I added those pragmas via a quilt patch, but I'm unsure if and how the patch should be submitted upstream. I was thinking about opening an openbios bug (as the patched code come from https://github.com/openbios/, brought into the qemu source tree as a git submodule), but apparently Debian can compile qemu 7.0+dfsg-7 with GCC 12, see:

https://buildd.debian.org/status/fetch.php?pkg=qemu&arch=amd64&ver=1%3A7.0%2Bdfsg-7%2Bb1&stamp=1660766914&raw=0

so I'm not sure we have a solid case for an upstream bug.

In any case I tried recompiling with those pragmas but qemu still ftbfs, with a different error this time. Again it only failed on amd64.

PPA: https://launchpad.net/~paride/+archive/ubuntu/qemu-lp1921664/+packages

Full amd64 build log: https://launchpadlibrarian.net/621847743/buildlog_ubuntu-kinetic-amd64.qemu_1%3A7.0+dfsg-7ubuntu2~ppa2_BUILDING.txt.gz

Log excerpt:

console.c: In function ‘do_console’:
console.c:130:12: internal compiler error: in emit_move_insn, at expr.cc:4010
  130 |     vga[0] = 'H' + attr;
      |     ~~~~~~~^~~~~~~~~~~~
0x137917b internal_error(char const*, ...)
	???:0
0x5a9326 fancy_abort(char const*, int, char const*)
	???:0
0xe0a692 alpha_split_const_mov(machine_mode, rtx_def**)
	???:0
0xe0a801 alpha_expand_mov(machine_mode, rtx_def**)
	???:0
0x112e2dd gen_movv4hi(rtx_def*, rtx_def*)
	???:0
0x7eedeb emit_move_insn_1(rtx_def*, rtx_def*)
	???:0
0x7ef1d7 emit_move_insn(rtx_def*, rtx_def*)
	???:0
0xe0d016 alpha_expand_movmisalign(machine_mode, rtx_def**)
	???:0
0x112e5aa gen_movmisalignv4hi(rtx_def*, rtx_def*)
	???:0
0xa278fc expand_insn(insn_code, unsigned int, expand_operand*)
	???:0
Please submit a full bug report, with preprocessed source (by using -freport-bug).
Please include the complete backtrace with any bug report.
See <file:///usr/share/doc/gcc-12/README.Bugs> for instructions.
alpha-linux-gnu-gcc -Wa,-m21264 -Wa,--noexecstack -DSYSTEM_H='"sys-clipper.h"'  -c -o console-low.o console-low.S
alpha-linux-gnu-gcc -O2 -g1 -Wall -fvisibility=hidden -fno-strict-aliasing -msmall-text -msmall-data -mno-fp-regs -mbuild-constants -mcpu=ev67 -DSYSTEM_H='"sys-clipper.h"'  -c -o ps2port.o ps2port.c
alpha-linux-gnu-gcc -O2 -g1 -Wall -fvisibility=hidden -fno-strict-aliasing -msmall-text -msmall-data -mno-fp-regs -mbuild-constants -mcpu=ev67 -DSYSTEM_H='"sys-clipper.h"'  -c -o pci.o pci.c
alpha-linux-gnu-gcc -O2 -g1 -Wall -fvisibility=hidden -fno-strict-aliasing -msmall-text -msmall-data -mno-fp-regs -mbuild-constants -mcpu=ev67 -DSYSTEM_H='"sys-clipper.h"'  -c -o vgaio.o vgaio.c
alpha-linux-gnu-gcc -O2 -g1 -Wall -fvisibility=hidden -fno-strict-aliasing -msmall-text -msmall-data -mno-fp-regs -mbuild-constants -mcpu=ev67 -DSYSTEM_H='"sys-clipper.h"'  -c -o vgatables.o vgatables.c
Preprocessed source stored into /tmp/cchX2bbT.out file, please attach this to your bugreport.
=== BEGIN GCC DUMP ===

[long dump]


=== END GCC DUMP ===
make[3]: *** [<builtin>: console.o] Error 1
make[3]: *** Waiting for unfinished jobs....
make[3]: Leaving directory '/<<PKGBUILDDIR>>/b/qemu-palcode'
make[2]: *** [debian/rules:560: b/qemu-palcode/palcode-clipper] Error 2
make[2]: Leaving directory '/<<PKGBUILDDIR>>'
make[1]: *** [debian/rules:657: install] Error 2
make[1]: Leaving directory '/<<PKGBUILDDIR>>'
make: *** [debian/rules:657: binary] Error 2