fs/ntfs3: add a subset of W=1 warnings for stricter checks

Enable a subset of W=1-style compiler warnings for the ntfs3 tree so we
catch small bugs early (unused symbols, missing declarations/prototypes,
possible uninitialized/mis-sized uses, etc).

Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>

Author: aalexandrovich

fs/ntfs3/Makefile

@@ -3,6 +3,26 @@
 # Makefile for the ntfs3 filesystem support.
 #
 
+# Subset of W=1 warnings
+subdir-ccflags-y += -Wextra -Wunused -Wno-unused-parameter
+subdir-ccflags-y += -Wmissing-declarations
+subdir-ccflags-y += -Wmissing-format-attribute
+subdir-ccflags-y += -Wmissing-prototypes
+subdir-ccflags-y += -Wold-style-definition
+subdir-ccflags-y += -Wmissing-include-dirs
+condflags := \
+	$(call cc-option, -Wunused-but-set-variable)		\
+	$(call cc-option, -Wunused-const-variable)		\
+	$(call cc-option, -Wpacked-not-aligned)			\
+	$(call cc-option, -Wstringop-truncation)		\
+	$(call cc-option, -Wmaybe-uninitialized)
+subdir-ccflags-y += $(condflags)
+# The following turn off the warnings enabled by -Wextra
+subdir-ccflags-y += -Wno-missing-field-initializers
+subdir-ccflags-y += -Wno-sign-compare
+subdir-ccflags-y += -Wno-type-limits
+subdir-ccflags-y += -Wno-shift-negative-value
+
 # to check robot warnings
 ccflags-y += -Wint-to-pointer-cast \
 	$(call cc-option,-Wunused-but-set-variable,-Wunused-const-variable) \