curl.h: stricter CURL_EXTERN linkage decorations logic

No API change involved.

Info: http://curl.haxx.se/mail/lib-2013-02/0234.html

8 files changed, 91 insertions, 107 deletions

diff --git a/configure.ac b/configure.ac
index 522d4cc33..d15f234a8 100644
--- a/configure.ac
+++ b/configure.ac
@@ -211,32 +211,37 @@ AM_CONDITIONAL([CURL_LT_SHLIB_USE_NO_UNDEFINED],
 AM_CONDITIONAL([CURL_LT_SHLIB_USE_MIMPURE_TEXT],
   [test "x$xc_lt_shlib_use_mimpure_text" = 'xyes'])
 
+#
+# Due to libtool and automake machinery limitations of not allowing
+# specifying separate CPPFLAGS or CFLAGS when compiling objects for
+# inclusion of these in shared or static libraries, we are forced to
+# build using separate configure runs for shared and static libraries
+# on systems where different CPPFLAGS or CFLAGS are mandatory in order
+# to compile objects for each kind of library. Notice that relying on
+# the '-DPIC' CFLAG that libtool provides is not valid given that the
+# user might for example choose to build static libraries with PIC.
+#
+
+#
+# Make our Makefile.am files use the staticlib CPPFLAG only when strictly
+# targeting a static library and not building its shared counterpart.
+#
+
+AM_CONDITIONAL([USE_CPPFLAG_CURL_STATICLIB],
+  [test "x$xc_lt_build_static_only" = 'xyes'])
+
+#
+# Make staticlib CPPFLAG variable and its definition visible in output
+# files unconditionally, providing an empty definition unless strictly
+# targeting a static library and not building its shared counterpart.
+#
+
+CPPFLAG_CURL_STATICLIB=
+if test "x$xc_lt_build_static_only" = 'xyes'; then
+  CPPFLAG_CURL_STATICLIB='-DCURL_STATICLIB'
+fi
+AC_SUBST([CPPFLAG_CURL_STATICLIB])
 
-AC_MSG_CHECKING([if we need BUILDING_LIBCURL])
-use_cppflag_building_libcurl="no"
-use_cppflag_curl_staticlib="no"
-CPPFLAG_CURL_STATICLIB=""
-case $host in
-  *-*-mingw*)
-    AC_MSG_RESULT(yes)
-    use_cppflag_building_libcurl="yes"
-    AC_MSG_CHECKING([if we need CURL_STATICLIB])
-    if test "X$enable_shared" = "Xno"
-    then
-      AC_MSG_RESULT(yes)
-      use_cppflag_curl_staticlib="yes"
-      CPPFLAG_CURL_STATICLIB="-DCURL_STATICLIB"
-    else
-      AC_MSG_RESULT(no)
-    fi
-    ;;
-  *)
-    AC_MSG_RESULT(no)
-    ;;
-esac
-AM_CONDITIONAL(USE_CPPFLAG_BUILDING_LIBCURL, test x$use_cppflag_building_libcurl = xyes)
-AM_CONDITIONAL(USE_CPPFLAG_CURL_STATICLIB, test x$use_cppflag_curl_staticlib = xyes)
-AC_SUBST(CPPFLAG_CURL_STATICLIB)
 
 # Determine whether all dependent libraries must be specified when linking
 if test "X$enable_shared" = "Xyes" -a "X$link_all_deplibs" = "Xno"
@@ -248,10 +253,6 @@ fi
 AC_SUBST(REQUIRE_LIB_DEPS)
 AM_CONDITIONAL(USE_EXPLICIT_LIB_DEPS, test x$REQUIRE_LIB_DEPS = xyes)
 
-dnl The install stuff has already been taken care of by the automake stuff
-dnl AC_PROG_INSTALL
-AC_PROG_MAKE_SET
-
 dnl check if there's a way to force code inline
 AC_C_INLINE
 
diff --git a/docs/examples/Makefile.am b/docs/examples/Makefile.am
index cbfdac502..8e2bc9a83 100644
--- a/docs/examples/Makefile.am
+++ b/docs/examples/Makefile.am
@@ -43,7 +43,6 @@ LIBDIR = $(top_builddir)/lib
 # Avoid libcurl obsolete stuff
 AM_CPPFLAGS += -DCURL_NO_OLDIES
 
