From: Junio C Hamano <gitster@pobox.com>
To: "Kyohei Kadota via GitGitGadget" <gitgitgadget@gmail.com>
Cc: git@vger.kernel.org, Eric Sunshine <sunshine@sunshineco.com>,
"KADOTA\, Kyohei" <lufia@lufia.org>
Subject: Re: [PATCH v3 2/2] Use $(LD) instead of $(CC) for linking the object files
Date: Wed, 09 Sep 2020 22:31:01 -0700 [thread overview]
Message-ID: <xmqq4ko6ryei.fsf@gitster.c.googlers.com> (raw)
In-Reply-To: <7d33e11867e0a75efb1a906610ff81da2ace9717.1599704262.git.gitgitgadget@gmail.com> (Kyohei Kadota via GitGitGadget's message of "Thu, 10 Sep 2020 02:17:42 +0000")
"Kyohei Kadota via GitGitGadget" <gitgitgadget@gmail.com> writes:
> diff --git a/Makefile b/Makefile
> index 86e5411f39..c0c0c280f0 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -543,6 +543,7 @@ export prefix bindir sharedir sysconfdir gitwebdir perllibdir localedir
>
> # Set our default programs
> CC = cc
> +LD = cc
This is good that any system that use 'cc' to link now will reach
the same 'cc' via $(LD) instead of $(CC).
But those who customize $(CC) to their taste now needs to override
not just CC but also LD. Can we avoid regressing for them? Perhaps
default the value of LD to $(CC) instead of hardcoded 'cc'?
> @@ -2121,7 +2122,7 @@ git.sp git.s git.o: EXTRA_CPPFLAGS = \
> '-DGIT_INFO_PATH="$(infodir_relative_SQ)"'
>
> git$X: git.o GIT-LDFLAGS $(BUILTIN_OBJS) $(GITLIBS)
> - $(QUIET_LINK)$(CC) $(ALL_CFLAGS) -o $@ $(ALL_LDFLAGS) \
> + $(QUIET_LINK)$(LD) -o $@ $(ALL_LDFLAGS) \
> $(filter %.o,$^) $(LIBS)
Are there those who depended on ALL_CFLAGS on the command line when
the final linking happens?
For example, people have '-g -O2' on CFLAGS, and that will be
included in ALL_CFLAGS and passed to the final linking phase. GNU
ld has "-O" option to optimize; when existing systems link with "cc
-g -O2 -o $@ ...", it is likely that "-O2" given to "cc" will cause
the "-O" option to be passed to underlying "ld".
But with the updated procedure (where LD is 'cc' for them), the
linkage will be done without ALL_CFLAGS passed on the command line,
and results in "cc -o $@ ...", without "-g -O2".
That sounds like a regression.
> @@ -2445,17 +2446,17 @@ compat/nedmalloc/nedmalloc.sp: SP_EXTRA_FLAGS += -Wno-non-pointer-null
> endif
>
> git-%$X: %.o GIT-LDFLAGS $(GITLIBS)
> - $(QUIET_LINK)$(CC) $(ALL_CFLAGS) -o $@ $(ALL_LDFLAGS) $(filter %.o,$^) $(LIBS)
> + $(QUIET_LINK)$(LD) -o $@ $(ALL_LDFLAGS) $(filter %.o,$^) $(LIBS)
>
> git-imap-send$X: imap-send.o $(IMAP_SEND_BUILDDEPS) GIT-LDFLAGS $(GITLIBS)
> - $(QUIET_LINK)$(CC) $(ALL_CFLAGS) -o $@ $(ALL_LDFLAGS) $(filter %.o,$^) \
> + $(QUIET_LINK)$(LD) -o $@ $(ALL_LDFLAGS) $(filter %.o,$^) \
> $(IMAP_SEND_LDFLAGS) $(LIBS)
>
> git-http-fetch$X: http.o http-walker.o http-fetch.o GIT-LDFLAGS $(GITLIBS)
> - $(QUIET_LINK)$(CC) $(ALL_CFLAGS) -o $@ $(ALL_LDFLAGS) $(filter %.o,$^) \
