build: link with curl-defined linker flags

jdknight · gitster · commit 23c4bbe28e61 · 2018-11-05T10:19:25.000+09:00
Adjusting the build process to rely more on curl-config to populate
linker flags instead of manually populating flags based off detected
features.

Originally, a configure-invoked build would check for SSL-support in the
target curl library. If enabled, NEEDS_SSL_WITH_CURL would be set and
used in the Makefile to append additional libraries to link against. As
for systems building solely with make, the defines NEEDS_IDN_WITH_CURL
and NEEDS_SSL_WITH_CURL could be set to indirectly enable respective
linker flags. Since both configure.ac and Makefile already rely on
curl-config utility to provide curl-related build information, adjusting
the respective assets to populate required linker flags using the
utility (unless explicitly configured).

Signed-off-by: James Knight &lt;james.d.knight@live.com&gt;
Signed-off-by: Junio C Hamano &lt;gitster@pobox.com&gt;
diff --git a/Makefile b/Makefile
@@ -59,6 +59,13 @@ all::
 # Define CURL_CONFIG to curl's configuration program that prints information
 # about the library (e.g., its version number).  The default is 'curl-config'.
 #
+# Define CURL_LDFLAGS to specify flags that you need to link when using libcurl,
+# if you do not want to rely on the libraries provided by CURL_CONFIG.  The
+# default value is a result of `curl-config --libs`.  An example value for
+# CURL_LDFLAGS is as follows:
+#
+#     CURL_LDFLAGS=-lcurl
+#
 # Define NO_EXPAT if you do not have expat installed.  git-http-push is
 # not built, and you cannot push using http:// and https:// transports (dumb).
 #
@@ -183,10 +190,6 @@ all::
 #
 # Define NEEDS_SSL_WITH_CRYPTO if you need -lssl when using -lcrypto (Darwin).
 #
-# Define NEEDS_SSL_WITH_CURL if you need -lssl with -lcurl (Minix).
-#
-# Define NEEDS_IDN_WITH_CURL if you need -lidn when using -lcurl (Minix).
-#
 # Define NEEDS_LIBICONV if linking with libc is not enough (Darwin).
 #
 # Define NEEDS_LIBINTL_BEFORE_LIBICONV if you need libintl before libiconv.
@@ -1307,20 +1310,17 @@ else
 	ifdef CURLDIR
 		# Try "-Wl,-rpath=$(CURLDIR)/$(lib)" in such a case.
 		BASIC_CFLAGS += -I$(CURLDIR)/include
-		CURL_LIBCURL = -L$(CURLDIR)/$(lib) $(CC_LD_DYNPATH)$(CURLDIR)/$(lib) -lcurl
+		CURL_LIBCURL = -L$(CURLDIR)/$(lib) $(CC_LD_DYNPATH)$(CURLDIR)/$(lib)
 	else
-		CURL_LIBCURL = -lcurl
-	endif
-	ifdef NEEDS_SSL_WITH_CURL
-		CURL_LIBCURL += -lssl
-		ifdef NEEDS_CRYPTO_WITH_SSL
-			CURL_LIBCURL += -lcrypto
-		endif
-	endif
-	ifdef NEEDS_IDN_WITH_CURL
-		CURL_LIBCURL += -lidn
+		CURL_LIBCURL =
 	endif
 
+ifdef CURL_LDFLAGS
+	CURL_LIBCURL += $(CURL_LDFLAGS)
+else
+	CURL_LIBCURL += $(shell $(CURL_CONFIG) --libs)
+endif
+
 	REMOTE_CURL_PRIMARY = git-remote-http$X
 	REMOTE_CURL_ALIASES = git-remote-https$X git-remote-ftp$X git-remote-ftps$X
 	REMOTE_CURL_NAMES = $(REMOTE_CURL_PRIMARY) $(REMOTE_CURL_ALIASES)
diff --git a/config.mak.uname b/config.mak.uname
@@ -431,8 +431,6 @@ ifeq ($(uname_S),Minix)
 	NO_NSEC = YesPlease
 	NEEDS_LIBGEN =
 	NEEDS_CRYPTO_WITH_SSL = YesPlease
-	NEEDS_IDN_WITH_CURL = YesPlease
-	NEEDS_SSL_WITH_CURL = YesPlease
 	NEEDS_RESOLV =
 	NO_HSTRERROR = YesPlease
 	NO_MMAP = YesPlease
@@ -458,7 +456,6 @@ ifeq ($(uname_S),NONSTOP_KERNEL)
 	# Missdetected, hence commented out, see below.
 	#NO_CURL = YesPlease
 	# Added manually, see above.
-	NEEDS_SSL_WITH_CURL = YesPlease
 	HAVE_LIBCHARSET_H = YesPlease
 	HAVE_STRINGS_H = YesPlease
 	NEEDS_LIBICONV = YesPlease
diff --git a/configure.ac b/configure.ac
@@ -600,17 +600,14 @@ AC_CHECK_PROG([CURL_CONFIG], [curl-config],
 
 if test $CURL_CONFIG != no; then
     GIT_CONF_SUBST([CURL_CONFIG])
-    if test -z "${NO_OPENSSL}"; then
-      AC_MSG_CHECKING([if Curl supports SSL])
-      if test $(curl-config --features|grep SSL) = SSL; then
-         NEEDS_SSL_WITH_CURL=YesPlease
-         AC_MSG_RESULT([yes])
-      else
-         NEEDS_SSL_WITH_CURL=
-         AC_MSG_RESULT([no])
-      fi
-      GIT_CONF_SUBST([NEEDS_SSL_WITH_CURL])
+
+    if test -z "$CURL_CONFIG_OPTS"; then
+        CURL_CONFIG_OPTS="--libs"
     fi
+
+    CURL_LDFLAGS=$($CURL_CONFIG $CURL_CONFIG_OPTS)
+    AC_MSG_NOTICE([Setting CURL_LDFLAGS to '$CURL_LDFLAGS'])
+    GIT_CONF_SUBST([CURL_LDFLAGS], [$CURL_LDFLAGS])
 fi
 
 fi
