The Wiert Corner – irregular stream of stuff

Jeroen W. Pluimers on .NET, C#, Delphi, databases, and personal interests

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Archive for the ‘Delphi’ Category

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More Delphi debug visualizers

Posted by jpluimers on 2019/05/07

I hope that by now they are available for more Delphi versions:

Some other posts around the Debug Visualiser topic:

–jeroen

Posted in Conference Topics, Conferences, Delphi, Development, Event, Software Development | Leave a Comment »

Registering/unregseting Windows file associations with Delphi

Posted by jpluimers on 2019/05/02

As I need this one day: [WayBack] Just in case I need this again… >Free library DSiWin32 … now implements this as DSiRegisterUserFileAssoc and DSiUnregisterUserFileAssoc <… – Thomas Mueller (dummzeuch) – Google+

Note file has moved from WayBack: gpdelphiunits.googlecode.com/svn/trunk/src/DSiWin32.pas to [WayBack] OmniThreadLibrary/DSiWin32.pas at master · gabr42/OmniThreadLibrary · GitHub because Google code has shut down.

There still is [WayBack] Google Code Archive – Long-term storage for Google Code Project Hosting: gpdelphiunits, but maintenance is now part of [WayBack] GitHub – gabr42/OmniThreadLibrary: A simple and powerful multithreading library for Delphi

Related: [WayBack] delphi – How to associate a program with a file type, but only for the current user? – Stack Overflow

–jeroen

Posted in Delphi, Development, Software Development | 1 Comment »

GExperts: searching for case-insensitive “T*List.Create” but not “TStringList.Create”

Posted by jpluimers on 2019/05/02

Just learned that partial exclusion can be done with the case-insensitive GExperts Grep Search like this:

T[^s][^t][^r][^i][^n][^g].*List.*\.Create

This will skip TStringList.Create, but matches TMyList.Create.

I’d rather have done something like this, but the Delphi RegEx does not support negative lookbehind:

^ *[a-zA-Z0-9_]* *: *T(<!string)[a-zA-Z0-9_]*ListO? *;$

So the alternative is to search for this:

^ *[a-zA-Z0-9_]* *: *T[a-zA-Z0-9_]*ListO? *;$

then exclude all the case insensitive TStringList entries from it, however GExperts did not support that at the time of writing.

This is an intermediate that works for some of the times:

^ *[a-zA-Z0-9_]* *: *T[^s][^t][^r][^i][^n][^g][a-zA-Z0-9_]*ListO? *;$

–jeroen

^ *[a-zA-Z0-9_]* *: *T[^s][^t][^r][^i][^n][^g][a-zA-Z0-9_]*ListO? *$;
^ *[a-zA-Z0-9_]*: .T[a-zA-Z0-9_]*ListO? *;$;
^ *[a-zA-Z0-9_]* *: *T(?!string)[a-zA-Z0-9_]*ListO? *;$

Posted in Delphi, Development, GExperts, RegEx, Software Development | Leave a Comment »

Note that the Delphi superobject library has changed to “not maintained” in december 2018, has problems with large address aware

Posted by jpluimers on 2019/05/02

A while ago I found out the [WayBack] not maintained status · hgourvest/superobject@f1c42db · GitHub.

This means you should not use the [WayBack] superobject JSON library in Delphi any more: there won’t be any fixes.

Many people use it, especially because it used to be much more stable than the built-in JSON support of Delphi.

One breaking issue in superobject is the lack of large address space support: due to the pointer calculations in various places, it does not support pointers above the 2 gibibyte boundary as filed in the 2016 [WayBack] Issues with {$SetPEFlags IMAGE_FILE_LARGE_ADDRESS_AWARE} · Issue #22 · hgourvest/superobject · GitHub

This gives problems in at least this case:

  • enabling {$SetPEFlags IMAGE_FILE_LARGE_ADDRESS_AWARE} (in older Delphi 7 through 2006 also versions this was {$SetPEFlags $20})
  • using top-down memory allocation, for instance by:
    • a user setting HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\Session Manager\Memory Management value AllocationPreference to hex value 00100000
    • using FastMM4 with the (default) {$define AlwaysAllocateTopDown} setting

Example registry file and batch file to enable top-down memory (reboot afterwards):

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management]
"AllocationPreference"=dword:00100000

Command to view:

reg query "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management" | findstr "AllocationPreference"

Command to enable:

reg add "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management" /v AllocationPreference /t REG_DWORD /d 00100000 /f

Command to disable:

reg delete "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management" /v AllocationPreference /f

Large Address Aware is a nightmare

Be very very very careful with this, and by enabling Large Address Aware to your executables, as many times they can load 3rd party libraries that often are beyond your control.

Even if there is a slight chance that your code is being used with Large Address Aware enabled, then follow guidelines line in [WayBack] windows – Unit Testing for x86 LargeAddressAware compatibility – Stack Overflow

Summary of [WayBack] memory – Drawbacks of using /LARGEADDRESSAWARE for 32 bit Windows executables? – Stack Overflow:

blindly applying the LargeAddressAware flag to your 32bit executable deploys a ticking time bomb!

by setting this flag you are testifying to the OS:

yes, my application (and all DLLs being loaded during runtime) can cope with memory addresses up to 4 GB.
so don’t restrict the VAS for the process to 2 GB but unlock the full range (of 4 GB)”.

but can you really guarantee?
do you take responsibility for all the system DLLs, microsoft redistributables and 3rd-party modules your process may use?

Edit 20240628

Earlier this year, the SuperObject Delphi library got archived on GitHub. Definitely unmaintained: [Wayback/Archive] GitHub – hgourvest/superobject: This repository has been archived by the owner on Feb 27, 2024. It is now read-only.

