[bug#74686] [PATCH] daemon: Fix linking gcrypt when --as-needed linker arg is used

[bug#74686] [PATCH] daemon: Fix linking gcrypt when --as-needed linker arg is used

[Doğan Çeçen]

As it is mentioned in autoconf manual that library names should be
specified in LIBS, not LDFLAGS. See:

https://www.gnu.org/savannah-checkouts/gnu/autoconf/manual/autoconf-2.72/html_node/Preset-Output-Variables.html#index-LDFLAGS-2

This change also brings back the save_* vars trick that was there
before. I missed in my earlier change that nix/local.mk was referring
LIBGCRYPT_* vars directly.

And, instead of CXXFLAGS, CPPFLAGS is used since the latter is probably
more correct as this is used for include dirs, therefore using
preprocessor flags.

Tested with ./configure LDFLAGS="-Wl,--as-needed" --with-libgcrypt-prefix=... combinations.

Change-Id: Iadb10e1994c9a78e2927847af2cfe5e096fbb2a8
---
 config-daemon.ac | 20 ++++++++++++++------
 nix/local.mk     |  8 ++++++--
 2 files changed, 20 insertions(+), 8 deletions(-)

diff --git a/config-daemon.ac b/config-daemon.ac
index 1ac204ceed1..6731c68bc39 100644
--- a/config-daemon.ac
+++ b/config-daemon.ac
@@ -39,27 +39,32 @@ if test "x$guix_build_daemon" = "xyes"; then
 
   case "$LIBGCRYPT_PREFIX" in
     no)
-      LIBGCRYPT_CXXFLAGS=""
+      LIBGCRYPT_CPPFLAGS=""
       ;;
     *)
-      LIBGCRYPT_CXXFLAGS="-I$LIBGCRYPT_PREFIX/include"
+      LIBGCRYPT_CPPFLAGS="-I$LIBGCRYPT_PREFIX/include"
       ;;
   esac
 
   case "$LIBGCRYPT_LIBDIR" in
     no | "")
-      LIBGCRYPT_LDFLAGS="-lgcrypt"
       ;;
     *)
-      LIBGCRYPT_LDFLAGS="-L$LIBGCRYPT_LIBDIR -lgcrypt"
+      LIBGCRYPT_LDFLAGS="-L$LIBGCRYPT_LIBDIR"
       ;;
   esac
 
-  AC_SUBST([LIBGCRYPT_CXXFLAGS])
+  LIBGCRYPT_LIBS="-lgcrypt"
+  AC_SUBST([LIBGCRYPT_CPPFLAGS])
   AC_SUBST([LIBGCRYPT_LDFLAGS])
+  AC_SUBST([LIBGCRYPT_LIBS])
 
-  CXXFLAGS="$CXXFLAGS $LIBGCRYPT_CXXFLAGS"
+  save_CPPFLAGS="$CPPFLAGS"
+  save_LDFLAGS="$LDFLAGS"
+  save_LIBS="$LIBS"
+  CPPFLAGS="$CPPFLAGS $LIBGCRYPT_CPPFLAGS"
   LDFLAGS="$LDFLAGS $LIBGCRYPT_LDFLAGS"
+  LIBS="$LIBS $LIBGCRYPT_LIBS"
 
   have_gcrypt=yes
   AC_CHECK_LIB([gcrypt], [gcry_md_open], [:], [have_gcrypt=no])
@@ -67,6 +72,9 @@ if test "x$guix_build_daemon" = "xyes"; then
   if test "x$have_gcrypt" != "xyes"; then
     AC_MSG_ERROR([GNU libgcrypt not found; please install it.])
   fi
+  CPPFLAGS="$save_CPPFLAGS"
+  LDFLAGS="$save_LDFLAGS"
+  LIBS="$save_LIBS"
 
   dnl Chroot support.
   AC_CHECK_FUNCS([chroot unshare])
diff --git a/nix/local.mk b/nix/local.mk
index 8a2b2b88e86..0d23a48a024 100644
--- a/nix/local.mk
+++ b/nix/local.mk
@@ -69,7 +69,8 @@ libutil_headers =				\
 libutil_a_CPPFLAGS =				\
   -I$(top_builddir)/nix				\
   -I$(top_srcdir)/%D%/libutil			\
-  $(libformat_a_CPPFLAGS)
+  $(libformat_a_CPPFLAGS)			\
+  $(LIBGCRYPT_CPPFLAGS)
 
 libstore_a_SOURCES =				\
   %D%/libstore/gc.cc				\
@@ -109,7 +110,7 @@ libstore_a_CPPFLAGS =				\
   -DDEFAULT_CHROOT_DIRS="\"\""
 
 libstore_a_CXXFLAGS = $(AM_CXXFLAGS)		\
-  $(SQLITE3_CFLAGS) $(LIBGCRYPT_CFLAGS)
+  $(SQLITE3_CFLAGS)
 
 bin_PROGRAMS = guix-daemon
 
@@ -122,6 +123,9 @@ guix_daemon_CPPFLAGS =				\
   $(libutil_a_CPPFLAGS)				\
   -I$(top_srcdir)/%D%/libstore
 
+guix_daemon_LDFLAGS = 				\
+  $(LIBGCRYPT_LDFLAGS)
+
 guix_daemon_LDADD =				\
   libstore.a libutil.a libformat.a -lz		\
   $(SQLITE3_LIBS) $(LIBGCRYPT_LIBS)

base-commit: 1c4a00820a1ba6265d2d96f4f7804d0807d69dcc
-- 
2.46.0

bug#74686: [PATCH] daemon: Fix linking gcrypt when --as-needed linker arg is used

[Ludovic Courtès]

Hi,

Doğan Çeçen <sepeth@fastmail.com> skribis:

> As it is mentioned in autoconf manual that library names should be
> specified in LIBS, not LDFLAGS. See:
>
> https://www.gnu.org/savannah-checkouts/gnu/autoconf/manual/autoconf-2.72/html_node/Preset-Output-Variables.html#index-LDFLAGS-2
>
> This change also brings back the save_* vars trick that was there
> before. I missed in my earlier change that nix/local.mk was referring
> LIBGCRYPT_* vars directly.
>
> And, instead of CXXFLAGS, CPPFLAGS is used since the latter is probably
> more correct as this is used for include dirs, therefore using
> preprocessor flags.
>
> Tested with ./configure LDFLAGS="-Wl,--as-needed" --with-libgcrypt-prefix=... combinations.
>
> Change-Id: Iadb10e1994c9a78e2927847af2cfe5e096fbb2a8

Applied with a ChangeLog-style commit log, thanks.

(I was surprised by some of the changes in the first patch; thanks for
following up!)

Ludo’.