Limit the exported symbols through a config.h trick.

3 files changed, 238 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
diff --git a/lib/declared.sh b/lib/declared.sh
new file mode 100755
index 0000000..c254417
--- /dev/null
+++ b/lib/declared.sh
@@ -0,0 +1,135 @@
+#! /bin/sh
+#
+# Copyright (C) 2009 Free Software Foundation, Inc.
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+
+# This script determines the declared global symbols in a C header file.
+# Assumptions:
+# - The header files are in C, with only C89 comments.
+# - No use of macros with parameters.
+# - All global declarations are marked with 'extern'.
+# - All declarations end in ';' on the same line.
+# - Not more than one symbol is declared in a declaration.
+
+# func_usage
+# outputs to stdout the --help usage message.
+func_usage ()
+{
+  echo "\
+Usage: declared.sh [OPTION]... < SOURCE.h
+
+Extracts the declared global symbols of a C header file.
+
+Options:
+      --help           print this help and exit
+      --version        print version information and exit
+
+Report bugs to <bruno@clisp.org>."
+}
+
+# func_version
+# outputs to stdout the --version message.
+func_version ()
+{
+  echo "declared.sh (GNU libunistring)"
+  echo "Copyright (C) 2006, 2009 Free Software Foundation, Inc.
+License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
+This is free software: you are free to change and redistribute it.
+There is NO WARRANTY, to the extent permitted by law."
+  echo "Written by" "Bruno Haible"
+}
+
+# func_fatal_error message
+# outputs to stderr a fatal error message, and terminates the program.
+func_fatal_error ()
+{
+  echo "declared.sh: *** $1" 1>&2
+  echo "declared.sh: *** Stop." 1>&2
+  exit 1
+}
+
+# Command-line option processing.
+while test $# -gt 0; do
+  case "$1" in
+    --help | --hel | --he | --h )
+      func_usage
+      exit 0 ;;
+   --version | --versio | --versi | --vers | --ver | --ve | --v )
+      func_version
+      exit 0 ;;
+    -- )      # Stop option prcessing
+      shift; break ;;
+    -* )
+      func_fatal_error "unrecognized option: $option"
+      ;;
+    * )
+      break ;;
+  esac
+done
+
+if test $# -gt 0; then
+  func_fatal_error "too many arguments"
+fi
+
+# A sed expression that removes ANSI C and ISO C99 comments.
+sed_remove_comments="
+/[/][/*]/{
+  ta
+  :a
+  s,^\\(\\([^\"'/]\\|\"\\([^\\\"]\\|[\\].\\)*\"\\|'\\([^\\']\\|[\\].\\)*'\\|[/][^\"'/*]\\|[/]\"\\([^\\\"]\\|[\\].\\)*\"\\|[/]'\\([^\\']\\|[\\].\\)*'\\)*\\)//.*,\\1,
+  te
+  s,^\\(\\([^\"'/]\\|\"\\([^\\\"]\\|[\\].\\)*\"\\|'\\([^\\']\\|[\\].\\)*'\\|[/][^\"'/*]\\|[/]\"\\([^\\\"]\\|[\\].\\)*\"\\|[/]'\\([^\\']\\|[\\].\\)*'\\)*\\)/[*]\\([^*]\\|[*][^/*]\\)*[*][*]*/,\\1 ,
+  ta
+  /^\\([^\"'/]\\|\"\\([^\\\"]\\|[\\].\\)*\"\\|'\\([^\\']\\|[\\].\\)*'\\|[/][^\"'/*]\\|[/]\"\\([^\\\"]\\|[\\].\\)*\"\\|[/]'\\([^\\']\\|[\\].\\)*'\\)*[/][*]/{
+    s,^\\(\\([^\"'/]\\|\"\\([^\\\"]\\|[\\].\\)*\"\\|'\\([^\\']\\|[\\].\\)*'\\|[/][^\"'/*]\\|[/]\"\\([^\\\"]\\|[\\].\\)*\"\\|[/]'\\([^\\']\\|[\\].\\)*'\\)*\\)/[*].*,\\1 ,
+    tu
+    :u
+    n
+    s,^\\([^*]\\|[*][^/*]\\)*[*][*]*/,,
+    tv
+    s,^.*\$,,
+    bu
+    :v
+  }
+  :e
+}"
+
+# Check that 'sed' supports the kind of regular expressions used in
+# sed_remove_comments. The use of \| meaning alternation of basic regular
+# expressions is a GNU extension.
+sed_test='s,^\(\(a\|X\)*\)//.*,\1,'
+sed_result=`echo 'aaa//bcd' | sed -e "$sed_test"`
+test "$sed_result" = 'aaa' \
+  || func_fatal_error "The 'sed' program is not GNU sed. Try installing GNU sed."
+
+# A sed expression that joins 'extern' declarations that are broken over
+# several lines.
+sed_join_multiline_externs='
+/^extern [^;]*$/{
+  :a
+  N
+  s/\n/ /g
+  /^extern [^;]*$/{
+    ba
+  }
+}'
+
+# A sed expression that extracts the identifier of each 'extern' declaration.
+sed_extract_extern_declared='s/^extern .* \([A-Za-z_][A-Za-z0-9_]*\) *[;(].*$/\1/p'
+
+sed -e "$sed_remove_comments" \
+  | sed -e "$sed_join_multiline_externs" \
+  | sed -n -e "$sed_extract_extern_declared"
diff --git a/lib/exported.sh.in b/lib/exported.sh.in
new file mode 100644
index 0000000..89e4008
--- /dev/null
+++ b/lib/exported.sh.in
@@ -0,0 +1,24 @@
+#! /bin/sh
+#
+# Copyright (C) 2006 Free Software Foundation, Inc.
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+
+# This is a script that determines the exported symbols of an object file.
+# This is a separate script because $(GLOBAL_SYMBOL_PIPE) cannot be used in a
+# Makefile, since it may contain dollar signs.
+
+nm_cmd="@NM@ $1 | @GLOBAL_SYMBOL_PIPE@"
+eval $nm_cmd