Merge 4.9.205 into android-4.9-q

[GitHub/LineageOS/G12/android_kernel_amlogic_linux-4.9.git] / Makefile

diff --git a/Makefile b/Makefile
index fc1a58ef7e561f1ce63e39f747a38f89274658ca..c571fb18b74af6f8d13d206beff96b67e604a71a 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -343,6 +343,7 @@ include scripts/Kbuild.include
 # Make variables (CC, etc...)
 AS             = $(CROSS_COMPILE)as
 LD             = $(CROSS_COMPILE)ld
+LDGOLD         = $(CROSS_COMPILE)ld.gold
 CC             = $(CROSS_COMPILE)gcc
 CPP            = $(CC) -E
 AR             = $(CROSS_COMPILE)ar
@@ -507,7 +508,11 @@ endif
 
 ifeq ($(cc-name),clang)
 ifneq ($(CROSS_COMPILE),)
-CLANG_FLAGS    += --target=$(notdir $(CROSS_COMPILE:%-=%))
+CLANG_TRIPLE   ?= $(CROSS_COMPILE)
+CLANG_FLAGS    += --target=$(notdir $(CLANG_TRIPLE:%-=%))
+ifeq ($(shell $(srctree)/scripts/clang-android.sh $(CC) $(CLANG_FLAGS)), y)
+$(error "Clang with Android --target detected. Did you specify CLANG_TRIPLE?")
+endif
 GCC_TOOLCHAIN_DIR := $(dir $(shell which $(CROSS_COMPILE)elfedit))
 CLANG_FLAGS    += --prefix=$(GCC_TOOLCHAIN_DIR)
 GCC_TOOLCHAIN  := $(realpath $(GCC_TOOLCHAIN_DIR)/..)
@@ -637,6 +642,20 @@ CFLAGS_GCOV        := -fprofile-arcs -ftest-coverage -fno-tree-loop-im $(call cc-disabl
 CFLAGS_KCOV    := $(call cc-option,-fsanitize-coverage=trace-pc,)
 export CFLAGS_GCOV CFLAGS_KCOV
 
+# Make toolchain changes before including arch/$(SRCARCH)/Makefile to ensure
+# ar/cc/ld-* macros return correct values.
+ifdef CONFIG_LTO_CLANG
+# use GNU gold with LLVMgold for LTO linking, and LD for vmlinux_link
+LDFINAL_vmlinux := $(LD)
+LD             := $(LDGOLD)
+LDFLAGS                += -plugin LLVMgold.so
+# use llvm-ar for building symbol tables from IR files, and llvm-dis instead
+# of objdump for processing symbol versions and exports
+LLVM_AR                := llvm-ar
+LLVM_DIS       := llvm-dis
+export LLVM_AR LLVM_DIS
+endif
+
 # The arch Makefile can set ARCH_{CPP,A,C}FLAGS to override the default
 # values of the respective KBUILD_* variables
 ARCH_CPPFLAGS :=
@@ -657,6 +676,53 @@ KBUILD_CFLAGS      += $(call cc-option,-ffunction-sections,)
 KBUILD_CFLAGS  += $(call cc-option,-fdata-sections,)
 endif
 
