ENH: avoid repeated CGAL builds

- now check for existing third-party build and skip if all build
  components are unchanged.

- skip build entirely for boost-none or CGAL-none

This is primarily useful when makeCGAL is called directly and not from
Allwmake.

STYLE: use WM_COMPILER_LIB_ARCH for boost system lib

makeCGAL

@@ -133,9 +133,24 @@ done
 
 [ -n "$cgalPACKAGE" ] || die "The cgal-VERSION was not specified"
 
+# nothing to build
+if _foamIsNone "$boostPACKAGE"
+then
+    echo "Using boost-none (skip ThirdParty build of BOOST/CGAL)"
+    exit 0
+fi
+if _foamIsNone "$cgalPACKAGE"
+then
+    echo "Using cgal-none (skip ThirdParty build of CGAL)"
+    exit 0
+fi
+
 #------------------------------------------------------------------------------
 #
 # Build Boost
+# For 64-bit
+# - Third-Party builds into 'lib'
+# - system is normally built into 'lib64'
 #
 #   BOOST_SOURCE_DIR : location of the original sources
 
@@ -148,18 +163,10 @@ then
     boostLib="$BOOST_ARCH_PATH/lib"
 elif _foamIsSystem $BOOST_ARCH_PATH
 then
-    echo "Using boost-system"
+    echo "Using boost-system (skip ThirdParty build of BOOST)"
 
     boostInc="/usr/include"
-
-    # For completeness:
-    # 64-bit needs lib64, but 32-bit needs lib (not lib32)
-    if [ "$WM_ARCH_OPTION" = 64 ]
-    then
-        boostLib="/usr/lib$WM_ARCH_OPTION"
-    else
-        boostLib="/usr/lib"
-    fi
+    boostLib="/usr/lib$WM_COMPILER_LIB_ARCH"
 else
     echo "Starting build: boost"
     echo
@@ -184,10 +191,10 @@ else
     }
 fi
 
-# nothing to build
+# nothing left to build
 if _foamIsSystem "$cgalPACKAGE"
 then
-    echo "Using CGAL-system"
+    echo "Using cgal-system (skip ThirdParty build of CGAL)"
     exit 0
 fi
 
@@ -202,10 +209,13 @@ fi
 # Retrieve boost version:
 if [ -f "$boostInc/boost/version.hpp" ]
 then
-    BOOST_VERSION_NO=`sed -ne 's/^#define *BOOST_VERSION *\([0-9][0-9]*\).*$/\1/p' $boostInc/boost/version.hpp`
+    BOOST_VERSION=$(sed -ne 's/^ *# *define *BOOST_VERSION *\([0-9][0-9]*\).*$/\1/p' $boostInc/boost/version.hpp)
 else
-    echo "Boost does not appear to be installed"
+    echo
+    echo "ERROR: boost does not appear to be installed, but is required to build CGAL"
+    echo "    Change your settings, or disable entirely (with cgal-system, cgal-none, boost-none)"
     echo "stopping build"
+    echo
     exit 1
 fi
 
@@ -224,6 +234,9 @@ SUMMARY
 #------------------------------------------------------------------------------
 #
 # Build CGAL
+# For 64-bit
+# - Third-Party builds into 'lib'
+# - system is normally built into 'lib64'
 #
 #   CGAL_SOURCE_DIR : location of the original sources
 #   CGAL_BINARY_DIR : location of the build
@@ -241,6 +254,67 @@ installBASE=$WM_THIRD_PARTY_DIR/platforms/$WM_ARCH$WM_COMPILER_ARCH
 GMP_ARCH_PATH=$installBASE/$gmpPACKAGE
 MPFR_ARCH_PATH=$installBASE/$mpfrPACKAGE
 
+#
+# build information recorded for later use
+#
+buildInfoFile=$CGAL_ARCH_PATH/share/openfoam-build
+
+recordCGALinfo()
+{
+    CGAL_VERSION=$(sed -ne 's/^ *# *define *CGAL_VERSION_NR *\([0-9][0-9]*\).*$/\1/p' $CGAL_ARCH_PATH/include/CGAL/version.h 2>/dev/null)
+
+    cat<<BUILD_INFO > $buildInfoFile
+CGAL=${CGAL_ARCH_PATH##*/}
+BOOST=${BOOST_ARCH_PATH##*/}
+GMP=${GMP_ARCH_PATH##*/}
+MPFR=${MPFR_ARCH_PATH##*/}
+CGAL_VERSION=$CGAL_VERSION
+BOOST_VERSION=$BOOST_VERSION
+BUILD_INFO
+}
+
+
+# compare expected vs what is extracted as KEY=... in text
+# $1 = key
+# $2 = expected
+# $3 = text to extract from
+infoValueEq()
+{
+    local val=$(echo "${3:-unset}" | sed -ne "s/^$1=//p")
+    if [ "$2" = "$val" ]
+    then
+       :
+    else
+        echo "    $1=$2, previous build had $1='${val:-not-found}'"
+        return 1
+    fi
+}
+
+# needs build
+cgalIsCurrent()
+{
+    local info=$(cat $buildInfoFile 2>/dev/null)
+    [ -n "$info" ] || return 1
+
+    echo "checking information from existing build ..."
+    echo "  ${CGAL_ARCH_PATH}"
+
+    infoValueEq CGAL  "${CGAL_ARCH_PATH##*/}"     "$info" || return 1
+    infoValueEq BOOST "${BOOST_ARCH_PATH##*/}"    "$info" || return 1
+    infoValueEq GMP   "${GMP_ARCH_PATH##*/}"      "$info" || return 1
+    infoValueEq MPFR  "${MPFR_ARCH_PATH##*/}"     "$info" || return 1
+    infoValueEq BOOST_VERSION "${BOOST_VERSION}"  "$info" || return 1
+
+    return 0
+}
+
+if cgalIsCurrent
+then
+    echo "    ${CGAL_ARCH_PATH##*/} build appears to be up-to-date - skipping"
+    echo
+    exit 0
+fi
+
 (
     # Remove any existing build folder and recreate
     if [ -d $CGAL_BINARY_DIR ]
@@ -255,7 +329,7 @@ MPFR_ARCH_PATH=$installBASE/$mpfrPACKAGE
 
     unset configBoost configGmp configMpfr
     echo "----"
-    echo "Configuring $cgalPACKAGE with boost $BOOST_VERSION_NO"
+    echo "Configuring $cgalPACKAGE with boost $BOOST_VERSION"
     echo "    Source         : $CGAL_SOURCE_DIR"
     echo "    Build          : $CGAL_BINARY_DIR"
     echo "    Target         : $CGAL_DIR"
@@ -271,7 +345,7 @@ MPFR_ARCH_PATH=$installBASE/$mpfrPACKAGE
  -DBoost_THREAD_LIBRARY_RELEASE=$boostLib/libboost_thread.so
  -DBoost_SYSTEM_LIBRARY=$boostLib/libboost_system.so
  -DBoost_SYSTEM_LIBRARY_RELEASE=$boostLib/libboost_system.so
- -DBoost_VERSION=$BOOST_VERSION_NO
+ -DBoost_VERSION=$BOOST_VERSION
 CMAKE_OPTIONS
 )
     else
@@ -336,6 +410,9 @@ CMAKE_OPTIONS
         fi
     done
 
+    # record our build-status
+    recordCGALinfo
+
     echo "Done CGAL"
 )