-# Mostly for Windows build targets, when using static libcurl
 if USE_CPPFLAG_CURL_STATICLIB
 AM_CPPFLAGS += -DCURL_STATICLIB
 endif
diff --git a/include/curl/curl.h b/include/curl/curl.h
index 5b39a24bf..50f40435e 100644
--- a/include/curl/curl.h
+++ b/include/curl/curl.h
@@ -7,7 +7,7 @@
  *                            | (__| |_| |  _ <| |___
  *                             \___|\___/|_| \_\_____|
  *
- * Copyright (C) 1998 - 2012, Daniel Stenberg, <daniel@haxx.se>, et al.
+ * Copyright (C) 1998 - 2013, Daniel Stenberg, <daniel@haxx.se>, et al.
  *
  * This software is licensed as described in the file COPYING, which
  * you should have received as part of this distribution. The terms
@@ -93,29 +93,21 @@ extern "C" {
 typedef void CURL;
 
 /*
- * Decorate exportable functions for Win32 and Symbian OS DLL linking.
- * This avoids using a .def file for building libcurl.dll.
+ * libcurl external API function linkage decorations.
  */
-#if (defined(WIN32) || defined(_WIN32) || defined(__SYMBIAN32__)) && \
-     !defined(CURL_STATICLIB)
-#if defined(BUILDING_LIBCURL)
-#define CURL_EXTERN  __declspec(dllexport)
-#else
-#define CURL_EXTERN  __declspec(dllimport)
-#endif
-#else
 
-#ifdef CURL_HIDDEN_SYMBOLS
-/*
- * This definition is used to make external definitions visible in the
- * shared library when symbols are hidden by default.  It makes no
- * difference when compiling applications whether this is set or not,
- * only when compiling the library.
- */
-#define CURL_EXTERN CURL_EXTERN_SYMBOL
+#ifdef CURL_STATICLIB
+#  define CURL_EXTERN
+#elif defined(WIN32) || defined(_WIN32) || defined(__SYMBIAN32__)
+#  if defined(BUILDING_LIBCURL)
+#    define CURL_EXTERN  __declspec(dllexport)
+#  else
+#    define CURL_EXTERN  __declspec(dllimport)
+#  endif
+#elif defined(BUILDING_LIBCURL) && defined(CURL_HIDDEN_SYMBOLS)
+#  define CURL_EXTERN CURL_EXTERN_SYMBOL
 #else
-#define CURL_EXTERN
-#endif
+#  define CURL_EXTERN
 #endif
 
 #ifndef curl_socket_typedef
diff --git a/lib/Makefile.am b/lib/Makefile.am
index 019e44ac9..925483b1f 100644
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -37,13 +37,16 @@ EXTRA_DIST = Makefile.b32 Makefile.m32 Makefile.vc6 config-win32.h	\
  objnames-test08.sh objnames-test10.sh objnames.inc
 
 lib_LTLIBRARIES = libcurl.la
-LIBCURL_LIBS = @LIBCURL_LIBS@
+
+if BUILD_UNITTESTS
+noinst_LTLIBRARIES = libcurlu.la
+else
+noinst_LTLIBRARIES =
+endif
 
 # This might hold -Werror
 CFLAGS += @CURL_CFLAG_EXTRAS@
 
-CFLAG_CURL_SYMBOL_HIDING = @CFLAG_CURL_SYMBOL_HIDING@
-
 # Specify our include paths here, and do it relative to $(top_srcdir) and
 # $(top_builddir), to ensure that these paths which belong to the library
 # being currently built and tested are searched before the library which
@@ -76,16 +79,6 @@ endif
 # Prevent LIBS from being used for all link targets
 LIBS = $(BLANK_AT_MAKETIME)
 
-# Mostly for Windows build targets, when building libcurl library
-if USE_CPPFLAG_BUILDING_LIBCURL
-AM_CPPFLAGS += -DBUILDING_LIBCURL
-endif
-
-# Mostly for Windows build targets, when building static libcurl
-if USE_CPPFLAG_CURL_STATICLIB
-AM_CPPFLAGS += -DCURL_STATICLIB
-endif
-
 if SONAME_BUMP
 #
 # Bumping of SONAME conditionally may seem like a weird thing to do, and yeah
@@ -114,9 +107,13 @@ endif
 #
 # For the full guide on libcurl ABI rules, see docs/libcurl/ABI
 
+AM_CPPFLAGS += -DBUILDING_LIBCURL
 AM_LDFLAGS =
+AM_CFLAGS =
 
+libcurl_la_CPPFLAGS_EXTRA =
 libcurl_la_LDFLAGS_EXTRA =
+libcurl_la_CFLAGS_EXTRA =
 
 if CURL_LT_SHLIB_USE_VERSION_INFO
 libcurl_la_LDFLAGS_EXTRA += $(VERSIONINFO)
@@ -134,25 +131,21 @@ if CURL_LT_SHLIB_USE_VERSIONED_SYMBOLS
 libcurl_la_LDFLAGS_EXTRA += -Wl,--version-script=libcurl.vers
 endif
 
