Partially revert "automake: allow only shared builds"

Evidently at least static OSMesa is still used as shared one
causes substantial increase in the load time for some programs
that use it (from seconds up-to ~30min).

Rather than forcing everyone to use shared mesa, revert commit
a6efbac9fb and default to shared
build when both shared and static are disabled.

v2: Whitespace cleanup, drop silly comment.

Reported-by: Burlen Loring <burlen.loring@gmail.com>
Reviewed-by: Matt Turner <mattst88@gmail.com>

configure.ac

@@ -284,15 +284,18 @@ dnl Can't have static and shared libraries, default to static if user
 dnl explicitly requested. If both disabled, set to static since shared
 dnl was explicitly requested.
 case "x$enable_static$enable_shared" in
-xnoyes )
+xyesyes)
+    AC_MSG_WARN([Cannot build static and shared libraries, disabling shared])
+    enable_shared=no
     ;;
-* )
-    AC_MSG_WARN([Messa build supports only shared libraries, enabling shared])
+xnono)
+    AC_MSG_WARN([Cannot disable both static and shared libraries, enabling shared])
     enable_shared=yes
-    enable_static=no
     ;;
 esac
 
+AM_CONDITIONAL(BUILD_SHARED, test "x$enable_shared" = xyes)
+
 dnl
 dnl other compiler options
 dnl
@@ -782,6 +785,10 @@ PKG_CHECK_MODULES([LIBUDEV], [libudev >= $LIBUDEV_REQUIRED],
                   have_libudev=yes, have_libudev=no)
 
 if test "x$enable_dri" = xyes; then
+    if test "$enable_static" = yes; then
+        AC_MSG_ERROR([Cannot use static libraries for DRI drivers])
+    fi
+
     # not a hard requirement as swrast does not depend on it
     if test "x$have_libdrm" = xyes; then
         DRI_PC_REQ_PRIV="libdrm >= $LIBDRM_REQUIRED"
@@ -1110,7 +1117,12 @@ x16|x32)
 esac
 
 if test "x$enable_osmesa" = xyes -o "x$enable_gallium_osmesa" = xyes; then
+    # only link libraries with osmesa if shared
+    if test "$enable_static" = no; then
         OSMESA_LIB_DEPS="-lm $PTHREAD_LIBS $SELINUX_LIBS $DLOPEN_LIBS"
+    else
+        OSMESA_LIB_DEPS=""
+    fi
     OSMESA_MESA_DEPS=""
     OSMESA_PC_LIB_PRIV="-lm $PTHREAD_LIBS $SELINUX_LIBS $DLOPEN_LIBS"
 fi
@@ -1159,9 +1171,12 @@ if test "x$enable_egl" = xyes; then
 
     AC_CHECK_FUNC(mincore, [DEFINES="$DEFINES -DHAVE_MINCORE"])
 
+    if test "$enable_static" != yes; then
         if test "x$enable_dri" = xyes; then
 	    HAVE_EGL_DRIVER_DRI2=1
 	fi
+
+    fi
 fi
 AM_CONDITIONAL(HAVE_EGL, test "x$enable_egl" = xyes)
 AC_SUBST([EGL_LIB_DEPS])

install-gallium-links.mk

@@ -1,6 +1,7 @@
 # Provide compatibility with scripts for the old Mesa build system for
 # a while by putting a link to the driver into /lib of the build tree.
 
+if BUILD_SHARED
 if HAVE_COMPAT_SYMLINKS
 all-local : .libs/install-gallium-links
 
@@ -23,3 +24,4 @@ all-local : .libs/install-gallium-links
 		fi;						\
 	done && touch $@
 endif
+endif

install-lib-links.mk

@@ -1,6 +1,7 @@
 # Provide compatibility with scripts for the old Mesa build system for
 # a while by putting a link to the driver into /lib of the build tree.
 
+if BUILD_SHARED
 if HAVE_COMPAT_SYMLINKS
 all-local : .libs/install-mesa-links
 
@@ -14,3 +15,4 @@ all-local : .libs/install-mesa-links
 		fi;						\
 	done && touch $@
 endif
+endif