Some influential environment variables:
CC C compiler command [detected]
CFLAGS C compiler flags [-Os -pipe ...]
+ CROSS_COMPILE prefix for cross compiler and tools [none]
Use these variables to override the choices made by configure.
CFLAGS=*) CFLAGS=${arg#*=} ;;
CPPFLAGS=*) CPPFLAGS=${arg#*=} ;;
LDFLAGS=*) LDFLAGS=${arg#*=} ;;
+CROSS_COMPILE=*) CROSS_COMPILE=${arg#*=} ;;
*=*) ;;
*) target=$arg ;;
esac
# Find a C compiler to use
#
printf "checking for C compiler... "
-trycc gcc
-trycc c99
-trycc cc
+trycc ${CROSS_COMPILE}gcc
+trycc ${CROSS_COMPILE}c99
+trycc ${CROSS_COMPILE}cc
printf "%s\n" "$CC"
test -n "$CC" || { echo "$0: cannot find a C compiler" ; exit 1 ; }
tryflag CFLAGS_AUTO -pipe
#
-# If debugging is disabled, omit bloated DWARF2 unwind tables & frame ptr
+# If debugging is disabled, omit frame pointer. Modern GCC does this
+# anyway on most archs even when debugging is enabled since the frame
+# pointer is no longer needed for debugging.
#
if fnmatch '-g*|*\ -g*' "$CFLAGS_AUTO $CFLAGS" ; then :
else
-tryflag CFLAGS_AUTO -fno-unwind-tables
-tryflag CFLAGS_AUTO -fno-asynchronous-unwind-tables
tryflag CFLAGS_AUTO -fomit-frame-pointer
fi
+#
+# Modern GCC wants to put DWARF tables (used for debugging and
+# unwinding) in the loaded part of the program where they are
+# unstrippable. These options force them back to debug sections (and
+# cause them not to get generated at all if debugging is off).
+#
+tryflag CFLAGS_AUTO -fno-unwind-tables
+tryflag CFLAGS_AUTO -fno-asynchronous-unwind-tables
+
#
# Some optimization levels add bloated alignment that hurt performance
#
# Some patched GCC builds have these defaults messed up...
tryflag CFLAGS_AUTO -fno-stack-protector
-tryldflag LDFLAGS_AUTO -Wl,--hash-style=sysv
+tryldflag LDFLAGS_AUTO -Wl,--hash-style=both
# Disable dynamic linking if ld is broken and can't do -Bsymbolic-functions
LDFLAGS_DUMMY=
CFLAGS_C99FSE = $CFLAGS_C99FSE
CPPFLAGS = $CPPFLAGS
LDFLAGS = $LDFLAGS_AUTO $LDFLAGS
+CROSS_COMPILE = $CROSS_COMPILE
EOF
test "x$static" = xno && echo "STATIC_LIBS ="
test "x$shared" = xno && echo "SHARED_LIBS ="