Tag Archives: prefixsuffix

Trying googletest

Recently I’ve played a bit with googletest in a couple of small projects: in murrayc-tuple-utils (and some later commits) and in prefixsuffix. It’s pretty straightforward and improved my test code and test result output (test-suite.log with autotools). Here are some notes.

Code Changes

I usually just use the standard autotools and CMake test features, sprinkling assert()s and “return EXIT_FAILURE;” in my C++ test code. However, googletest lets me replace a simple assert():

assert(foo.get_thing() == "hello");

with an EXPECT_EQ() call that will give me a clue when the test fails:

EXPECT_EQ("hello", foo.get_thing());

There are some other simple assertions.

googletest also wants me to declare test functions, previously simply declared like so,

void test_thing_something() {

now like so:

TEST("TestThing", "Something") {

which is all a bit macrotastic, unfortunately, but it works.

I chose to use the standard main() implementation, so I just removed my main() function that called these tests and compiled gtest_main.cc into the gtest library, as suggested in the googletest documentation.

Build Changes

googletest is meant to be built in your project, not built separately and just linked to as a library. For performance testing, I can see the benefit of building the test framework with exactly the same environment and options as the code being tested, but this does seem rather awkward. I guess it’s just what Google do in their monolithic builds so there’s nobody making an effort to support any other build system.

Anyway, it’s fairly easy to add googletest as a git submodule and build the library in your autotools or CMake project. For autotools, I did this with libtool in murrayc-tuple-utils and without libtool in prefixsuffix.

Unfortunately, I had to list the individual googletest source files in EXTRA_DIST to make this work with autotool’s “make distcheck”.

This is easier with CMake, because googletest has a CMakeList.txt file so you can use “add_subdirectory (googletest)”. Of course, CMake doesn’t have an equivalent for “make distcheck”.

Also unfortunately, I had to stop using the wonderful -Wsuggest-override warning with warnings as error, because googletest doesn’t use the override keyword. I think it hasn’t really caught up with C++11 yet, which seems odd as I guess Google is using at least C++11 in all its code.


The end result is not overwhelming so far, and it’s arguable if it’s worth having to deal with the git submodule awkwardness. But in theory, when the tests fail, I now won’t have to add so many printfs to find out what happened. This makes it a bit more like using JUnit with Java projects.

Also in theory, the test output would integrate nicely with a proper continuous integration system, such as Jenkins, or whatever Google use internally. But I’m not using any of those on these projects. Travis-CI is free with github projects, but it seems to be all about builds, with no support for test results.

Trying CMake Again

I’ve recently been playing with CMake again, with much more success than last time. I still don’t love it, but:

I first tried it in the cmake branch of my little PrefixSuffix application because its build is rather simple.

I then finally allowed libsigc++ to have an additional CMake build system, at least in libsigc++-3.0, and Marcin Kolny got it done. This was possible now that libsigc++ doesn’t generate code from .m4 files. We wouldn’t have wanted to maintain two complicated build systems, but two simple build systems seems acceptable. I noticed many questions on StackExchange about actually using libsigc++ in CMake builds systems, so I added a hint about that to the documentation.

I also added a CMake build system to my Glom source code, to test something bigger, with many awkward dependencies such as Python, Boost, and PostgreSQL. It’s working well now, though I haven’t yet added all the tests to the build. This let me really try out CLion.

Minor Conclusions

I’m fairly pleased with the result. CMake doesn’t now feel massively more annoying than autotools, though it makes no attempt to do the dist and distcheck that I really need. I have now achieved a level of acceptance that means I wouldn’t mind much working on a project that uses CMake. I wouldn’t even need to hold my nose. The following complaints don’t seem to bother me quite so much any more:

I still find invoking CMake horribly obscure compared to ./configure. For instance

cmake -DCMAKE_INSTALL_PREFIX:PATH=/opt/something

seems ugly compared to

./configure --prefix=/opt/gnome

and I don’t see an equivalent for “./configure –help” to list all generic and project-specific build options. I also haven’t tried to replace mm-commons‘s wonderful  –enable-warnings=fatal to easily turn on compiler warnings as errors, encouraging my code to be free of warnings and deprecated API while not troubling people who just want to build the project with the least difficulties.

