[x264-devel] Have configure script define libm variable if present

[Jason Garrett-Glaser]

On Sat, Aug 25, 2012 at 6:14 AM, Brad Smith <brad at comstyle.com> wrote:
> On Tue, Aug 21, 2012 at 12:09:43PM +0300, Georgi Chorbadzhiyski wrote:
>> On 8/21/12 10:30 AM, Brad Smith wrote:
>> >Have the configure script set libm if the OS has libm. Idea
>> >copied from libpthread and just move setting LDFLAGS to below
>> >the OS case check. I also did this to be able to use $libm in
>> >another diff I'll send after this.
>> >
>> >
>> >diff --git a/configure b/configure
>> >index 086b399..5b18b1b 100755
>> >--- a/configure
>> >+++ b/configure
>> >@@ -448,6 +448,7 @@ else
>> >      fi
>> >  fi
>> >
>> >+libm=""
>> >  case $host_os in
>> >      beos*)
>> >          SYS="BEOS"
>> >@@ -456,37 +457,37 @@ case $host_os in
>> >      darwin*)
>> >          SYS="MACOSX"
>> >          CFLAGS="$CFLAGS -falign-loops=16"
>> >-        LDFLAGS="$LDFLAGS -lm"
>> >+        libm="-lm"
>> >          if [ "$pic" = "no" ]; then
>> >              cc_check "" -mdynamic-no-pic && CFLAGS="$CFLAGS -mdynamic-no-pic"
>> >          fi
>> >          ;;
>> >      freebsd*)
>> >          SYS="FREEBSD"
>> >-        LDFLAGS="$LDFLAGS -lm"
>> >+        libm="-lm"
>> >          ;;
>> >      kfreebsd*-gnu)
>> >          SYS="FREEBSD"
>> >          define HAVE_MALLOC_H
>> >-        LDFLAGS="$LDFLAGS -lm"
>> >+        libm="-lm"
>> >          ;;
>> >      netbsd*)
>> >          SYS="NETBSD"
>> >-        LDFLAGS="$LDFLAGS -lm"
>> >+        libm="-lm"
>> >          ;;
>> >      openbsd*)
>> >          SYS="OPENBSD"
>> >-        LDFLAGS="$LDFLAGS -lm"
>> >+        libm="-lm"
>> >          ;;
>> >      *linux*)
>> >          SYS="LINUX"
>> >          define HAVE_MALLOC_H
>> >-        LDFLAGS="$LDFLAGS -lm"
>> >+        libm="-lm"
>> >          ;;
>> >      gnu*)
>> >          SYS="HURD"
>> >          define HAVE_MALLOC_H
>> >-        LDFLAGS="$LDFLAGS -lm"
>> >+        libm="-lm"
>> >          ;;
>> >      cygwin*)
>> >          EXE=".exe"
>> >@@ -512,7 +513,7 @@ case $host_os in
>> >      sunos*|solaris*)
>> >          SYS="SunOS"
>> >          define HAVE_MALLOC_H
>> >-        LDFLAGS="$LDFLAGS -lm"
>> >+        libm="-lm"
>> >          if cc_check "" /usr/lib/64/values-xpg6.o; then
>> >              LDFLAGS="$LDFLAGS /usr/lib/64/values-xpg6.o"
>> >          else
>> >@@ -525,6 +526,8 @@ case $host_os in
>> >          ;;
>> >  esac
>> >
>> >+LDFLAGS="$LDFLAGS $libm"
>> >+
>> >  case $host_cpu in
>> >      i*86)
>> >          ARCH="X86"
>> >
>>
>> It would be nicer if libm is set by default to -lm and then only
>> platforms that have named this library differently, would need
>> to change it?
>
> Either way would be fine with me and I can understand the appeal
> of your suggestion as you can just clear the libm variable for
> the OS's without a libm. OS's without libm are the exception.
>
> Jason, any comments?

I don't have the experience/expertise to say anything meaningful about
this kind of configure stuff, so I'll let other people decide.

Jason