mirandabanda.org/cogblog/build-image/).
Then Eliot gave me this script once:
| cos |
cos := CogVMSimulator newWithOptions: #(Cogit SistaStackToRegisterMappingCogit).
cos desiredNumStackPages: 8.
cos openOn: 'my/favourite.image'.
cos openAsMorph; toggleTranscript; halt; run
You don't need the SistaStackToRegisterMappingCogit option. I guess some similar script with the StackVMSimulator should work.
Lastly there are some documentation about the simulator but it is only for the CogSimulator (these documentations expects you already knows how the StackSimulator works, and just give you hints about how to use it with the JIT):
http://www.mirandabanda.org/cogblog/2008/12/12/simulate-out-of-the-bochs/
and in one of the video named "Cog VM (part x)", x being from 1 to 6, Eliot shows how he uses the simulator to disassemble x86, print the stack and inspect the heap.
Another tip, ask your questions on the pharo mailing list (pharo users or pharo dev), because here no one may notice your question (fortunately someone pointed me out your question this time).
And tell on the pharo mailing list if you managed to run the simulator in Pharo 2.0, some people (as me) are very interested in it. I was planning to do it at some point.
Good luck ! Nice project anyway.
The last time I tried to use the simulator is roughly a year ago, and I did not make it work.
However, there are a few patches, which I assume never got integrated that might be of help:
https://code.google.com/p/cog/issues/detail?id=106
https://code.google.com/p/cog/issues/detail?id=107
https://code.google.com/p/cog/issues/detail?id=108
Issue 107 includes a patch for your asDisplayText issue.
I handed in a C program which contained a lot of verbose printf debug lines. I always compiled it command line with gcc.
Now it's been turned into an Eclipse-CDT (Helios) project, and my
\n
no longer do carriage returns. I get an unreadable "staircase" in my console.
RCINAHFM. Is there a check box in the IDE I need to modify or do I need to go back and carefully modify hundreds of lines of code?
Any help greatly appreciated.
Bert
RCINAHFM=Remaining calm / I need a hug from Mom
Eclipse does not compile C all by itself. It uses an external compiler for that, usually gcc. So it’s highly unlikely that the compiled program is incorrect, unless the compiler configuration within Eclipse does something very, very weird.
If you get a “staircase”, it sounds as if the new line part is carried out, but no carriage return happens. This might happen under systems that use CR/LF as their line ending, such as DOS/Windows.
Unfortunately, you give way to little detail. Are you using Unix or Windows? Where does the program run, in an XTerm, a Windows DOS console, within the Eclipse console? If the answer is “Eclipse console”, then have you tried running it in another terminal instead; or tried running your original program in the Eclipse console? Are you using printf or some other function?
I'm new to VB6 but i'm currently in charge of maintaining a horror of editor like tool with plenty of forms, classes, modules and 3rd party tools all chunk together like the skin faces on that guy in the texas chainsaw massacre...
What i don't understand is why i get different results when i run the app in debugging mode, vs when i compiled it and run it on my devevelopment pc vs when i installed it on a different pc.
Yes i know i'm dumb, so please direct me to where i can find out more about this. I'm hoping to find out something like different linking, registry related etc connection that i'm simply not getting right now, i.e. something like wax on, wax off :P
The main pain in the neck is when i'm trying to debug some errors from my QA and i need to find a spare pc to test this on plus i can't directly debug because i don't know where the code is if i do it that manner.
Thanks.
i run the app in debugging mode vs when i compiled it and run it on my
devevelopment pc
When you compile you have the option of compiling to native code or pcode. The debugger runs using pcode only. Under rare circumstances when you compile to native code there will be a change in behavior. This particular is really rare. I used VB6 since it's release and I may get it once or twice a year. My application is a complex CAD/CAM creating shapes and running metal cutting machine and has two dozen DLLs. Not a typical situation. At home with my hobby software I never ran into this problem.
There are another class of errors that result from event sequencing problems. While VB6 isn't truly multi-tasking it has the ability to jump out of the current code block to process a event. If it re-enters the same block for the new event interesting things (to say the least) can result. I think this is the likely source of your problems as you software is an editor which is a highly interactive type of software.
In general the problem is fixed by reordering the effected areas. You find the effected area by inserting MsgBox or write to a text file to log where you are. I recommend logging to a text file as MsgBox tend to alter behavior that are timing or multi-tasking related.
Remember if a event fire while VB6 in the middle of a code block and there a DoEvents floating around then it will leave the code block process the event and return to the original code block. If it re-enters the same code block and you didn't mean for this to happen then you will have problems. And you will have different problems on different computers as the timing will be different for each.
The easiest way to deal with this type of issues is create some flag variables. In multi-tasking parlance they are known as semaphores or mutexes. WHen you enter a critical section of code, you set it true. When you leave the routine you set it to false. If it is already true when you enter that section of code you don't execute it.
when i installed it on a different pc.
These are usually the result of the wrong DLL installed. Most likely you have an older version while the target has a newer version. I would download the free Virtual PC and create a clean Window XP install to double check this.
If your problem is event timing this too can be different on different computers. This is found by logging (not MsgBox) suspect regions.
If you can display a screen shot or the text of your specific errors then I can help better.
The first thing to check would be the versions of all the dlls that your app depends on - including the service pack version of the VB6 dll.
Have you any more specific details about what's behaving differently?