Merge branch 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild

Pull kbuild updates from Michal Marek:

 - new option CONFIG_TRIM_UNUSED_KSYMS which does a two-pass build and
   unexports symbols which are not used in the current config [Nicolas
   Pitre]

 - several kbuild rule cleanups [Masahiro Yamada]

 - warning option adjustments for gcov etc [Arnd Bergmann]

 - a few more small fixes

* 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild: (31 commits)
  kbuild: move -Wunused-const-variable to W=1 warning level
  kbuild: fix if_change and friends to consider argument order
  kbuild: fix adjust_autoksyms.sh for modules that need only one symbol
  kbuild: fix ksym_dep_filter when multiple EXPORT_SYMBOL() on the same line
  gcov: disable -Wmaybe-uninitialized warning
  gcov: disable tree-loop-im to reduce stack usage
  gcov: disable for COMPILE_TEST
  Kbuild: disable 'maybe-uninitialized' warning for CONFIG_PROFILE_ALL_BRANCHES
  Kbuild: change CC_OPTIMIZE_FOR_SIZE definition
  kbuild: forbid kernel directory to contain spaces and colons
  kbuild: adjust ksym_dep_filter for some cmd_* renames
  kbuild: Fix dependencies for final vmlinux link
  kbuild: better abstract vmlinux sequential prerequisites
  kbuild: fix call to adjust_autoksyms.sh when output directory specified
  kbuild: Get rid of KBUILD_STR
  kbuild: rename cmd_as_s_S to cmd_cpp_s_S
  kbuild: rename cmd_cc_i_c to cmd_cpp_i_c
  kbuild: drop redundant "PHONY += FORCE"
  kbuild: delete unnecessary "@:"
  kbuild: mark help target as PHONY
  ...

7 files changed, 215 insertions, 48 deletions

diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include
index b2ab2a9..0f82314 100644
--- a/scripts/Kbuild.include
+++ b/scripts/Kbuild.include
@@ -7,6 +7,7 @@ quote   := "
 squote  := '
 empty   :=
 space   := $(empty) $(empty)
+space_escape := _-_SPACE_-_
 
 ###
 # Name of target with a '.' as filename prefix. foo/bar.o => foo/.bar.o
@@ -226,10 +227,10 @@ objectify = $(foreach o,$(1),$(if $(filter /%,$(o)),$(o),$(obj)/$(o)))
 # See Documentation/kbuild/makefiles.txt for more info
 
 ifneq ($(KBUILD_NOCMDDEP),1)
-# Check if both arguments has same arguments. Result is empty string if equal.
-# User may override this check using make KBUILD_NOCMDDEP=1
-arg-check = $(strip $(filter-out $(cmd_$(1)), $(cmd_$@)) \
-                    $(filter-out $(cmd_$@),   $(cmd_$(1))) )
+# Check if both arguments are the same including their order. Result is empty
+# string if equal. User may override this check using make KBUILD_NOCMDDEP=1
+arg-check = $(filter-out $(subst $(space),$(space_escape),$(strip $(cmd_$@))), \
+                         $(subst $(space),$(space_escape),$(strip $(cmd_$1))))
 else
 arg-check = $(if $(strip $(cmd_$@)),,1)
 endif
@@ -256,10 +257,42 @@ if_changed = $(if $(strip $(any-prereq) $(arg-check)),                       \
 # Execute the command and also postprocess generated .d dependencies file.
 if_changed_dep = $(if $(strip $(any-prereq) $(arg-check) ),                  \
 	@set -e;                                                             \
+	$(cmd_and_fixdep), @:)
+
+ifndef CONFIG_TRIM_UNUSED_KSYMS
+
+cmd_and_fixdep =                                                             \
 	$(echo-cmd) $(cmd_$(1));                                             \
 	scripts/basic/fixdep $(depfile) $@ '$(make-cmd)' > $(dot-target).tmp;\
 	rm -f $(depfile);                                                    \
-	mv -f $(dot-target).tmp $(dot-target).cmd, @:)
+	mv -f $(dot-target).tmp $(dot-target).cmd;
+
+else
+
+# Filter out exported kernel symbol names from the preprocessor output.
+# See also __KSYM_DEPS__ in include/linux/export.h.
+# We disable the depfile generation here, so as not to overwrite the existing
+# depfile while fixdep is parsing it.
+flags_nodeps = $(filter-out -Wp$(comma)-M%, $($(1)))
+ksym_dep_filter =                                                            \
+	case "$(1)" in                                                       \
+	  cc_*_c|cpp_i_c)                                                    \
+	    $(CPP) $(call flags_nodeps,c_flags) -D__KSYM_DEPS__ $< ;;        \
+	  as_*_S|cpp_s_S)                                                    \
+	    $(CPP) $(call flags_nodeps,a_flags) -D__KSYM_DEPS__ $< ;;        \
+	  boot*|build*|*cpp_lds_S|dtc|host*|vdso*) : ;;                      \
+	  *) echo "Don't know how to preprocess $(1)" >&2; false ;;          \
+	esac | tr ";" "\n" | sed -rn 's/^.*=== __KSYM_(.*) ===.*$$/KSYM_\1/p'
+
+cmd_and_fixdep =                                                             \
+	$(echo-cmd) $(cmd_$(1));                                             \
+	$(ksym_dep_filter) |                                                 \
+		scripts/basic/fixdep -e $(depfile) $@ '$(make-cmd)'          \
+			> $(dot-target).tmp;	                             \
+	rm -f $(depfile);                                                    \
+	mv -f $(dot-target).tmp $(dot-target).cmd;
+
+endif
 
