Re: [PATCH 01/12] RISC-V: Build Infastructure

[Adhemerval Zanella <adhemerval dot zanella at linaro dot org>]

On 14/06/2017 15:30, Palmer Dabbelt wrote:
> This patch lays out the top-level orginazition of the RISC-V port.  It
> contains all the Implies files as well as various other fragments of
> build infastructure for the RISC-V port.  This contains the only change
> to a shared file: config.h.in.
> 
> RISC-V is a family of base ISAs with optional extensions.  The base ISAs
> are RV32I and RV64I, which are 32-bit and 64-bit integer-only ISAs.
> Support for these live in sysdeps/riscv/rv{32,64}.  In addition to these
> ISAs, our glibc port supports most of the currently-defined extensions:
> the A extension for atomics, the M extension for multiplication, the C
> extension for compressed instructions, and the F/D extensions for
> single/double precision IEEE floating-point.  Most of these extensions
> are handled by GCC, but glibc defines various floating-point wrappers
> (in sysdeps/riscv/rv{32,64}/rv{f,d}) and emulation routines (in
> sysdeps/riscv/soft-fp).
> 
> We support running glibc-based programs on Linux, the suppor for which
> lives in sysdeps/unix/sysv/linux/riscv.
> ---
>  config.h.in                                  |  5 ++
>  sysdeps/riscv/Implies                        |  6 ++
>  sysdeps/riscv/Makefile                       | 45 +++++++++++++++
>  sysdeps/riscv/Versions                       |  5 ++
>  sysdeps/riscv/configure                      | 86 ++++++++++++++++++++++++++++
>  sysdeps/riscv/configure.in                   |  4 ++
>  sysdeps/riscv/nptl/Makefile                  | 25 ++++++++
>  sysdeps/riscv/preconfigure                   | 50 ++++++++++++++++
>  sysdeps/riscv/rv32/Implies-after             |  1 +
>  sysdeps/riscv/rv32/rvd/Implies               |  2 +
>  sysdeps/riscv/rv32/rvf/Implies               |  1 +
>  sysdeps/riscv/rv64/Implies-after             |  1 +
>  sysdeps/riscv/rv64/rvd/Implies               |  2 +
>  sysdeps/riscv/rv64/rvf/Implies               |  1 +
>  sysdeps/riscv/soft-fp/Makefile               |  3 +
>  sysdeps/unix/sysv/linux/riscv/Implies        |  1 +
>  sysdeps/unix/sysv/linux/riscv/Makefile       | 26 +++++++++
>  sysdeps/unix/sysv/linux/riscv/configure      |  7 +++
>  sysdeps/unix/sysv/linux/riscv/configure.in   |  8 +++
>  sysdeps/unix/sysv/linux/riscv/rv32/Implies   |  3 +
>  sysdeps/unix/sysv/linux/riscv/rv64/Implies   |  3 +
>  sysdeps/unix/sysv/linux/riscv/rv64/Makefile  |  9 +++
>  sysdeps/unix/sysv/linux/riscv/shlib-versions | 17 ++++++
>  23 files changed, 311 insertions(+)
>  create mode 100644 sysdeps/riscv/Implies
>  create mode 100644 sysdeps/riscv/Makefile
>  create mode 100644 sysdeps/riscv/Versions
>  create mode 100644 sysdeps/riscv/configure
>  create mode 100644 sysdeps/riscv/configure.in
>  create mode 100644 sysdeps/riscv/nptl/Makefile
>  create mode 100644 sysdeps/riscv/preconfigure
>  create mode 100644 sysdeps/riscv/rv32/Implies-after
>  create mode 100644 sysdeps/riscv/rv32/rvd/Implies
>  create mode 100644 sysdeps/riscv/rv32/rvf/Implies
>  create mode 100644 sysdeps/riscv/rv64/Implies-after
>  create mode 100644 sysdeps/riscv/rv64/rvd/Implies
>  create mode 100644 sysdeps/riscv/rv64/rvf/Implies
>  create mode 100644 sysdeps/riscv/soft-fp/Makefile
>  create mode 100644 sysdeps/unix/sysv/linux/riscv/Implies
>  create mode 100644 sysdeps/unix/sysv/linux/riscv/Makefile
>  create mode 100644 sysdeps/unix/sysv/linux/riscv/configure
>  create mode 100644 sysdeps/unix/sysv/linux/riscv/configure.in
>  create mode 100644 sysdeps/unix/sysv/linux/riscv/rv32/Implies
>  create mode 100644 sysdeps/unix/sysv/linux/riscv/rv64/Implies
>  create mode 100644 sysdeps/unix/sysv/linux/riscv/rv64/Makefile
>  create mode 100644 sysdeps/unix/sysv/linux/riscv/shlib-versions
> 
> diff --git a/config.h.in b/config.h.in
> index 22418576a0..f870267870 100644
> --- a/config.h.in
> +++ b/config.h.in
> @@ -99,6 +99,11 @@
>  /* AArch64 big endian ABI */
>  #undef HAVE_AARCH64_BE
>  
> +/* RISC-V integer ABI for ld.so.  */
> +#undef RISCV_ABI_XLEN
> +
> +/* RISC-V floating-point ABI for ld.so.  */
> +#undef RISCV_ABI_FLEN
>  
>  /* Defined to some form of __attribute__ ((...)) if the compiler supports
>     a different, more efficient calling convention.  */
> diff --git a/sysdeps/riscv/Implies b/sysdeps/riscv/Implies
> new file mode 100644
> index 0000000000..15b9e02448
> --- /dev/null
> +++ b/sysdeps/riscv/Implies
> @@ -0,0 +1,6 @@
> +init_array
> +
> +ieee754/ldbl-128
> +ieee754/dbl-64
> +ieee754/flt-32
> +riscv/soft-fp
> diff --git a/sysdeps/riscv/Makefile b/sysdeps/riscv/Makefile
> new file mode 100644
> index 0000000000..5a699a2e64
> --- /dev/null
> +++ b/sysdeps/riscv/Makefile
> @@ -0,0 +1,45 @@
> +ifneq ($(all-rtld-routines),)
> +CFLAGS-rtld.c += -mno-plt

