From b13e17fcbed1b20ce0ff072af718fad4f2b7e6f0 Mon Sep 17 00:00:00 2001 From: Matt Whitlock Date: Thu, 31 Aug 2023 00:32:26 -0400 Subject: [PATCH] configure.ac: support --with-system-secp256k1 (Modified from the original submission). Libwally-core, in its stock configuration, compiles and statically links against a private copy of libsecp256k1_zkp. However, Gentoo unbundles libsecp256k1_zkp and instead links libwally-core against a system-wide shared libsecp256k1_zkp with headers in /usr/include/secp256k1_zkp and a libsecp256k1_zkp.pc that specifies the relevant CFLAGS and LIBS. Implement a --with-system-secp256k1 configure option to allow compiling and linking against a system-installed libsecp256k1. Pass the user- specified package name (or 'libsecp256k1' or 'libsecp256k1_zkp' by default, depending on --enable-standard-secp) to PKG_CHECK_MODULES to find the CFLAGS and LIBS of a system-installed libsecp256k1. Call AC_CHECK_FUNCS to assert that the required modules are present in the system-installed libsecp256k1. If the user does not specify --with-system-secp256k1 (or specifies --without-system-secp256k1), the build will use the bundled copy of libsecp256k1_zkp as before. Remove the existing libtool hack: When building as a static library, the user will need to link libsecp256k1.a in addition to libwallycore.a. --- configure.ac | 68 ++++++++++++++++++++++++++++++++----------------- src/Makefile.am | 4 ++- 2 files changed, 48 insertions(+), 24 deletions(-) diff --git a/configure.ac b/configure.ac index 165f1eb49..703f25d5d 100644 --- a/configure.ac +++ b/configure.ac @@ -259,29 +259,49 @@ fi # # libsecp256k1 # -libsecp256k1_CFLAGS='-I$(top_srcdir)/src/secp256k1/include' +AC_ARG_WITH([system-secp256k1], + [AS_HELP_STRING([[--with-system-secp256k1[=PKG]]], + [build using system-installed libsecp256k1 instead of bundled, passing PKG (default: libsecp256k1 or libsecp256k1_zkp, depending on --enable-standard-secp) to pkg-config (default: no)])], + [AS_IF([test "x$withval" = xyes], + [AM_COND_IF([BUILD_STANDARD_SECP], [with_system_secp256k1=libsecp256k1], [with_system_secp256k1=libsecp256k1_zkp])])], + [with_system_secp256k1=no]) + +AM_CONDITIONAL([LINK_SYSTEM_SECP256K1], [test "x$with_system_secp256k1" != xno]) +AM_COND_IF([LINK_SYSTEM_SECP256K1], [ + dnl Use the secp installed system-wide (after checking it for suitability) + saved_LIBS=$LIBS + m4_ifdef([PKG_CHECK_MODULES], + [PKG_CHECK_MODULES([libsecp256k1], [$with_system_secp256k1])], + [AC_MSG_ERROR([You need to install pkg-config to use --with-system-secp256k1.])]) + LIBS="$libsecp256k1_LIBS $LIBS" + missing_modules= + AC_DEFUN([CHECK_MODULE], [ + AC_CHECK_FUNCS([$2], [], [missing_modules="${missing_modules} $1"]) + ]) + CHECK_MODULE([ecdh], [secp256k1_ecdh]) + CHECK_MODULE([extrakeys], [secp256k1_xonly_pubkey_parse]) + CHECK_MODULE([recovery], [secp256k1_ecdsa_recover]) + CHECK_MODULE([schnorrsig], [secp256k1_schnorrsig_verify]) + AM_COND_IF([BUILD_STANDARD_SECP], [], [ + CHECK_MODULE([ecdsa-s2c], [secp256k1_ecdsa_s2c_sign]) + ]) + AM_COND_IF([BUILD_ELEMENTS], [ + CHECK_MODULE([generator], [secp256k1_generator_parse]) + CHECK_MODULE([rangeproof], [secp256k1_rangeproof_verify]) + CHECK_MODULE([surjectionproof], [secp256k1_surjectionproof_initialize]) + CHECK_MODULE([whitelist], [secp256k1_whitelist_sign]) + ]) + AS_IF([test -n "${missing_modules}"], [ + AC_MSG_ERROR([system-installed $with_system_secp256k1 does not support these required modules:${missing_modules}]) + ]) + LIBS=$saved_LIBS +], [ + dnl Use the secp in-tree submodule + libsecp256k1_CFLAGS='-I$(top_srcdir)/src/secp256k1/include' + libsecp256k1_LIBS='$(top_srcdir)/src/secp256k1/libsecp256k1.la' +]) AC_SUBST([libsecp256k1_CFLAGS]) - -# FIXME: This is needed to force libtool to use all object files from secp. -# We can only build secp properly by recursively invoking -# configure/make, and can't include it as a noinst_ library. Libtool -# assumes that such libraries will be installed along with our library -# target and so won't force all object files in the library to be -# included in ours - despite the fact that we are making a shared -# library and linking to a static one. This is broken and we work -# around it by hacking the secp objects directly into the library -# via the _LDADD variable for wallycore. -# We previously achieved this by adding the libsecp256k1.a archive, -# but changes to libtool and apples linkers mean that -# archives-within-archives no longer work. -# Because automake tries to police its users very strictly and fails -# hard when flags are passed in this way, we have to substitute the -# flags here. -# Because libtool both intercepts -Wl and arbitrarily re-orders its -# command line inputs, we have to concoct a single expression to -# enforce linking that cannot be split, hence the below expression. -LIBADD_SECP256K1="-Wl,secp256k1/src/libsecp256k1_la-secp256k1.${OBJEXT},secp256k1/src/libsecp256k1_precomputed_la-precomputed_ecmult_gen.${OBJEXT},secp256k1/src/libsecp256k1_precomputed_la-precomputed_ecmult.${OBJEXT}" -AC_SUBST([LIBADD_SECP256K1]) +AC_SUBST([libsecp256k1_LIBS]) # # Python facilities @@ -408,6 +428,8 @@ export AR_FLAGS export LD export LDFLAGS -AX_SUBDIRS_CONFIGURE([src/secp256k1], [[--disable-shared], [--enable-static], [--with-pic], [--enable-experimental], [--enable-module-ecdh], [--enable-module-recovery], [--enable-module-ecdsa-s2c], [--enable-module-rangeproof], [--enable-module-surjectionproof], [--enable-module-whitelist], [--enable-module-generator], [--enable-module-extrakeys], [--enable-module-schnorrsig], [$secp256k1_test_opt], [--enable-exhaustive-tests=no], [--enable-benchmark=no], [--disable-dependency-tracking], [$secp_asm]]) +AM_COND_IF([LINK_SYSTEM_SECP256K1], [], [ + AX_SUBDIRS_CONFIGURE([src/secp256k1], [[--disable-shared], [--enable-static], [--with-pic], [--enable-experimental], [--enable-module-ecdh], [--enable-module-recovery], [--enable-module-ecdsa-s2c], [--enable-module-rangeproof], [--enable-module-surjectionproof], [--enable-module-whitelist], [--enable-module-generator], [--enable-module-extrakeys], [--enable-module-schnorrsig], [$secp256k1_test_opt], [--enable-exhaustive-tests=no], [--enable-benchmark=no], [--disable-dependency-tracking], [$secp_asm]]) +]) AC_OUTPUT diff --git a/src/Makefile.am b/src/Makefile.am index 436cb8ef7..ec1f07049 100644 --- a/src/Makefile.am +++ b/src/Makefile.am @@ -208,9 +208,11 @@ endif endif # SHARED_BUILD_ENABLED libwallycore_la_CFLAGS = -I$(top_srcdir) -I$(srcdir)/ccan $(libsecp256k1_CFLAGS) -DWALLY_CORE_BUILD=1 $(AM_CFLAGS) -libwallycore_la_LIBADD = $(LIBADD_SECP256K1) $(noinst_LTLIBRARIES) +libwallycore_la_LIBADD = $(libsecp256k1_LIBS) $(noinst_LTLIBRARIES) +if !LINK_SYSTEM_SECP256K1 SUBDIRS = secp256k1 +endif TESTS = noinst_PROGRAMS =