The XSuperObject library mentioned below in a comment has not been maintained for 4 years either ( [Wayback/Archive] GitHub – onryldz/x-superobject: Delphi Cross Platform Rapid JSON: “vkrapotkin Now ParseFromFile can read UTF8-BOM files (#136) 2d3ec01 · 2020-12-09”), so I wonder what alternatives are still available.

--jeroen

Posted in Conference Topics, Conferences, Delphi, Development, EKON, Event, Software Development | 4 Comments »

Delphi function result assignments before the function returns…

Posted by jpluimers on 2019/05/01

Eric Grange:

Actually it is not that assignments of function return values can happen “when the function raises an exception” but rather than they can happen before the function returns.

Note that this is not limited to large return types, it can also happen on reference counted types (string, dynamic array, variant and interface), though this is contextual as well…

Got bit by the interface thing a few months ago, an interface release was triggering an exception when the result was assigned, the call stack looked way out of synch with the code, so various compilation and and map file mismatch issues got investigated, before I dropped in asm view in the debugger, which made it all obvious.

I’ve quoted it in full as I’ve been bitten by this a few times as well, but never got to making a proper blog post on it.

Thanks Eric for phrasing this and David for bringing it up.

It actually has been the case since somewhere toward the end of the Turbo Pascal era.

Source: [WayBack] This program: {$APPTYPE CONSOLE} uses System.SysUtils; type TRec1 = r…

–jeroen

Posted in Delphi, Development, History, Pascal, Software Development, Turbo Pascal | Leave a Comment »

Does anyone have the source from the book: The Tomes of Delphi: Algorithms and Data Structures…

Posted by jpluimers on 2019/04/25

Since I need this one day: [WayBack] Does anyone have the source from the book: The Tomes of Delphi: Algorithms and Data Structures by Julian Bucknall? – John Kouraklis – Google+

–jeroen

Read the rest of this entry »

Posted in Delphi, Development, Software Development | Leave a Comment »

Getting rid of bugs: mark them as “new feature” – as cancelling a  THTTPClient.BeginGet() does not work as intended

Posted by jpluimers on 2019/04/24

I have seen this happen before, but it seems to be a habit on the Quality Portal: getting rid of bugs by marking them as “new feature”:

[WayBack] I’m using THTTPClient.BeginGet() to create an async get request to a webservice that holds a connection open until it has data to return (sort of like a… – Brian Ford – Google+. which basically was another person finding out about [RSP-20827] THTTPClient request can not be canceld – Embarcadero Technologies, which got marked (a month after submission!) as “Issue is reclassified as ‘New Feature'”.

I get why it happens (there was something exposed, but some of the functionality is missing a feature which needs to be added).

Marking it as such however sends the wrong signal to your users: we do not see bugs as bugs, so they get on the “new feature” pile with no estimate on when the feature will be done.

–jeroen

Posted in Delphi, Development, Issue/Bug tracking, Software Development | Leave a Comment »

Where do you place your unit uses?

Posted by jpluimers on 2019/04/18

Over the years, I have had the question of where to put uses list entries a lot.

Last year, there was one again from a very experienced developer: [WayBack] Where do you place your unit uses? Over the years, I’ve come to preferring to place my uses in the Interface section only, even if its types, constants… – Lars Fosdal – Google+

The answer is really simple, and comes down to this:

  • use only the units you need (Law of Demeter)
  • use the units as close as possible to where you need them (this helps Minimizing Scope which is related to Information Hiding and the Proximity Principle)

Besides these Clean Code and Code Complete arguments, there is another very important argument:

The larger the scope of a unit, the more resources it takes to compile your project.

This gets worse when you have cycles in your unit dependencies.

I think it gets more than progressively worse; I have seen ~5 million line projects use close to 2 gigabytes of RAM during compilation when they had deep/long cyclic dependencies, forcing a full project build with DDevExtensions configured correctly in order to avoid out-of-memory at all.

For the above question, the poll seems to indicate the public at large gets it right:

References

A few tips from the thread:

Read the rest of this entry »

Posted in Conference Topics, Conferences, Delphi, Development, Event, Software Development | Leave a Comment »

Just found out about the SysUtils.FindCmdLineSwitch Function

Posted by jpluimers on 2019/04/17

I learn new things every day. So today I learned about [WayBack] SysUtils.FindCmdLineSwitch Function, which was introduced in Delphi 4, but I was still messing with ParamCount/ParamStr loops.

It as not changed over time. The above docs are Delphi 2007, and these are some of the newer:

–jeroen

Posted in Conference Topics, Conferences, Delphi, Development, Event, Software Development | Leave a Comment »

Debugging RTL/VCL Code with CodeSite – Dave’s Development Blog

Posted by jpluimers on 2019/04/17

This is so cool! [WayBack] Debugging RTL/VCL Code with CodeSite – Dave’s Development Blog.

It comes down to performing CodeSite.Send(...) calls as evaluation expressions in non-breaking breakpoints.

Ensure you have the CodeSite.Logging unit in your uses lists and you’re good to go.

Thanks David for pointing me to this!

This is even more useful than the breakpoint Log Message itself (which is only a string) or plain Eval Expression (which puts just one item into the Delphi event log) despite them being there since Delphi <= 5:[WayBack] Debugging code in Delphi XE – Stack Overflow.

–jeroen

via: [WayBack] Debugging RTL/VCL Code with CodeSite – David Hoyle – Google+

 

Posted in Delphi, Development, Software Development | 2 Comments »

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