Merge pull request #3532 from martin-frbg/issue3528-2

Fix building a shared library on Mac with flang-classic

exports/Makefile

@@ -142,10 +142,14 @@ ifneq (,$(filter 1 2,$(NOFORTRAN)))
 else
 ifeq ($(F_COMPILER), INTEL)
 	$(FC) $(FFLAGS) $(LDFLAGS) -all-load -headerpad_max_install_names -install_name "$(CURDIR)/../$(INTERNALNAME)" -dynamiclib -o ../$(LIBDYNNAME) $< -Wl,-exported_symbols_list,osx.def
+else
+ifeq ($(F_COMPILER), FLANG)
+	$(FC) $(FFLAGS) $(LDFLAGS) -fno-fortran-main -Mnomain -all_load -headerpad_max_install_names -install_name "$(CURDIR)/../$(INTERNALNAME)" -dynamiclib -o ../$(LIBDYNNAME) $< -Wl,-exported_symbols_list,osx.def  $(FEXTRALIB)
 else
 	$(FC) $(FFLAGS) $(LDFLAGS) -all_load -headerpad_max_install_names -install_name "$(CURDIR)/../$(INTERNALNAME)" -dynamiclib -o ../$(LIBDYNNAME) $< -Wl,-exported_symbols_list,osx.def  $(FEXTRALIB)
 endif
 endif
+endif
 
 dllinit.$(SUFFIX) : dllinit.c
 	$(CC) $(CFLAGS) -c -o $(@F) -s $<

f_check

@@ -361,6 +361,7 @@ if ($link ne "") {
 	    ($flags =~ /^\-l/)
 	    && ($flags !~ /ibrary/)
 	    && ($flags !~ /gfortranbegin/)
+	    && ($flags !~ /flangmain/)
 	    && ($flags !~ /frtbegin/)
 	    && ($flags !~ /pathfstart/)
 	    && ($flags !~ /crt[0-9]/)