configure: fix bad gcc verison check.

* configure: The way the verison is represented in the output
of gcc varies. A vendor build version may be indicated in
parentheses, and that may precede or follow the version number
by itself. I don't know all the variations. What I'm
implementing here is looping over the white-space separated
output of gcc --version, looking for an item of the form
number.number.number where number is any decimal string from 0
to 99 with no leading zero, except for zero itself. If we find
this item, we assume that is the gcc version, and break it up
and process it as before, terminating the loop. We print
the parsed gcc version in parentheses to help with spotting
problems.

1 files changed, 24 insertions, 9 deletions

diff --git a/configure b/configure
index 4738c840..0b545d8f 100755
--- a/configure
+++ b/configure
@@ -1106,23 +1106,38 @@ if ! [ $diag_flags_given ] ; then
   done
 fi
 
-printf "Checking compiler version for various workarounds ... "
+printf "Checking gcc version for various workarounds ... "
 
 output=$($make conftest.ccver)
 set -- $output
 if [ "$1" = "gcc" ] ; then
-  gcc_version=$3
-  save_ifs=$IFS ; IFS=. ; set -- $gcc_version ; IFS=$save_ifs
-  if [ $1 -lt 4 ] || [ $1 -eq 4 -a $2 -le 3 ] ; then
-    broken128=y
-  fi
-  [ $1 -lt 5 ] && do_nopie=
+  shift;
+
+  while [ $# -gt 0 ] ; do
+    case $1 in
+    [0-9].[0-9].[0-9] | [0-9].[0-9].[1-9][0-9] | \
+    [0-9].[1-9][0-9].[0-9] | [0-9].[1-9][0-9].[1-9][0-9] | \
+    [1-9][0-9].[0-9].[0-9] | [1-9][0-9].[0-9].[1-9][0-9] | \
+    [1-9][0-9].[1-9][0-9].[0-9] | [1-9][0-9].[1-9][0-9].[1-9][0-9] )
+      gcc_version=$1
+      save_ifs=$IFS ; IFS=. ; set -- $gcc_version ; IFS=$save_ifs
+      printf "(%s)\n" "$*"
+      if [ $1 -lt 4 ] || [ $1 -eq 4 -a $2 -le 3 ] ; then
+        broken128=y
+      fi
+      [ $1 -lt 5 ] && do_nopie=
+      break
+      ;;
+    esac
+    shift
+  done
 elif [ "$1" = "clang" -o "$2" = "clang" ] ; then
+  printf "(clang)\n"
   do_nopie=
+else
+  printf "(unrecognized)\n"
 fi
 
-printf "done\n"
-
 printf "Checking whether executables require an .exe suffix ... "
 
 if ls conftest.exe > /dev/null 2>&1 ; then