https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71757
--- Comment #9 from Timo Teräs <timo.teras at iki dot fi> ---
Adding the following also works for me:
--- gcc-6.1.0/libjava/Makefile.am
+++ gcc-6.1.0/libjava/Makefile.am
@@ -488,10 +488,14 @@
nat_files = $(nat_source_files:.cc=.lo)
xlib_nat_files = $(xlib_nat_source_files:.cc=.lo)
+libgcj_la_CPPFLAGS = \
+ $(AM_CPPFLAGS) \
+ $(LIBSTDCXX_RAW_CXX_CXXFLAGS)
+
# Include THREADLIBS here to ensure that the correct version of
# certain linuxthread functions get linked:
## The mysterious backslash in the grep pattern is consumed by make.
-libgcj_la_LDFLAGS = -rpath $(toolexeclibdir) $(THREADLDFLAGS) $(extra_ldflags)
$(THREADLIBS) \
+libgcj_la_LDFLAGS = $(LIBSTDCXX_RAW_CXX_LDFLAGS) -rpath $(toolexeclibdir)
$(THREADLDFLAGS) $(extra_ldflags) $(THREADLIBS) \
$(LIBLTDL) $(SYS_ZLIBS) $(LIBJAVA_LDFLAGS_NOUNDEF) \
-version-info `grep -v '^\#' $(srcdir)/libtool-version` \
$(LIBGCJ_LD_SYMBOLIC_FUNCTIONS) $(LIBGCJ_LD_EXPORT_ALL)
--- gcc-6.1.0/libjava/Makefile.in
+++ gcc-6.1.0/libjava/Makefile.in
@@ -1103,9 +1103,13 @@
nat_files = $(nat_source_files:.cc=.lo)
xlib_nat_files = $(xlib_nat_source_files:.cc=.lo)
+libgcj_la_CPPFLAGS = \
+ $(AM_CPPFLAGS) \
+ $(LIBSTDCXX_RAW_CXX_CXXFLAGS)
+
# Include THREADLIBS here to ensure that the correct version of
# certain linuxthread functions get linked:
-libgcj_la_LDFLAGS = -rpath $(toolexeclibdir) $(THREADLDFLAGS) $(extra_ldflags)
$(THREADLIBS) \
+libgcj_la_LDFLAGS = $(LIBSTDCXX_RAW_CXX_LDFLAGS) -rpath $(toolexeclibdir)
$(THREADLDFLAGS) $(extra_ldflags) $(THREADLIBS) \
$(LIBLTDL) $(SYS_ZLIBS) $(LIBJAVA_LDFLAGS_NOUNDEF) \
-version-info `grep -v '^\#' $(srcdir)/libtool-version` \
$(LIBGCJ_LD_SYMBOLIC_FUNCTIONS) $(LIBGCJ_LD_EXPORT_ALL)
After this the proper .so dependency is picked up for libstdc++.
