Make it easier to build libminijail on Chromium Linux.
- Move libsyscalls.gen.c generation code out of the Makefile and into a
script.
- Add SECURE_ALL_* defines for systems that do not linux/securebits.h.
BUG=chromium-os:35482
TEST=FEATURES=test emerge chromeos-minijail
Change-Id: I922c579f1fcf09db2379659dbde737f246200e51
Reviewed-on: https://gerrit.chromium.org/gerrit/35928
Reviewed-by: Jorge Lucangeli Obes <jorgelo@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
Commit-Ready: Lei Zhang <thestig@chromium.org>
Tested-by: Lei Zhang <thestig@chromium.org>
diff --git a/gen_syscalls.sh b/gen_syscalls.sh
new file mode 100755
index 0000000..3121b42
--- /dev/null
+++ b/gen_syscalls.sh
@@ -0,0 +1,49 @@
+#!/bin/sh
+
+# Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+# Generates a header file with a system call table made up of "name",
+# syscall_nr entries by including the build target <asm/unistd.h> and
+# emitting the list of defines. Use of the compiler is needed to
+# dereference the actual provider of syscall definitions.
+# E.g., asm/unistd_32.h or asm/unistd_64.h, etc.
+
+set -e
+
+if [ $# -ne 1 ] && [ $# -ne 3 ]; then
+ echo "Usage: $(basename "$0") OUTFILE"
+ echo "Usage: $(basename "$0") CC CFLAGS OUTFILE"
+ exit 1
+fi
+
+if [ $# -eq 3 ]; then
+ CC="$1"
+ shift
+ CFLAGS="$1"
+ shift
+fi
+OUTFILE="$1"
+
+# sed expression which extracts system calls that are
+# defined via asm/unistd.h. It converts them from:
+# #define __NR_read foo
+# to:
+# #ifdef __NR_read
+# { "read", __NR_read },
+# #endif
+SED_MULTILINE='s/#define __(ARM_)?(NR_)([a-z0-9_]*) (.*)$/#ifdef __\1\2\3\
+{ "\1\3", __\1\2\3 },\n#endif/g p;'
+
+cat <<-EOF > "${OUTFILE}"
+/* GENERATED BY MAKEFILE */
+#include <stddef.h>
+#include <asm/unistd.h>
+#include "libsyscalls.h"
+const struct syscall_entry syscall_table[] = {
+$(echo '#include <asm/unistd.h>' | \
+ ${CC} ${CFLAGS} -dD - -E | sed -rne "${SED_MULTILINE}")
+ { NULL, -1 },
+};
+EOF