Why exactly do you need no plt in loader code?

> +CFLAGS-dl-load.c += -mno-plt
> +CFLAGS-dl-cache.c += -mno-plt
> +CFLAGS-dl-lookup.c += -mno-plt
> +CFLAGS-dl-object.c += -mno-plt
> +CFLAGS-dl-reloc.c += -mno-plt
> +CFLAGS-dl-deps.c += -mno-plt
> +CFLAGS-dl-runtime.c += -mno-plt
> +CFLAGS-dl-error.c += -mno-plt
> +CFLAGS-dl-init.c += -mno-plt
> +CFLAGS-dl-fini.c += -mno-plt
> +CFLAGS-dl-debug.c += -mno-plt
> +CFLAGS-dl-misc.c += -mno-plt
> +CFLAGS-dl-version.c += -mno-plt
> +CFLAGS-dl-profile.c += -mno-plt
> +CFLAGS-dl-conflict.c += -mno-plt
> +CFLAGS-dl-tls.c += -mno-plt
> +CFLAGS-dl-origin.c += -mno-plt
> +CFLAGS-dl-scope.c += -mno-plt
> +CFLAGS-dl-execstack.c += -mno-plt
> +CFLAGS-dl-caller.c += -mno-plt
> +CFLAGS-dl-open.c += -mno-plt
> +CFLAGS-dl-close.c += -mno-plt
> +CFLAGS-dl-sysdep.c += -mno-plt
> +CFLAGS-dl-environ.c += -mno-plt
> +CFLAGS-dl-minimal.c += -mno-plt
> +CFLAGS-dl-static.c += -mno-plt
> +CFLAGS-dl-brk.c += -mno-plt
> +CFLAGS-dl-sbrk.c += -mno-plt
> +CFLAGS-dl-getcwd.c += -mno-plt
> +CFLAGS-dl-openat64.c += -mno-plt
> +CFLAGS-dl-opendir.c += -mno-plt
> +CFLAGS-dl-fxstatat64.c += -mno-plt
> +endif
> +
> +CFLAGS-closedir.c += -mno-plt
> +CFLAGS-exit.c += -mno-plt
> +CFLAGS-cxa_atexit.c += -mno-plt
> +
> +ifeq ($(subdir),misc)
> +sysdep_headers += sys/asm.h
> +endif
> +
> +ASFLAGS-.os += $(pic-ccflag)
> diff --git a/sysdeps/riscv/Versions b/sysdeps/riscv/Versions
> new file mode 100644
> index 0000000000..5a0c2d23f8
> --- /dev/null
> +++ b/sysdeps/riscv/Versions
> @@ -0,0 +1,5 @@
> +libc {
> +  GLIBC_2.14 {
> +    __memcpy_g;
> +  }
> +}

