I want to distribute some software that was compiled with the MinGW compiler which is bound by the GPL but my software is closed source and my software requires the GCC run time environment. (It uses the DLLs so no static linking).
According to this:
You have permission to propagate a work of Target Code formed by combining the Runtime Library with Independent Modules, even if such propagation would otherwise violate the terms of GPLv3, provided that all Target Code was generated by Eligible Compilation Processes. You may then convey such a combination under terms of your choice, consistent with the licensing of the Independent Modules.
Based on my understanding, I can keep my code closed as far as I don't mess with the original source files (which I don't, I only use the compiler to compile the program). Then it says this:
The GCC Runtime Library Exception covers any file that has a notice in its license headers stating that the exception applies. This includes libgcc, libstdc++, libfortran, libgomp, libdecnumber, libgcov, and other libraries distributed with GCC.
It doesn't meantion: libwinpthread-1 but it does say "and other libraries distributed with GCC." I spent quite some time searching for the answer but I could not find out if it's covered or not. So I had to download the MinGW source code and try to make sense (this is the first time I was looking at its source code) and I found a file called: "thread.c" in src-4.8.0-release-rev1.tar\src-4.8.0-release-rev1\src\gcc-4.8.0\gcc\ada and in it:
* As a special exception under Section 7 of GPL version 3, you are granted *
* additional permissions described in the GCC Runtime Library Exception, *
* version 3.1, as published by the Free Software Foundation. *
But I don't know if this file is responsible for "libwinpthread-1.dll" because there is also a folder called "winpthreads" and in it there some files and not one of them mentions "GCC Runtime Library Exception" so I am really really confused.
I have done so much research but I could not find an answer.
My objective is to release the software without later on being forced to release my code because if that's the case I may as well buy Vision Studio and compile it using VS.
Best Answer snaphat (Myles Landwehr) , 28 December 2013 - 02:33
Yes, I get the point now and I agree, that is a good point.
In my case, the software I'd like to redistribute as a freeware (I am an independent developer) was developed with the Qt framework (which is a top-notch framework without a doubt).
I dynamically link to Qt DLL files as well as the MinGW DLLs. When I say dynamically, what I mean is my EXE requires the DLLs in order for it to run. So the DLL code is not built-into the exe itself. It depends on the DLLs and take one DLL away, it won't run. My app is closed source and have done zero modifications to the Qt libraries. I just #included the header files so I can utilize the API.
So I will need to have Qt's source code handy in case someone asks for it (which I do, it comes with installer as far as I am aware).
I know I am bound to include the LGPL license file with the files I am redistributing and acknowledge the use of Qt LGPL edition in the about box.
That's basically all I intend to do and the LGPL allows having the source closed if you dynamically link the libraries (as far as I am aware).
This all sounds perfectly permissible to me (and quite common). Dynamic linking is required as per the license AFAIK because of the part I highlighted in my previous post. I don't believe static linking is allowed because it would make it impossible for the user to relink to a newer revision of the library (as required under the licensing terms). Anyway, I just took a look at the specific revision that QT is using and it it looks like newer revisions of the LGPL have a stipulation that exempts you from having to directly redistribute the source after all (this is not in the older versions: https://www.gnu.org/licenses/lgpl.html). So you can go ahead and do what you were thinking and just provide a link:
If distribution of executable or object code is made by offering access to copy from a designated place, then offering equivalent access to copy the source code from the same place counts as distribution of the source code, even though third parties are not compelled to copy the source along with the object code.
Be careful though, if the version or the license the software is under doesn't have that stipulation then you should be wary of doing doing it that way. It's important to check the terms exactly.Go to the full post