Restore LIBS if some component is not found

[m4-moved-to-github.git] / boost.m4

diff --git a/boost.m4 b/boost.m4
index ff8e0f6..38060ca 100644 (file)
--- a/boost.m4
+++ b/boost.m4
@@ -68,16 +68,39 @@ version_is:BOOST_VERSION
            fi
            for c in $1; do
                case $c in 
+                   system)
+                       AC_SUBST([BOOST_SYSTEM_LIB])
+                       BOOST_SYSTEM_LIB=""
+                       if test "$BOOST_GOT_VERSION" -ge 104100; then
+                           AC_MSG_CHECKING([Boost system])
+                           saveLIBS="${LIBS}"
+                           for l in "${BOOST_TOOLSET}-mt" "${BOOST_TOOLSET}"; do
+                               trylib="-lboost_system${l}"
+                               LIBS="${saveLIBS} ${trylib}"
+                               AC_LINK_IFELSE([AC_LANG_PROGRAM([[
+#include <boost/version.hpp>
+#include <boost/system/error_code.hpp>
+]],[[ 
+int x = BOOST_VERSION;
+]])],[
+                                       BOOST_SYSTEM_LIB="${trylib}"
+                                       break],[])
+                           done
+                           if test "${BOOST_SYSTEM_LIB}"; then
+                               AC_MSG_RESULT([yes])
+                           else
+                               AC_MSG_RESULT([no])
+                               LIBS="${saveLIBS}"
+                           fi
+                       fi
+                       ;;
                    thread)
                        AC_MSG_CHECKING([Boost threads])
                        AC_SUBST([BOOST_THREAD_LIB])
                        saveLIBS="${LIBS}"
                        BOOST_THREAD_LIB=""
-                       for l in ${BOOST_TOOLSET}-mt ${BOOST_TOOLSET}; do
+                       for l in "${BOOST_TOOLSET}-mt" "${BOOST_TOOLSET}"; do
                            trylib="-lboost_thread${l}"
-                           if test "$BOOST_GOT_VERSION" -ge 104100; then
-                               trylib="-lboost_system${l} ${trylib}"
-                           fi
                            LIBS="${saveLIBS} ${trylib}"
                        AC_LINK_IFELSE([AC_LANG_PROGRAM([[
 #include <boost/version.hpp>
@@ -92,6 +115,7 @@ int x = BOOST_VERSION;
                            AC_MSG_RESULT([yes])
                        else
                            AC_MSG_RESULT([no])
+                           LIBS="${saveLIBS}"
                        fi
                        ;;
                    test)
@@ -142,6 +166,7 @@ int x = BOOST_VERSION;
                            AC_MSG_RESULT([yes])
                        else
                            AC_MSG_RESULT([no])
+                           LIBS="${saveLIBS}"
                        fi
                        ;;
                esac