sgx_init.m4

# SGX_INIT
# --------
# Initialize automake/autoconf with Intel SGX build options.
# Calling this macro from configure.ac will enforce SGX support
# in the build.
AC_DEFUN([SGX_INIT],[
    AS_VAR_IF([ac_cv_sgx_init], [yes], [AC_MSG_ERROR([[already called SGX_INIT or SGX_INIT_OPTIONAL]])])
	AC_ARG_WITH([enclave-libdir],
		[AS_HELP_STRING([--with-enclave-libdir=path],
			[Set the directory where enclave libraries should be installed (default: EPREFIX/libexec)])
		], [enclave_libdir=$withval],
			[enclave_libdir=\$\{exec_prefix\}/libexec])

	AC_ARG_ENABLE([sgx-simulation],
		[AS_HELP_STRING([--enable-sgx-simulation],
			[Use Intel SGX in simulation mode. Implies --enable-sgx (default: disabled)])
		], [sgxsim=${enableval}], [sgxsim=no])

	AC_ARG_WITH([sgx-build],
		[AS_HELP_STRING([--with-sgx-build=debug|prerelease|release],
			[Set Intel SGX build mode (default: debug)])
		], [_sgxbuild=$withval], [_sgxbuild=debug])

	AC_ARG_WITH([sgxssl],
		[AS_HELP_STRING([--with-sgxssl=path],
			[Set the path to your Intel SGX SSL directory (defaults to /opt/intel/sgxssl)])
		], [SGXSSL=$withval],[SGXSSL=/opt/intel/sgxssl])

	AC_ARG_WITH([sgxsdk],
		[AS_HELP_STRING([--with-sgxsdk=path],
			[Set the path to your Intel SGX SDK directory (defaults to auto-detection)])
		], [SGXSDK=$withval],[SGXSDK="detect"])

	AS_IF([test "x$sgxsim" = "yes"], [sgxenable=yes])
	AS_IF([test "x$sgxenable" != "xno"],
		[ac_cv_enable_sgx=yes], [ac_cv_enable_sgx=no])

	AM_CONDITIONAL([SGX_ENABLED], [test "$ac_cv_enable_sgx" = "yes"])
	AM_COND_IF([SGX_ENABLED], [

	AS_IF([test "x$sgxsim" = "xyes"], [
			AC_SUBST(SGX_TRTS_LIB, [sgx_trts_sim])
			AC_SUBST(SGX_TSERVICE_LIB, [sgx_tservice_sim])
			AC_SUBST(SGX_UAE_SERVICE_LIB, [sgx_uae_service_sim])
			AC_SUBST(SGX_URTS_LIB, [sgx_urts_sim])
			AC_SUBST(LIBS_HW_SIMU, ["-lsgx_urts_sim -lsgx_uae_service_sim"])
			AC_DEFINE(SGX_HW_SIM, 1, [Enable hardware simulation mode])
		], [
			AC_SUBST(SGX_TRTS_LIB, [sgx_trts])
			AC_SUBST(SGX_TSERVICE_LIB, [sgx_tservice])
			AC_SUBST(SGX_UAE_SERVICE_LIB, [sgx_uae_service])
			AC_SUBST(SGX_URTS_LIB, [sgx_urts])
		]
	)
	AS_IF([test "x$_sgxbuild" = "xdebug"], [
			AC_DEFINE(DEBUG, 1, [Enable debugging])
			AC_SUBST(ENCLAVE_SIGN_TARGET, [signed_enclave_dev])
		],
		[test "x$_sgxbuild" = "xprerelease"], [
			AC_DEFINE(NDEBUG, 1, [Flag set for prerelease and release builds])
			AC_DEFINE(EDEBUG, 1, [Flag set for prerelease builds])
			AC_SUBST(ENCLAVE_SIGN_TARGET, [signed_enclave_dev])
		],
		[test "x$_sgxbuild" = "xrelease"], [
			AS_IF(test "x$_sgxsim" = "xyes", [
				AC_MSG_ERROR([Can't build in both release and simulation mode])
			],
			[
				AC_DEFINE(NDEBUG, 1)
				AC_SUBST(ENCLAVE_SIGN_TARGET, [signed_enclave_rel])
			])
		],
		[AC_MSG_ERROR([Unknown build mode $_sgxbuild])]
	)
	AC_SUBST(SGX_DEBUG_FLAGS, [$_sgxdebug])
	AS_IF([test "x$SGX_SDK" = "x"], [SGXSDK=detect], [SGXSDK=env])

	AS_IF([test "x$SGXSDK" = "xenv"], [SGXSDK=$SGX_SDK],
		[test "x$SGXSDK" != "xdetect"], [],
		[test -d /opt/intel/sgxsdk], [SGXSDK=/opt/intel/sgxsdk],
		[test -d ~/sgxsdk], [SGXSDK=~/sgxsdk],
		[test -d ${PWD}/sgx-sdk-build/sgxsdk], [SGXSDK=${PWD}/sgx-sdk-build/sgxsdk],
		[AC_MSG_ERROR([Can't detect your Intel SGX SDK installation directory])])