This seems wrong, risc-v won't have any GLIBC_2.14 symbols since its ABI will
start from current one (2.26).

> diff --git a/sysdeps/riscv/configure b/sysdeps/riscv/configure
> new file mode 100644
> index 0000000000..9f790ec527
> --- /dev/null
> +++ b/sysdeps/riscv/configure

You do not need to post auto-generated files.


> @@ -0,0 +1,86 @@
> +
> +# as_fn_set_status STATUS
> +# -----------------------
> +# Set $? to STATUS, without forking.
> +as_fn_set_status ()
> +{
> +  return $1
> +} # as_fn_set_status
> +
> +# as_fn_exit STATUS
> +# -----------------
> +# Exit the shell with STATUS, even in a "trap 0" or "set -e" context.
> +as_fn_exit ()
> +{
> +  set +e
> +  as_fn_set_status $1
> +  exit $1
> +} # as_fn_exit
> +if expr a : '\(a\)' >/dev/null 2>&1 &&
> +   test "X`expr 00001 : '.*\(...\)'`" = X001; then
> +  as_expr=expr
> +else
> +  as_expr=false
> +fi
> +
> +if (basename -- /) >/dev/null 2>&1 && test "X`basename -- / 2>&1`" = "X/"; then
> +  as_basename=basename
> +else
> +  as_basename=false
> +fi
> +
> +as_me=`$as_basename -- "$0" ||
> +$as_expr X/"$0" : '.*/\([^/][^/]*\)/*$' \| \
> +	 X"$0" : 'X\(//\)$' \| \
> +	 X"$0" : 'X\(/\)' \| . 2>/dev/null ||
> +$as_echo X/"$0" |
> +    sed '/^.*\/\([^/][^/]*\)\/*$/{
> +	    s//\1/
> +	    q
> +	  }
> +	  /^X\/\(\/\/\)$/{
> +	    s//\1/
> +	    q
> +	  }
> +	  /^X\/\(\/\).*/{
> +	    s//\1/
> +	    q
> +	  }
> +	  s/.*/./; q'`
> +
> +
> +  as_lineno_1=$LINENO as_lineno_1a=$LINENO
> +  as_lineno_2=$LINENO as_lineno_2a=$LINENO
> +  eval 'test "x$as_lineno_1'$as_run'" != "x$as_lineno_2'$as_run'" &&
> +  test "x`expr $as_lineno_1'$as_run' + 1`" = "x$as_lineno_2'$as_run'"' || {
> +  # Blame Lee E. McMahon (1931-1989) for sed's syntax.  :-)
> +  sed -n '
> +    p
> +    /[$]LINENO/=
> +  ' <$as_myself |
> +    sed '
> +      s/[$]LINENO.*/&-/
> +      t lineno
> +      b
> +      :lineno
> +      N
> +      :loop
> +      s/[$]LINENO\([^'$as_cr_alnum'_].*\n\)\(.*\)/\2\1\2/
> +      t loop
> +      s/-\n.*//
> +    ' >$as_me.lineno &&
> +  chmod +x "$as_me.lineno" ||
> +    { $as_echo "$as_me: error: cannot create $as_me.lineno; rerun with a POSIX shell" >&2; as_fn_exit 1; }
> +
> +  # Don't try to exec as it changes $[0], causing all sort of problems
> +  # (the dirname of $[0] is not the place where we might find the
> +  # original and so on.  Autoconf is especially sensitive to this).
> +  . "./$as_me.lineno"
> +  # Exit status is that of the last command.
> +  exit
> +}
> +
> +# This file is generated from configure.in by Autoconf.  DO NOT EDIT!
> + # Local configure fragment for sysdeps/riscv/elf.
> +
> +$as_echo "#define PI_STATIC_AND_HIDDEN 1" >>confdefs.h
> diff --git a/sysdeps/riscv/configure.in b/sysdeps/riscv/configure.in
> new file mode 100644
> index 0000000000..34f62d4b4b
> --- /dev/null
> +++ b/sysdeps/riscv/configure.in

We do not use .in file anymore, please change to .ac ones.


