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author | Ævar Arnfjörð Bjarmason <avarab@gmail.com> | 2019-02-22 15:41:27 +0100 |
---|---|---|
committer | Junio C Hamano <gitster@pobox.com> | 2019-02-24 07:35:07 -0800 |
commit | 6d5d4b4e9326021f080508126be38ea1beaba6aa (patch) | |
tree | 9587a14921a60e0db3d7fe1d6f96bd4effd8eadd | |
parent | Makefile: move the setting of *FLAGS closer to "include" (diff) | |
download | tgif-6d5d4b4e9326021f080508126be38ea1beaba6aa.tar.xz |
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 <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
-rw-r--r-- | Makefile | 8 | ||||
-rw-r--r-- | config.mak.dev | 44 |
2 files changed, 28 insertions, 24 deletions
@@ -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 |