 # Usage: $(call if_changed_rule,foo)
 # Will check if $(cmd_foo) or any of the prerequisites changed,
@@ -341,8 +374,6 @@ endif
 #
 ###############################################################################
 #
-space_escape := %%%SPACE%%%
-#
 define config_filename
 ifneq ($$(CONFIG_$(1)),"")
 $(1)_FILENAME := $$(subst \\,\,$$(subst \$$(quote),$$(quote),$$(subst $$(space_escape),\$$(space),$$(patsubst "%",%,$$(subst $$(space),$$(space_escape),$$(CONFIG_$(1)))))))
diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index e1bc190..0d1ca5b 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -152,11 +152,11 @@ cmd_cc_s_c       = $(CC) $(c_flags) $(DISABLE_LTO) -fverbose-asm -S -o $@ $<
 $(obj)/%.s: $(src)/%.c FORCE
 	$(call if_changed_dep,cc_s_c)
 
-quiet_cmd_cc_i_c = CPP $(quiet_modtag) $@
-cmd_cc_i_c       = $(CPP) $(c_flags)   -o $@ $<
+quiet_cmd_cpp_i_c = CPP $(quiet_modtag) $@
+cmd_cpp_i_c       = $(CPP) $(c_flags) -o $@ $<
 
 $(obj)/%.i: $(src)/%.c FORCE
-	$(call if_changed_dep,cc_i_c)
+	$(call if_changed_dep,cpp_i_c)
 
 cmd_gensymtypes =                                                           \
     $(CPP) -D__GENKSYMS__ $(c_flags) $< |                                   \
@@ -266,26 +266,24 @@ endif # CONFIG_STACK_VALIDATION
 
 define rule_cc_o_c
 	$(call echo-cmd,checksrc) $(cmd_checksrc)			  \
-	$(call echo-cmd,cc_o_c) $(cmd_cc_o_c);				  \
+	$(call cmd_and_fixdep,cc_o_c)					  \
 	$(cmd_modversions)						  \
-	$(cmd_objtool)						  \
-	$(call echo-cmd,record_mcount)					  \
-	$(cmd_record_mcount)						  \
-	scripts/basic/fixdep $(depfile) $@ '$(call make-cmd,cc_o_c)' >    \
-	                                              $(dot-target).tmp;  \
-	rm -f $(depfile);						  \
-	mv -f $(dot-target).tmp $(dot-target).cmd
+	$(cmd_objtool)						          \
+	$(call echo-cmd,record_mcount) $(cmd_record_mcount)
 endef
 
 define rule_as_o_S
-	$(call echo-cmd,as_o_S) $(cmd_as_o_S);				  \
-	$(cmd_objtool)						  \
-	scripts/basic/fixdep $(depfile) $@ '$(call make-cmd,as_o_S)' >    \
-	                                              $(dot-target).tmp;  \
-	rm -f $(depfile);						  \
-	mv -f $(dot-target).tmp $(dot-target).cmd
+	$(call cmd_and_fixdep,as_o_S)					  \
+	$(cmd_objtool)
 endef
 
