I have classes that are never directly mentioned in other code, but only accessed using Type.resolveClass. I want them to be compiled and included in the app, but I can't get how to do this. I thought that #:keep (or #:keepSub) is exactly for this, but it does not work as I expected. This is what I do:
Main.hx:
package;
//import Foo; //uncomment this line to make it work
class Main {
static function main() trace(Type.resolveClass('Foo'));
}
Foo.hx:
package;
#:keep class Foo {}
But this traces null (I've tested JS and Flash)
Even if I compile with -dce no it still traces null.
Not sure if it's a compiler issue or I do not understand how it works.
This is not a compiler issue, it's correct behavior. If a module is never imported, it is never included in compilation to begin with. The compiler never gets to see the #:keep.
A common workaround for this is to use --macro include('package') (see Compiler.include()), which forces all modules in package to be compiled.
Note that a wildcard import (import package.*;) won't work, since wildcard imports are lazy:
When using wildcard imports on a package the compiler does not eagerly process all modules in that package. This means that these modules are never actually seen by the compiler unless used explicitly and are then not part of the generated output.
#:keep and #:keepSub only keep classes. In your case, Foo has never been included in the compilation so the compiler has nothing to keep.
You can list more than one entry point for your application in your hxml (or in your haxe ... command) to include some classes: haxe -cp src -main MainFoo Foo --interp will find Foo. (more on --interp here: http://old.haxe.org/doc/compiler#macro-options)
You can also include a package and all its classes with --macro include('my.package') but in your example your classes are on the root package and I don't know if you can include this one.
More info on include: http://api.haxe.org/haxe/macro/Compiler.html#include
Related
I am writing haxe code which I want to compile to an arbitrary target as a module and then use the results from another module compiled for this same target. I don’t want to handle this the “Haxe way” (which is to fully inline all libraries at compiletime). Instead I want to be able to write distinct Haxe modules and reference them with full type safety without inlining between the modules. The natural way to do this would be to have both source Haxe files and a separate directory of “headers” filled with extern describing the public API of my module, with these externs somehow automatically generated so that they don’t need to be manually maintained.
I cannot figure out how to get Haxe to emit externs. It would make sense to me if haxe-externs were an actual “target platform” so that I could do something like:
$ haxe ClassName -hxe externsoutdir
It would make less sense but still be acceptable if one of the -D flags like -D dump (which seems to sort of get one part of the way there) or some imaginary, nonexistent -D dump-externs existed. Then you could generate externs while compiling to your favorite target:
$ haxe ClassName -js outfile.js -D shallow-expose -D dump-externs=externsoutdir
The idea is to take a class definition like this:
#:expose
class ClassName {
function quack() {
trace('quack');
}
}
and emit something like this in a separate directory:
extern class ClassName {
function quack():Void;
}
so that I can consume it from another module like this:
#:expose
class MyClassName extends ClassName {
override function quack() {
super.quack();
trace('…and again I say “quack”');
}
}
$ haxe -cp path\to\externsoutdir MyClassName -js outfile.js -D shallow-expose
It would only make sense to generate externs for things decorated with #:expose or some other decorator.
I will figure out how to wrap the emitted modules to load each other correctly. That’s easy. The hard part is generating the extern definitions—shouldn’t Haxe already have a way to do this?
Is there already some tool or built-in way I’m missing to do this? When Googling, all I see are projects that supposedly help with generating externs for existing JavaScript libraries. But that’s not my use case…
Update: --gen-hx-classes was removed sometime aroudn Haxe 4.0.0-rc3. Apparently the functionality still exists secretly as -D gen-hx-classes, but beware, if you rely on this, it seems like its going away.
I believe --gen-hx-classes option might be what you're looking for. Oddly I don't see it in the compiler flags list.
I use it in a modular JavaScript build system that is similar to what you're talking about.
I believe it creates a directory of .hx files that are externs for every class generated by the build (including those from the Haxe standard library.) Actually, getting duplicates of the classes in the standard library may be a problem you will face.
You may also need to use #:keep (or the related macro) to ensure dead code elimination doesn't remove things the other build will need.
You might also need to exclude a class from one or the other builds, e.g. --macro 'exclude("haxe.io.Input")' (or, excludeFile is actually more performant for a whole list of exclusions.)
I've been tasked with creating conformance tests of user input, the task if fairly tricky and we need very high levels of reliability. The server runs on PHP, the client runs on JS, and I thought Haxe might reduce duplicative work.
However, I'm having trouble with deadcode removal. Since I am just creating helper functions (utilObject.isMeaningOfLife(42)) I don't have a main program that calls each one. I tried adding #:keep: to a utility class, but it was cut out anyway.
I tried to specify that utility class through the -main switch, but I had to add a dummy main() method and this doesn't scale beyond that single class.
You can force the inclusion of all the files defined in a given package and its sub packages to be included in the build using a compiler argument.
haxe --macro include('my.package') ..etc
This is a shortcut to the macro.Compiler.include function.
