autotools: accept linker flags via `CURL_LDFLAGS_{LIB,BIN}`
To allow passing `LDFLAGS` specific to libcurl (`CURL_LDFLAGS_LIB`) and
curl tool (`CURL_LDFLAGS_BIN`).
This makes it possible to build libcurl and curl with a single
invocation with lib- and tool-specific custom linker flags.
Such flag can be enabling `.map` files, a `.def` file for libcurl DLL,
controlling static/shared, incl. requesting a static curl tool (with
`-static-libtool-libs`) while building both shared and static libcurl.
curl-for-win uses the above and some more.
These options are already supported in `Makefile.mk`. CMake has built-in
variables for this.
Closes #12312
diff --git a/lib/Makefile.am b/lib/Makefile.am
index 3c0a709..cae1dec 100644
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -110,7 +110,7 @@
endif
libcurl_la_CPPFLAGS = $(AM_CPPFLAGS) $(libcurl_la_CPPFLAGS_EXTRA)
-libcurl_la_LDFLAGS = $(AM_LDFLAGS) $(libcurl_la_LDFLAGS_EXTRA) $(LDFLAGS) $(LIBCURL_LIBS)
+libcurl_la_LDFLAGS = $(AM_LDFLAGS) $(libcurl_la_LDFLAGS_EXTRA) $(LDFLAGS) $(CURL_LDFLAGS_LIB) $(LIBCURL_LIBS)
libcurl_la_CFLAGS = $(AM_CFLAGS) $(libcurl_la_CFLAGS_EXTRA)
libcurlu_la_CPPFLAGS = $(AM_CPPFLAGS) -DCURL_STATICLIB -DUNITTESTS
diff --git a/src/Makefile.am b/src/Makefile.am
index b22ece6..dced53e 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -61,6 +61,8 @@
$(CURL_RCFILES): tool_version.h
endif
+curl_LDFLAGS = $(AM_LDFLAGS) $(CURL_LDFLAGS_BIN)
+
# This might hold -Werror
CFLAGS += @CURL_CFLAG_EXTRAS@