+ifdef CONFIG_LTO_CLANG
+lto-clang-flags        := -flto -fvisibility=hidden
+
+# allow disabling only clang LTO where needed
+DISABLE_LTO_CLANG := -fno-lto -fvisibility=default
+export DISABLE_LTO_CLANG
+endif
+
+ifdef CONFIG_LTO
+lto-flags      := $(lto-clang-flags)
+KBUILD_CFLAGS  += $(lto-flags)
+
+DISABLE_LTO    := $(DISABLE_LTO_CLANG)
+export DISABLE_LTO
+
+# LDFINAL_vmlinux and LDFLAGS_FINAL_vmlinux can be set to override
+# the linker and flags for vmlinux_link.
+export LDFINAL_vmlinux LDFLAGS_FINAL_vmlinux
+endif
+
+ifdef CONFIG_CFI_CLANG
+cfi-clang-flags        += -fsanitize=cfi
+DISABLE_CFI_CLANG := -fno-sanitize=cfi
+ifdef CONFIG_MODULES
+cfi-clang-flags        += -fsanitize-cfi-cross-dso
+DISABLE_CFI_CLANG += -fno-sanitize-cfi-cross-dso
+endif
+ifdef CONFIG_CFI_PERMISSIVE
+cfi-clang-flags        += -fsanitize-recover=cfi -fno-sanitize-trap=cfi
+endif
+
+# also disable CFI when LTO is disabled
+DISABLE_LTO_CLANG += $(DISABLE_CFI_CLANG)
+# allow disabling only clang CFI where needed
+export DISABLE_CFI_CLANG
+endif
+
+ifdef CONFIG_CFI
+# cfi-flags are re-tested in prepare-compiler-check
+cfi-flags      := $(cfi-clang-flags)
+KBUILD_CFLAGS  += $(cfi-flags)
+
+DISABLE_CFI    := $(DISABLE_CFI_CLANG)
+DISABLE_LTO    += $(DISABLE_CFI)
+export DISABLE_CFI
+endif
+
 ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
 KBUILD_CFLAGS  += -Os $(call cc-disable-warning,maybe-uninitialized,)
 else
@@ -721,6 +787,7 @@ ifeq ($(cc-name),clang)
 KBUILD_CPPFLAGS += $(call cc-option,-Qunused-arguments,)
 KBUILD_CFLAGS += $(call cc-disable-warning, format-invalid-specifier)
 KBUILD_CFLAGS += $(call cc-disable-warning, gnu)
+KBUILD_CFLAGS += $(call cc-disable-warning, duplicate-decl-specifier)
 # Quiet clang warning: comparison of unsigned expression < 0 is always false
 KBUILD_CFLAGS += $(call cc-disable-warning, tautological-compare)
 # CLANG uses a _MergedGlobals as optimization, but this breaks modpost, as the
@@ -1107,6 +1174,22 @@ prepare-objtool: $(objtool_target)
 # CC_STACKPROTECTOR_STRONG! Why did it build with _REGULAR?!")
 PHONY += prepare-compiler-check
 prepare-compiler-check: FORCE
+# Make sure we're using a supported toolchain with LTO_CLANG
+ifdef CONFIG_LTO_CLANG
+  ifneq ($(call clang-ifversion, -ge, 0500, y), y)
+       @echo Cannot use CONFIG_LTO_CLANG: requires clang 5.0 or later >&2 && exit 1
+  endif
+  ifneq ($(call gold-ifversion, -ge, 112000000, y), y)
+       @echo Cannot use CONFIG_LTO_CLANG: requires GNU gold 1.12 or later >&2 && exit 1
+  endif
+endif
+# Make sure compiler supports LTO flags
+ifdef lto-flags
+  ifeq ($(call cc-option, $(lto-flags)),)
+       @echo Cannot use CONFIG_LTO: $(lto-flags) not supported by compiler \
+               >&2 && exit 1
+  endif
+endif
 # Make sure compiler supports requested stack protector flag.
 ifdef stackp-name
   ifeq ($(call cc-option, $(stackp-flag)),)
@@ -1120,6 +1203,11 @@ ifdef stackp-check
        @echo Cannot use CONFIG_CC_STACKPROTECTOR_$(stackp-name): \
                   $(stackp-flag) available but compiler is broken >&2 && exit 1
   endif
+endif
+ifdef cfi-flags
+  ifeq ($(call cc-option, $(cfi-flags)),)
+       @echo Cannot use CONFIG_CFI: $(cfi-flags) not supported by compiler >&2 && exit 1
+  endif
 endif
        @:
 
@@ -1593,7 +1681,8 @@ clean: $(clean-dirs)
                -o -name modules.builtin -o -name '.tmp_*.o.*' \
                -o -name '*.c.[012]*.*' \
                -o -name '*.ll' \
-               -o -name '*.gcno' \) -type f -print | xargs rm -f
+               -o -name '*.gcno' \
+               -o -name '*.*.symversions' \) -type f -print | xargs rm -f
 
 # Generate tags for editors
 # ---------------------------------------------------------------------------