# Licensed to the Apache Software Foundation (ASF) under one
# or more contributor license agreements.  See the NOTICE file
# distributed with this work for additional information
# regarding copyright ownership.  The ASF licenses this file
# to you under the Apache License, Version 2.0 (the
# "License"); you may not use this file except in compliance
# with the License.  You may obtain a copy of the License at
#
#   http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing,
# software distributed under the License is distributed on an
# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
# KIND, either express or implied.  See the License for the
# specific language governing permissions and limitations
# under the License..
#
#

# -----------------------------------------------------------------------------
# Function : parent-dir
# Arguments: 1: path
# Returns  : Parent dir or path of $1, with final separator removed.
# -----------------------------------------------------------------------------
parent-dir = $(patsubst %/,%,$(dir $(1:%/=%)))

# -----------------------------------------------------------------------------
# Macro    : my-dir
# Returns  : the directory of the current Makefile
# Usage    : $(my-dir)
# -----------------------------------------------------------------------------
my-dir = $(realpath $(call parent-dir,$(lastword $(MAKEFILE_LIST))))


ROOT_DIR              := $(call my-dir)
ifneq ($(words $(subst :, ,$(ROOT_DIR))), 1)
  $(error main directory cannot contain spaces nor colons)
endif

COMMON_DIR            := $(ROOT_DIR)/common

CP    := /bin/cp -f
MKDIR := mkdir -p
STRIP := strip
OBJCOPY := objcopy
CC ?= gcc

# clean the content of 'INCLUDE' - this variable will be set by vcvars32.bat
# thus it will cause build error when this variable is used by our Makefile,
# when compiling the code under Cygwin tainted by MSVC environment settings.
INCLUDE :=

# this will return the path to the file that included the buildenv.mk file
CUR_DIR := $(realpath $(call parent-dir,$(lastword $(wordlist 2,$(words $(MAKEFILE_LIST)),x $(MAKEFILE_LIST)))))

CC_VERSION := $(shell $(CC) -dumpversion)
CC_VERSION_MAJOR := $(shell echo $(CC_VERSION) | cut -f1 -d.)
CC_VERSION_MINOR := $(shell echo $(CC_VERSION) | cut -f2 -d.)
CC_BELOW_4_9 := $(shell [ $(CC_VERSION_MAJOR) -lt 4 -o \( $(CC_VERSION_MAJOR) -eq 4 -a $(CC_VERSION_MINOR) -le 9 \) ] && echo 1)
CC_BELOW_5_2 := $(shell [ $(CC_VERSION_MAJOR) -lt 5 -o \( $(CC_VERSION_MAJOR) -eq 5 -a $(CC_VERSION_MINOR) -le 2 \) ] && echo 1)

# turn on stack protector for SDK
ifeq ($(CC_BELOW_4_9), 1)
    COMMON_FLAGS += -fstack-protector
else
    COMMON_FLAGS += -fstack-protector-strong
endif

ifdef DEBUG
    COMMON_FLAGS += -O0 -g -DDEBUG -UNDEBUG
else
    COMMON_FLAGS += -O2 -D_FORTIFY_SOURCE=2 -UDEBUG -DNDEBUG
endif

COMMON_FLAGS += -ffunction-sections -fdata-sections

# turn on compiler warnings as much as possible
COMMON_FLAGS += -Wall -Wextra -Winit-self -Wpointer-arith -Wreturn-type \
		-Waddress -Wsequence-point -Wformat-security \
		-Wmissing-include-dirs -Wfloat-equal -Wundef -Wshadow \
		-Wcast-align -Wconversion -Wredundant-decls

# additional warnings flags for C
CFLAGS += -Wjump-misses-init -Wstrict-prototypes -Wunsuffixed-float-constants

# additional warnings flags for C++
CXXFLAGS += -Wnon-virtual-dtor

# for static_assert()
CXXFLAGS += -std=c++14

.DEFAULT_GOAL := all
# this turns off the RCS / SCCS implicit rules of GNU Make
% : RCS/%,v
% : RCS/%
% : %,v
% : s.%
% : SCCS/s.%