> @@ -0,0 +1,4 @@
> +GLIBC_PROVIDES dnl See aclocal.m4 in the top level source directory.
> +# Local configure fragment for sysdeps/riscv/elf.
> +
> +AC_DEFINE(PI_STATIC_AND_HIDDEN)
> diff --git a/sysdeps/riscv/nptl/Makefile b/sysdeps/riscv/nptl/Makefile
> new file mode 100644
> index 0000000000..d0c59a5091
> --- /dev/null
> +++ b/sysdeps/riscv/nptl/Makefile
> @@ -0,0 +1,25 @@
> +# Copyright (C) 2005 Free Software Foundation, Inc.

Missing descriptive line for new files and copyright dates seems wrong.

> +# This file is part of the GNU C Library.
> +#
> +# The GNU C Library is free software; you can redistribute it and/or
> +# modify it under the terms of the GNU Lesser General Public
> +# License as published by the Free Software Foundation; either
> +# version 2.1 of the License, or (at your option) any later version.
> +#
> +# The GNU C Library is distributed in the hope that it will be useful,
> +# but WITHOUT ANY WARRANTY; without even the implied warranty of
> +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> +# Lesser General Public License for more details.
> +#
> +# You should have received a copy of the GNU Lesser General Public
> +# License along with the GNU C Library; if not, write to the Free
> +# Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
> +# 02111-1307 USA.
> +
> +ifeq ($(subdir),csu)
> +gen-as-const-headers += tcb-offsets.sym
> +endif

You are adding a tcb-offsets.sym rule but there is no tcb-offsets.sym
file in this patch.

> +
> +ifeq ($(subdir),nptl)
> +libpthread-sysdep_routines += nptl-sysdep
> +endif

Same as before.

