I am running a mvn dependency:analyze (Maven3.0.2 Java 1.6.0_45) and it is reporting several modules as "unused declared dependencies found"
I would assume that items reported under that heading could be safely removed, and I know I am not using them directly in my project, but when I delete them, things break.
Am I misunderstanding dependency:analyze? Or is it reporting inaccurate results? Or is it really just a best effort report?
Related
Having just switched to VS2019 I’m exploring whether to use code analysis. In the project properties, “code analysis” tab, there are numerous built-in Microsoft rule sets, and I can see the editor squiggles when my code violates one of these rules. I can customise these rule sets and “save as” to create my own.
I have also seen code analyser NuGet packages such as “Roslynator” and “StyleCop.Analyzers”. What’s the difference between these and the built-in MS rules? Is it really just down to more comprehensive sets of rules/more choice?
If I wanted to stick with the built-in MS rules, are there any limitations? E.g. will they still get run and be reported on during a TFS/Azure DevOps build?
What's the difference between legacy FxCop and FxCop analyzers?
Legacy FxCop runs post-build analysis on a compiled assembly. It runs as a separate executable called FxCopCmd.exe. FxCopCmd.exe loads the compiled assembly, runs code analysis, and then reports the results (or diagnostics).
FxCop analyzers are based on the .NET Compiler Platform ("Roslyn"). You install them as a NuGet package that's referenced by the project or solution. FxCop analyzers run source-code based analysis during compiler execution. FxCop analyzers are hosted within the compiler process, either csc.exe or vbc.exe, and run analysis when the project is built. Analyzer results are reported along with compiler results.
Note
You can also install FxCop analyzers as a Visual Studio extension. In this case, the analyzers execute as you type in the code editor, but they don't execute at build time. If you want to run FxCop analyzers as part of continuous integration (CI), install them as a NuGet package instead.
https://learn.microsoft.com/en-us/visualstudio/code-quality/fxcop-analyzers-faq?view=vs-2019
So, the built-in legacy FxCop and NuGet analyzers only run at build time while the extension analyzers can run at the same time the JIT compiler does as you type. Also, you have to specifically say to run legacy code analysis on build, whereas the NuGet analyzers will run on build just because they are installed. And analyzers installed as NuGet or extensions won't run when you go to the menu option "Run Code Analysis".
At least, that's what I get out of that page.
There's a link near the bottom of that page that takes you to what code analysis rules have moved over to the new analyzers, including rules that are now deprecated.
https://learn.microsoft.com/en-us/visualstudio/code-quality/fxcop-rule-port-status?view=vs-2019
The different analyzers attempt to cover different coding styles and things Microsoft didn't cover when they built FxCop. With the little research I just did on this, there's a whole rabbit hole to follow, Alice, that would take more time than I have right now to devote to it. And it seems to be filled with lots of arcane knowledge and OCD style code nitpicks that make Wonderland seem normal. But that's just my opinion.
There's lots of personal and professional opinion about various rules in these and basic Microsoft rules, so there's plenty of room to use what you want and disable what you don't. For a beginner, I'd suggest turning on only a few rules at a time. That way you aren't inundated with more warnings and errors than lines of code you might have. Ok, so that might be a bit of an exaggeration, but there's so many rules that really are nitpicks, especially on legacy code, that they aren't really worth it to have enabled, since you likely won't have time to fix it all. You will also want to do basic research and use "common sense" when you decide what to enable. ("Do I really need to worry about variable capitalization coding style consistency on an app that's been ported into 4 different languages over 15+ years and has 10k files?") This is both personal and professional opinion here, so follow it or not.
And don't forget the rules that contradict each other. Those are fun to deal with.......
Errors range from 404s, IOExceptions, or encoding exceptions. They can be buried in the error stack, and occasionally suggest a versioning problem.
How can I prevent or address this class of errors?
The Dataflow service's SDKs and worker take dependencies on common third-party components, which themselves import various dependencies. Version collisions can result in unexpected behavior in the service. If you are using any of these packages in your code, be aware that some libraries are not forward-compatible and you may need to pin to the listed versions that will be in scope during execution. In order to determine whether your JAR has a conflicting version in use, consider inspecting the dependency tree of your project. Consult the list of specifically pinned versions if you suspect a problem here, and also avoid using "latest" for any of these libraries.
