Re: [PATCH] Fix build with LDFLAGS="-Wl,--as-needed"
From: Junio C Hamano <hidden>
Date: 2016-06-15 23:03:09
Lars Wendler [off-list ref] writes:
Subject: Re: [PATCH] Fix build with LDFLAGS="-Wl,--as-needed"
Please identify what area you are touching, e.g.
Subject: contrib/svn-fe: avoid early $(EXTLIBS) on linker invocation
or whatever.
"Fix build" does not tell us why this change is needed; it does not
say what breaks, how and most importantly why it breaks. Please
have explanation in the commit message body, e.g.
When attempting to build svn-fe with LDFLAGS=-Wl,--as-needed,
I noticed that ... breaks in such and such way. This is
because you must not have X before Y due to Z.
Fix this by doing A, B and C, which makes sure X comes after
Y.
or somesuch.
Signed-off-by: Lars Wendler <redacted> ---
quoted hunk
contrib/svn-fe/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)diff --git a/contrib/svn-fe/Makefile b/contrib/svn-fe/Makefile index e8651aa..b90cf87 100644 --- a/contrib/svn-fe/Makefile +++ b/contrib/svn-fe/Makefile@@ -74,7 +74,7 @@ endif endif svn-fe$X: svn-fe.o $(VCSSVN_LIB) $(XDIFF_LIB) $(GIT_LIB) - $(QUIET_LINK)$(CC) $(CFLAGS) $(LDFLAGS) $(EXTLIBS) -o $@ svn-fe.o $(LIBS) + $(QUIET_LINK)$(CC) $(CFLAGS) $(LDFLAGS) -o $@ svn-fe.o $(LIBS) $(EXTLIBS)
I do not understand the original, which has EXTLIBS = GIT_LIB = ../../libgit.a VCSSVN_LIB = ../../vcs-svn/lib.a LIBS = $(VCSSVN_LIB) $(GIT_LIB) $(EXTLIBS) i.e. it shouldn't be necessary to explicitly list EXTLIBS, as it already has LIBS at the end, which in turn has EXTLIBS at the end. Which in turn means I do not understand your updated version, either. If having EXTLIBS before svn-fe.o is bad (and it is---a linker invocation lists *.o files that need to be linked first, and then libraries to find the symbols requested by those *.o files), wouldn't a fix be to just drop $(EXTLIBS)? Why is it necessary to list it twice?