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The problem isn't that the compiler chooses not to compile something if it deems it broken. The problem is that the broken code's behaviour is coupled to the co

The problem isn't that the compiler chooses not to compile something if it deems it broken. The problem is that the broken code's behaviour is coupled to the compiler of the time. The behaviour you want isn't "compile this version of Linux even though it has a bug", it's "compile this version of Linux as if you were a compiler at the time which accepted this broken code in this way", which is a very tall order, along the lines of bug-for-bug compatibility while also fixing the bug.

rascul 3y ago
I vaguely recall that when I was building LFS some time in the past, gcc 2.95 was recommended over the 3.x series for some reason. So I looked it up and found a line about it in an old version of the book: > This is an older release of GCC which we are going to install for the purpose of compiling the Linux kernel in Chapter 8. This version is recommended by the kernel developers when you need absolute stability. Later versions of GCC have not received as much testing for Linux kernel compilation. Using a later version is likely to work, however, we recommend adhering to the kernel developer's advice and using the version here to compile your kernel. https://www.linuxfromscratch.org/museum/lfs-museum/5.0/LFS-BOOK-5.0-HTML/chapter06/gcc-2953.html https://www.linuxfromscratch.org/museum/lfs-museum/5.0/LFS-B... I wish I had a better reference. The bit about "compile this version of Linux as if you were a compiler at the time which accepted this broken code in this way" made me think of that.
jandrese 3y ago
GCC 2.95 was a tremendously sticky release. The 3.x series was notorious for compiler bugs for a long time so many people stayed with 2.95 for years. I think a good number of people ended up skipping the entire 3.x release.
mst 3y ago
Maintaining bugwards compatibility is a pain in the arse and eventually you really just have to cry havoc and let slip the dogs of breakage.

rascul 3y ago

I vaguely recall that when I was building LFS some time in the past, gcc 2.95 was recommended over the 3.x series for some reason. So I looked it up and found a line about it in an old version of the book: > This is an older release of GCC which we are going to install for the purpose of compiling the Linux kernel in Chapter 8. This version is recommended by the kernel developers when you need absolute stability. Later versions of GCC have not received as much testing for Linux kernel compilation. Using a later version is likely to work, however, we recommend adhering to the kernel developer's advice and using the version here to compile your kernel. https://www.linuxfromscratch.org/museum/lfs-museum/5.0/LFS-BOOK-5.0-HTML/chapter06/gcc-2953.html https://www.linuxfromscratch.org/museum/lfs-museum/5.0/LFS-B... I wish I had a better reference. The bit about "compile this version of Linux as if you were a compiler at the time which accepted this broken code in this way" made me think of that.

jandrese 3y ago

GCC 2.95 was a tremendously sticky release. The 3.x series was notorious for compiler bugs for a long time so many people stayed with 2.95 for years. I think a good number of people ended up skipping the entire 3.x release.

mst 3y ago

Maintaining bugwards compatibility is a pain in the arse and eventually you really just have to cry havoc and let slip the dogs of breakage.