configure: fix shared build on Solaris 10 (#846)

GNU tools are often installed with g-prefix on Solaris. Unfortunately, a check
in configure was using grep directly instead of through a variable, which lead
to wrong results due to missing option `-q`. Additionally, the check will fail
silently if `readelf` is not on `PATH` instead of trying `greadelf`.

diff --git a/configure.ac b/configure.ac
index b35a999fb94348260cb5b39cf993cacb41da6d23..b5a7a49f1eefb2b8cd84fddb09a8516c346e16fa 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -42,7 +42,7 @@ AC_PROG_EGREP
 LT_INIT
 AC_CONFIG_MACRO_DIR([m4])
 
-AC_CHECK_TOOL(READELF, readelf)
+AC_CHECK_TOOLS([READELF], [readelf greadelf])
 
 # Test for 64-bit build.
 AC_CHECK_SIZEOF([size_t])
@@ -171,7 +171,7 @@ case "$TARGET" in
        libffi_cv_as_s390_zarch=no
        echo 'void foo(void) { bar(); bar(); }' > conftest.c
        if $CC $CFLAGS -S conftest.c > /dev/null 2>&1; then
-           if grep -q brasl conftest.s; then
+           if $GREP -q brasl conftest.s; then
                libffi_cv_as_s390_zarch=yes
            fi
        fi
@@ -277,7 +277,7 @@ if test "x$GCC" = "xyes"; then
        libffi_cv_ro_eh_frame=yes
        echo 'extern void foo (void); void bar (void) { foo (); foo (); }' > conftest.c
        if $CC $CFLAGS -c -fpic -fexceptions $libffi_cv_no_lto -o conftest.o conftest.c > /dev/null 2>&1; then
-           if $READELF -WS conftest.o 2>/dev/null | grep -q -n 'eh_frame .* WA'; then
+           if $READELF -WS conftest.o 2>/dev/null | $GREP -q -n 'eh_frame .* WA'; then
                libffi_cv_ro_eh_frame=no
            fi
        fi