> Before Apple built Clang, they made a GCC plugin[0] which dumped the AST from the GCC frontend, and fed it into the LLVM backend.
But they didn't! Dragonegg is a GCC plugin, which didn't exist when work started on Clang--GCC plugins date to GCC 4.5, released in 2010, which is the same year that Clang became self-hosting.
The timeline is rather like this: LLVM originally relied on a hacked-up version of gcc 4.2 called llvm-gcc to create LLVM IR from source code. When GCC added support for plugins, there was the attempt to move that frontend to a more reliable framework, and that was Dragonegg. As far as I'm aware, Apple never contributed to the Dragonegg project itself. Dragonegg didn't last that long; by 2014, the project was completely dead. And for most of its life, the biggest interest in Dragonegg was to have some modicum of support for Fortran.
> Meanwhile, Stallman handcuffed GNU projects like Emacs for years[1] by refusing to expose GCC's AST in an effort to prevent something like this from happening.
By the time of that message, RMS's worst nightmare had come true with Dragonegg... only for Dragonegg to have already died due to a lack of demand for it.
You're right, I got Dragonegg mixed up with llvm-gcc. But my point stands – the GPL was completely ineffective at preventing someone from using it to bootstrap a new compiler infrastructure under a more permissive license.
But they didn't! Dragonegg is a GCC plugin, which didn't exist when work started on Clang--GCC plugins date to GCC 4.5, released in 2010, which is the same year that Clang became self-hosting.
The timeline is rather like this: LLVM originally relied on a hacked-up version of gcc 4.2 called llvm-gcc to create LLVM IR from source code. When GCC added support for plugins, there was the attempt to move that frontend to a more reliable framework, and that was Dragonegg. As far as I'm aware, Apple never contributed to the Dragonegg project itself. Dragonegg didn't last that long; by 2014, the project was completely dead. And for most of its life, the biggest interest in Dragonegg was to have some modicum of support for Fortran.
> Meanwhile, Stallman handcuffed GNU projects like Emacs for years[1] by refusing to expose GCC's AST in an effort to prevent something like this from happening.
By the time of that message, RMS's worst nightmare had come true with Dragonegg... only for Dragonegg to have already died due to a lack of demand for it.