+# List module undefined symbols (or empty line if not enabled)
+ifdef CONFIG_TRIM_UNUSED_KSYMS
+cmd_undef_syms = $(NM) $@ | sed -n 's/^ \+U //p' | xargs echo
+else
+cmd_undef_syms = echo
+endif
+
 # Built-in and composite module parts
 $(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_obj) FORCE
 	$(call cmd,force_checksrc)
@@ -296,7 +294,8 @@ $(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_obj) FORCE
 $(single-used-m): $(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_obj) FORCE
 	$(call cmd,force_checksrc)
 	$(call if_changed_rule,cc_o_c)
-	@{ echo $(@:.o=.ko); echo $@; } > $(MODVERDIR)/$(@F:.o=.mod)
+	@{ echo $(@:.o=.ko); echo $@; \
+	   $(cmd_undef_syms); } > $(MODVERDIR)/$(@F:.o=.mod)
 
 quiet_cmd_cc_lst_c = MKLST   $@
       cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \
@@ -314,11 +313,11 @@ modkern_aflags := $(KBUILD_AFLAGS_KERNEL) $(AFLAGS_KERNEL)
 $(real-objs-m)      : modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE)
 $(real-objs-m:.o=.s): modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE)
 
-quiet_cmd_as_s_S = CPP $(quiet_modtag) $@
-cmd_as_s_S       = $(CPP) $(a_flags)   -o $@ $<
+quiet_cmd_cpp_s_S = CPP $(quiet_modtag) $@
+cmd_cpp_s_S       = $(CPP) $(a_flags) -o $@ $<
 
 $(obj)/%.s: $(src)/%.S FORCE
-	$(call if_changed_dep,as_s_S)
+	$(call if_changed_dep,cpp_s_S)
 
 quiet_cmd_as_o_S = AS $(quiet_modtag)  $@
 cmd_as_o_S       = $(CC) $(a_flags) -c -o $@ $<
@@ -426,7 +425,8 @@ $(call multi_depend, $(multi-used-y), .o, -objs -y)
 
 $(multi-used-m): FORCE
 	$(call if_changed,link_multi-m)
-	@{ echo $(@:.o=.ko); echo $(link_multi_deps); } > $(MODVERDIR)/$(@F:.o=.mod)
+	@{ echo $(@:.o=.ko); echo $(link_multi_deps); \
+	   $(cmd_undef_syms); } > $(MODVERDIR)/$(@F:.o=.mod)
 $(call multi_depend, $(multi-used-m), .o, -objs -y -m)
 
 targets += $(multi-used-y) $(multi-used-m)
diff --git a/scripts/Makefile.extrawarn b/scripts/Makefile.extrawarn
index f9e47a7..53449a6 100644
--- a/scripts/Makefile.extrawarn
+++ b/scripts/Makefile.extrawarn
@@ -24,6 +24,7 @@ warning-1 += $(call cc-option, -Wmissing-prototypes)
 warning-1 += -Wold-style-definition
 warning-1 += $(call cc-option, -Wmissing-include-dirs)
 warning-1 += $(call cc-option, -Wunused-but-set-variable)
+warning-1 += $(call cc-option, -Wunused-const-variable)
 warning-1 += $(call cc-disable-warning, missing-field-initializers)
 warning-1 += $(call cc-disable-warning, sign-compare)
 
diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index ed1b7c4..e7df0f5 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -96,10 +96,10 @@ obj-dirs	:= $(addprefix $(obj)/,$(obj-dirs))
 # Note: Files that end up in two or more modules are compiled without the
 #       KBUILD_MODNAME definition. The reason is that any made-up name would
 #       differ in different configs.
-name-fix = $(subst $(comma),_,$(subst -,_,$1))
-basename_flags = -D"KBUILD_BASENAME=KBUILD_STR($(call name-fix,$(basetarget)))"
+name-fix = $(squote)$(quote)$(subst $(comma),_,$(subst -,_,$1))$(quote)$(squote)
+basename_flags = -DKBUILD_BASENAME=$(call name-fix,$(basetarget))
 modname_flags  = $(if $(filter 1,$(words $(modname))),\
-                 -D"KBUILD_MODNAME=KBUILD_STR($(call name-fix,$(modname)))")
+                 -DKBUILD_MODNAME=$(call name-fix,$(modname)))
 
 orig_c_flags   = $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(KBUILD_SUBDIR_CCFLAGS) \
                  $(ccflags-y) $(CFLAGS_$(basetarget).o)
@@ -162,7 +162,7 @@ endif
 
