How to remove unused units from all source files on Delphi XE2? - delphi

How to automatically remove unused units from uses section on all source files of the project on Delphi XE2?
P.S. IDE will work much faster after that.

There is no way to fully automate this.
There are a few tools I'm aware of that take a wizard approach:
CnPack Uses Units Cleaner
Peganza's Pascal Analyzer (and it's sidekick icarus).
The Lazarus IDE has a "Unused Units" dialog in it's CodeTools package.
Peganza's tools simply show a report. CnPack will prompt to remove the unused units for you but you must confirm. Lazarus presents you with a list of unit's it thinks are unused and gives you the choice of removing some or all of them.
Why isn't it automated?
Because this is static analysis. Even the most sophisticated tools cannot determine with 100% certainty whether a specific line of code will be used at runtime let alone an entire unit. These tools have implemented their own parsers to accomplish this feat but they aren't fool proof.
In any case the main benefit of cleaning up the uses clause is removing visual clutter from both the source itself and the code completion feature. Yes there is some performance gained during compiling and certain IDE background operations will speed up slightly but I think you'll be disappointed if you think the IDE will miraculously speed up.
You'll see better IDE and compiler performance by:
Breaking your projects into smaller pieces that can be worked on independently.
Eliminating duplicate code.
Disabling unneeded IDE packages.
I'm certainly not trying to dissuade you from removing unused unit references. As I said it will help unclutter your source. Just make sure you're doing it for the right reasons.

We have a utility called the Delphi Unit Dependency Scanner (DUDS). It scans your entire project and builds a fully searchable tree of the units and dependencies. It can be very useful in finding unused units.
The application is Freeware and you can find it here.
Disclaimer-I am the author.

Don't think I would want a tool that would automatically rip out unnecessary units in the Uses section...
but there are tools out there to identify them...look at Icarus...freeware that you can get at http://www.peganza.com/downloads.htm

CnPack has "Use Cleaner..." option that I have used unit by unit basis without a problem. It also has the ability to do the entire project - which I haven't tried due to the size of the project.

Use reFind.exe utility provided since Delphi XE, use this command
reFind *.pas /X:unuse.txt
And unuse.txt is a text file with something like this:
#unuse Unit1
#unuse Unit2
#unuse Unit3
And that's it. It will remove the units in the uses clause taking care if the unit is the last one used and there is a ; after the unit.

Related

Can I create a Unit for common utility routines in Delphi in a way that unused class routines won't contribute to the Release Build size?

We are using Delphi 10.4.2 Sydney. I would like to create a single unit (or possibly multiple units) that houses all the utility functions we use in our various software products. The idea is we would just include this unit in every project we start and then we can rely on it being there and use these functions freely in all our code. These would probably be mostly class routines and such.
I'm concerned though that some of our projects might only use a single routine in this large unit. The size of our apps is important and we want to keep that size to a minimum. I am not familiar with how Delphi's compiler works or how much space adding a superfluous unit might add or any other issues with this.
Is there perhaps a way to create a Unit where only the functions we actually use will contribute to the final build's size? Is this even something to worry about? How are common utilities library usually handled in Delphi?
The Delphi Linker is supposedly smart enough to detect unused functions and will not include the code for them in the executable it generates. This also applies to class methods. (*1)
So, go ahead and create these units.
You can easily check whether code was generated for a method by looking for the blue dots during debugging.
(*1: That feature can be a major pain in the lower back when you want to call such a function from the Evaluate/Modify dialog during debugging.)
Put the units into a separate package project. If you build your exe as a monolithic exe (so packages are linked in) then the compiler should only link in the units that are actually referenced, not the entire package.

how to build custom system.pas in delphi to create system.dcu? [duplicate]

