How to set collapseProperties in an Ant build file for Closure Compiler? - google-closure-compiler

I've seen some reference to a collapseProperties option when compiling with the Google Closure Compiler, but I don't understand how to set it in an Ant build file.
Will someone please provide an example? Or some documentation that has examples?
Also, if I'm compiling with compilationLevel="advanced", is collapseProperties already true?

"collapseProperties" is one of standard optimization passes enabled in ADVANCED mode. It is not available as a separate command-line option or as part of the ANT support that is part of the compiler's source tree. It is configurable using the Java API, should you wish to change it.
It basically attempts to remove objects used as namespaces, simplifying further analysis and making additional optimization possible.

if you are using advanced mode collapsed is true by default.

Related

Qt Lite and configuration changes in Qt 5.8

So allegedly, the configuration tool for Qt went through some changes, necessary to be able to make more streamlined Qt builds, a.k.a "Qt Lite". However, there doesn't seem to be any documentation about how to use that feature, or at least I don't find any, and looking at the comments from the release announcement, others can't neither.
What's more, the changes are definitely in there, judging by the fact that the configuration that I've been using for the last couple of years fails in a bunch of ways. I am not sure how up-to-date the built in help is, since the last time I tried using it for guidance, it turned out it was largely outdated and contained options that were no longer supported.
So it would be nice if someone could shed some light on what has changed and how, and how to configure for "Lite" builds. And especially on module and feature dependencies, because I think we'd all like to avoid wasting time on builds that will start building despite an improper configuration that omits necessary dependencies just to have it inevitably fail and result in nothing but a waste of time.
Per to the changelog:
The configuration system has been rewritten almost from scratch. This improved the consistency between builds on Unix and Windows, but some subtle unintended behavior changes are also possible. Also, some obsolete options have been entirely removed and will now cause errors.
It is not permissible any more to manually #define QT_NO_
anywhere. Instead, configure's -no-feature-* options must be used.
Note that this does not apply to defines which modify behavior rather
than entirely removing features.
The -no-feature-* option family was integrated with the rest of the
configuration system. Numerous existing features were made optional,
and build problems in various reduced configurations were fixed.
This is an ongoing effort known as "Qt Lite".
Features for -no-feature-* lists are in qtbase\src\corelib\global\qfeatures.txt.
All features are enabled by default.
More information can be found in the Qt Lite Overview Presentation and its slides.
You can also use the new UI Tool which is known as Qt Configuration Tool and which is a part of Qt for Embedded Devices package - see its documentation. The configuration tool is available for commercial Qt customers only at the moment (Qt 5.8).
The changes that are behind my failed configuration:
there is no longer the option to specify whether sql support is built-in or plug-in, so the format is now just -sql-<driver>, the documentation is still not updated and lists the old format - -<option>-sql-<driver>.
the -l option to add a specific library has been removed, which is turning out to be problematic in multiple areas.
Edit: Also, this blog entry just posted on doing lite builds might be useful.
Everything that describes what the new configuration system understands is given in the configure.json files scattered around Qt modules. The configure tool uses these files to build a list of command line arguments it understands.
Without the use of other tools, to learn about Qt features you need to inspect these json files and choose the features/options you wish turned on or off.
Sub Configurations
These act as includes, and refer to the configure.json file in a given folder. E.g. qtbase/configure.json includes qtbase/src/corelib/configure.json, qtbase/src/network/configure.json etc.:
"subconfigs": [
"src/corelib",
"src/network",
[...]
],
Explicit Command Line Options
The commandline/options value lists the configure options a given Qt module understands. These options are separate from the feature system, although they may be used for convenience to provide shorthand aliases that control features. For example, in qtbase/configure.json, we have:
{ "commandline": { "options": { "accessibility": "boolean", [...] }
This command line option controls the identically named accessibility feature. It is more convenient to use than dealing with the feature system's option [-no]-feature-accessibility. The following pairs have identical effects:
-accessibility or -feature-accessibility
-no-accessibility or -no-feature-accessibility
Values:
boolean options are given to configure as -option and -no-option, meaning true and false, respectively.
all other options are given as -option value.
Feature Options
The features value lists the features available in a given module. The features are effectively booleans. They are all enabled by default, subject to passing configuration tests that enable them.
To control a feature foo:
-no-feature-foo disables the feature. E.g. to disable the iconv feature, you'd do configure -no-feature-iconv [...].
-feature-foo enables the feature and ensures that it is available. This will cause an error if a configuration test for the feature fails. It's useful in build systems that build a particularly configured Qt along with your application: it ensures that the features your code depends on will be available.
Failing Builds
Generally speaking, no matter what combination of feature selections you provide, if configure doesn't fail, the build is supposed to succeed.
we'd all like to avoid wasting time on builds that will start building despite an improper configuration
The configure tool will detect any invalid configurations. If configure succeeds yet the build fails, it's a Qt bug and you should report it.