-libcurl_la_LDFLAGS = $(AM_LDFLAGS) $(libcurl_la_LDFLAGS_EXTRA) $(LIBCURL_LIBS)
+if USE_CPPFLAG_CURL_STATICLIB
+libcurl_la_CPPFLAGS_EXTRA += -DCURL_STATICLIB
+endif
 
 if DOING_CURL_SYMBOL_HIDING
-libcurl_la_CPPFLAGS = $(AM_CPPFLAGS) -DCURL_HIDDEN_SYMBOLS
-libcurl_la_CFLAGS = $(AM_CFLAGS) $(CFLAG_CURL_SYMBOL_HIDING)
-else
-libcurl_la_CPPFLAGS = $(AM_CPPFLAGS)
-libcurl_la_CFLAGS = $(AM_CFLAGS)
+libcurl_la_CPPFLAGS_EXTRA += -DCURL_HIDDEN_SYMBOLS
+libcurl_la_CFLAGS_EXTRA += $(CFLAG_CURL_SYMBOL_HIDING)
 endif
 
-# unit testing static library built only along with unit tests
-if BUILD_UNITTESTS
-noinst_LTLIBRARIES = libcurlu.la
-else
-noinst_LTLIBRARIES =
-endif
+libcurl_la_CPPFLAGS = $(AM_CPPFLAGS) $(libcurl_la_CPPFLAGS_EXTRA)
+libcurl_la_LDFLAGS = $(AM_LDFLAGS) $(libcurl_la_LDFLAGS_EXTRA) $(LIBCURL_LIBS)
+libcurl_la_CFLAGS = $(AM_CFLAGS) $(libcurl_la_CFLAGS_EXTRA)
 
-libcurlu_la_CPPFLAGS = $(AM_CPPFLAGS) -DUNITTESTS
-libcurlu_la_LDFLAGS = -static $(LIBCURL_LIBS)
+libcurlu_la_CPPFLAGS = $(AM_CPPFLAGS) -DCURL_STATICLIB -DUNITTESTS
+libcurlu_la_LDFLAGS = $(AM_LDFLAGS) -static $(LIBCURL_LIBS)
 libcurlu_la_CFLAGS = $(AM_CFLAGS)
 
 # Makefile.inc provides the CSOURCES and HHEADERS defines
diff --git a/src/Makefile.am b/src/Makefile.am
index 081820558..814af6ed0 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -44,7 +44,6 @@ AM_CPPFLAGS = -I$(top_builddir)/include/curl \
 
 bin_PROGRAMS = curl
 
-# Mostly for Windows build targets, when using static libcurl
 if USE_CPPFLAG_CURL_STATICLIB
 AM_CPPFLAGS += -DCURL_STATICLIB
 endif
diff --git a/tests/libtest/Makefile.am b/tests/libtest/Makefile.am
index 256fcec1d..80707b165 100644
--- a/tests/libtest/Makefile.am
+++ b/tests/libtest/Makefile.am
@@ -5,7 +5,7 @@
 #                            | (__| |_| |  _ <| |___
 #                             \___|\___/|_| \_\_____|
 #
-# Copyright (C) 1998 - 2012, Daniel Stenberg, <daniel@haxx.se>, et al.
+# Copyright (C) 1998 - 2013, Daniel Stenberg, <daniel@haxx.se>, et al.
 #
 # This software is licensed as described in the file COPYING, which
 # you should have received as part of this distribution. The terms
@@ -70,11 +70,6 @@ endif
 LDADD = $(SUPPORTFILES_LIBS)
 DEPENDENCIES = $(top_builddir)/lib/libcurl.la
 
-# Mostly for Windows build targets, when using static libcurl
-if USE_CPPFLAG_CURL_STATICLIB
-AM_CPPFLAGS += -DCURL_STATICLIB
-endif
-
 # Makefile.inc provides the source defines (TESTUTIL, SUPPORTFILES,
 # noinst_PROGRAMS, lib*_SOURCES, and lib*_CFLAGS)
 include Makefile.inc
@@ -88,25 +83,35 @@ else
 noinst_LTLIBRARIES =
 endif
 
+if USE_CPPFLAG_CURL_STATICLIB
+AM_CPPFLAGS += -DCURL_STATICLIB
+endif
+
 AM_LDFLAGS =
+AM_CFLAGS =
 
+libhostname_la_CPPFLAGS_EXTRA =
 libhostname_la_LDFLAGS_EXTRA = -module -avoid-version -rpath /nowhere
+libhostname_la_CFLAGS_EXTRA =
 
 if CURL_LT_SHLIB_USE_NO_UNDEFINED
 libhostname_la_LDFLAGS_EXTRA += -no-undefined
 endif
 