This question requires a bit of backstory... At my company, we produce a set of PDF and HTML files. A very large set. The current build process (which I designed, in haste) is a Perl script that reads a set of files, where each file contains a new ant command to execute.
It is designed terribly.
Now, I'm trying to shift the entire project over to using ant for the majority of the tasks. Within a target, I can construct a list of files that need to be built, as either PDF or HTML. However, when I call the ant command to build each file, after about three builds (of, say, five), the entire process crashes with an OutOfMemory error. Furthermore, my buildlog.xml ends up being something like 20 megs--it concatenates every ant command's output into one giant log, since they are being called from a single target. With the earlier Perl solution, I was able to get a buildlog.xml for each ant command--simply save and rename the buildlog to something else.
Even if I set ant or java heap sizes in my user.properties, I still fail with an OOM eventually. I wonder if an appropriate solution is to call <exec> to launch a script that does some of what I described and desire: namely, call ant, rename the buildlog, and die--theoretically allocating and freeing up space better than one "giant" ant call. I am worried that I am going to be heading down another "hacky" solution to a problem that's well-defined, and can be entirely confined to ant. Then again, <exec> does exist for a reason, so should I not feel bad for using it?
As with most corporate software (at least those which have deadlines and, if yours don't, please let me know where you work so I can try get a job there), the first step is to get it working.
Then, worry about getting it working well.
For that first step, you can use any tool at your disposal, no matter how ugly you think it looks.
But you might want to make sure that the powers-that-be know that you've had to do all sorts of kludgy things to get it working for them, so that they allow you to hopefully fix it up before maintenance has to start on it. You probably don't want to be maintaining a hideously ugly code base or design.
We've unleashed such wonders on the world as applications that shut themselves down nightly to avoid memory leaks (leaving the OS to restart them), putting "questionable" code at the other end of a TCP socket so their crashing doesn't bring down the main application and, I'm sure, many other horrors that my brain has decided to remove all trace of.
My Delphi installation has been going downhill for the past few months. It seems though that every so often when I build a release it has strange errors in it which are resolved if I build, then compile, then build, compile, etc.
I've talked to another developer who thinks that this is a compiler error. This sort of degrading performance over time has happened on other computers to us too.
What does stack overflow think could be the problem.
What I've seen most is a case where multiple versions of the same units/dcus exist in different folders/paths, and depending on almost insignificant variations the compiler/linker uses a different path and picks different versions of the units to build the exe.
I would make a huge Spring clean-up, scrutinize the lib/search paths, remove all dcus and make sure there is no duplicate versions of any unit.
And, agreed, reinstalling Delphi could help start with a clean state.
I agree with #François about the DCUs, but also want to point out an observation: sometimes it matters what was built prior to what you're building. i.e. if you have several projects that contain source code that results in various .dcu/bpl files being created in a common directory, but the project that you're concerned with doesn't explicitly call for them to be rebuilt, then you're going to end up with whatever is there. If you clear the dcus/dcps prior to building, and then find that your project doesn't build, then you are missing a uses/requires clause somewhere. Every project shoudl be able to build on a "clean slate", and not rely on leftover binaries.
That's not much to go on, but it sounds like a classic case of "bit rot". Too many things interacting in too many ways for too much time under a poorly-designed OS, leading to strange forms of data corruption.
First thing I'd do is uninstall Delphi and reinstall. If that doesn't work, try reinstalling Windows. (If it's been around long enough for this to be happening, you're probably due for an OS reinstall anyway.) And if that doesn't work, contact Embarcadero tech support.
Our team had been using Delphi 6 for many years, then switched to Delphi 2006 years ago. With both versions we have the following problem: frequently the compiler complains about a unit which is supposedly used recursively. This unit is a 40k LOC unit which is at the core of a project with almost 1 million LOC (third party included).
The error message is incorrect: a full build on the project always works. Unfortunately, the error message does not tell us where the supposed circular reference is, just the name of that unit. Sometimes it even happens that valid error messages are listed 2-4 times until that circular reference problem is "found". Clearly the compiler is running in a circle here. Because of the size of that project it is hard to find the problem manually. Therefore I made a tool which proves that there really is no circular reference (the tool creates a directed dependency graph of the units and determines the coherence components in that graph - there are none except if I deliberately put some in).
This is not only affecting F9 compilation but also code completion / insight which is not working most of the time. Sometimes it works when I press ctrl-space a second time...
