glibc/sysdeps/riscv/configure.ac

GLIBC_PROVIDES dnl See aclocal.m4 in the top level source directory.
# Local configure fragment for sysdeps/riscv/elf.

# Check if static linker supports R_RISCV_ALIGN
AC_CACHE_CHECK([for R_RISCV_ALIGN linker relaxation support], [libc_cv_riscv_r_align],[dnl
  cat > conftest.S <<EOF
.align 3
foo:
  li a0,42
  ret
EOF
  libc_cv_riscv_r_align=no
  if AC_TRY_COMMAND([${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS -nostdlib -nostartfiles $no_ssp -shared -fPIC -o contests.o conftest.S])
  then
    libc_cv_riscv_r_align=yes
  fi
  rm -rf conftest.*])
LIBC_CONFIG_VAR([riscv-r-align], [$libc_cv_riscv_r_align])
RISC-V: Build Infastructure 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, but this port currently only supports RV64I based systems. Support for RISC-V lives in in sysdeps/riscv. 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 and emulation routines as well as some atomic wrappers. We support running glibc-based programs on Linux, the support for which lives in sysdeps/unix/sysv/linux/riscv. 2018-01-29 Palmer Dabbelt <palmer@sifive.com> * sysdeps/riscv/Implies: New file. * sysdeps/riscv/Makefile: Likewise. * sysdeps/riscv/configure: Likewise. * sysdeps/riscv/configure.ac: Likewise. * sysdeps/riscv/nptl/Makefile: Likewise. * sysdeps/riscv/preconfigure: Likewise. * sysdeps/riscv/rv64/Implies-after: Likewise. * sysdeps/riscv/rv64/rvd/Implies: Likewise. * sysdeps/riscv/rv64/rvf/Implies: Likewise. * sysdeps/unix/sysv/linux/riscv/Implies: Likewise. * sysdeps/unix/sysv/linux/riscv/Makefile: Likewise. * sysdeps/unix/sysv/linux/riscv/Versions: Likewise. * sysdeps/unix/sysv/linux/riscv/configure: Likewise. * sysdeps/unix/sysv/linux/riscv/configure.ac: Likewise. * sysdeps/unix/sysv/linux/riscv/ldd-rewrite.sed: Likewise. * sysdeps/unix/sysv/linux/riscv/rv64/Implies: Likewise. * sysdeps/unix/sysv/linux/riscv/rv64/Makefile: Likewise. * sysdeps/unix/sysv/linux/riscv/shlib-versions: Likewise. 2018-01-29 18:30:24 +00:00			`GLIBC_PROVIDES dnl See aclocal.m4 in the top level source directory.`
			`# Local configure fragment for sysdeps/riscv/elf.`

riscv: Build with -mno-relax if linker does not support R_RISCV_ALIGN It allows build both glibc and tests with lld (Since lld does not support R_RISCV_ALIGN linker relaxation). Checked with a build for riscv32-linux-gnu-rv32imafdc-ilp32d and riscv64-linux-gnu-rv64imafdc-lp64d. Reviewed-by: H.J. Lu <hjl.tools@gmail.com> Reviewed-by: Fangrui Song <maskray@google.com> 2021-11-02 19:51:39 +00:00			`# Check if static linker supports R_RISCV_ALIGN`
			`AC_CACHE_CHECK([for R_RISCV_ALIGN linker relaxation support], [libc_cv_riscv_r_align],[dnl`
			`cat > conftest.S <<EOF`
			`.align 3`
			`foo:`
			`li a0,42`
			`ret`
			`EOF`
			`libc_cv_riscv_r_align=no`
			`if AC_TRY_COMMAND([${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS -nostdlib -nostartfiles $no_ssp -shared -fPIC -o contests.o conftest.S])`
			`then`
			`libc_cv_riscv_r_align=yes`
			`fi`
			`rm -rf conftest.*])`
			`LIBC_CONFIG_VAR([riscv-r-align], [$libc_cv_riscv_r_align])`