Using MSBUILD like a classic MAKEfile -- how do I do this?

I'm frustrated by the lack of flexibility in the Visual Studio project/solution, but I realized that now that it uses MSBUILD it might be quite powerful but just doesn't expose that to the IDE. So I took a look at MSBUILD docs and don't know where to start! I wish there was a Nutshell book for that. Is there any good tutorial someone could point me to?
More specifically, here is the kinds of things I want to do:
Run a utility pre-processor to generate .CPP and .H files, which are then used by a regular C++ project. There are multiple inputs (to figure dependencies of; specifically should know if a normal .h file it uses has changed) and multiple outputs (at least one .cpp and one .h file) that are used as files in another project.
FWIW, the most complex case involves using Qt in a "normal" C++ project that can be built using VS Express 2010 or MSBUILD directly from a script on a server. Since that is a common library, there might be some guides or whatever to help? Note that a VS plug-in is not useful for the building stage, but could be used to initially generate project files that then rely only on MSBUILD and stuff included with the source code.
Would somebody please point me in the right direction?
--John
It gets worse from there, but that's my first goal.
I found the kind of information I was looking for in a book MSBuild Trickery: 99 Ways to Bend the Build Engine to Your Will by Brian Kretzler.
In the first 18 pages I found a few key pieces of information that, along with the on-line documentations I've already gone through, helps clear things up enough to try tackling my project. Details of interest include the processing order of how MSBuild reads and operates on the things in the file, quick points on when wildcard in items are expanded and how to handle generated files, and how to see what's happening in some practical cases or even step in the debugger.
FWIW, I managed to attack my problem without using the murky ".targets"/rules files that I have yet to understand, but only using better documented/exampled features (in particular, a Target that has wildcard items doesn't care that the file name extension is not in any ".target"; is simple enough to copy from example and allows the files to be seen in the IDE Project and added to the list using the IDE; again, the FileExtension there just works OK.)

What is the implication of exportjars := true?

I've just started using an sbt plugin for packaging JavaFx/ScalaFx applications sbt-javafx. This under Java 7.
While the plugin seems to work pretty well, it is not able to properly package multi-module project. A workaround they have found is to use exportsJars := true in all the modules on which the JavaFX modules depends on.
I also have IntelliJ IDEA that can produce a JavaFX application for me, though that would break the automated build. I'd very much like to have the executable automated.
I need to understand the broad implication of that parameter on my sbt build. Why is the setting needed to be true?
Here is the help definition:
Determines whether the exported classpath for this project contains classes (false) or a packaged jar (true).
It sounds like by default it's false. Why?
p.s. If someone has a cleaner solution to package JavaFX/ScalaFX applications using sbt, please feel free to share.