> diff --git a/sysdeps/riscv/preconfigure b/sysdeps/riscv/preconfigure
> new file mode 100644
> index 0000000000..43e2a4fac0
> --- /dev/null
> +++ b/sysdeps/riscv/preconfigure
> @@ -0,0 +1,50 @@
> +xlen=`$CC $CFLAGS $CPPFLAGS -E -dM -xc /dev/null | sed -n 's/^#define __riscv_xlen \(.*\)/\1/p'`
> +flen=`$CC $CFLAGS $CPPFLAGS -E -dM -xc /dev/null | sed -n 's/^#define __riscv_flen \(.*\)/\1/p'`
> +float_abi=`$CC $CFLAGS $CPPFLAGS -E -dM -xc /dev/null | sed -n 's/^#define __riscv_float_abi_\([^ ]*\) .*/\1/p'`
> +
> +case "$xlen" in
> +32 | 64)
> +	;;
> +*)
> +	echo "Unable to determine XLEN" >&2
> +	exit 1
> +	;;
> +esac
> +
> +case "$flen" in
> +64)
> +	float_machine=rvd
> +	;;
> +32)
> +	float_machine=rvf
> +	;;
> +"")
> +	float_machine=
> +	;;
> +*)
> +	echo "Unable to determine FLEN" >&2
> +	exit 1
> +	;;
> +esac
> +
> +case "$float_abi" in
> +soft)
> +	abi_flen=0
> +	;;
> +single)
> +	abi_flen=32
> +	;;
> +double)
> +	abi_flen=64
> +	;;
> +*)
> +	echo "Unable to determine floating-point ABI" >&2
> +	exit 1
> +	;;
> +esac
> +
> +base_machine=riscv
> +machine=riscv/rv$xlen/$float_machine
> +
> +$as_echo "#define RISCV_ABI_XLEN $xlen" >>confdefs.h
> +$as_echo "#define RISCV_ABI_FLEN $abi_flen" >>confdefs.h
> diff --git a/sysdeps/riscv/rv32/Implies-after b/sysdeps/riscv/rv32/Implies-after
> new file mode 100644
> index 0000000000..39a34c5f57
> --- /dev/null
> +++ b/sysdeps/riscv/rv32/Implies-after
> @@ -0,0 +1 @@
> +wordsize-32
> diff --git a/sysdeps/riscv/rv32/rvd/Implies b/sysdeps/riscv/rv32/rvd/Implies
> new file mode 100644
> index 0000000000..9438838e98
> --- /dev/null
> +++ b/sysdeps/riscv/rv32/rvd/Implies
> @@ -0,0 +1,2 @@
> +riscv/rvd
> +riscv/rvf
> diff --git a/sysdeps/riscv/rv32/rvf/Implies b/sysdeps/riscv/rv32/rvf/Implies
> new file mode 100644
> index 0000000000..66c401443b
> --- /dev/null
> +++ b/sysdeps/riscv/rv32/rvf/Implies
> @@ -0,0 +1 @@
> +riscv/rvf
> diff --git a/sysdeps/riscv/rv64/Implies-after b/sysdeps/riscv/rv64/Implies-after
> new file mode 100644
> index 0000000000..a8cae95f9d
> --- /dev/null
> +++ b/sysdeps/riscv/rv64/Implies-after
> @@ -0,0 +1 @@
> +wordsize-64
> diff --git a/sysdeps/riscv/rv64/rvd/Implies b/sysdeps/riscv/rv64/rvd/Implies
> new file mode 100644
> index 0000000000..9438838e98
> --- /dev/null
> +++ b/sysdeps/riscv/rv64/rvd/Implies
> @@ -0,0 +1,2 @@
> +riscv/rvd
> +riscv/rvf
> diff --git a/sysdeps/riscv/rv64/rvf/Implies b/sysdeps/riscv/rv64/rvf/Implies
> new file mode 100644
> index 0000000000..66c401443b
> --- /dev/null
> +++ b/sysdeps/riscv/rv64/rvf/Implies
> @@ -0,0 +1 @@
> +riscv/rvf
> diff --git a/sysdeps/riscv/soft-fp/Makefile b/sysdeps/riscv/soft-fp/Makefile
> new file mode 100644
> index 0000000000..ada13e8b70
> --- /dev/null
> +++ b/sysdeps/riscv/soft-fp/Makefile
> @@ -0,0 +1,3 @@
> +ifeq ($(subdir),math)
> +CPPFLAGS += -I../soft-fp
> +endif

I would suggest you to avoid relative paths for inclusion.

> diff --git a/sysdeps/unix/sysv/linux/riscv/Implies b/sysdeps/unix/sysv/linux/riscv/Implies
> new file mode 100644
> index 0000000000..6faec70115
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/riscv/Implies
> @@ -0,0 +1 @@
> +riscv/nptl
> diff --git a/sysdeps/unix/sysv/linux/riscv/Makefile b/sysdeps/unix/sysv/linux/riscv/Makefile
> new file mode 100644
> index 0000000000..a71840f70c
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/riscv/Makefile
> @@ -0,0 +1,26 @@
> +ifeq ($(subdir),elf)
> +ifeq ($(build-shared),yes)
> +# This is needed for DSO loading from static binaries.
> +sysdep-dl-routines += dl-static
> +sysdep_routines += dl-static
> +sysdep-rtld-routines += dl-static
> +endif
> +endif
> +
> +ifeq ($(subdir),stdlib)
> +gen-as-const-headers += ucontext_i.sym
> +endif

Again this seems to missing a actual file target.

> +
> +ifeq ($(subdir),crypt)
> +libcrypt-sysdep_routines += sysdep
> +endif
> +
> +ifeq ($(subdir),nss)
> +libnss_db-sysdep_routines += sysdep
> +libnss_db-shared-only-routines += sysdep
> +endif
> +
> +ifeq ($(subdir),rt)
> +librt-sysdep_routines += sysdep
> +librt-shared-only-routines += sysdep
> +endif
> diff --git a/sysdeps/unix/sysv/linux/riscv/configure b/sysdeps/unix/sysv/linux/riscv/configure
> new file mode 100644
> index 0000000000..2bb3062cc3
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/riscv/configure
> @@ -0,0 +1,7 @@
> +# This file is generated from configure.in by Autoconf.  DO NOT EDIT!
> + # Local configure fragment for sysdeps/unix/sysv/linux/riscv.
> +
> +if test -z "$arch_minimum_kernel"; then
> +  arch_minimum_kernel=3.0.0
> +  libc_cv_gcc_unwind_find_fde=no
> +fi
> diff --git a/sysdeps/unix/sysv/linux/riscv/configure.in b/sysdeps/unix/sysv/linux/riscv/configure.in
> new file mode 100644
> index 0000000000..5b48e1aed6
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/riscv/configure.in

As before, change to configure.ac.