> + $(QUIET_LINK)$(LD) -o $@ $(ALL_LDFLAGS) $(filter %.o,$^) \
> $(CURL_LIBCURL) $(LIBS)
> git-http-push$X: http.o http-push.o GIT-LDFLAGS $(GITLIBS)
> - $(QUIET_LINK)$(CC) $(ALL_CFLAGS) -o $@ $(ALL_LDFLAGS) $(filter %.o,$^) \
> + $(QUIET_LINK)$(LD) -o $@ $(ALL_LDFLAGS) $(filter %.o,$^) \
> $(CURL_LIBCURL) $(EXPAT_LIBEXPAT) $(LIBS)
>
> $(REMOTE_CURL_ALIASES): $(REMOTE_CURL_PRIMARY)
> @@ -2465,7 +2466,7 @@ $(REMOTE_CURL_ALIASES): $(REMOTE_CURL_PRIMARY)
> cp $< $@
>
> $(REMOTE_CURL_PRIMARY): remote-curl.o http.o http-walker.o GIT-LDFLAGS $(GITLIBS)
> - $(QUIET_LINK)$(CC) $(ALL_CFLAGS) -o $@ $(ALL_LDFLAGS) $(filter %.o,$^) \
> + $(QUIET_LINK)$(LD) -o $@ $(ALL_LDFLAGS) $(filter %.o,$^) \
> $(CURL_LIBCURL) $(EXPAT_LIBEXPAT) $(LIBS)
>
> @@ -2753,7 +2754,7 @@ perf: all
> t/helper/test-tool$X: $(patsubst %,t/helper/%,$(TEST_BUILTINS_OBJS))
>
> t/helper/test-%$X: t/helper/test-%.o GIT-LDFLAGS $(GITLIBS)
> - $(QUIET_LINK)$(CC) $(ALL_CFLAGS) -o $@ $(ALL_LDFLAGS) $(filter %.o,$^) $(filter %.a,$^) $(LIBS)
> + $(QUIET_LINK)$(LD) -o $@ $(ALL_LDFLAGS) $(filter %.o,$^) $(filter %.a,$^) $(LIBS)
Likewise for all of the above.
> diff --git a/ci/lib.sh b/ci/lib.sh
> index 3eefec500d..19c5beb277 100755
> --- a/ci/lib.sh
> +++ b/ci/lib.sh
> @@ -125,6 +125,7 @@ then
All changes to this file to pass LD=cc everywhere CC=cc is passed
look good to me.
> diff --git a/config.mak.in b/config.mak.in
> index e6a6d0f941..76ea7e781e 100644
> --- a/config.mak.in
> +++ b/config.mak.in
> @@ -2,6 +2,7 @@
> # @configure_input@
>
> CC = @CC@
> +LD = @CC@
> CFLAGS = @CFLAGS@
> CPPFLAGS = @CPPFLAGS@
> LDFLAGS = @LDFLAGS@
OK.
> diff --git a/config.mak.uname b/config.mak.uname
> index c7eba69e54..886ce068f8 100644
> --- a/config.mak.uname
> +++ b/config.mak.uname
> @@ -69,6 +69,7 @@ ifeq ($(uname_S),GNU/kFreeBSD)
> endif
> ifeq ($(uname_S),UnixWare)
> CC = cc
> + LD = $(CC)
> NEEDS_SOCKET = YesPlease
> NEEDS_NSL = YesPlease
> NEEDS_SSL_WITH_CRYPTO = YesPlease
> @@ -90,6 +91,7 @@ ifeq ($(uname_S),SCO_SV)
> endif
> ifeq ($(uname_R),5)
> CC = cc
> + LD = $(CC)
> BASIC_CFLAGS += -Kthread
> endif
> NEEDS_SOCKET = YesPlease
> @@ -435,6 +437,7 @@ ifeq ($(uname_S),Windows)
> DEFAULT_HELP_FORMAT = html
>
> CC = compat/vcbuild/scripts/clink.pl
> + LD = $(CC)
> AR = compat/vcbuild/scripts/lib.pl
> CFLAGS =
> BASIC_CFLAGS = -nologo -I. -Icompat/vcbuild/include -DWIN32 -D_CONSOLE -DHAVE_STRING_H -D_CRT_SECURE_NO_WARNINGS -D_CRT_NONSTDC_NO_DEPRECATE
> @@ -525,6 +528,7 @@ ifeq ($(uname_S),NONSTOP_KERNEL)
> ifeq ($(uname_R).$(uname_V),L17.02)
> CC += -WRVU=L16.05
> endif
> + LD = $(CC)
> # Disable all optimization, seems to result in bad code, with -O or -O2
> # or even -O1 (default), /usr/local/libexec/git-core/git-pack-objects
> # abends on "git push". Needs more investigation.
