From: Giulio Benetti Date: Mon, 15 Oct 2018 21:59:55 +0000 (+0200) Subject: netsnmp: improve linking avoiding useless -lz listing in shared build X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=c5a7c287de4a3108d8aaf965731ef7978a903875;p=buildroot.git netsnmp: improve linking avoiding useless -lz listing in shared build In commit: https://git.buildroot.net/buildroot/commit/?id=13722d58f77d0e9fea9eefc50bf083d19f835433 Patch "0003-configure-Invert-AC_CHECK_LIB-EVP_md5-.-without-lz-w.patch" was intended to fix AC_CHECK_FUNCS() failure on openssl functions. This was due to missing -lz during static linking. But the patch is wrong and results in explicitly linking against -lz in both shared and static build. This makes no sense, since shared linking has transitive dependency so it doesn't need to list -lz after -lssl, -lssl is enough. Differently static linking needs -lz to be listed after -lssl. So the real cause of previous build failure: http://autobuild.buildroot.net/results/881/881139fb049738b16609d39ad5a49bd77ff6b4aa/ is that when AC_CHECK_FUNCS(), $LIBS variable is overwritten with $LIBCRYPTO without taking into accout previous $LIBS content(i.e. where -lz is present). This results in AC_CHEC_FUNCS() to fail while trying to statically link without listing -lz. Then: - Remove current "0003-configure-Invert-AC_CHECK_LIB-EVP_md5-.-without-lz-w.patch" - Add patch "0003-configure-fix-AC_CHECK_FUNCS-EVP_sha224-EVP_sha384-..patch" where add $LIBS content to tail of new $LIBS variable like this: LIBS="$LIBCRYPTO $LIBS" NOTE: $LIBS is at the end to ensure static linking to work correctly. - Add patch 0004-configure-fix-AC_CHECK_FUNCS-TLS_method-TLSv1_method.patch where add $LIBS content to tail of new $LIBS variable like this: LIBS="-lssl $LIBCRYPTO $LIBS" NOTE: $LIBS is at the end to ensure static linking to work correctly. This way AC_CHECK_FUNCS(), when static linking, try to link with -lz too appending it at the end of linking library list. And after every AC_CHECK_FUNCS(), previously saved $LIBS variable gets back to its original value(i.e. containing -lz if present) resulting in having or not -lz appended to library list according to static or shared build. Signed-off-by: Giulio Benetti Signed-off-by: Peter Korsgaard --- diff --git a/package/netsnmp/0003-configure-Invert-AC_CHECK_LIB-EVP_md5-.-without-lz-w.patch b/package/netsnmp/0003-configure-Invert-AC_CHECK_LIB-EVP_md5-.-without-lz-w.patch deleted file mode 100644 index 5cbc35600f..0000000000 --- a/package/netsnmp/0003-configure-Invert-AC_CHECK_LIB-EVP_md5-.-without-lz-w.patch +++ /dev/null @@ -1,41 +0,0 @@ -From 77062d4a76f5dbd8aee03a25e9eb514b7d924bcc Mon Sep 17 00:00:00 2001 -From: Giulio Benetti -Date: Mon, 17 Sep 2018 21:44:20 +0200 -Subject: [PATCH 3/3] configure: Invert AC_CHECK_LIB(EVP_md5,..) without -lz - with -lz - -First AC_CHECK_LIB(EVP_md5,...) is going to succeed due to -[other-libraries] fields, but in that case it won't add -lz to LIBCRYPTO -resulting in failing AC_CHECH_FUNCS() with LIBS=LIBCRYPTO. - -Try AC_CHECK_LIB(EVP_md5,..) where LIBS can miss -lz -and in action-if-not-found try AC_CHECK_LIB(EVP_md5,...) without -lz. -In the first case append -lz to LIBCRYPTO, in the second don't. -This is done to check if -lz is present and used in -lcrypto. - -Signed-off-by: Giulio Benetti ---- - configure.d/config_os_libs2 | 5 ++--- - 1 file changed, 2 insertions(+), 3 deletions(-) - -diff --git a/configure.d/config_os_libs2 b/configure.d/config_os_libs2 -index 81788a209..bfd14c191 100644 ---- a/configure.d/config_os_libs2 -+++ b/configure.d/config_os_libs2 -@@ -307,11 +307,10 @@ if test "x$tryopenssl" != "xno" -a "x$tryopenssl" != "xinternal"; then - - if test x$CRYPTO = x; then - AC_CHECK_LIB([crypto], [EVP_md5], -- [CRYPTO="crypto"; LIBCRYPTO="-lcrypto"], [ -+ [CRYPTO="crypto"; LIBCRYPTO="-lcrypto -lz"], [ - unset ac_cv_lib_crypto_EVP_md5 - AC_CHECK_LIB([crypto], [EVP_md5], -- [CRYPTO="crypto"; LIBCRYPTO="-lcrypto -lz"], [], -- [-lz]) -+ [CRYPTO="crypto"; LIBCRYPTO="-lcrypto"], []) - ]) - else - LIBCRYPTO="-l${CRYPTO}" --- -2.17.1 - diff --git a/package/netsnmp/0003-configure-fix-AC_CHECK_FUNCS-EVP_sha224-EVP_sha384-..patch b/package/netsnmp/0003-configure-fix-AC_CHECK_FUNCS-EVP_sha224-EVP_sha384-..patch new file mode 100644 index 0000000000..0829042128 --- /dev/null +++ b/package/netsnmp/0003-configure-fix-AC_CHECK_FUNCS-EVP_sha224-EVP_sha384-..patch @@ -0,0 +1,39 @@ +From 8e273c688aa235ed9c68570a700d31596bac14df Mon Sep 17 00:00:00 2001 +From: Giulio Benetti +Date: Mon, 15 Oct 2018 19:07:05 +0200 +Subject: [PATCH 1/2] configure: fix AC_CHECK_FUNCS(EVP_sha224 EVP_sha384 ...) + failure on static linking + +If building as static lib, AC_CHECK_FUNCS(EVP_sha224 EVP_sha384 ...) +fails due to missing -lz in $LIBS. +At the moment, $LIBS contains $LIBCRYPTO only discarding previous $LIBS +content. + +Add $LIBS to: +LIBS="$LIBCRYPTO" +as: +LIBS="$LIBCRYPTO $LIBS" +This way $LIBS will contain -lz at the end of linking command that in +static linking build is mandatory. + +Signed-off-by: Giulio Benetti +--- + configure.d/config_os_libs2 | 2 +- + 1 file changed, 1 insertion(+), 1 deletion(-) + +diff --git a/configure.d/config_os_libs2 b/configure.d/config_os_libs2 +index 81788a209..93044000b 100644 +--- a/configure.d/config_os_libs2 ++++ b/configure.d/config_os_libs2 +@@ -321,7 +321,7 @@ if test "x$tryopenssl" != "xno" -a "x$tryopenssl" != "xinternal"; then + AC_DEFINE(HAVE_LIBCRYPTO, 1, + [Define to 1 if you have the OpenSSL library (-lcrypto or -leay32).]) + netsnmp_save_LIBS="$LIBS" +- LIBS="$LIBCRYPTO" ++ LIBS="$LIBCRYPTO $LIBS" + AC_CHECK_FUNCS([AES_cfb128_encrypt]dnl + [EVP_sha224 EVP_sha384 ]dnl + [EVP_MD_CTX_create EVP_MD_CTX_destroy]dnl +-- +2.17.1 + diff --git a/package/netsnmp/0004-configure-fix-AC_CHECK_FUNCS-TLS_method-TLSv1_method.patch b/package/netsnmp/0004-configure-fix-AC_CHECK_FUNCS-TLS_method-TLSv1_method.patch new file mode 100644 index 0000000000..a731f25761 --- /dev/null +++ b/package/netsnmp/0004-configure-fix-AC_CHECK_FUNCS-TLS_method-TLSv1_method.patch @@ -0,0 +1,39 @@ +From 1ab6e3fc3cf61fa5a7b7363e59095e868474524b Mon Sep 17 00:00:00 2001 +From: Giulio Benetti +Date: Mon, 15 Oct 2018 19:34:26 +0200 +Subject: [PATCH 2/2] configure: fix AC_CHECK_FUNCS(TLS_method TLSv1_method + ...) failure on static linking + +If building as static lib, AC_CHECK_FUNCS(TLS_method TLSv1_method ...) +fails due to missing -lz in $LIBS. +At the moment, $LIBS contains "-lssl $LIBCRYPTO" only discarding +previous $LIBS content. + +Add $LIBS to: +LIBS="-lssl $LIBCRYPTO" +as: +LIBS="-lssl $LIBCRYPTO $LIBS" +This way $LIBS will contain -lz at the end of linking command that in +static linking build is mandatory. + +Signed-off-by: Giulio Benetti +--- + configure.d/config_os_libs2 | 2 +- + 1 file changed, 1 insertion(+), 1 deletion(-) + +diff --git a/configure.d/config_os_libs2 b/configure.d/config_os_libs2 +index 93044000b..c811c63ec 100644 +--- a/configure.d/config_os_libs2 ++++ b/configure.d/config_os_libs2 +@@ -349,7 +349,7 @@ if test "x$tryopenssl" != "xno" -a "x$tryopenssl" != "xinternal"; then + LIBS="$netsnmp_save_LIBS" + fi + netsnmp_save_LIBS="$LIBS" +- LIBS="-lssl $LIBCRYPTO" ++ LIBS="-lssl $LIBCRYPTO $LIBS" + AC_CHECK_FUNCS([TLS_method TLSv1_method DTLS_method DTLSv1_method]dnl + [SSL_library_init SSL_load_error_strings]) + LIBS="$netsnmp_save_LIBS" +-- +2.17.1 +