From: Ævar Arnfjörð Bjarmason Date: Fri, 22 Feb 2019 14:41:27 +0000 (+0100) Subject: Makefile: allow for combining DEVELOPER=1 and CFLAGS="..." X-Git-Tag: v2.22.0-rc0~144^2 X-Git-Url: http://git.ipfire.org/?p=thirdparty%2Fgit.git;a=commitdiff_plain;h=6d5d4b4e9326021f080508126be38ea1beaba6aa Makefile: allow for combining DEVELOPER=1 and CFLAGS="..." Ever since the DEVELOPER=1 facility introduced there's been no way to have custom CFLAGS (e.g. CFLAGS="-O0 -g -ggdb3") while still benefiting from the set of warnings and assertions DEVELOPER=1 enables. This is because the semantics of variables in the Makefile are such that the user setting CFLAGS overrides anything we set, including what we're doing in config.mak.dev[1]. So let's introduce a "DEVELOPER_CFLAGS" variable in config.mak.dev and add it to ALL_CFLAGS. Before this the ALL_CFLAGS variable would (basically, there's some nuance we won't go into) be set to: $(CPPFLAGS) [$(CFLAGS) *or* $(CFLAGS) in config.mak.dev] $(BASIC_CFLAGS) $(EXTRA_CPPFLAGS) But will now be: $(DEVELOPER_CFLAGS) $(CPPFLAGS) $(CFLAGS) $(BASIC_CFLAGS) $(EXTRA_CPPFLAGS) The reason for putting DEVELOPER_CFLAGS first is to allow for selectively overriding something DEVELOPER=1 brings in. On both GCC and Clang later settings override earlier ones. E.g. "-Wextra -Wno-extra" will enable no "extra" warnings, but not if those two arguments are reversed. Examples of things that weren't possible before, but are now: # Use -O0 instead of -O2 for less painful debuggng DEVELOPER=1 CFLAGS="-O0 -g" # DEVELOPER=1 plus -Wextra, but disable some of the warnings DEVELOPER=1 DEVOPTS="no-error extra-all" CFLAGS="-O0 -g -Wno-unused-parameter" The reason for the patches leading up to this one re-arranged the various *FLAGS assignments and includes is just for readability. The Makefile supports assignments out of order, e.g.: $ cat Makefile X = $(A) $(B) $(C) A = A B = B include c.mak all: @echo $(X) $ cat c.mak C=C $ make A B C So we could have gotten away with the much smaller change of changing "CFLAGS" in config.mak.dev to "DEVELOPER_CFLAGS" and adding that to ALL_CFLAGS earlier in the Makefile "before" the config.mak.* includes. But I think it's more readable to use variables "after" they're included. 1. https://www.gnu.org/software/make/manual/html_node/Overriding.html Signed-off-by: Ævar Arnfjörð Bjarmason Signed-off-by: Junio C Hamano --- diff --git a/Makefile b/Makefile index 82cfd6c2e4..710a3475a9 100644 --- a/Makefile +++ b/Makefile @@ -479,7 +479,11 @@ all:: # # Define DEVELOPER to enable more compiler warnings. Compiler version # and family are auto detected, but could be overridden by defining -# COMPILER_FEATURES (see config.mak.dev) +# COMPILER_FEATURES (see config.mak.dev). You can still set +# CFLAGS="..." in combination with DEVELOPER enables, whether that's +# for tweaking something unrelated (e.g. optimization level), or for +# selectively overriding something DEVELOPER or one of the DEVOPTS +# (see just below) brings in. # # When DEVELOPER is set, DEVOPTS can be used to control compiler # options. This variable contains keywords separated by @@ -1169,7 +1173,7 @@ ifdef DEVELOPER include config.mak.dev endif -ALL_CFLAGS = $(CPPFLAGS) $(CFLAGS) +ALL_CFLAGS = $(DEVELOPER_CFLAGS) $(CPPFLAGS) $(CFLAGS) ALL_LDFLAGS = $(LDFLAGS) comma := , diff --git a/config.mak.dev b/config.mak.dev index 7354fe15b3..bf1f3fcdee 100644 --- a/config.mak.dev +++ b/config.mak.dev @@ -1,41 +1,41 @@ ifeq ($(filter no-error,$(DEVOPTS)),) -CFLAGS += -Werror +DEVELOPER_CFLAGS += -Werror endif ifneq ($(filter pedantic,$(DEVOPTS)),) -CFLAGS += -pedantic +DEVELOPER_CFLAGS += -pedantic # don't warn for each N_ use -CFLAGS += -DUSE_PARENS_AROUND_GETTEXT_N=0 -endif -CFLAGS += -Wall -CFLAGS += -Wdeclaration-after-statement -CFLAGS += -Wformat-security -CFLAGS += -Wno-format-zero-length -CFLAGS += -Wold-style-definition -CFLAGS += -Woverflow -CFLAGS += -Wpointer-arith -CFLAGS += -Wstrict-prototypes -CFLAGS += -Wunused -CFLAGS += -Wvla +DEVELOPER_CFLAGS += -DUSE_PARENS_AROUND_GETTEXT_N=0 +endif +DEVELOPER_CFLAGS += -Wall +DEVELOPER_CFLAGS += -Wdeclaration-after-statement +DEVELOPER_CFLAGS += -Wformat-security +DEVELOPER_CFLAGS += -Wno-format-zero-length +DEVELOPER_CFLAGS += -Wold-style-definition +DEVELOPER_CFLAGS += -Woverflow +DEVELOPER_CFLAGS += -Wpointer-arith +DEVELOPER_CFLAGS += -Wstrict-prototypes +DEVELOPER_CFLAGS += -Wunused +DEVELOPER_CFLAGS += -Wvla ifndef COMPILER_FEATURES COMPILER_FEATURES := $(shell ./detect-compiler $(CC)) endif ifneq ($(filter clang4,$(COMPILER_FEATURES)),) -CFLAGS += -Wtautological-constant-out-of-range-compare +DEVELOPER_CFLAGS += -Wtautological-constant-out-of-range-compare endif ifneq ($(or $(filter gcc6,$(COMPILER_FEATURES)),$(filter clang4,$(COMPILER_FEATURES))),) -CFLAGS += -Wextra +DEVELOPER_CFLAGS += -Wextra # if a function is public, there should be a prototype and the right # header file should be included. If not, it should be static. -CFLAGS += -Wmissing-prototypes +DEVELOPER_CFLAGS += -Wmissing-prototypes ifeq ($(filter extra-all,$(DEVOPTS)),) # These are disabled because we have these all over the place. -CFLAGS += -Wno-empty-body -CFLAGS += -Wno-missing-field-initializers -CFLAGS += -Wno-sign-compare -CFLAGS += -Wno-unused-parameter +DEVELOPER_CFLAGS += -Wno-empty-body +DEVELOPER_CFLAGS += -Wno-missing-field-initializers +DEVELOPER_CFLAGS += -Wno-sign-compare +DEVELOPER_CFLAGS += -Wno-unused-parameter endif endif @@ -43,6 +43,6 @@ endif # not worth fixing since newer compilers correctly stop complaining ifneq ($(filter gcc4,$(COMPILER_FEATURES)),) ifeq ($(filter gcc5,$(COMPILER_FEATURES)),) -CFLAGS += -Wno-uninitialized +DEVELOPER_CFLAGS += -Wno-uninitialized endif endif