Documentation for writing GNOME Shell extensions

I've been asked to customise the layout of the GNOME 3 desktop. Apparently the way to do that is by writing an "extension".
I've managed to do some of the things I wanted to do, but I feel utterly starved of information. I cannot find any useful documentation anywhere. I've wasted entire days of my life frantically googling every imaginable search term in a desperate attempt to find useful information.
The GNOME website has hundreds of extensions for download. These are not trivial 3-liners; they're sophisticated pieces of code. It defies belief that anybody could write these without documentation explaining how to do it.
Please, can somebody tell me where the actual documentation is? So far, the best I've managed to do is take apart existing extensions trying to track down the magic command that does the specific bit I'm interested in. (Not an easy task!)
Command names, object paths, example programs, anything would be helpful!
I have recently dug into it myself. The documentation is usually sparse or outdated. Here are some sources which helped me to get started (and through development):
Basic Stuff
Step-by-step tutorial (Gnome 3.4)
Unofficial documentation for the JavaScript bindings of many libraries
The sources of the gnome-shell's JavaScript bindings
Explanation of the St (Shell Toolkit) Ui-Toolkit components.
Some unofficial guidelines to get your extension on extensions.gnome.org
Since the documentation is nearly unavailable (or up to date), you'll need to do a lot of source-reading. I linked the gnome-shell sources above (the JavaScript part) which is a good start when diving into parts that are not covered by the In-official documentation (which is the most complete thing you'll find).
What's also particular helpful is checking extensions.gnome.org for extensions which do similar things to what you want to create, and look at their sources (most of them are open-source on GitHub or Bitbucket. You can also install them and find the sources under ~/.local/share/gnome-shell/extensions/).
When searching for something to use or more documentation on a particular function, you can also consult manuals for bindings in different languages (thought the parameters and return-values might not match).
Last but not least, here is some debugging advice:
LookingGlass is not particularly helpful. It only shows one line of an exception (the description) and only if they occur at startup time (when your extension is first started).
For full StackTraces and runtime-exceptions, consult the ~/.xsession-errors-file. It might be very long and bloated. I use this handy script to read it:
# Grabs the last session-errors from the current X11 session.
# This includes full Stack-Trace of gnome-shell-extension errors.
# See https://live.gnome.org/GnomeShell/Extensions/StepByStepTutorial#lookingGlass
tail -n100 ~/.cache/gdm/session.log | less
Note that since Gnome 3.6, if you are using gdm as display manager, the current session log is the file ~/.cache/gdm/session.log.
On some newer distros using systemd, you can get the error logs with:
journalctl -f /usr/bin/gnome-session
For debugging the prefs-part of your extension, you can launch the preferences by using the gnome-shell-extension-prefs-tool from a terminal, to see any exception-output on the console (you can also call the tool like gnome-shell-extension-prefs [uuid], to directly show your extensions preferences).
Since there is currently no real way of debugging with breakpoints (there is, but it's tricky), you can log on the console for quick checking, use the print()-function. You will see the output as mentioned above (either in the sessions-error file or on the terminal when starting gnome-shell-extension-prefs-tool).
Although it might be a little hard to get into it, the extension framework is quite powerful. Have fun!
I wrote a Blog-Post with somewhat greater detail, which can be found here: Making Gnome-Shell Extensions
An extensive list of references can be found on the Gnome Developer - API Reference page.
I used the following for my extension, but your use may vary:
GTK+ 3
GTK+ is the primary library used to construct user interfaces in GNOME applications. It provides user interface controls and signal callbacks to control user interfaces.
GDK 3
GDK is an intermediate layer which isolates GTK+ from the details of the windowing system.
Clutter
Clutter is a GObject based library for creating fast, visually rich, graphical user interfaces.
GObject Introspection
GObject Introspection is striving to provide a middleware layer between (GObject based) C libraries and language bindings.
Shell
Shell Reference Manual
St
St - Shell Toolkit - is the GNOME Shell's custom Clutter-based toolkit that defines useful actors. Some of these actors, such as StBoxLayout and StBin implement various layout options.
Icon Theme Specification
This freedesktop.org specification describes a common way to store icon themes.
NOTE: These last two are very helpful in finding visual element parameters!
PyGTK
PyGTK is GTK+ for Python. This reference contains a chapter for each Python PyGTK module (that corresponds to the underlying GTK+ library) containing the class descriptions.
PyGObject
PyGObject is a Python extension module that gives clean and consistent access to the entire GNOME software platform through the use of GObject Introspection. Specifically speaking, it is Python Bindings for GLib, GObject, GIO and GTK+.
This reference contains a chapter for each PyGObject module containing the class descriptions.
The documentation is on:
https://gjs.guide/extensions/
For the documentation of libraries:
https://gjs-docs.gnome.org/
More details on https://gjs.guide/extensions/overview/architecture.html
The other stuff you might want to check are
https://gitlab.gnome.org/GNOME/gnome-shell/blob/main/js/ui/popupMenu.js
https://gitlab.gnome.org/GNOME/gnome-shell/blob/main/js/ui/dialog.js
https://gitlab.gnome.org/GNOME/gnome-shell/blob/main/js/ui/modalDialog.js
https://gitlab.gnome.org/GNOME/gnome-shell/blob/main/js/ui/panelMenu.js
https://gitlab.gnome.org/GNOME/gnome-shell/tree/main/js
https://gitlab.gnome.org/GNOME/mutter
You can browse under js/ for more code to be reused.
You might also want to check https://gi.readthedocs.io/en/latest/index.html
Question:
I could not find anything under https://gjs-docs.gnome.org/ except some CSS and Javascript documentation ?!?!
Answer:
You have to first enable the docs to use them. Here, you will be mainly looking for:
clutter
meta
shell
st
Create a file like:
echo '{"docs":"clutter9~9_api/clutterx118~8_api/gobject20~2.66p/meta9~9_api/shell01~0.1_api/st10~1.0_api","hideIntro":"1"}' > devdocs.json
Import this file to https://gjs-docs.gnome.org/settings
Now you will be able to visit:
https://gjs-docs.gnome.org/shell01~0.1_api-global/
https://gjs-docs.gnome.org/shell01~0.1_api/
https://gjs-docs.gnome.org/meta9~9_api/
https://gjs-docs.gnome.org/st10~1.0_api/
https://gjs-docs.gnome.org/clutter9~9_api/
https://gjs-docs.gnome.org/clutter9~9_api-actor/
Warning: The version on the devdocs.json file is hardcoded. It will be outdated in no time, so you might want to check the version. The point is - you can not access docs until you enable them.
P.S. I know, this is a mess. This is how they did it.