I have this craving to do some experiments with modifying the underbelly of the Delphi run time library (RTL), system.pas and the likes... It is possible or not?
I'm very fond of challenges like "yes, but you'll have to provide custom .obj files for some assembler wizardry because they were never distributed with the official Delphi source". Fine with me, I just want to know.
I want to do this experiment with Delphi 7, but inside information on any other version is fine. It is one of the perks of being with a company that worked with Delphi since the Stone Age.
(I always figured this to be one of those RTFM questions, with the answer being a resounding "NO!", but for some reason google won't confirm it.)
You can recompile the RTL like any other unit.
For System.pas you must use the command line compiler.
For instance, here is a working batch file content (there is some not well documented command line switches):
del *.dcu /s
"c:\program files\borland\delphi7\bin\dcc32.exe" -O+ -Q -M -Y -Z -$D+ System.pas
This will recompile System.pas and SysInit.pas (both lowest level RTL files).
But in order to use your recreated dcu files, you'll have to put the folder containing the updated dcu files into the first position of your IDE: for instance, in Delphi 7 it's Option / Environment Options / Library, then put your folder FIRST in both "Libary path" and "Browsing path" field.
And it's perhaps worth deleting the original .dcu files in your Delphi installation directory.
But be sure you won't change the "interface" part of the unit, or you'll have troubles with compiling with other not modified units of the RTL (or third-party components). You can change the "implementation" part, apply fixes or rewrite some part for speed or such, but don't change the "interface" part to avoid any linking error.
Always make a backup of the original .pas and .dcu files which you are changing. And it's a good idea to make some automated compilation test, so that you could be sure that your modifications of the RTL won't add any regression.
We made such a RTL recompilation for our Enhanced Run Time Library for better speed of low-level RTL functions (mostly System.pas and SysUtils.pas). Designed for Delphi 7 and 2007. For more recent Delphi version, you still can use the same principle.
You can only recompile the RTL from the command-line. There should be a makefile in the RTL source directory of your installation. It is designed to be used with the make.exe command-line utility which should be in the "bin" folder of your installation. I would recommend you copy the relevant sources to a separate location for experimentation. I must caution you that the System unit is tightly coupled with the compiler which expects many functions to have a specific name and have particular parameter lists, if any are even declared. Many RTL "helper" functions don't have any formally declared parameters, yet expect parameters to be passed in a certain fashion.
Another bit of caution is changing the interface declarations of certain classes, functions or types. Doing so may cause serious incompatibilities with existing DCU files and components. For this reason you must be very careful when intermixing DCU files from the included RTL or third-party components with your custom modified versions. I would suggest you start by only making implementation section changes only before venturing into the mine-field of interface breaking changes.

How to change VCL code?

I need (to make some quick and dirty tests) to modify the code of Variants and SysUtils.
What I need to do to "compile" the changes?
I can of course open those units in the IDE, but if I change them and I buoild a project again I don't see those units recompiled.
What is needed to be done?
The problem is you would need to compile ALL of the RTL/VCL against the 'new' units.
Instead modify a copy of the units in question and add them to your project when you want to use them. Delphi should use these over those in the RTL/VCL.
Unless you do not change the interface part of the unit (that is, you only modify the implementation side), you can make your own version of the RTL units (only exception is System.pas and SysInit.pas, but this is not in your scope - see our blog site for some enhancements of those units).
What you need is to put your own version of Variants.pas and SysUtils.pas in the search path of your project. They will be taken in account instead of the default RTL.
But be aware that you may easily break anything.
For testing purpose, this is OK, but if you want to use those modifications, you shall better use some automated regression tests, and know explicitly what you are doing.
Please note that you can use the "debug" version of the RTL units (from the project options), then step with the debugger within the official source code. It may help finding issues without touching the source.
If you change the interface part of the unit, you'll have to recompile all units which call the modified unit - for SysUtils and Variants, this is almost all RTL.
Delphi runtime DCUs are precompiled. It would be a waste of time to compile them at every build.
If the code you are trying to modify is a method of a built-in class, then a class helper may help:
http://docwiki.embarcadero.com/RADStudio/en/Class_and_Record_Helpers
So the question is which part of code do you want to modify in the runtime?
If you really wish to recompile the RTL you can do so (Make a backup first!). Versions of Delphi prior to Delphi 2010 had a makefile in the source folder that could be run from the command line to rebuild the rtl/vcl. I don't know for sure (I'm still using D2009) but from what I've heard this file is no longer present in newer versions. Hopefully there is an alternative. Otherwise you would wind up wasting a lot of time trying to guess that the compiler settings for each unit.
If you wish to "patch" a bug in the rtl for your project only you can copy the unit you want to modify into your project's folder and make your change. If the unit your modifying is used throughout the RTL/VCL you may find yourself copying quite a few dependent units into your project folder in order for it to compile.
If this significantly slows down the compile time for your project you can always do your initial compile then remove the "patched" units, leaving behind the compiled dcus.