I still cannot understand how it’s normal in the CMake world to create these awful little Find*() scripts for each library that you might depend on, instead of just using pkg-config, though CMake’s pkg-config support seems to work well now. And hoping that your own library’s Find*() script ends up in CMake itself does not seem scalable.

It’s also a little odd that I cannot specify the link directories (-L flags) per target. link_directories() seems to apply to all targets.

CMake’s syntax still seems like a toy language. Its quoting (none/implicit/unknown) and separating (spaces, not commas) and use of whitespace (occasionally significant) sometimes makes m4 feel almost friendly. The non-case-sensitivity of function names (but case-sensitivity of variable names) just leads to arbitrarily inconsistent code and unnecessary style differences between projects.

I don’t like the CMake tradition of having separate CMakeList.txt files in sub-directories, because this can lead to duplication and makes it harder to see the whole build system at once. I prefer non-recursive autotools, so I tried to use just one CMakeList.txt for my CMake projects too, which was only a little awkward.

Playing with xdg-app for PrefixSuffix and Glom

xdg-app lets us package applications and their dependencies together for Linux, so a user can just download the application and run it without either the developer or the user worrying about whether the correct versions of the dependencies are on the system. The various “runtimes”, such as the GNOME runtime, get you most of the way there, so you might not need to package many extra dependencies.

I put a lot of work into developing Glom, but I could never get it in front of enough non-technical users. Although it was eventually packaged for the main Linux distros, such as Ubuntu and Fedora, those packages were almost always broken or horribly outdated. I’d eagerly fix bugs reported by users, only to wait 2 years for the fix to get into a Linux distro package.

At this point, I probably couldn’t find the time to work more on Glom even if these problems went away. However, I really want something like xdg-app to succeed so the least I could do is try it out. It was pleasantly straightforward and worked very well for me. Alexander Larsson was patient and clear whenever I needed help.

xdg-app- builder

I first tried creating an xdg-app package for PrefixSuffix, because it’s a very simple app, but one that still needs dependencies that are not in the regular xdg-app GNOME runtime, such as gtkmm, glibmm and libsigc++.

I used xdg-app-builder, which reads a JSON manifest file, which lists your application and its dependencies, telling xdg-app-builder where to get the source tarballs and how to build them. Wisely, it assumes that each dependency can be built with the standard configure/make steps, but it also has support for CMake and lets you add in dummy configure and Makefile files. xdg-app-builder’s documentation is here, though I really wish the built HTML was online so I could link to it instead.

Here is the the manifest.json file for PrefixSuffix. I can run xdg-app-builder with that manifest, like so:

xdg-app-builder --require-changes ../prefixsuffix-xdgapp manifest.json

xdg-app-builder then builds each dependency in the order of its appearance in the manifest file, installing the files in a prefix in that prefixsuffix-xdgapp folder.

You also need to specify contexts in the “finish-args” though they aren’t explicitly called contexts in the manifest file. For instance, you can give your app access to the network subsystem or the host filesystem subsystem.

Creating the manifest.json file feels a lot like creating a build.gradle file for Android apps, where we would also list the base SDK version needed, along with each version of each dependency, and what permissions the app needs (though permissions are partly requested at runtime now in Android).

Here is the far larger xdg-app-builder manifest file for Glom, which I worked on after I had PrefixSuffix working. I had to provide many more build options for the dependencies and cleanup many more installed files that I didn’t need for Glom. For instance, it builds both PostgreSQL and MySQL, as well as avahi, evince, libgda, gtksourceview, goocanvas, and various *mm C++ wrappers. I could have just installed everything but that would have made the package much larger and it doesn’t generally seem safe to install lots of unnecessary binaries and files that I wouldn’t be using. I do wish that JSON allowed comments so I could explain why I’ve used various options.

