riscv64 libgccjit stopped working

[Sergio Durigan Junior]

Hi,

This bug is affecting Emacs, as can be seen here:

https://launchpad.net/ubuntu/+source/emacs/1:28.2+1-12ubuntu1/+build/25649207

I was able to track this down to a problem with libgccjit and LIBRARY_PATH on riscv64. Basically, compiling the example program from https://gcc.gnu.org/onlinedocs/jit/intro/tutorial01.html and running it leads to:

$ gcc /tmp/1.c -lgccjit
$ ./a.out
ld: cannot find crtbeginS.o: No such file or directory
libgccjit.so: error: error invoking gcc driver
NULL result

If we explicitly specify LIBRARY_PATH, it works:

$ LIBRARY_PATH=/usr/lib/gcc/ ./a.out
hello world

[Matthias Klose (doko)]

please run strace --trace=file ./a.out

[Sergio Durigan Junior (sergiodj)]

Hm, here's the interesting part from the strace output:

faccessat(AT_FDCWD, "/usr/lib/gcc/riscv64-linux-gnu/13riscv64-linux-gnu/13/crtbeginS.o", R_OK) = -1 ENOENT (No such file or directory)
faccessat(AT_FDCWD, "/usr/lib/gcc/riscv64-linux-gnu/13riscv64-linux-gnu/crtbeginS.o", R_OK) = -1 ENOENT (No such file or directory)
faccessat(AT_FDCWD, "/usr/lib/gcc/riscv64-linux-gnu/13crtbeginS.o", R_OK) = -1 ENOENT (No such file or directory)
faccessat(AT_FDCWD, "/usr/lib/gcc/riscv64-linux-gnu/../../riscv64-linux-gnu/lib/riscv64-linux-gnu/13/crtbeginS.o", R_OK) = -1 ENOENT (No such file or directory)
faccessat(AT_FDCWD, "/usr/lib/gcc/riscv64-linux-gnu/../../riscv64-linux-gnu/lib/riscv64-linux-gnu/crtbeginS.o", R_OK) = -1 ENOENT (No such file or directory)
faccessat(AT_FDCWD, "/usr/lib/gcc/riscv64-linux-gnu/../../riscv64-linux-gnu/lib/crtbeginS.o", R_OK) = -1 ENOENT (No such file or directory)
faccessat(AT_FDCWD, "/lib64/lp64d/riscv64-linux-gnu/13/crtbeginS.o", R_OK) = -1 ENOENT (No such file or directory)
faccessat(AT_FDCWD, "/lib64/lp64d/riscv64-linux-gnu/crtbeginS.o", R_OK) = -1 ENOENT (No such file or directory)
faccessat(AT_FDCWD, "/lib64/lp64d/crtbeginS.o", R_OK) = -1 ENOENT (No such file or directory)
faccessat(AT_FDCWD, "/usr/lib64/lp64d/riscv64-linux-gnu/13/crtbeginS.o", R_OK) = -1 ENOENT (No such file or directory)
faccessat(AT_FDCWD, "/usr/lib64/lp64d/riscv64-linux-gnu/crtbeginS.o", R_OK) = -1 ENOENT (No such file or directory)
faccessat(AT_FDCWD, "/usr/lib64/lp64d/crtbeginS.o", R_OK) = -1 ENOENT (No such file or directory)
faccessat(AT_FDCWD, "/lib/riscv64-linux-gnu/13/crtbeginS.o", R_OK) = -1 ENOENT (No such file or directory)
faccessat(AT_FDCWD, "/lib/riscv64-linux-gnu/crtbeginS.o", R_OK) = -1 ENOENT (No such file or directory)
faccessat(AT_FDCWD, "/lib/crtbeginS.o", R_OK) = -1 ENOENT (No such file or directory)
faccessat(AT_FDCWD, "/usr/lib/riscv64-linux-gnu/13/crtbeginS.o", R_OK) = -1 ENOENT (No such file or directory)
faccessat(AT_FDCWD, "/usr/lib/riscv64-linux-gnu/crtbeginS.o", R_OK) = -1 ENOENT (No such file or directory)
faccessat(AT_FDCWD, "/usr/lib/crtbeginS.o", R_OK) = -1 ENOENT (No such file or directory)

For some reason, it's trying to load crtbeginS.so from gcc-13, even though I compiled the program using gcc-12 and don't even have libgccjit-13-dev installed. I wonder why this doesn't happen in other architectures, though. I will double check.

[Sergio Durigan Junior (sergiodj)]

Interestingly, this is the strace output for amd64:

access("/usr/lib/gcc/x86_64-linux-gnu/13x86_64-linux-gnu/13/crtbeginS.o", R_OK) = -1 ENOENT (No such file or directory)
access("/usr/lib/gcc/x86_64-linux-gnu/13x86_64-linux-gnu/crtbeginS.o", R_OK) = -1 ENOENT (No such file or directory)
access("/usr/lib/gcc/x86_64-linux-gnu/13crtbeginS.o", R_OK) = -1 ENOENT (No such file or directory)
access("/usr/lib/gcc/x86_64-linux-gnu/../../x86_64-linux-gnu/lib/x86_64-linux-gnu/13/crtbeginS.o", R_OK) = -1 ENOENT (No such file or directory)
access("/usr/lib/gcc/x86_64-linux-gnu/../../x86_64-linux-gnu/lib/x86_64-linux-gnu/crtbeginS.o", R_OK) = -1 ENOENT (No such file or directory)
access("/usr/lib/gcc/x86_64-linux-gnu/../../x86_64-linux-gnu/lib/../lib/crtbeginS.o", R_OK) = -1 ENOENT (No such file or directory)
access("/usr/lib/gcc/x86_64-linux-gnu/../x86_64-linux-gnu/13/crtbeginS.o", R_OK) = 0

Again, libgccjit-13-dev is not installed. So it seems that it's expected (although IMHO wrong) for a program compiled with gcc-12 to load .o files from libgcc-13-dev. But that's another issue.

The real problem here seems to be the fact that we see an attempt to load "/usr/lib/gcc/x86_64-linux-gnu/../x86_64-linux-gnu/13/crtbeginS.o" on amd64, which is successful; but we don't see an attempt to load "/usr/lib/gcc/riscv64-linux-gnu/../riscv64-linux-gnu/13/crtbeginS.o" on riscv64.

[Sergio Durigan Junior (sergiodj)]

I ran the test on Mantic using both gcc-12 and gcc-13, and I can't reproduce this anymore. Marking the bug as Fix Released.