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.

7 files changed, 13 insertions, 13 deletions

diff --git a/configure.ac b/configure.ac
index 0386d11f5..b8268b392 100644
--- 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 49c20361f..865f09371 100644
--- 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 c8a88cd13..91790267a 100644
--- 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 7839904d5..6de750114 100644
--- 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 a9d0b9031..df13df111 100644
--- 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 85e0c097c..d4ef252db 100644
--- 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 058216814..eb29241ad 100644
--- 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