You can test the app out like so:

$ xdg-app build ../prefixsuffix-xdgapp prefixsuffix
... Use the app ...
$ exit

Or you can start a shell in the xdg-app environment and then run the app, maybe via a debugger:

$ xdg-app build ../prefixsuffix-xdgapp bash
$ prefixsuffix
... Use the app ...
$ exit

Creating or updating an xdg-app repository

xdg-app can install files from online repositories. You can put your built app into a repository like so:

$ xdg-app build-export --gpg-sign="murrayc@murrayc.com" /repos/prefixsuffix ../prefixsuffix-xdgapp
$ xdg-app repo-update /repos/prefixsuffix

You can then copy that directory to a website, so it is available via http(s). You’ll want to make your GPG public key available too, so that xdg-app can check that the packages were really signed by you.

Installing with xdg-app

I uploaded the resulting xdg-app repository for PrefixSuffix to the website, so you should be able to install it like so:

$ wget https://murraycu.github.io/prefixsuffix/keys/prefixsuffix.gpg
$ xdg-app add-remote --user --gpg-import=prefixsuffix.gpg prefixsuffix https://murraycu.github.io/prefixsuffix/repo/
$ xdg-app install-app --user prefixsuffix io.github.murraycu.PrefixSuffix

I imagine that there will be a user interface for this in the future.

Then you can then run it like so, though it will also be available via your desktop menus like a regular application.

$ xdg-app run io.github.murraycu.PrefixSuffix

Here are similar instructions for installing my xdg-app Glom package.

I won’t promise to keep these packages updated, but I probably will if there is demand, and I’ll try to keep up to date on developments with xdg-app.

gtkmm 3.18 and glibmm 2.46

A couple of days ago I made the usual bunch of *mm releases for GNOME 3.18, including glibmm 2.46 and gtkmm 3.18, wrapping glib and GTK+ for C++. This adds the usual collection of new API from glib and GTK+, but the big change is the use of C++ 11.

Until C++11 is the default for g++, you’ll probably want to use the AX_CXX_COMPILE_STDCXX_11() autoconf macro. For instance, I used this to use C++11 in PrefixSuffix. Most people won’t need to make any other changes to their code or to their build. You won’t notice any change unless you care about using C++11 features.

Using C++11 in gtkmm and friends has been the most fun I’ve had with gtkmm since I had to delve deep into the GObject lifecycle back during gtkmm 1.2. I even made actual code changes to libsigc++, which I’m usually afraid to touch even though I’m the official maintainer.

Learning in general about the deep implications of  C++11’s new features reminded me how much I enjoyed learning about C++ at the beginning. It’s once again an interesting time for C++.

PrefixSuffix revived

In 2002 I released a little GNOME app to rename files by changing the start or end of the filename, using gtkmm and gnome-vfs(mm). It worked well enough and was even packaged for distros for a while before the dependencies became too awkward.

I’ve never heard of a single person using it, but I still need the app now and then so I just updated it and put it in github, changing it from gtkmm 2.4 to gtkmm 3, removing the bakery dependency, and changing from gnome-vfs to GIO. I also removed most signs of my 2002 code style.

It seems to work, but it really needs a set of test cases.

I’m sure that the performance could be vastly improved but I’m not greatly interested in that so far. Patches are welcome. In particular, I haven’t found an equivalent for the gnome_vfs_xfer_uri_list() function for renaming several files at once and I guess that repeated sequential calls to g_file_set_display_name_async() are probably not ideal.


Going gnome-vfs

I rewrote regexxer and PrefixSuffix a bit to use our new C++ gnome-vfs bindings rather than just local file systems. Regexxer was much easier than I expected because danielk‘s code is so well structured. I haven’t done a comparison, but I suspect that regexxer is slower now. If Daniel ever shows up again he’s going to slap me around that. I am not worthy of hacking on Daniel’s code.

It’s nice to know that gnome-vfsmm really works. We will freeze the API for 2.0 soon, so we can branch for the parallel-installable gtkmm 2.4/GNOME 2.6 stuff.