Any ideas how we can isolate or even fix the problem? Note that it will be very hard to split the 40k LOC unit into smaller ones because it contains about 15 large classes which depend on each other in the interface section (I know it's bad but should work anyway).
Update
We are constantly refactoring but this is one tough unit to refactor because everything depends on everything, almost. Have been trying to get around it via interfaces but we are talking about some classes with 100s of methods and properties. And it would be slower.
Upgrading to D2009 may be an option down the road but right now we're stuck with D2006 (the unicode stuff and the price tag are two of the stoppers here). Question is anyway if it would help since the problem is in there since D6 at least.
About trimming the uses clauses, we have been doing this frequently with Icarus. But that did not help so far. We are down to 90 custom units in the interface section now. However, with a true circular reference the problem could be in any unit. Also tried to add all units to the dpr.
The project shares a lot of code with other projects, and there are some IFDEFs. However, the defines are not set up in project options but via a common include file. Therefore all modules should see the same defines. Also, the problem reoccurs shortly after a full rebuild without switching to another project.
I will probably be downvoted for this. In D2005 I had a 10k loc unit (datamodule) that flat out stopped compiling. Had to separate out some datasets/code to another datamodule. That 10k unit was and is a mess. You really should consider refactoring out some code to other units. My module has since D2005 / separation grown even worse, but it still compiles in D2007. So my answer is a) refactor and b) upgrade to D2009.
It seems clear that this is due to a slight difference between the background compiler and the real thing. You could look around (QualityCentral) what's known on that topic.
Also, since you didn't explicitly state this, you should remove unnecessary units and move uses statements down to implementation if possible. Maybe your tool could help with this.
And just to be sure you should check the unit aliases and Path settings.
You write that a full build does always succeed, but shortly after the incremental build fails with this error. Assuming that you experience this in the IDE, have you tried to use the command line compiler dcc32 to do incremental builds?
If you don't feed it the "-Q" switch (which probably most Makefiles or scripts for command line builds do) it will output a lot of information what files it compiles in what order. You could either try to do an incremental build after the error appeared in the IDE, or you could keep a command line open next to the IDE and Alt+Tab to it for compilation, skipping compilation in the IDE completely.
I simply assume you have a way to build using dcc32, one way or another - with the size of your project I can't imagine otherwise.
We regularly fall in similar problems, and we never managed (or bothered long enough) to find the precise cause. There seems to be a problem in the order which Delphi chooses to compile the units when hitting Ctrl-F9, which is incompatible with the actual dependency order of the units.
Have you tried deleting "MyBigFatUnit.dcu" before hitting Ctrl-F9?
Have you tried to re-order the declaration of your units in your dpr/dpk files, so that units appear in a correct compilation order? (i.e.: if unit B depends on unit A, unit A should appear first in the dpr/dpk)
Do you have any other projects that use part of the same codebase? If you compile one of them under different compiler settings or IFDEFs, it might change certain things in some of the DCUs which would lead to a circular dependency. A full build rebuilds all DCUs and then the problem goes away.
Try Icarus (free) from Peganza. If that does not tell you what the problem is, try their Pascal Analyzer.
We have this problem as well, also with a fairly large codebase.
We are currently using D2009, but have had this problem with all previous versions of Delphi.
It most frequently happens immediately after doing an update from source control, so I suspect there is some timestamp issue within the Delphi build process.
In our case, if Ctrl-F9 fails and reports the circular reference, a second Ctrl-F9 will generally work
A way I have been told to deal with this is to open another arbitrary file in the project, change that file, save it, and then try running the incremental compile again. Surprisingly enough, this usually works.
We have a 4 MLOC project where this comes up from time to time and this "solution" works for me.
I've fought this before, in my experience the error is quasi-legitimate. It's been a quite a while (the error has nothing to do with the version) but my memory of the situation is that it involves a loop in which part of the loop is in the implementation.
Unit A uses B in the implementation. Unit B uses A in the interface. If you compile B first it calls for A but since the call for B is in the implementation it succeeds. If you compile A first it calls for B, B turns around and calls for A in the interface, boom. Such loops are only safe if both cross references are in the implementation.
The solution is to design things so there is a minimum of stuff used in the interface and to make certain there's nothing resembling a loop in those units. So long as you keep your type definitions separate from units with code this is pretty easy to do.
The error coming and going depending on what you are doing is a hallmark of this issue as it comes down to how you enter the loop. When you do a full build the order is consistent and you either get it 100% or 0%, it's not random.