+if CURL_LT_SHLIB_USE_MIMPURE_TEXT
+libhostname_la_LDFLAGS_EXTRA += -mimpure-text
+endif
+
+if DOING_CURL_SYMBOL_HIDING
+libhostname_la_CPPFLAGS_EXTRA += -DCURL_HIDDEN_SYMBOLS
+libhostname_la_CFLAGS_EXTRA += $(CFLAG_CURL_SYMBOL_HIDING)
+endif
+
+libhostname_la_CPPFLAGS = $(AM_CPPFLAGS) $(libhostname_la_CPPFLAGS_EXTRA)
 libhostname_la_LDFLAGS = $(AM_LDFLAGS) $(libhostname_la_LDFLAGS_EXTRA)
+libhostname_la_CFLAGS = $(AM_CFLAGS) $(libhostname_la_CFLAGS_EXTRA)
 
 libhostname_la_SOURCES = sethostname.c sethostname.h
 
 libhostname_la_LIBADD =
 libhostname_la_DEPENDENCIES =
-
-if DOING_CURL_SYMBOL_HIDING
-libhostname_la_CPPFLAGS = $(AM_CPPFLAGS) -DCURL_HIDDEN_SYMBOLS
-libhostname_la_CFLAGS = $(AM_CFLAGS) $(CFLAG_CURL_SYMBOL_HIDING)
-else
-libhostname_la_CPPFLAGS = $(AM_CPPFLAGS)
-libhostname_la_CFLAGS = $(AM_CFLAGS)
-endif
diff --git a/tests/libtest/sethostname.h b/tests/libtest/sethostname.h
index e2633dd7f..192f037ab 100644
--- a/tests/libtest/sethostname.h
+++ b/tests/libtest/sethostname.h
@@ -5,7 +5,7 @@
  *                            | (__| |_| |  _ <| |___
  *                             \___|\___/|_| \_\_____|
  *
- * Copyright (C) 1998 - 2011, Daniel Stenberg, <daniel@haxx.se>, et al.
+ * Copyright (C) 1998 - 2013, Daniel Stenberg, <daniel@haxx.se>, et al.
  *
  * This software is licensed as described in the file COPYING, which
  * you should have received as part of this distribution. The terms
@@ -20,18 +20,18 @@
  *
  ***************************************************************************/
 
-#if (defined(WIN32) || defined(__SYMBIAN32__)) && !defined(CURL_STATICLIB)
+#ifdef CURL_STATICLIB
+#  define LIBHOSTNAME_EXTERN
+#elif defined(WIN32) || defined(__SYMBIAN32__)
 #  if defined(BUILDING_LIBCURL)
 #    define LIBHOSTNAME_EXTERN  __declspec(dllexport)
 #  else
 #    define LIBHOSTNAME_EXTERN  __declspec(dllimport)
 #  endif
+#elif defined(BUILDING_LIBCURL) && defined(CURL_HIDDEN_SYMBOLS)
+#  define LIBHOSTNAME_EXTERN CURL_EXTERN_SYMBOL
 #else
-#  ifdef CURL_HIDDEN_SYMBOLS
-#    define LIBHOSTNAME_EXTERN CURL_EXTERN_SYMBOL
-#  else
-#    define LIBHOSTNAME_EXTERN
-#  endif
+#  define LIBHOSTNAME_EXTERN
 #endif
 
 #ifdef USE_WINSOCK
diff --git a/tests/unit/Makefile.am b/tests/unit/Makefile.am
index 12d5fe314..666fc00ea 100644
--- a/tests/unit/Makefile.am
+++ b/tests/unit/Makefile.am
@@ -5,7 +5,7 @@
 #                            | (__| |_| |  _ <| |___
 #                             \___|\___/|_| \_\_____|
 #
-# Copyright (C) 1998 - 2012, Daniel Stenberg, <daniel@haxx.se>, et al.
+# Copyright (C) 1998 - 2013, Daniel Stenberg, <daniel@haxx.se>, et al.
 #
 # This software is licensed as described in the file COPYING, which
 # you should have received as part of this distribution. The terms
@@ -59,12 +59,7 @@ LIBS = $(BLANK_AT_MAKETIME)
 
 LDADD = $(top_builddir)/lib/libcurlu.la @LDFLAGS@ @LIBCURL_LIBS@
 DEPENDENCIES = $(top_builddir)/lib/libcurlu.la
-AM_CPPFLAGS += -DUNITTESTS
-
-# Mostly for Windows build targets, when using static libcurl
-if USE_CPPFLAG_CURL_STATICLIB
-AM_CPPFLAGS += -DCURL_STATICLIB
-endif
+AM_CPPFLAGS += -DCURL_STATICLIB -DUNITTESTS
 
 # Makefile.inc provides neat definitions
 include Makefile.inc