# If a rule fails, delete $@.
.DELETE_ON_ERROR:

HOST_FILE_PROGRAM := file

UNAME := $(shell uname -m)
ifneq (,$(findstring 86,$(UNAME)))
    HOST_ARCH := x86
    ifneq (,$(shell $(HOST_FILE_PROGRAM) -L $(SHELL) | grep 'x86[_-]64'))
        HOST_ARCH := x86_64
    endif
else
    $(info Unknown host CPU arhitecture $(UNAME))
    $(error Aborting)
endif


ifeq "$(findstring __INTEL_COMPILER, $(shell $(CC) -E -dM -xc /dev/null))" "__INTEL_COMPILER"
  ifeq ($(shell test -f /usr/bin/dpkg; echo $$?), 0)
    ADDED_INC := -I /usr/include/$(shell dpkg-architecture -qDEB_BUILD_MULTIARCH)
  endif
endif

ARCH := $(HOST_ARCH)
ifeq "$(findstring -m32, $(CXXFLAGS))" "-m32"
  ARCH := x86
endif

ifeq ($(ARCH), x86)
COMMON_FLAGS += -DITT_ARCH_IA32
else
COMMON_FLAGS += -DITT_ARCH_IA64
endif

CFLAGS   += $(COMMON_FLAGS)
CXXFLAGS += $(COMMON_FLAGS)

# Enable the security flags
COMMON_LDFLAGS := -Wl,-z,relro,-z,now,-z,noexecstack

# mitigation options
MITIGATION_INDIRECT ?= 0
MITIGATION_RET ?= 0
MITIGATION_C ?= 0
MITIGATION_ASM ?= 0
MITIGATION_AFTERLOAD ?= 0
MITIGATION_LIB_PATH :=

ifeq ($(MITIGATION-CVE-2020-0551), LOAD)
    MITIGATION_C := 1
    MITIGATION_ASM := 1
    MITIGATION_INDIRECT := 1
    MITIGATION_RET := 1
    MITIGATION_AFTERLOAD := 1
    MITIGATION_LIB_PATH := cve_2020_0551_load
else ifeq ($(MITIGATION-CVE-2020-0551), CF)
    MITIGATION_C := 1
    MITIGATION_ASM := 1
    MITIGATION_INDIRECT := 1
    MITIGATION_RET := 1
    MITIGATION_AFTERLOAD := 0
    MITIGATION_LIB_PATH := cve_2020_0551_cf
endif

ifeq ($(MITIGATION_C), 1)
ifeq ($(MITIGATION_INDIRECT), 1)
    MITIGATION_CFLAGS += -mindirect-branch-register
endif
ifeq ($(MITIGATION_RET), 1)
CC_NO_LESS_THAN_8 := $(shell expr $(CC_VERSION) \>\= "8")
ifeq ($(CC_NO_LESS_THAN_8), 1)
    MITIGATION_CFLAGS += -fcf-protection=none
endif
    MITIGATION_CFLAGS += -mfunction-return=thunk-extern
endif
endif

ifeq ($(MITIGATION_ASM), 1)
    MITIGATION_ASFLAGS += -fno-plt
ifeq ($(MITIGATION_AFTERLOAD), 1)
    MITIGATION_ASFLAGS += -Wa,-mlfence-after-load=yes -Wa,-mlfence-before-indirect-branch=memory
else
    MITIGATION_ASFLAGS += -Wa,-mlfence-before-indirect-branch=all
endif
ifeq ($(MITIGATION_RET), 1)
    MITIGATION_ASFLAGS += -Wa,-mlfence-before-ret=shl
endif
endif

MITIGATION_CFLAGS += $(MITIGATION_ASFLAGS)

# Compiler and linker options for an Enclave
#
# We are using '--export-dynamic' so that `g_global_data_sim' etc.
# will be exported to dynamic symbol table.
#
# When `pie' is enabled, the linker (both BFD and Gold) under Ubuntu 14.04
# will hide all symbols from dynamic symbol table even if they are marked
# as `global' in the LD version script.
ENCLAVE_CFLAGS   = -ffreestanding -nostdinc -fvisibility=hidden -fpie -fno-strict-overflow -fno-delete-null-pointer-checks
ENCLAVE_CXXFLAGS = $(ENCLAVE_CFLAGS) -nostdinc++
ENCLAVE_LDFLAGS  = $(COMMON_LDFLAGS) -Wl,-Bstatic -Wl,-Bsymbolic -Wl,--no-undefined \
                   -Wl,-pie,-eenclave_entry -Wl,--export-dynamic  \
                   -Wl,--gc-sections \
                   -Wl,--defsym,__ImageBase=0

ENCLAVE_CFLAGS += $(MITIGATION_CFLAGS)
ENCLAVE_ASFLAGS = $(MITIGATION_ASFLAGS)