Sunday, December 15, 2013

Eclipse, CDT and the codan syntax checker

I have been using eclipse CDT recently on a legacy C++ project and it took a while for me to get the codan syntax checker to work. When it wasn't working it gave syntax errors for things that weren't syntax errors and claimed it couldn't find standard headers like stdlib.h, string.h etc. Use this command to invoke the GNU compiler so that it tells you where it is looking for includes:
g++ -E -x c++ - -v < /dev/null
These are the include directories that need to be configured. I got this tip from StackOverflow at

You need to turn on full tracing when invoking eclipse (as explain my earlier post), then you will see if all the paths are resolved or not.

There are lots of posts of how to solve the codan problem but they are tend to be superficial and dismissive, often saying things like "put /usr/include" in the path. That is not good enough, you have to put in all the paths that the compiler uses, including the internal ones. Don't forget that when using cygwin and codan that the paths will have to be DOS-like, i.e. starting with the C:/cygwinDir..blahBlah.

Monday, December 02, 2013

How to install eclipse plugins on a machine that is cut off from the internet

Recently I have been using a proprietary eclipse plugin in a corporate environment. The plugin seems to assume java and windoze but the project was in unix-specific C/C++ and on linux. So I was faced with the task of setting up the plugin on linux. It was then I discovered that all the linux machines are cut off from the internet. What to do? I asked around and I amazed to discover that apparantly, no-one else has ever had to deal with this issue. Lots of people guessed that you just copy the jar files over from the plugins directory and restart eclipse. Wrong.

Copying files from the plugin directory plays a part in the solution but is by no means the be all and end all. For a start, sometimes the plugin is OS-specific, so it might contain DLLs (windoze) or shared libraries (UNIX). Any such plugin has to be obtained on the target machine somehow.

One of the main challenges of installing your own plugins without using a network connection is that you will have to chase down any dependencies. By default, eclipse does not tell you when there is a problem installing plugins but you really do need this information. Here is what you do:

create a file called .options which contains:

then enter this command:
./eclipse -clean -console -consoleDebug -debug ./.options

This produces output that tells you what troubles it had loading plugins.

Under the eclipse directory create a directory called dropins. It should be a peer of plugins and features. Below dropins create eclipse and below that create plugins and features.

For any plugins that are missing, copy them from a windows environment that has them. They can be directories, files or a combination of the two. Be careful to copy to the correct target directory, either dropins/eclipse/features or dropins/eclipse/plugins depending on where it comes from in the source. To copy them, using WinCp. This is often allowed in a corporate environment.