What use does ./configure serve (other than checking dependencies)

Why does every source package that uses a makefile come with a ./configure script, what does it do? As far as I can tell, it actually generates the makefile?
Is there anything that can't be done in the makefile?
configure is usually a result of the 'autoconf' system. It can generate headers, makefiles, really anything. 'Usually,' since some are hand-crafted.
The reason for these things is to allow source code to be compiled in disparate environments. There are many variations on Unix / Linux, with slightly different system headers and libraries. configure scripts allow code to auto-adapt.
The configure step is a sort of meta build. It generates the makefile that will work on the specific hardware / distribution you're running. For instance it determines the name of the C or C++ compiler and embeds that in the makefile.
The configure step will also frequently take a set of parameters, the values of which may determine what libraries need to be linked against. For instance if you compile Apache HTTP with SSL enabled it needs to link against more shared libraries than if you don't. Since linking is handled by the makefile, you need an extra step to create a custom makefile (rather than requiring the make command to require dozens or hundreds of options.
Everything can be done from within the makefile but some build systems were implemented otherwise.
I don't personally use configure files for my projects but I admit I mostly export Erlang & Python based projects.
I don't think of the makefile as a script, I think of it as an input to the make utility.
The configure script (as its name suggests) configures the makefile, including as you say resolving dependencies.
If only from the idea of avoiding self-modifying code, the things in the configure script don't really belong in the makefile.
the point is that autoconf autohdr automake form an integrated system the makes cross platform building on unix relatively str8forward. THe docs are really bad and there are lots of horrible gotchas but on the other hand there are a lot of working samples
When I first came across this stuff I thought - "ha I can do that with a nice clean makefile" and proceeded to rework the source that way. Big mistake. Learn to write and edit configure.ac and makefile.am files, you will be happy in the end
To answer your question. Configure is good for
is function foo available on this platform and if so which include and library do I need
letting the builder choose if they want feature wizzbang included in a nice simple consistent way

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