Limit the exported symbols through a config.h trick.

1 files changed, 79 insertions, 0 deletions

diff --git a/lib/Makefile.am b/lib/Makefile.am
index 4e8d6a6..6eaed43 100644
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -136,6 +136,85 @@ clean-local: clean-generic
 	fi; \
         :
 
+# List of header files that get installed and that declared 'extern' symbols.
+HEADERS_WITH_EXTERNS = \
+  unitypes.h \
+  unistr.h \
+  uniconv.h \
+  unistdio.h \
+  uniname.h \
+  unictype.h \
+  uniwidth.h \
+  uniwbrk.h \
+  unilbrk.h \
+  uninorm.h \
+  unicase.h \
+  localcharset.h \
+  iconveh.h
+
+# List of exported symbols.
+# We extract it from the header files that get installed, removing symbols
+# start with "_UC".
+# This file has the same format as the one expected by the libtool option
+# '-export-symbols', but we don't use this option, because it would prevent us
+# from building some of the gnulib unit tests.
+libunistring.sym : $(HEADERS_WITH_EXTERNS)
+	for f in $(HEADERS_WITH_EXTERNS); do cat $(srcdir)/$$f; done \
+	  | $(srcdir)/declared.sh | LC_ALL=C sort | LC_ALL=C uniq \
+	  | grep -v '^_UC' \
+	  > $@-t
+	mv $@-t $@
+# We distribute it because declared.sh relies on GNU sed.
+MOSTLYCLEANFILES     += libunistring.sym-t
+MAINTAINERCLEANFILES += libunistring.sym
+EXTRA_DIST           += libunistring.sym
+
+# Hide undesired symbols that are defined by libunistring_la_SOURCES or
+# libunistring_la_LIBADD from the global namespace, by prefixing them with
+# "libunistring_".
+all check install: config.h
+config.h: $(BUILT_SOURCES) libunistring.sym
+	{ echo '/* DO NOT EDIT! GENERATED AUTOMATICALLY! */'; \
+	  : "Avoid double inclusion, to avoid a warning about redefinition of DLL_VARIABLE."; \
+	  echo '#ifndef UNISTRING_CONFIG_H'; \
+	  echo '#define UNISTRING_CONFIG_H'; \
+	  echo; \
+	  echo '#include "../config.h"'; \
+	  : "All code is collected in a single library,"; \
+	  : "No references to variables in other libraries exist."; \
+	  echo '#undef DLL_VARIABLE'; \
+	  echo '#define DLL_VARIABLE'; \
+	  echo; \
+	  echo '#endif /* UNISTRING_CONFIG_H */'; \
+	} > config.h && \
+	if test -n "$(HAVE_GLOBAL_SYMBOL_PIPE)"; then \
+	  { \
+	    for f in $(libunistring_la_SOURCES) $(libunistring_la_LIBADD); do \
+	      case $$f in \
+	        *.c | *.$(OBJEXT) | *.lo ) \
+	          sf=`echo "$$f" | sed -e 's,\\.[^.]*$$,,'`.c; \
+	          test -f $$sf || sf=$(srcdir)/$$sf; \
+	          of=`echo "$$f" | sed -e 's,^.*/,,' -e 's,\\.[^.]*$$,,'`.$(OBJEXT); \
+	          $(COMPILE) -c $$sf || { rm -f config.h; exit 1; }; \
+	          sh ./exported.sh $$of 1>&5; \
+	          rm -f $$of `echo "$$of" | sed -e 's,\\.$(OBJEXT)$$,.lo,'`; \
+	          ;; \
+	      esac; \
+	    done; \
+	  } 5>&1 \
+	    | sed -e 's,.* ,,' | LC_ALL=C sort | LC_ALL=C uniq \
+	    | LC_ALL=C join -v 1 - $(srcdir)/libunistring.sym \
+	    | sed -e 's,^\(.*\)$$,#define \1 libunistring_\1,' > config.h-t && \
+	  if test -f config.h; then \
+	    cat config.h-t >> config.h; \
+	    rm -f config.h-t; \
+	  else \
+	    rm -f config.h-t; \
+	    exit 1; \
+	  fi \
+	fi
+MOSTLYCLEANFILES += config.h config.h-t
+
 # Libtool's library version information for libunistring.
 # See the libtool documentation, section "Library interface versions".
 LTV_CURRENT=0