configure.ac: WIP

Author: bgoodri

configure.ac

@@ -0,0 +1,62 @@
+AC_PREREQ(2.62)
+AC_INIT([DESCRIPTION])
+
+: ${R_HOME=`R RHOME`}
+if test -z "${R_HOME}"; then
+  echo "could not determine R_HOME"
+  exit 1
+fi
+
+LTO=-flto
+CXX=$(${R_HOME}/bin/R CMD config CXX) $(LTO)
+
+AC_LANG(C++)
+AC_REQUIRE_CPP
+AC_PROG_CXX
+
+AC_ARG_ENABLE([lto],
+[AS_HELP_STRING([--enable-lto],[enable link-time optimization @<:@yes@:>@])],
+[want_lto="${enableval}"], [want_lto=yes])
+if test "x${want_lto}" != xno; then
+  AC_LINK_IFELSE([AC_LANG_PROGRAM([[]], [[int main (void) { return 0; }]])],
+  [AC_MSG_RESULT(yes)], [AC_MSG_RESULT(no) LTO=""])
+fi
+
+if test "${GXX}" = yes && test -z "${LTO}"; then
+  gxx_version=`${CXX} -v 2>&1 | grep "^.*g.. version" | sed -e 's/^.*g.. version *//'`
+  case ${gxx_version} in
+    1.*|2.*|3.*|4.0.*|4.1.*|4.2.*|4.3.*|4.4.*|4.5.*|4.6.*|4.7.*|4.8.*)
+      AC_MSG_WARN([It is preferable to use g++ version 4.9 or greater with rstanarm.])
+   ;;
+   *)
+      LTO=-flto=jobserver
+  esac
+fi
+
+if [[ $CXX == *"clang"* ]] && test -z "${LTO}"; then
+  clang_version=`${CXX} --version 2>&1 | grep "version"`
+  if [[ $clang_version == *"Apple"* ]]; then
+    clang_version=`${CXX} --version 2>&1 | grep "version"` | \
+     sed -e 's/^Apple LLVM version *//'
+     case ${clang_version} in 2.*|3.*|4.*5.*|6.*|7.*|8.*)
+      AC_MSG_WARN([It is preferable to use Apple LLVM version 9 or greater with rstanarm.])
+     ;;
+     *)
+       LTO="-flto=thin"
+    esac
+  fi
+  elif
+    case ${clang_version} in 1.*|2.*|3.1.*|3.2.*|3.3.*|3.4.*|3.5.*|3.6.*|3.7.*|3.8.*)
+      AC_MSG_WARN([It is preferable to use clang++ version 3.9 or greater with rstanarm.])
+     ;;
+     *)
+       LTO="-flto=thin"
+     esac
+  fi
+fi
+
+AC_SUBST(LTO)
+AM_CONDITIONAL(BUILD_LTO, [test "x${want_lto}" != xno])
+
+AC_CONFIG_FILES([src/Makevars])
+AC_OUTPUT