Plugins system for Delphi application - bpl vs dll?

I'm writing delphi app which should have capability of loading plugins. I'm using JvPluginManager as plugin system/manager ;) Now, in the new plugin wizard they say it's better to use .bpl type plugins instead of .dll plugins ... What are the pros of this solution versus dll type plugins?
So far I've found only cons of this solution:
I have to put all the common interface units in separate package so that while loading plugins it won't throw any error about the other package containing common unit
if, let's say, one of plugin developers decides to uses some well-known unit (like synapse), which doesn't have runtime package by default, and the second plugin developer does the same, than bump... it's crash here ...
So, what are actually the pros of using bpls instead of dlls compiled with runtime packages?
Thanks in advance
Another disadvantage to BPL's. When you switch Delphi versions you will have to re-distribute new plugins. After many attempts at attempting to find the perfect plugin system, I ended up with COM and I have never regretted that decision. In a commercial application which has had the plugin requirement for over 8 years, the application has continued to move forward and yet some of the plugins that were released with the first iteration still exist in their ORIGINAL form.
If you choose this method, do yourself a favor and start with a simple interface and then add new interfaces upon it. You don't want to ever change your base interface, so keep it simple and sweet.
As Alexander said, a BPL is basically a DLL. But there are some conditions (from a not-so-short summary I made: http://wiki.freepascal.org/packages ):
A unit can only exist once in BPL's +Exe. This avoids duplication of state (twice the heapmanager and other global vars of system etc, VMT tables etc)
.BPL's can only USE other .BPLs.
This means that dynamic types like ansistring and IS/AS work properly over BPL interfaces.
Initialization/finalization are separate procedure and their initialization order is strictly controlled. For static dynamic loading this is simpler, for dynamic loading (plugin-like) all dependancies on units are checked .
Everything is essentially one big program, which means that the BPL's must be compiled with the same compiler version and RTL and depends on the versions other dependancies. It might be harder to make .BPL's to plugin to an existing EXE, since the Delphi version must match.
This also means that you must deliver .dcp's for (non Delphi) .BPLs the plugin .BPLs depend on
In short: if the plugin architecture is open, make it a DLL. Otherwise people have to have the exact same Delphi version to write plugins.
Hybrid is also possible. An higher level .BPL interface for functionality you factor out into .BPL yourself and selected devels, and a rock bottom procedure DLL interface for the rest.
A third option is using DLLs, but ordain Sharemem. Strings will work, multiple Delphi versions will work. Objects can work but are unsafe (e.g. I guess e.g. D2009 with an earlier version wouldn't work). Even other language users might be able to allocate over COM, not entirely excluding non Delphi.
Your first con is also a pro. If you replicate shared code in each dll the dlls get bigger and bigger. Even when using dlls you can prevent this by moving shared code in a separate dll.
Pros:
Types are shared. No TFont is not a TFont problem
Memory manager is shared. Strings and classes can be used as parameter between plugins without problems.
Cons:
Plugins can be built using Delphi or BCB only.
Plugins should use the same Delphi or BCB version.
Have you considerd using COM? COM makes it possible to share types, strings and classes and the plugins can be written in many programming languages.
I'm not familiar of JvPluginManager, but it depends on how you're going to use BPLs.
Basically, BPL - is just a usual DLL, but its initialization/finalization work is stripped from DllMain to separate functions: 'Initialize'/'Finalize'.
So, if you're going to use BPL like usual DLL, there are no cons that I'm aware of, only pros: there will be no more troubles with DllMain. That's all. The only difference.
But BPL in Delphi also provide a convient way to share code. This means great advantages (common memory manager, no duplicated code, etc, etc). So usual BPL does a lot more than "being just a DLL".
But this also means, that now your plugin system is limited to Delphi only (well, may be C++ Builder too). I.e. both plugins and exe MUST be compiled in the very same compiler to run smoothly.
If this is acceptable for you (i.e. no MS Visual Studio, no, sir, never) - then go ahead, you can use all power of BPLs.
P.S. But upgrading such BPLs plugins can be also a nightmare, if you do not design interface side carefully. In certain worst cases, you may need to recompile everything.
P.P.S. Like I said: I have no idea, how it is applied to plugins, created by JvPluginManager.
Avoid blp approach as you will have to ship a big bag of bpl with you software and thus, distribution will become bulky.
why do we use Delphi to compile small stand alone programs that just RUN anywhere without any runtime dependency. Using bpls means defeating this very purpose.
I don't know as to how comfortable you are with DLLs, but I would suggest you to use DLLs.
This will give other developers (who
may get interested in your software)
a chance to use any development
language (as long as that language
can spit out dll) to write their own
plugins that can be used in your
developed software.
Another thing is that you will be
saved from Delphi's vcl version
dependency tyranny. A major weak
point of Delphi till date.