 c_flags        = -Wp,-MD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE)     \
 		 $(__c_flags) $(modkern_cflags)                           \
-		 -D"KBUILD_STR(s)=\#s" $(basename_flags) $(modname_flags)
+		 $(basename_flags) $(modname_flags)
 
 a_flags        = -Wp,-MD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE)     \
 		 $(__a_flags) $(modkern_aflags)
diff --git a/scripts/adjust_autoksyms.sh b/scripts/adjust_autoksyms.sh
new file mode 100755
index 0000000..8dc1918
--- /dev/null
+++ b/scripts/adjust_autoksyms.sh
@@ -0,0 +1,101 @@
+#!/bin/sh
+
+# Script to create/update include/generated/autoksyms.h and dependency files
+#
+# Copyright:	(C) 2016  Linaro Limited
+# Created by:	Nicolas Pitre, January 2016
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 2 as
+# published by the Free Software Foundation.
+
+# Create/update the include/generated/autoksyms.h file from the list
+# of all module's needed symbols as recorded on the third line of
+# .tmp_versions/*.mod files.
+#
+# For each symbol being added or removed, the corresponding dependency
+# file's timestamp is updated to force a rebuild of the affected source
+# file. All arguments passed to this script are assumed to be a command
+# to be exec'd to trigger a rebuild of those files.
+
+set -e
+
+cur_ksyms_file="include/generated/autoksyms.h"
+new_ksyms_file="include/generated/autoksyms.h.tmpnew"
+
+info() {
+	if [ "$quiet" != "silent_" ]; then
+		printf "  %-7s %s\n" "$1" "$2"
+	fi
+}
+
+info "CHK" "$cur_ksyms_file"
+
+# Use "make V=1" to debug this script.
+case "$KBUILD_VERBOSE" in
+*1*)
+	set -x
+	;;
+esac
+
+# We need access to CONFIG_ symbols
+case "${KCONFIG_CONFIG}" in
+*/*)
+	. "${KCONFIG_CONFIG}"
+	;;
+*)
+	# Force using a file from the current directory
+	. "./${KCONFIG_CONFIG}"
+esac
+
+# In case it doesn't exist yet...
+if [ -e "$cur_ksyms_file" ]; then touch "$cur_ksyms_file"; fi
+
+# Generate a new ksym list file with symbols needed by the current
+# set of modules.
+cat > "$new_ksyms_file" << EOT
+/*
+ * Automatically generated file; DO NOT EDIT.
+ */
+
+EOT
+sed -ns -e '3{s/ /\n/g;/^$/!p;}' "$MODVERDIR"/*.mod | sort -u |
+while read sym; do
+	if [ -n "$CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX" ]; then
+		sym="${sym#_}"
+	fi
+	echo "#define __KSYM_${sym} 1"
+done >> "$new_ksyms_file"
+
+# Special case for modversions (see modpost.c)
+if [ -n "$CONFIG_MODVERSIONS" ]; then
+	echo "#define __KSYM_module_layout 1" >> "$new_ksyms_file"
+fi
+
+# Extract changes between old and new list and touch corresponding
+# dependency files.
+changed=$(
+count=0
+sort "$cur_ksyms_file" "$new_ksyms_file" | uniq -u |
+sed -n 's/^#define __KSYM_\(.*\) 1/\1/p' | tr "A-Z_" "a-z/" |
+while read sympath; do
+	if [ -z "$sympath" ]; then continue; fi
+	depfile="include/config/ksym/${sympath}.h"
+	mkdir -p "$(dirname "$depfile")"
+	touch "$depfile"
+	echo $((count += 1))
+done | tail -1 )
+changed=${changed:-0}
+
+if [ $changed -gt 0 ]; then
+	# Replace the old list with tne new one
+	old=$(grep -c "^#define __KSYM_" "$cur_ksyms_file" || true)
+	new=$(grep -c "^#define __KSYM_" "$new_ksyms_file" || true)
+	info "KSYMS" "symbols: before=$old, after=$new, changed=$changed"
+	info "UPD" "$cur_ksyms_file"
+	mv -f "$new_ksyms_file" "$cur_ksyms_file"
+	# Then trigger a rebuild of affected source files
+	exec $@
+else
+	rm -f "$new_ksyms_file"
+fi
diff --git a/scripts/basic/fixdep.c b/scripts/basic/fixdep.c
index caef815..746ec1e 100644
--- a/scripts/basic/fixdep.c
+++ b/scripts/basic/fixdep.c
@@ -120,13 +120,15 @@
 #define INT_NFIG ntohl(0x4e464947)
 #define INT_FIG_ ntohl(0x4649475f)
 
