| 1 | # SPDX-License-Identifier: GPL-2.0 |
| 2 | # ========================================================================== |
| 3 | # make W=... settings |
| 4 | # |
| 5 | # There are three warning groups enabled by W=1, W=2, W=3. |
| 6 | # They are independent, and can be combined like W=12 or W=123. |
| 7 | # ========================================================================== |
| 8 | |
| 9 | KBUILD_CFLAGS += $(call cc-disable-warning, packed-not-aligned) |
| 10 | |
| 11 | # backward compatibility |
| 12 | KBUILD_EXTRA_WARN ?= $(KBUILD_ENABLE_EXTRA_GCC_CHECKS) |
| 13 | |
| 14 | ifeq ("$(origin W)", "command line") |
| 15 | KBUILD_EXTRA_WARN := $(W) |
| 16 | endif |
| 17 | |
| 18 | export KBUILD_EXTRA_WARN |
| 19 | |
| 20 | # |
| 21 | # W=1 - warnings which may be relevant and do not occur too often |
| 22 | # |
| 23 | ifneq ($(findstring 1, $(KBUILD_EXTRA_WARN)),) |
| 24 | |
| 25 | KBUILD_CFLAGS += -Wextra -Wunused -Wno-unused-parameter |
| 26 | KBUILD_CFLAGS += -Wmissing-declarations |
| 27 | KBUILD_CFLAGS += -Wmissing-format-attribute |
| 28 | KBUILD_CFLAGS += -Wmissing-prototypes |
| 29 | KBUILD_CFLAGS += -Wold-style-definition |
| 30 | KBUILD_CFLAGS += -Wmissing-include-dirs |
| 31 | KBUILD_CFLAGS += $(call cc-option, -Wunused-but-set-variable) |
| 32 | KBUILD_CFLAGS += $(call cc-option, -Wunused-const-variable) |
| 33 | KBUILD_CFLAGS += $(call cc-option, -Wpacked-not-aligned) |
| 34 | KBUILD_CFLAGS += $(call cc-option, -Wstringop-truncation) |
| 35 | # The following turn off the warnings enabled by -Wextra |
| 36 | KBUILD_CFLAGS += -Wno-missing-field-initializers |
| 37 | KBUILD_CFLAGS += -Wno-sign-compare |
| 38 | |
| 39 | KBUILD_CPPFLAGS += -DKBUILD_EXTRA_WARN1 |
| 40 | |
| 41 | else |
| 42 | |
| 43 | # Some diagnostics enabled by default are noisy. |
| 44 | # Suppress them by using -Wno... except for W=1. |
| 45 | |
| 46 | ifdef CONFIG_CC_IS_CLANG |
| 47 | KBUILD_CFLAGS += -Wno-initializer-overrides |
| 48 | KBUILD_CFLAGS += -Wno-format |
| 49 | KBUILD_CFLAGS += -Wno-sign-compare |
| 50 | KBUILD_CFLAGS += -Wno-format-zero-length |
| 51 | endif |
| 52 | |
| 53 | endif |
| 54 | |
| 55 | # |
| 56 | # W=2 - warnings which occur quite often but may still be relevant |
| 57 | # |
| 58 | ifneq ($(findstring 2, $(KBUILD_EXTRA_WARN)),) |
| 59 | |
| 60 | KBUILD_CFLAGS += -Wcast-align |
| 61 | KBUILD_CFLAGS += -Wdisabled-optimization |
| 62 | KBUILD_CFLAGS += -Wnested-externs |
| 63 | KBUILD_CFLAGS += -Wshadow |
| 64 | KBUILD_CFLAGS += $(call cc-option, -Wlogical-op) |
| 65 | KBUILD_CFLAGS += -Wmissing-field-initializers |
| 66 | KBUILD_CFLAGS += -Wsign-compare |
| 67 | KBUILD_CFLAGS += $(call cc-option, -Wmaybe-uninitialized) |
| 68 | KBUILD_CFLAGS += $(call cc-option, -Wunused-macros) |
| 69 | |
| 70 | KBUILD_CPPFLAGS += -DKBUILD_EXTRA_WARN2 |
| 71 | |
| 72 | endif |
| 73 | |
| 74 | # |
| 75 | # W=3 - more obscure warnings, can most likely be ignored |
| 76 | # |
| 77 | ifneq ($(findstring 3, $(KBUILD_EXTRA_WARN)),) |
| 78 | |
| 79 | KBUILD_CFLAGS += -Wbad-function-cast |
| 80 | KBUILD_CFLAGS += -Wcast-qual |
| 81 | KBUILD_CFLAGS += -Wconversion |
| 82 | KBUILD_CFLAGS += -Wpacked |
| 83 | KBUILD_CFLAGS += -Wpadded |
| 84 | KBUILD_CFLAGS += -Wpointer-arith |
| 85 | KBUILD_CFLAGS += -Wredundant-decls |
| 86 | KBUILD_CFLAGS += -Wswitch-default |
| 87 | KBUILD_CFLAGS += $(call cc-option, -Wpacked-bitfield-compat) |
| 88 | |
| 89 | KBUILD_CPPFLAGS += -DKBUILD_EXTRA_WARN3 |
| 90 | |
| 91 | endif |