Ditto.
> @@ -665,8 +669,10 @@ else
> BASIC_LDFLAGS += -Wl,--large-address-aware
> endif
> CC = gcc
> + LD = $(CC)
> COMPAT_CFLAGS += -D__USE_MINGW_ANSI_STDIO=0 -DDETECT_MSYS_TTY \
> -fstack-protector-strong
> + BASIC_LDFLAGS += -fstack-protector-strong
> EXTLIBS += -lntdll
> INSTALL = /bin/install
> NO_R_TO_GCC_LINKER = YesPlease
This is an example of the problem we discussed earlier for not
passing ALL_CFLAGS to the linking phase. I am not sure what the
best solution is, though.
Thanks.
prev parent reply other threads:[~2020-09-10 5:31 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-06 1:05 [PATCH 0/4] Fit the building tools to Plan 9 environment KADOTA, Kyohei via GitGitGadget
2020-08-06 1:05 ` [PATCH 1/4] Use $(SHELL_PATH) instead of sh in Makefile lufia via GitGitGadget
2020-08-06 2:13 ` brian m. carlson
2020-08-06 4:10 ` Eric Sunshine
2020-08-06 14:39 ` Kyohei Kadota
2020-08-06 17:30 ` Junio C Hamano
2020-08-10 9:04 ` Kyohei Kadota
2020-08-06 1:05 ` [PATCH 2/4] Define TAR_CF and TAR_XF variables " lufia via GitGitGadget
2020-08-06 17:50 ` Junio C Hamano
2020-08-06 1:05 ` [PATCH 3/4] Fit to Plan 9's ANSI/POSIX compatibility layer lufia via GitGitGadget
2020-08-06 2:04 ` brian m. carlson
2020-08-06 13:49 ` Kyohei Kadota
2020-08-06 23:51 ` brian m. carlson
2020-08-06 23:57 ` Eric Sunshine
2020-08-06 18:10 ` Junio C Hamano
2020-08-10 10:53 ` Kyohei Kadota
2020-08-06 1:05 ` [PATCH 4/4] Use $(LD) instead of $(CC) for linking the object files lufia via GitGitGadget
2020-08-06 2:23 ` [PATCH 0/4] Fit the building tools to Plan 9 environment brian m. carlson
2020-09-09 19:47 ` [PATCH v2 0/2] " KADOTA, Kyohei via GitGitGadget
2020-09-09 19:47 ` [PATCH v2 1/2] Fit to Plan 9's ANSI/POSIX compatibility layer Kyohei Kadota via GitGitGadget
2020-09-09 19:56 ` Eric Sunshine
2020-09-09 20:34 ` Junio C Hamano
2020-09-10 0:35 ` Kyohei Kadota
2020-09-09 19:47 ` [PATCH v2 2/2] Use $(LD) instead of $(CC) for linking the object files Kyohei Kadota via GitGitGadget
2020-09-10 2:17 ` [PATCH v3 0/2] Fit the building tools to Plan 9 environment KADOTA, Kyohei via GitGitGadget
2020-09-10 2:17 ` [PATCH v3 1/2] Fit to Plan 9's ANSI/POSIX compatibility layer Kyohei Kadota via GitGitGadget
2020-09-10 5:13 ` Junio C Hamano
2020-09-10 2:17 ` [PATCH v3 2/2] Use $(LD) instead of $(CC) for linking the object files Kyohei Kadota via GitGitGadget
2020-09-10 5:31 ` Junio C Hamano [this message]
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