> @@ -0,0 +1,8 @@
> +sinclude(./aclocal.m4)dnl Autoconf lossage
> +GLIBC_PROVIDES dnl See aclocal.m4 in the top level source directory.
> +# Local configure fragment for sysdeps/unix/sysv/linux/riscv.
> +
> +if test -z "$arch_minimum_kernel"; then
> +  arch_minimum_kernel=3.0.0
> +  libc_cv_gcc_unwind_find_fde=no
> +fi

I think the minimum kernel is wrong here, as from cover letter I think it
should be 4.14.

> diff --git a/sysdeps/unix/sysv/linux/riscv/rv32/Implies b/sysdeps/unix/sysv/linux/riscv/rv32/Implies
> new file mode 100644
> index 0000000000..8b7deb33cd
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/riscv/rv32/Implies
> @@ -0,0 +1,3 @@
> +unix/sysv/linux/riscv
> +unix/sysv/linux/generic/wordsize-32
> +unix/sysv/linux/generic
> diff --git a/sysdeps/unix/sysv/linux/riscv/rv64/Implies b/sysdeps/unix/sysv/linux/riscv/rv64/Implies
> new file mode 100644
> index 0000000000..f042343bf7
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/riscv/rv64/Implies
> @@ -0,0 +1,3 @@
> +unix/sysv/linux/riscv
> +unix/sysv/linux/generic
> +unix/sysv/linux/wordsize-64
> diff --git a/sysdeps/unix/sysv/linux/riscv/rv64/Makefile b/sysdeps/unix/sysv/linux/riscv/rv64/Makefile
> new file mode 100644
> index 0000000000..0a37c5b9b4
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/riscv/rv64/Makefile
> @@ -0,0 +1,9 @@
> +ifeq ($(subdir),socket)
> +CFLAGS-recv.c += -fexceptions
> +CFLAGS-send.c += -fexceptions
> +endif
> +
> +ifeq ($(subdir),nptl)
> +CFLAGS-recv.c += -fexceptions
> +CFLAGS-send.c += -fexceptions
> +endif

Do you actually need to add this rules here? They are already covered after
recv/send Linux syscall consolidation.

> diff --git a/sysdeps/unix/sysv/linux/riscv/shlib-versions b/sysdeps/unix/sysv/linux/riscv/shlib-versions
> new file mode 100644
> index 0000000000..66214b953e
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/riscv/shlib-versions
> @@ -0,0 +1,17 @@
> +DEFAULT		GLIBC_2.25

You will need to update the default version to 2.26.

> +
> +%if RISCV_ABI_XLEN == 64 && RISCV_ABI_FLEN == 64
> +ld=ld-linux-riscv64-lp64d.so.1
> +%elif RISCV_ABI_XLEN == 64 && RISCV_ABI_FLEN == 32
> +ld=ld-linux-riscv64-lp64f.so.1
> +%elif RISCV_ABI_XLEN == 64 && RISCV_ABI_FLEN == 0
> +ld=ld-linux-riscv64-lp64.so.1
> +%elif RISCV_ABI_XLEN == 32 && RISCV_ABI_FLEN == 64
> +ld=ld-linux-riscv32-ilp32d.so.1
> +%elif RISCV_ABI_XLEN == 32 && RISCV_ABI_FLEN == 32
> +ld=ld-linux-riscv32-ilp32f.so.1
> +%elif RISCV_ABI_XLEN == 32 && RISCV_ABI_FLEN == 0
> +ld=ld-linux-riscv32-ilp32.so.1
> +%else
> +%error cannot determine ABI
> +%endif
>