	AC_SUBST(SGXSDK)
	AC_SUBST(SGXSDK_INCDIR, $SGXSDK/include)

	ac_cv_sgx_sdk=$SGXSDK
	ac_cv_sgx_sdk_incdir=$SGXSDK/include

	AS_IF([test -d $SGXSDK/lib], [
		AC_SUBST(SGXSDK_LIBDIR, $SGXSDK/lib)
		ac_cv_sgx_sdk_libdir=$SGXSDK/lib
	], [test -d $SGXSDK/lib64], [
		AC_SUBST(SGXSDK_LIBDIR, $SGXSDK/lib64)
		ac_cv_sgx_sdk_libdir=$SGXSDK/lib64
	], [
		AC_MSG_ERROR(Can't find Intel SGX SDK lib directory)
	])

	AS_IF([test -d $SGXSDK/bin/ia32], [
		ac_cv_sgx_sdk_bindir=$SGXSDK/bin
		AC_SUBST(SGXSDK_BINDIR, $SGXSDK/bin/ia32)
	], [test -d $SGXSDK/bin/x64], [
		ac_cv_sgx_sdk_bindir=$SGXSDK/bin/x64
		AC_SUBST(SGXSDK_BINDIR, $SGXSDK/bin/x64)
	], [
		AC_MSG_ERROR(Can't find Intel SGX SDK bin directory)
	])

	AC_MSG_NOTICE([Found your Intel SGX SDK in $SGXSDK])

	AC_SUBST(enclave_libdir)
	AC_SUBST(SGXSSL)
	AC_SUBST(SGXSSL_INCDIR, $SGXSSL/include)
	AC_SUBST(SGXSSL_LIBDIR, $SGXSSL/lib64)

	dnl These are not quite the same as the Makefile substitution variables.
	dnl They are set in a manner to allow autoconf to use them when running
	dnl a compiler or linker for things like header and function checks.

	ac_cv_sgx_tlib_cflags="-nostdinc -fvisibility=hidden -fpie -fstack-protector"
	ac_cv_sgx_tlib_cppflags="-I${ac_cv_sgx_sdk_incdir} -I${ac_cv_sgx_sdk_incdir}/tlibc"
	ac_cv_sgx_tlib_cxxflags="-nostdinc++ -fvisibility=hidden -fpie -fstack-protector"
	ac_cv_sgx_enclave_ldflags="-nostdlib -nodefaultlibs -nostartfiles -L${ac_cv_sgx_sdk_libdir}"
	ac_cv_sgx_enclave_ldadd="-Wl,--no-undefined -Wl,--whole-archive -lsgx_trts -Wl,--no-whole-archive -Wl,--start-group -lsgx_tstdc -lsgx_tcrypto -lsgx_tservice_lib -Wl,--end-group -Wl,-Bstatic -Wl,-Bsymbolic -Wl,-pie,-eenclave_entry -Wl,--export-dynamic -Wl,--defsym,__ImageBase=0"


	dnl Substitutions for building a trusted library

	AC_SUBST(SGX_TLIB_CFLAGS,
		["-nostdinc -fvisibility=hidden -fpie -fstack-protector"])
	AC_SUBST(SGX_TLIB_CPPFLAGS,
		["-I\$(SGXSDK_INCDIR) -I\$(SGXSDK_INCDIR)/tlibc"])
	AC_SUBST(SGX_TLIB_CXXFLAGS,
		["-nostdinc++ -fvisibility=hidden -fpie -fstack-protector"])

	dnl Substitutions for building an enclave

	AC_SUBST(SGX_ENCLAVE_CFLAGS,
	 	["-nostdinc -fvisibility=hidden -fpie -ffunction-sections -fdata-sections -fstack-protector"])
	AC_SUBST(SGX_ENCLAVE_CPPFLAGS, 
		["-I\$(SGXSDK_INCDIR) -I\$(SGXSDK_INCDIR)/tlibc"])
	AC_SUBST(SGX_ENCLAVE_CXXFLAGS, ["-nostdinc++ -fvisibility=hidden -fpie -ffunction-sections -fdata-sections -fstack-protector"])
	AC_SUBST(SGX_ENCLAVE_LDFLAGS,
		["-nostdlib -nodefaultlibs -nostartfiles -L\$(SGXSDK_LIBDIR)"])
	AC_SUBST(SGX_ENCLAVE_LDADD,
		["-Wl,--no-undefined -Wl,--whole-archive -l\$(SGX_TRTS_LIB) -Wl,--no-whole-archive -Wl,--start-group \$(SGX_EXTRA_TLIBS) -lsgx_tstdc -lsgx_tcrypto -l\$(SGX_TSERVICE_LIB) -Wl,--end-group -Wl,-Bstatic -Wl,-Bsymbolic -Wl,-pie,-eenclave_entry -Wl,--export-dynamic -Wl,--defsym,__ImageBase=0"])

	])

	AM_CONDITIONAL([ENCLAVE_RELEASE_SIGN], [test "x$_sgxbuild" = "xrelease"])
	AM_CONDITIONAL([SGX_HW_SIM], [test "x$sgxsim" = "xyes"])
	AC_MSG_NOTICE([enabling SGX... ${ac_cv_enable_sgx}])
	ac_cv_sgx_init=yes
])

# SGX_IF_ENABLED(ACTION_IF_TRUE, ACTION_IF_FALSE)
# -----------------------------------------------
# Execute ACTION_IF_TRUE if SGX is enabled for the build
# (SGX_INIT was called in configure.ac, or SGX_INIT_OPTIONAL
# was called and the user supplied --enable-sgx on the
# command line).
AC_DEFUN([SGX_IF_ENABLED],[
	AS_IF([test "x${ac_cv_enable_sgx}" = "xyes"], [$1], [$2])
])