Adapt Configure to GCC version 10

I got a notice from Jeff Law <law@redhat.com>:

    Your particular package fails its testsuite. This was ultimately
    tracked down to a Configure problem. The perl configure script treated
    gcc-10 as gcc-1 and turned on -fpcc-struct-return. This is an ABI
    changing flag and caused Perl to not be able to interact properly with
    the dbm libraries on the system leading to a segfault.

His proposed patch corrected only this one instance of the version
mismatch. Reading the Configure script revealed more issues. This
patch fixes all of them I found.

Please note I do not have GCC 10 available, I tested it by faking the version
with:

--- a/Configure
+++ b/Configure
@@ -4672,7 +4672,7 @@ $cat >try.c <<EOM
 int main() {
 #if defined(__GNUC__) && !defined(__INTEL_COMPILER)
 #ifdef __VERSION__
-       printf("%s\n", __VERSION__);
+       printf("%s\n", "10.0.0");
 #else
        printf("%s\n", "1");
 #endif

(cherry picked from commit 6bd6308fcea3541e505651bf8e8127a4a03d22cd, which
was accidentally reverted by commit e849841dca2a8b11119997585f795647c52cdcdf)

diff --git a/Configure b/Configure
index ec1c282..f6f8254 100755 (executable)
--- a/Configure
+++ b/Configure
@@ -4703,7 +4703,7 @@ else
 fi
 $rm -f try try.*
 case "$gccversion" in
 fi
 $rm -f try try.*
 case "$gccversion" in

-1*) cpp=`./loc gcc-cpp $cpp $pth` ;;
+1.*) cpp=`./loc gcc-cpp $cpp $pth` ;;

 esac
 case "$gccversion" in
 '') gccosandvers='' ;;
 esac
 case "$gccversion" in
 '') gccosandvers='' ;;


@@ -4743,7 +4743,7 @@ esac
 # gcc 3.* complain about adding -Idirectories that they already know about,
 # so we will take those off from locincpth.
 case "$gccversion" in
 # gcc 3.* complain about adding -Idirectories that they already know about,
 # so we will take those off from locincpth.
 case "$gccversion" in

-3*)
+3.*)

     echo "main(){}">try.c
     for incdir in $locincpth; do
        warn=`$cc $ccflags -I$incdir -c try.c 2>&1 | \
     echo "main(){}">try.c
     for incdir in $locincpth; do
        warn=`$cc $ccflags -I$incdir -c try.c 2>&1 | \


@@ -5469,13 +5469,13 @@ fi
 case "$hint" in
 default|recommended)
        case "$gccversion" in
 case "$hint" in
 default|recommended)
        case "$gccversion" in

-       1*) dflt="$dflt -fpcc-struct-return" ;;
+       1.*) dflt="$dflt -fpcc-struct-return" ;;

        esac
        case "$optimize:$DEBUGGING" in
        *-g*:old) dflt="$dflt -DDEBUGGING";;
        esac
        case "$gccversion" in
        esac
        case "$optimize:$DEBUGGING" in
        *-g*:old) dflt="$dflt -DDEBUGGING";;
        esac
        case "$gccversion" in

-       2*) if $test -d /etc/conf/kconfig.d &&
+       2.*) if $test -d /etc/conf/kconfig.d &&

                        $contains _POSIX_VERSION $usrinc/sys/unistd.h >/dev/null 2>&1
                then
                        # Interactive Systems (ISC) POSIX mode.
                        $contains _POSIX_VERSION $usrinc/sys/unistd.h >/dev/null 2>&1
                then
                        # Interactive Systems (ISC) POSIX mode.


@@ -5484,7 +5484,7 @@ default|recommended)
                ;;
        esac
        case "$gccversion" in
                ;;
        esac
        case "$gccversion" in

-       1*) ;;
+       1.*) ;;

        2.[0-8]*) ;;
        ?*)     set strict-aliasing -fno-strict-aliasing
                eval $checkccflag
        2.[0-8]*) ;;
        ?*)     set strict-aliasing -fno-strict-aliasing
                eval $checkccflag


@@ -5602,7 +5602,7 @@ case "$cppflags" in
     ;;
 esac
 case "$gccversion" in
     ;;
 esac
 case "$gccversion" in

-1*) cppflags="$cppflags -D__GNUC__"
+1.*) cppflags="$cppflags -D__GNUC__"

 esac
 case "$mips_type" in
 '');;
 esac
 case "$mips_type" in
 '');;


@@ -23229,7 +23229,7 @@ fi
 
 : add -D_FORTIFY_SOURCE if feasible and not already there
 case "$gccversion" in
 
 : add -D_FORTIFY_SOURCE if feasible and not already there
 case "$gccversion" in

-[456789].*)    case "$optimize$ccflags" in
+[456789].*|[1-9][0-9]*)        case "$optimize$ccflags" in

        *-O*)   case "$ccflags$cppsymbols" in
                *_FORTIFY_SOURCE=*) # Don't add it again.
                        echo "You seem to have -D_FORTIFY_SOURCE already, not adding it." >&4
        *-O*)   case "$ccflags$cppsymbols" in
                *_FORTIFY_SOURCE=*) # Don't add it again.
                        echo "You seem to have -D_FORTIFY_SOURCE already, not adding it." >&4