build: explain current role of LIBS in our Makefile.am files

BLANK_AT_MAKETIME may be used in our Makefile.am files to blank
LIBS variable used in generated makefile at makefile processing
time. Doing this functionally prevents LIBS from being used for
all link targets in given makefile.

diff --git a/configure.ac b/configure.ac
index 0386d11f527a82af1875cb7dce90ea39bedf9737..b8268b392881096cb2f9284682b10aebbdad92e2 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -3364,12 +3364,11 @@ LIBCURL_LIBS=$LIBS
 AC_SUBST(LIBCURL_LIBS)
 AC_SUBST(CURL_NETWORK_LIBS)
 AC_SUBST(CURL_NETWORK_AND_TIME_LIBS)
-dnl LIBS is a magic variable that's used for every link
 
-dnl BLANK_AT_MAKETIME might be used in some of our Makefile.am files to
-dnl blank LIBS variable used in generated makefile at makefile processing
-dnl time. Our test server's Makefile.am uses this to prevent global LIBS
-dnl from being used for any test server build target.
+dnl BLANK_AT_MAKETIME may be used in our Makefile.am files to blank
+dnl LIBS variable used in generated makefile at makefile processing
+dnl time. Doing this functionally prevents LIBS from being used for
+dnl all link targets in given makefile.
 BLANK_AT_MAKETIME=
 AC_SUBST(BLANK_AT_MAKETIME)
 

diff --git a/docs/examples/Makefile.am b/docs/examples/Makefile.am
index 49c20361f5fda22c87a82aa6575410a406700e30..865f0937123813814210b14e093d747578726453 100644 (file)
--- a/docs/examples/Makefile.am
+++ b/docs/examples/Makefile.am
@@ -48,7 +48,7 @@ if USE_CPPFLAG_CURL_STATICLIB
 AM_CPPFLAGS += -DCURL_STATICLIB
 endif
 
-# Prevent global LIBS from influencing examples build targets
+# Prevent LIBS from being used for all link targets
 LIBS = $(BLANK_AT_MAKETIME)
 
 # Dependencies

diff --git a/lib/Makefile.am b/lib/Makefile.am
index c8a88cd1383e0639dc856726eb3b828ec9f882cf..91790267a55cfdc8e8b94ab793d345cbdbb2b9a5 100644 (file)
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -132,7 +132,7 @@ if VERSIONED_SYMBOLS
 VERSIONED_SYMBOLS = -Wl,--version-script=libcurl.vers
 endif
 
-# Prevent global LIBS from influencing lib build targets
+# Prevent LIBS from being used for all link targets
 LIBS = $(BLANK_AT_MAKETIME)
 
 libcurl_la_LDFLAGS = $(UNDEF) $(VERSIONINFO) $(MIMPURE) $(VERSIONED_SYMBOLS) $(LIBCURL_LIBS)

diff --git a/src/Makefile.am b/src/Makefile.am
index 7839904d53cc11ad932ed3c86b53f701ede6c584..6de750114e06129510303cb9ffce52966fe71b72 100644 (file)
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -54,7 +54,7 @@ include Makefile.inc
 # This might hold -Werror
 CFLAGS += @CURL_CFLAG_EXTRAS@ @LIBMETALINK_CFLAGS@
 
-# Prevent global LIBS from influencing src build targets
+# Prevent LIBS from being used for all link targets
 LIBS = $(BLANK_AT_MAKETIME)
 
 if USE_EXPLICIT_LIB_DEPS

diff --git a/tests/libtest/Makefile.am b/tests/libtest/Makefile.am
index a9d0b90310c529791561cba6b143de1874f5c0b8..df13df1110dbffb70dbf32310c97412be898ffb5 100644 (file)
--- a/tests/libtest/Makefile.am
+++ b/tests/libtest/Makefile.am
@@ -55,8 +55,7 @@ test1022.pl Makefile.inc notexists.pl
 
 CFLAG_CURL_SYMBOL_HIDING = @CFLAG_CURL_SYMBOL_HIDING@
 
-# Prevent global LIBS from influencing libtest build targets
-BLANK_AT_MAKETIME = @BLANK_AT_MAKETIME@
+# Prevent LIBS from being used for all link targets
 LIBS = $(BLANK_AT_MAKETIME)
 
 if USE_EXPLICIT_LIB_DEPS

diff --git a/tests/server/Makefile.am b/tests/server/Makefile.am
index 85e0c097c1fb177b49ec5469407655cca3a66fef..d4ef252db13f697919931c52ed009c326f2a6e78 100644 (file)
--- a/tests/server/Makefile.am
+++ b/tests/server/Makefile.am
@@ -50,8 +50,7 @@ AM_CPPFLAGS = -I$(top_builddir)/include/curl \
               -I$(top_srcdir)/lib
 endif
 
-# Prevent global LIBS from influencing test server build targets
-BLANK_AT_MAKETIME = @BLANK_AT_MAKETIME@
+# Prevent LIBS from being used for all link targets
 LIBS = $(BLANK_AT_MAKETIME)
 
 if DOING_NATIVE_WINDOWS

diff --git a/tests/unit/Makefile.am b/tests/unit/Makefile.am
index 0582168141fd05d0d63828785c16845925f857b9..eb29241ad43cfdd867d698b9388512486c470071 100644 (file)
--- a/tests/unit/Makefile.am
+++ b/tests/unit/Makefile.am
@@ -54,7 +54,10 @@ endif
 
 EXTRA_DIST = Makefile.inc
 
-LDADD = $(top_builddir)/lib/libcurlu.la @LDFLAGS@ @LIBCURL_LIBS@ @LIBS@
+# Prevent LIBS from being used for all link targets
+LIBS = $(BLANK_AT_MAKETIME)
+
+LDADD = $(top_builddir)/lib/libcurlu.la @LDFLAGS@ @LIBCURL_LIBS@
 DEPENDENCIES = $(top_builddir)/lib/libcurlu.la
 AM_CPPFLAGS += -DUNITTESTS