From a96eadd871207cc7a811def35fb32a971c6be1bb Mon Sep 17 00:00:00 2001 From: Andrew Burgess Date: Thu, 9 Dec 2021 17:51:10 +0000 Subject: [PATCH] gdb: only include mips and riscv targets if building with 64-bit bfd While testing another patch I was trying to build different configurations of GDB, and, during one test build I ran into a problem, I configured with `--enable-targets=all --host=i686-w64-mingw32` and saw this error while linking GDB: .../i686-w64-mingw32/bin/ld: mips-tdep.o: in function `mips_gdbarch_init': .../src/gdb/mips-tdep.c:8730: undefined reference to `disassembler_options_mips' .../i686-w64-mingw32/bin/ld: riscv-tdep.o: in function `riscv_gdbarch_init': .../src/gdb/riscv-tdep.c:3851: undefined reference to `disassembler_options_riscv' So the `disassembler_options_mips` and `disassembler_options_riscv` symbols are missing. This turns out to be because mips-dis.c and riscv-dis.c, in which these symbols are defined, are in the TARGET64_LIBOPCODES_CFILES list in opcodes/Makefile.am, these files are only built when we are building with a 64-bit bfd. If we look further, into bfd/Makefile.am, we can see that all the files matching elf*-riscv.lo are in the BFD64_BACKENDS list, as are the elf*-mips.lo files, and (I know because I tried), the two disassemblers do, not surprisingly, depend on features supplied from libbfd. So, though we can build most of GDB just fine for riscv and mips with a 32-bit bfd, if I understand correctly, the final GDB executable (assuming we could get it to link) would not understand these architectures at the bfd level, nor would there be any disassembler available. This sounds like a pretty useless GDB to me. So, in this commit, I move the riscv and mips targets into GDB's list of targets that require a 64-bit bfd. After this I can build GDB just fine with the configure options given above. This was discussed on the mailing list in a couple of threads: https://sourceware.org/pipermail/gdb-patches/2021-December/184365.html https://sourceware.org/pipermail/binutils/2021-November/118498.html and it is agreed, that it is unfortunate that the 32-bit riscv and 32-bit mips targets require a 64-bit bfd. If in the future this situation ever changes then it would be expected that some (or all) of this patch would be reverted. Until then though, this patch allows GDB to build when configured with --enable-targets=all, and when using a 32-bit libbfd. --- gdb/Makefile.in | 22 +++++++++++----------- 1 file changed, 11 insertions(+), 11 deletions(-) diff --git a/gdb/Makefile.in b/gdb/Makefile.in index bff27577b95..f2966cf6c00 100644 --- a/gdb/Makefile.in +++ b/gdb/Makefile.in @@ -710,10 +710,21 @@ ALL_64_TARGET_OBS = \ arch/aarch64-insn.o \ arch/aarch64-mte-linux.o \ arch/amd64.o \ + arch/riscv.o \ ia64-linux-tdep.o \ ia64-tdep.o \ ia64-vms-tdep.o \ + mips-fbsd-tdep.o \ + mips-linux-tdep.o \ + mips-netbsd-tdep.o \ + mips-sde-tdep.o \ + mips-tdep.o \ mips64-obsd-tdep.o \ + riscv-fbsd-tdep.o \ + riscv-linux-tdep.o \ + riscv-none-tdep.o \ + riscv-ravenscar-thread.o \ + riscv-tdep.o \ sparc64-fbsd-tdep.o \ sparc64-linux-tdep.o \ sparc64-netbsd-tdep.o \ @@ -734,7 +745,6 @@ ALL_TARGET_OBS = \ arch/arm-linux.o \ arch/i386.o \ arch/ppc-linux-common.o \ - arch/riscv.o \ arm-bsd-tdep.o \ arm-fbsd-tdep.o \ arm-linux-tdep.o \ @@ -793,11 +803,6 @@ ALL_TARGET_OBS = \ mep-tdep.o \ microblaze-linux-tdep.o \ microblaze-tdep.o \ - mips-fbsd-tdep.o \ - mips-linux-tdep.o \ - mips-netbsd-tdep.o \ - mips-sde-tdep.o \ - mips-tdep.o \ mn10300-linux-tdep.o \ mn10300-tdep.o \ moxie-tdep.o \ @@ -818,11 +823,6 @@ ALL_TARGET_OBS = \ ppc-sysv-tdep.o \ ppc64-tdep.o \ ravenscar-thread.o \ - riscv-fbsd-tdep.o \ - riscv-linux-tdep.o \ - riscv-none-tdep.o \ - riscv-ravenscar-thread.o \ - riscv-tdep.o \ rl78-tdep.o \ rs6000-aix-tdep.o \ rs6000-lynx178-tdep.o \ -- 2.30.2