rework how pthread is handled on openbsd

- remove -pthread from PTHREAD_CFLAGS
- add pthread to gb_STDLIBS
- redefine gb_LinkTarget__command_dynamiclink so that we can
  substitute -lpthread with -pthread in the list of libraries
  that we link to

configure.in

@@ -1513,7 +1513,7 @@ case "$host_os" in
         test_gtk=yes
         test_kde=yes
         test_freetype=yes
-        PTHREAD_CFLAGS="-pthread -D_THREAD_SAFE"
+        PTHREAD_CFLAGS="-D_THREAD_SAFE"
         PTHREAD_LIBS="-pthread"
         _os=OpenBSD
         ;;

solenv/gbuild/platform/openbsd.mk

@@ -37,7 +37,22 @@ endif
 
 gb_Library_DLLPOSTFIX := ob
 gb_COMPILERDEFAULTOPTFLAGS := -O2
+gb_STDLIBS := pthread
 
 include $(GBUILDDIR)/platform/unxgcc.mk
 
+define gb_LinkTarget__command_dynamiclink
+$(call gb_Helper_abbreviate_dirs,\
+	mkdir -p $(dir $(1)) && \
+	$(gb_CXX) \
+		$(if $(filter Library CppunitTest,$(TARGETTYPE)),$(gb_Library_TARGETTYPEFLAGS)) \
+		$(subst \d,$$,$(RPATH)) $(LDFLAGS) \
+		$(foreach object,$(COBJECTS),$(call gb_CObject_get_target,$(object))) \
+		$(foreach object,$(CXXOBJECTS),$(call gb_CxxObject_get_target,$(object))) \
+		$(foreach object,$(GENCXXOBJECTS),$(call gb_GenCxxObject_get_target,$(object))) \
+		-Wl$(COMMA)--start-group $(foreach lib,$(LINKED_STATIC_LIBS),$(call gb_StaticLibrary_get_target,$(lib))) -Wl$(COMMA)--end-group \
+		$(subst -lpthread,$(PTHREAD_LIBS),$(patsubst lib%.so,-l%,$(foreach lib,$(LINKED_LIBS),$(call gb_Library_get_filename,$(lib))))) \
+		-o $(1))
+endef
+
 # vim: set noet sw=4: