[Tutorial] SketchUp Ruby C Extension

Anton_S

When recompiling Win32::API under own namespace, do not use -Ox flag.
The -Ox flag from [Compiler Options](http://msdn.microsoft.com/en-US/library/19z1t1wy(v), which creates maximum optimization causes SketchUp to produce a bugsplat right after completion of callback function enumeration.

Example:

module My;;CallbackTest
  EnumWindows = My;;Win32;;API.new('EnumWindows', 'KP', 'I', 'User32')
  EnumWindowsProc = My;;Win32;;API;;Callback.new('IP', 'I'){ |hwnd, lParam|
    puts hwnd
    1 # continue process
  }
  
  def self.listWindowHandles
    EnumWindows.call(EnumWindowsProc, nil)
    # With Compiled $CFLAGS = '-MT -Ox -W4'
    #   SU crashes right after enumation through all parent handles.
    # With Compiled $CFLAGS = '-MT -W4'
    #   SU works fine, although the size looks ~1.5 KB greater than with the -Ox flag.
  end
end

When compiling Win32::API, I have $CFLAGS = '-MT -W4'

...just sharing some Win32::API compilation experiments

thomthom

Good to know!

I should add some warning about the -Ox flag that it might cause problems - since it's very aggressive optimization.

thomthom

Call for information

I´ve only used a Mac Mini PPC with 10.4 and a Mac Mini Intel with 105 when compiling C Extensions under OSX.

I´m getting all sorts of warning that 10.5 isn´t supported anymore, from Apple and the software. Fair enough.

But what I´d like to know is:
If I update to Montain Lion - what would I need to get SketchUp Ruby C Extensions running?
I take it that the OS Ruby versions is much newer now - and I´d have to link the build to something other than the OS Ruby?

Also, when compiling a C Extension under Mountain Lion - how backwards compatible will it be?

AdamB

@thomthom said:

I take it that the OS Ruby versions is much newer now - and I´d have to link the build to something other than the OS Ruby?

No, a Plugin resolves the symbols on load.

@thomthom said:

Also, when compiling a C Extension under Mountain Lion - how backwards compatible will it be?

As much as you ask for it to be: eg -mmacosx-version-min=10.4 will ensure it runs on 10.4 and up.

@thomthom said:

I should add some warning about the -Ox flag that it might cause problems - since it's very aggressive optimization.

Just to correct this. The optimization does not produce 'wrong code' per se. Its that it commonly will remove leaf function stack frames to increase performance, meaning Ruby's GC can't find a reference to a Object and it gets marked for collection. So ensure you keep references and you'll be fine.

thomthom

@adamb said:

No, a Plugin resolves the symbols on load.

Really? But if the OS Ruby is 1.9, and I compile without doing anything. Won't it be compiled for 1.9 only then? Isn't there completely different functions between 1.8 and 1.9?

@adamb said:

As much as you ask for it to be: eg -mmacosx-version-min=10.4 will ensure it runs on 10.4 and up.

Where does this flag go in the compile process? In the MAKEFILE? In the arguments of the make command?
(I'm very green to this.)

@adamb said:

Just to correct this. The optimization does not produce 'wrong code' per se. Its that it commonly will remove leaf function stack frames to increase performance, meaning Ruby's GC can't find a reference to a Object and it gets marked for collection. So ensure you keep references and you'll be fine.

Thanks for the clarification.

thomthom

@designingcrime said:

Hey guys, so I finally got a Ruby C extension to compile on both os x and windows and link curllib. I got a lot of help from Luis at the RubyInstaller group and ended up using RubyInstaller and DevKit to link curl and build using the gcc compiler included with devkit.
Here is the extension. Its a modified version of Dana's sketchup downloader, but also included uploading, basic http authentication and ssl certificate checking(all through curl). I provided instructions on how to build on both os x and windows.

https://github.com/sunglass/SunglassPlugins/tree/master/SG-SketchupHook/src/Connection%20Manager

Thanks for all your help guys.

Dana - Lets get your Sketchup downloader plugin working.

Link is dead.

Whaat

Just wanted to thank Thomas and everyone else for the contributions in this thread. I tried to get Thomas' Hello World extension working and had no problems at all, thanks to his clear documentation.

My next experiment will be to incorporate SketchUp SDK calls into the Ruby Extension. Has anyone done this? Is it relatively straightforward? Any 'gotchas' that you could warn me about? Thanks

Whaat

Problems already...
I have the SDK .h files installed in the same folder as 'SX_HelloWorld.c'. I'm not sure what to do with the binary files provided with the SDK.

I tried to include just one header <slapi/model/model.h> file from the SDK and this was the result.

Feeling clueless...

tt_su

We're actually working on a Hello World example for Visual Studio and Xcode for compiling Ruby C/C++ Extensions for SketchUp. We can expand that (create a work or extra branch) with SLAPI configured as well.

By the way can you post a Gist of your code? You got some syntax errors there that appear to not be related to linking to the correct headers.

Whaat

@tt_su said:

We're actually working on a Hello World example for Visual Studio and Xcode for compiling Ruby C/C++ Extensions for SketchUp. We can expand that (create a work or extra branch) with SLAPI configured as well.

By the way can you post a Gist of your code? You got some syntax errors there that appear to not be related to linking to the correct headers.

Interesting, I was just now doing some research into 'extconf.rb' and I'm starting to think my problem is related to not configuring the location of the .lib and .h files inside of 'extconf.rb' using the 'dir_config' and 'have_library' commands.

BTW, the only difference between my code and your 'hello world' code on bitbucket is that I #included one the SLAPI .h files at the top.

I had assumed (or hoped) that it would be properly linked since I put the files in the same location as the .c file that I was trying to compile.

It goes without saying that I am a complete noob at this.

tt_su

Hi Dale

I looked into this and found that you cannot use Visual Studio's nmake for this as it's C89 - and the SLAPI is written in C99.

It would work if you install the DevKit at Ruby Windows Installer - though I'm still working out some minor quirks. We're preparing some Hello World examples to get started with Ruby C Extensions. Can you hang in there a little bit more?

Whaat

@tt_su said:

Hi Dale

I looked into this and found that you cannot use Visual Studio's nmake for this as it's C89 - and the SLAPI is written in C99.

It would work if you install the DevKit at Ruby Windows Installer - though I'm still working out some minor quirks. We're preparing some Hello World examples to get started with Ruby C Extensions. Can you hang in there a little bit more?

No problem. Thanks for looking into this. I am excited to see the new examples...

tt_su

Good news is that I got the SLAPI example compiling under OSX. I need to test on Windows and clean up the extconf.rb file a little.

Whaat

@tt_su said:

Good news is that I got the SLAPI example compiling under OSX. I need to test on Windows and clean up the extconf.rb file a little.

Cool!

tomasz

@tt_su said:

Good news is that I got the SLAPI example compiling under OSX. I need to test on Windows and clean up the extconf.rb file a little.

It will be very good indeed to have those examples easy to compile and ready to expand.

cncmachineguy

Hello All,
I am just starting on C extensions for SU and have a quick question. I have been successful following Thom's hello world example on bit bucket. My first question is are there any known IDE solutions to compile from? I don't relish the idea of writing code in notepad++ or other, then compiling from command line, then loading into SU and hoping it works.
Is this the way this is being done now or have I missed something?
In any event, THANK you all for the hard work you have put into this so far, if this is the best known solution, I will follow it.

BTW, working within Win7(64)

tt_su

We are setting up a C++ Hello World example for Visual Studio and Xcode. That will give you better environments to work and debug in.

cncmachineguy

Thanks Thomas, I offer to do testing if you need it. Otherwise I will keep my eye on this.

cncmachineguy

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