[kvm-unit-tests PATCH v3 3/5] configure: Support cross compiling with clang
From: Andrew Jones <hidden>
Date: 2024-09-11 09:15:02
Also in:
kvm, kvm-riscv, kvmarm, linux-s390
Subsystem:
the rest · Maintainer:
Linus Torvalds
When a user specifies the compiler with --cc assume it's already
fully named, even if the user also specifies a cross-prefix. This
allows clang to be selected for the compiler, which doesn't use
prefixes, but also still provide a cross prefix for binutils. If
a user needs a prefix on the compiler that they specify with --cc,
then they'll just have to specify it with the prefix prepended.
Also ensure user provided cflags are used when testing the compiler,
since the flags may drastically change behavior, such as the --target
flag for clang.
With these changes it's possible to cross compile for riscv with
clang after configuring with
./configure --arch=riscv64 --cc=clang --cflags='--target=riscv64' \
--cross-prefix=riscv64-linux-gnu-
Reviewed-by: Thomas Huth <redacted>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Andrew Jones <redacted>
---
configure | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)
diff --git a/configure b/configure
index 27ae9cc89657..337af07374df 100755
--- a/configure
+++ b/configure@@ -130,6 +130,7 @@ while [[ "$1" = -* ]]; do ;; --cc) cc="$arg" + cc_selected=yes ;; --cflags) cflags="$arg"
@@ -200,6 +201,10 @@ while [[ "$1" = -* ]]; do esac done +if [ -z "$cc_selected" ] && [ "$cross_prefix" ]; then + cc="$cross_prefix$cc" +fi + if [ -z "$efi" ] || [ "$efi" = "n" ]; then [ "$efi_direct" = "y" ] && efi_direct= fi
@@ -370,7 +375,7 @@ fi cat << EOF > lib-test.c __UINT32_TYPE__ EOF -u32_long=$("$cross_prefix$cc" -E lib-test.c | grep -v '^#' | grep -q long && echo yes) +u32_long=$("$cc" $cflags -E lib-test.c | grep -v '^#' | grep -q long && echo yes) rm -f lib-test.c # check if slash can be used for division
@@ -379,7 +384,7 @@ if [ "$arch" = "i386" ] || [ "$arch" = "x86_64" ]; then foo: movl (8 / 2), %eax EOF - wa_divide=$("$cross_prefix$cc" -c lib-test.S >/dev/null 2>&1 || echo yes) + wa_divide=$("$cc" $cflags -c lib-test.S >/dev/null 2>&1 || echo yes) rm -f lib-test.{o,S} fi
@@ -442,7 +447,7 @@ ARCH=$arch ARCH_NAME=$arch_name ARCH_LIBDIR=$arch_libdir PROCESSOR=$processor -CC=$cross_prefix$cc +CC=$cc CFLAGS=$cflags LD=$cross_prefix$ld OBJCOPY=$cross_prefix$objcopy
--
2.46.0