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

Pull kbuild updates from Michal Marek:

 - make dtbs_install fix

 - Error handling fix fixdep and link-vmlinux.sh

 - __UNIQUE_ID fix for clang

 - Fix for if_changed_* to suppress the "is up to date." message

 - The kernel is built with -Werror=incompatible-pointer-types

* 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
  kbuild: Add option to turn incompatible pointer check into error
  kbuild: suppress annoying "... is up to date." message
  kbuild: fixdep: Check fstat(2) return value
  scripts/link-vmlinux.sh: force error on kallsyms failure
  Kbuild: provide a __UNIQUE_ID for clang
  dtbsinstall: don't move target directory out of the way

Makefile

@@ -782,6 +782,9 @@ KBUILD_CFLAGS   += $(call cc-option,-Werror=strict-prototypes)
 # Prohibit date/time macros, which would make the build non-deterministic
 KBUILD_CFLAGS   += $(call cc-option,-Werror=date-time)
 
+# enforce correct pointer usage
+KBUILD_CFLAGS   += $(call cc-option,-Werror=incompatible-pointer-types)
+
 # use the deterministic mode of AR if available
 KBUILD_ARFLAGS := $(call ar-option,D)
 

include/linux/compiler-clang.h

@@ -10,3 +10,8 @@
 #undef uninitialized_var
 #define uninitialized_var(x) x = *(&(x))
 #endif
+
+/* same as gcc, this was present in clang-2.6 so we can assume it works
+ * with any version that can compile the kernel
+ */
+#define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __COUNTER__)

scripts/Kbuild.include

@@ -251,7 +251,7 @@ any-prereq = $(filter-out $(PHONY),$?) $(filter-out $(PHONY) $(wildcard $^),$^)
 if_changed = $(if $(strip $(any-prereq) $(arg-check)),                       \
 	@set -e;                                                             \
 	$(echo-cmd) $(cmd_$(1));                                             \
-	printf '%s\n' 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd)
+	printf '%s\n' 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd, @:)
 
 # Execute the command and also postprocess generated .d dependencies file.
 if_changed_dep = $(if $(strip $(any-prereq) $(arg-check) ),                  \
@@ -259,14 +259,14 @@ if_changed_dep = $(if $(strip $(any-prereq) $(arg-check) ),                  \
 	$(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, @:)
 
 # Usage: $(call if_changed_rule,foo)
 # Will check if $(cmd_foo) or any of the prerequisites changed,
 # and if so will execute $(rule_foo).
 if_changed_rule = $(if $(strip $(any-prereq) $(arg-check) ),                 \
 	@set -e;                                                             \
-	$(rule_$(1)))
+	$(rule_$(1)), @:)
 
 ###
 # why - tell why a a target got build

scripts/Makefile.dtbinst

@@ -23,8 +23,6 @@ include $(src)/Makefile
 PHONY += __dtbs_install_prep
 __dtbs_install_prep:
 ifeq ("$(dtbinst-root)", "$(obj)")
-	$(Q)if [ -d $(INSTALL_DTBS_PATH).old ]; then rm -rf $(INSTALL_DTBS_PATH).old; fi
-	$(Q)if [ -d $(INSTALL_DTBS_PATH) ]; then mv $(INSTALL_DTBS_PATH) $(INSTALL_DTBS_PATH).old; fi
 	$(Q)mkdir -p $(INSTALL_DTBS_PATH)
 endif
 

scripts/basic/fixdep.c

@@ -274,7 +274,11 @@ static void do_config_file(const char *filename)
 		perror(filename);
 		exit(2);
 	}
-	fstat(fd, &st);
+	if (fstat(fd, &st) < 0) {
+		fprintf(stderr, "fixdep: error fstat'ing config file: ");
+		perror(filename);
+		exit(2);
+	}
 	if (st.st_size == 0) {
 		close(fd);
 		return;

scripts/link-vmlinux.sh

@@ -97,9 +97,10 @@ kallsyms()
 	local aflags="${KBUILD_AFLAGS} ${KBUILD_AFLAGS_KERNEL}               \
 		      ${NOSTDINC_FLAGS} ${LINUXINCLUDE} ${KBUILD_CPPFLAGS}"
 
-	${NM} -n ${1} | \
-		scripts/kallsyms ${kallsymopt} | \
-		${CC} ${aflags} -c -o ${2} -x assembler-with-cpp -
+	local afile="`basename ${2} .o`.S"
+
+	${NM} -n ${1} | scripts/kallsyms ${kallsymopt} > ${afile}
+	${CC} ${aflags} -c -o ${2} ${afile}
 }
 
 # Create map file with all symbols from ${1}