kbuild: lto: force rebuilds when switching CONFIG_LTO

[linux-2.6-microblaze.git] / Makefile

diff --git a/Makefile b/Makefile
index e30cf02..639873d 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -1,8 +1,8 @@
 # SPDX-License-Identifier: GPL-2.0
 VERSION = 5
-PATCHLEVEL = 10
+PATCHLEVEL = 11
 SUBLEVEL = 0
-EXTRAVERSION =
+EXTRAVERSION = -rc2
 NAME = Kleptomaniac Octopus
 
 # *DOCUMENTATION*
@@ -450,7 +450,7 @@ LEX         = flex
 YACC           = bison
 AWK            = awk
 INSTALLKERNEL  := installkernel
-DEPMOD         = /sbin/depmod
+DEPMOD         = depmod
 PERL           = perl
 PYTHON         = python
 PYTHON3                = python3
@@ -851,12 +851,8 @@ KBUILD_CFLAGS += $(DEBUG_CFLAGS)
 export DEBUG_CFLAGS
 
 ifdef CONFIG_FUNCTION_TRACER
-ifdef CONFIG_FTRACE_MCOUNT_RECORD
-  # gcc 5 supports generating the mcount tables directly
-  ifeq ($(call cc-option-yn,-mrecord-mcount),y)
-    CC_FLAGS_FTRACE    += -mrecord-mcount
-    export CC_USING_RECORD_MCOUNT := 1
-  endif
+ifdef CONFIG_FTRACE_MCOUNT_USE_CC
+  CC_FLAGS_FTRACE      += -mrecord-mcount
   ifdef CONFIG_HAVE_NOP_MCOUNT
     ifeq ($(call cc-option-yn, -mnop-mcount),y)
       CC_FLAGS_FTRACE  += -mnop-mcount
@@ -864,6 +860,15 @@ ifdef CONFIG_FTRACE_MCOUNT_RECORD
     endif
   endif
 endif
+ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL
+  CC_FLAGS_USING       += -DCC_USING_NOP_MCOUNT
+endif
+ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
+  ifdef CONFIG_HAVE_C_RECORDMCOUNT
+    BUILD_C_RECORDMCOUNT := y
+    export BUILD_C_RECORDMCOUNT
+  endif
+endif
 ifdef CONFIG_HAVE_FENTRY
   ifeq ($(call cc-option-yn, -mfentry),y)
     CC_FLAGS_FTRACE    += -mfentry
@@ -873,12 +878,6 @@ endif
 export CC_FLAGS_FTRACE
 KBUILD_CFLAGS  += $(CC_FLAGS_FTRACE) $(CC_FLAGS_USING)
 KBUILD_AFLAGS  += $(CC_FLAGS_USING)
-ifdef CONFIG_DYNAMIC_FTRACE
-       ifdef CONFIG_HAVE_C_RECORDMCOUNT
-               BUILD_C_RECORDMCOUNT := y
-               export BUILD_C_RECORDMCOUNT
-       endif
-endif
 endif
 
 # We trigger additional mismatches with less inlining
@@ -897,6 +896,25 @@ KBUILD_CFLAGS      += $(CC_FLAGS_SCS)
 export CC_FLAGS_SCS
 endif
 
+ifdef CONFIG_LTO_CLANG
+ifdef CONFIG_LTO_CLANG_THIN
+CC_FLAGS_LTO   := -flto=thin -fsplit-lto-unit
+KBUILD_LDFLAGS += --thinlto-cache-dir=$(extmod-prefix).thinlto-cache
+else
+CC_FLAGS_LTO   := -flto
+endif
+CC_FLAGS_LTO   += -fvisibility=hidden
+
+# Limit inlining across translation units to reduce binary size
+KBUILD_LDFLAGS += -mllvm -import-instr-limit=5
+endif
+
+ifdef CONFIG_LTO
+KBUILD_CFLAGS  += -fno-lto $(CC_FLAGS_LTO)
+KBUILD_AFLAGS  += -fno-lto
+export CC_FLAGS_LTO
+endif
+
 ifdef CONFIG_DEBUG_FORCE_FUNCTION_ALIGN_32B
 KBUILD_CFLAGS += -falign-functions=32
 endif
@@ -1222,6 +1240,10 @@ uapi-asm-generic:
 PHONY += prepare-objtool prepare-resolve_btfids
 prepare-objtool: $(objtool_target)
 ifeq ($(SKIP_STACK_VALIDATION),1)
+ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL
+       @echo "error: Cannot generate __mcount_loc for CONFIG_DYNAMIC_FTRACE=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel" >&2
+       @false
+endif
 ifdef CONFIG_UNWINDER_ORC
        @echo "error: Cannot generate ORC metadata for CONFIG_UNWINDER_ORC=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel" >&2
        @false
@@ -1483,7 +1505,7 @@ MRPROPER_FILES += include/config include/generated          \
                  *.spec
 
 # Directories & files removed with 'make distclean'
-DISTCLEAN_FILES += tags TAGS cscope* GPATH GTAGS GRTAGS GSYMS
+DISTCLEAN_FILES += tags TAGS cscope* GPATH GTAGS GRTAGS GSYMS .thinlto-cache
 
 # clean - Delete most, but leave enough to build external modules
 #
@@ -1729,7 +1751,7 @@ PHONY += compile_commands.json
 
 clean-dirs := $(KBUILD_EXTMOD)
 clean: rm-files := $(KBUILD_EXTMOD)/Module.symvers $(KBUILD_EXTMOD)/modules.nsdeps \
-       $(KBUILD_EXTMOD)/compile_commands.json
+       $(KBUILD_EXTMOD)/compile_commands.json $(KBUILD_EXTMOD)/.thinlto-cache
 
 PHONY += help
 help:
@@ -1826,7 +1848,8 @@ clean: $(clean-dirs)
                -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
 # ---------------------------------------------------------------------------