| Message ID | 20240904105020.1179006-9-andrew.jones@linux.dev (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Support cross compiling with clang | expand |
On Wed Sep 4, 2024 at 8:50 PM AEST, Andrew Jones wrote: > 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. Makes sense. > 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. Could be a separate patch but no big deal. > > 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- Nice. Perhaps add a recipe to README? Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Thanks, Nick > > Reviewed-by: Thomas Huth <thuth@redhat.com> > Signed-off-by: Andrew Jones <andrew.jones@linux.dev> > --- > 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
On Wed, Sep 11, 2024 at 10:24:34AM GMT, Nicholas Piggin wrote: > On Wed Sep 4, 2024 at 8:50 PM AEST, Andrew Jones wrote: > > 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. > > Makes sense. > > > 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. > > Could be a separate patch but no big deal. > > > > > 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- > > Nice. Perhaps add a recipe to README? Sure. > > Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Thanks, drew
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
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 <thuth@redhat.com> Signed-off-by: Andrew Jones <andrew.jones@linux.dev> --- configure | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-)