How can I identify and get rid of unused units in the "uses clause" in Delphi 7?

This should reduce the executable size quite a bit in some of my very large projects. I am sure there would be other benefits too.
EDIT: Is there perhaps a utility that will scan the project and remove redundant ones automatically? I do have 100s of projects and "automatic remove" would be first prize although if I have to I will go the manual way with the help of identifying utilities.
You might want to take a look at at CnPack.
CnPack includes a Uses cleaner wizard wich hasn't failed me yet.
I used to use Icarus that gave me a report of unused uses entries.
From the web page
ICARUS parses Delphi or Borland Pascal source code and generates a Uses Report. This report will help you remove unneeded units from your uses lists. You will also know which units that can be moved from the interface uses list to the implementation uses list.
Removing unused uses references has multiple benefits:
Cleaner code to maintain, no need to bother about code that is not used
Code from initialization and finalization sections in unused units is not linked in
Compilation runs smoother and quicker
ICARUS is very easy to use, just select a source file, set a few options, and start analyzing. Or let the built-in wizard guide you through this process.
ICARUS is FREEWARE.
Such a tool can never analyze if the initialization or finalization sections of a used unit need to be executed or not. Removing units from the uses could result in not running initialization and finalization sections and therefore result in bugs.
If your code can be compiled with Free Pascal, the Free Pascal compiler also will emit hints about unused units in your code.
See also this SO entry with additional information about possible problems, like RTTI based methods:
https://stackoverflow.com/questions/605977/tools-to-detect-dead-code-in-delphi2007-or-above/
Remember that the linker will strip anything that can't be called. If no use is made of a unit and it has no initialization or finalization it's going to be completely stripped anyway. Anything referenced in the initialization or finalization will stay but in general this shouldn't bring in much anyway.
It's possible for a unit to consist of only initialization so full-auto stripping is limited anyway. Units which merely change system behavior in some fashion might very well have no references and yet be needed. (The replacement memory manager with good leak tracking comes to mind. While it does have things you can reference there's no need to, just use it and get the leak report. Nice double-check for your code.)
See some of the answers here.
Peganza has similar tools: http://www.peganza.com/

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