+int insert_extra_deps;
 char *target;
 char *depfile;
 char *cmdline;
 
 static void usage(void)
 {
-	fprintf(stderr, "Usage: fixdep <depfile> <target> <cmdline>\n");
+	fprintf(stderr, "Usage: fixdep [-e] <depfile> <target> <cmdline>\n");
+	fprintf(stderr, " -e  insert extra dependencies given on stdin\n");
 	exit(1);
 }
 
@@ -138,6 +140,40 @@ static void print_cmdline(void)
 	printf("cmd_%s := %s\n\n", target, cmdline);
 }
 
+/*
+ * Print out a dependency path from a symbol name
+ */
+static void print_config(const char *m, int slen)
+{
+	int c, i;
+
+	printf("    $(wildcard include/config/");
+	for (i = 0; i < slen; i++) {
+		c = m[i];
+		if (c == '_')
+			c = '/';
+		else
+			c = tolower(c);
+		putchar(c);
+	}
+	printf(".h) \\\n");
+}
+
+static void do_extra_deps(void)
+{
+	if (insert_extra_deps) {
+		char buf[80];
+		while(fgets(buf, sizeof(buf), stdin)) {
+			int len = strlen(buf);
+			if (len < 2 || buf[len-1] != '\n') {
+				fprintf(stderr, "fixdep: bad data on stdin\n");
+				exit(1);
+			}
+			print_config(buf, len-1);
+		}
+	}
+}
+
 struct item {
 	struct item	*next;
 	unsigned int	len;
@@ -197,23 +233,12 @@ static void define_config(const char *name, int len, unsigned int hash)
 static void use_config(const char *m, int slen)
 {
 	unsigned int hash = strhash(m, slen);
-	int c, i;
 
 	if (is_defined_config(m, slen, hash))
 	    return;
 
 	define_config(m, slen, hash);
-
-	printf("    $(wildcard include/config/");
-	for (i = 0; i < slen; i++) {
-		c = m[i];
-		if (c == '_')
-			c = '/';
-		else
-			c = tolower(c);
-		putchar(c);
-	}
-	printf(".h) \\\n");
+	print_config(m, slen);
 }
 
 static void parse_config_file(const char *map, size_t len)
@@ -250,7 +275,7 @@ static void parse_config_file(const char *map, size_t len)
 	}
 }
 
-/* test is s ends in sub */
+/* test if s ends in sub */
 static int strrcmp(const char *s, const char *sub)
 {
 	int slen = strlen(s);
@@ -333,6 +358,7 @@ static void parse_dep_file(void *map, size_t len)
 
 			/* Ignore certain dependencies */
 			if (strrcmp(s, "include/generated/autoconf.h") &&
+			    strrcmp(s, "include/generated/autoksyms.h") &&
 			    strrcmp(s, "arch/um/include/uml-config.h") &&
 			    strrcmp(s, "include/linux/kconfig.h") &&
 			    strrcmp(s, ".ver")) {
@@ -378,6 +404,8 @@ static void parse_dep_file(void *map, size_t len)
 		exit(1);
 	}
 
+	do_extra_deps();
+
 	printf("\n%s: $(deps_%s)\n\n", target, target);
 	printf("$(deps_%s):\n", target);
 }
@@ -434,7 +462,10 @@ int main(int argc, char *argv[])
 {
 	traps();
 
-	if (argc != 4)
+	if (argc == 5 && !strcmp(argv[1], "-e")) {
+		insert_extra_deps = 1;
+		argv++;
+	} else if (argc != 4)
 		usage();
 
 	depfile = argv[1];
diff --git a/scripts/genksyms/genksyms.c b/scripts/genksyms/genksyms.c
index dafaf96..06121ce 100644
--- a/scripts/genksyms/genksyms.c
+++ b/scripts/genksyms/genksyms.c
@@ -873,5 +873,8 @@ int main(int argc, char **argv)
 			(double)nsyms / (double)HASH_BUCKETS);
 	}
 
+	if (dumpfile)
+		fclose(dumpfile);
+
 	return errors != 0;
 }