X-Git-Url: https://git.dogcows.com/gitweb?a=blobdiff_plain;f=configure.ac;h=fbf41e64a6608c87ea14eb091fdafa2a2a9f9654;hb=53358983ebbdb88c20d1a0121398534ec03aa485;hp=2310600677c9b1f8f0edcf68673e343db060b842;hpb=7c43775f4f667c435c9f67cbaf4738b3bcd59c03;p=chaz%2Ftar

diff --git a/configure.ac b/configure.ac
index 2310600..fbf41e6 100644
--- a/configure.ac
+++ b/configure.ac
@@ -112,6 +112,24 @@ gl_INIT
 # paxutils modules
 tar_PAXUTILS
 
+# gl_GCC_VERSION_IFELSE([major], [minor], [run-if-found], [run-if-not-found])
+# ------------------------------------------------
+# If $CPP is gcc-MAJOR.MINOR or newer, then run RUN-IF-FOUND.
+# Otherwise, run RUN-IF-NOT-FOUND.
+AC_DEFUN([gl_GCC_VERSION_IFELSE],
+  [AC_PREPROC_IFELSE(
+    [AC_LANG_PROGRAM(
+      [[
+#if ($1) < __GNUC__ || (($1) == __GNUC__ && ($2) <= __GNUC_MINOR__)
+/* ok */
+#else
+# error "your version of gcc is older than $1.$2"
+#endif
+      ]]),
+    ], [$3], [$4])
+  ]
+)
+
 AC_ARG_ENABLE([gcc-warnings],
   [AS_HELP_STRING([--enable-gcc-warnings],
      [turn on many GCC warnings (for developers; best with GNU make)])],
@@ -120,10 +138,9 @@ AC_ARG_ENABLE([gcc-warnings],
      *)      AC_MSG_ERROR([bad value $enableval for gcc-warnings option]) ;;
    esac
    gl_gcc_warnings=$enableval],
-  [if test -d "$srcdir"/.git; then
-     gl_gcc_warnings=yes
-   else
-     gl_gcc_warnings=no
+  [gl_gcc_warnings=no
+   if test -d "$srcdir"/.git; then
+     gl_GCC_VERSION_IFELSE([4], [6], [gl_gcc_warnings=yes])
    fi]
 )