As you can see the signature of this function allows you to do it recursive and also exclude packages.
static include (pack:String, rec:Bool = true, ?ignore:Array<String>, ?classPaths:Array<String>):Void
I think you don't have to use #:keep in that case for each library class.
I'm not sure if this is what you are looking for, I hope it helps.
Otherwise this could be helpful checks:
Is it bad that the code is cut away if you don't use it?
It could also be the case some code is inlined in the final output?
Compile your code using the compiler flag -dce std as mentioned in comments.
If you use the static analyzer, don't use it.
Add #:keep and reference the class+function somewhere.
Otherwise provide minimal setup if you can reproduce.
If I have multiple .rs files in the src directory of a Cargo package, what are the rules for visibility, importing, etc.?
Currently, any extra (i.e. not the file that is explicitly identified as the source for the executable in Cargo.toml) files are ignored.
What do I need to do to fix this?
There is nothing special about Cargo at all in this way. It’s all the perfectly normal Rust module system. If Cargo will be compiling src/lib.rs, that’s more or less equivalent to having executed rustc --crate-type lib src/lib.rs (there are more command line arguments in practice, but that’s the basics of it).
Other files are then used with mod, use and so forth. Files are not automatically imported or anything like that. This part is not documented very clearly yet; a couple of things that show briefly how to achieve things are http://rustbyexample.com/mod/split.html and http://doc.rust-lang.org/reference.html#modules, but any non-trivial code base will use them and so you can pick just about any code base to look at for examples.
It's hard to say what you're getting tripped up on from the info you shared. Here are three seemingly trivial things that I still had to refer to the documentaton to figure out:
First of all,
mod foo;
looks like a declaration, but it without arguments it is actually something like an include. So you use the same keyword both for declaring and including modules, i.e. there is no using:: keyword.
Second, modules themselves can be public or private. If you didn't add a pub keyword both on the function in question AND on the containing module, that may be tripping you up.
pub mod foo {pub fn bar();}
Third, there seems to be an implicit module added at the top of every file. This is confusing; the reference manual talks about a strict separation between file paths and names, and the module paths in your code, but that abstraction seems to be leaky here.
Note, Rust is still pre-1.0 (0.12) at the time of writing, at the module system and file paths are relatively high level, so don't be surprised if what I said may already wrong by the time you read this.
Files are implicitly included from your rust code.
For instance, if a file src/foo.rs pointed by path in a [lib] or [[bin]] section of your Cargo.toml contains:
mod bar;
It tells cargo to build src/bar.rs too, and include it.
A simple Groovy Class in a package com.something
package com.something
class A {
}
Another class in the same package
package com.something
class B {
def variable=new A() //DOES NOT WORK TILL I EXPLICITLY say "import com.something.A"
}
Why Class B is not able to access class A, even though they both are in the same package?
Sadly the question does not really have the needed information to answer it completely. But I can tell the following. If you make a directory ./com/something/ and out A.groovy and B.groovy in there and then compile them using the commandline groovyc ./com/something/A.groovy ./com/something/B.groovy, then this must work. So far the directory is not really important, but that changes if you change to groovyc ./com/something/B.groovy, because now groovyc has to "discover" A.groovy and requires the correct directory structure for this.
Now, how the ant, gradle and maven version of groovyc normally work is by supplying a complete list of sources. If this is not done, compilation may fail. But if the root directories for A and B are different and you do not give both to the compiler, then it will surely fail.
I cannot know if that is the reason, so I want this answer more understood as a pointer to what might be wrong. Hope this helps
I know that since Groovy 2.0 there are annotations for static compilation.
However it's ease to omit such annotation by accident and still run into troubles.
Is there any way to achieve the opposite compiler behaviour, like compile static all project files by default and compile dynamic only files chosen by purpose with some kind #CompileDynamic annotation for example?
I have found some (I believe recently introduced) feature which allows doing so with Gradle.
In build.gradle file for the project containing groovy sources we need to add following lines:
compileGroovy {
configure(groovyOptions) {
configurationScript = file("$rootDir/config/groovy/compiler-config.groovy")
}
}
or compileTestGroovy { ... for applying the same to test sources. Keep in mind that neither static compilation nor type checking works well with Spock Framework though. Spock by its nature utilizes dynamic 'groovyness' a lot.
Then on a root of the project create folder config/groovy/ and a file named compiler-config.groovy within. The content of the file is as follows:
import groovy.transform.CompileStatic
withConfig(configuration) {
ast(CompileStatic)
}
Obviously path and name of the configurationScript may vary and it's up to you. It shouldn't rather go to the same src/main/groovy though as it would be mixing totally separate concerns.
The same may be done with groovy.transform.TypeChecked or any other annotation, of course.
To reverse applied behaviour on certain classes or methods then #CompileDynamic annotation or #TypeChecked(TypeCheckingMode.SKIP) respectively may be used.
I'm not sure how to achieve the same when no Gradle is in use as build tool. I may update this answer in the future with such info though.
Not at this time, but there is an open Jira issue here you can follow to watch progress for this feature
There was also a discussion about methods for doing this on the Groovy developers list