[libstdc++] Port-specific symbol exports, porting notes

[Phil Edwards <phil at jaj dot com>]

Some time ago, some symbols had to be added to the export list for the
sake of (at the time) a single platform.  I worked up a patch to allow
ports to individually list symbols that would be additionally exported,
but it also involved fixing more of GNU ld's linker versioning parser.
Now that a version of binutils has been officially released (2.14) which
contains the fix, we can start using the functionality on the trunk.

This also brings the "porting to a new platform" docs up to date.

(My editor keeps wanting to trim trailing whitespace in the makfiles,
so finally I just let it have its way for this patch.)

Tested on x86/linux for a long time.  Post-specific functionality tested
by just adding fake stuff to a random port and checking the output.


2003-07-05  Phil Edwards  <pme@gcc.gnu.org>

	* acinclude.m4 (GLIBCXX_ENABLE_SYMVERS):  Bump minimal version
	requirement.  Add port_specific_symbol_file variable.
	* configure.host:  Add docs for port_specific_symbol_file.
	Clean up try_cpu block for x86.
	* config/linker-map.gnu:  No more "last symbol can't have a
	semicolon" kaka.  Add hook for port-specific symbols.
	* src/Makefile.am:  Remove trailing whitespace.
	(libstdc++-symbol.ver):  Detect the presence of port-specific
	symbols, and add them accordingly.

	* docs/html/17_intro/porting.texi:  Bring up to date.

	* src/Makefile.in, aclocal.m4, configure,
	docs/html/17_intro/porting.html:  Regenerated.


Index: acinclude.m4
===================================================================
RCS file: /cvs/gcc/gcc/libstdc++-v3/acinclude.m4,v
retrieving revision 1.253
diff -u -3 -p -r1.253 acinclude.m4
--- acinclude.m4	5 Jul 2003 04:05:18 -0000	1.253
+++ acinclude.m4	6 Jul 2003 03:56:55 -0000
@@ -2258,9 +2258,9 @@ if test $enable_symvers != no; then
   AC_MSG_RESULT($glibcxx_shared_libgcc)
 fi
 
-# For GNU ld, we need at least this version.  It's 2.12 in the same format
+# For GNU ld, we need at least this version.  It's 2.14 in the same format
 # as the tested-for version.  See GLIBCXX_CHECK_LINKER_FEATURES for more.
-glibcxx_min_gnu_ld_version=21200
+glibcxx_min_gnu_ld_version=21400
 
 # Check to see if unspecified "yes" value can win, given results
 # above.
@@ -2305,6 +2305,7 @@ case $enable_symvers in
 esac
 
 AC_SUBST(SYMVER_MAP)
+AC_SUBST(port_specific_symbol_file)
 AM_CONDITIONAL(GLIBCXX_BUILD_VERSIONED_SHLIB, test $enable_symvers != no)
 AC_MSG_CHECKING([versioning on shared library symbols])
 AC_MSG_RESULT($enable_symvers)
Index: configure.host
===================================================================
RCS file: /cvs/gcc/gcc/libstdc++-v3/configure.host,v
retrieving revision 1.12
diff -u -3 -p -r1.12 configure.host
--- configure.host	5 Jul 2003 04:05:26 -0000	1.12
+++ configure.host	6 Jul 2003 03:56:58 -0000
@@ -41,6 +41,11 @@
 #                          the form '-Wl,blah'
 #                          (defaults to empty in acinclude.m4)
 #
+#   port_specific_symbol_file
+#                          whitespace-seperated list of files containing
+#                              additional symbols to export from the shared
+#                              library, when symbol versioning is in use
+#
 #
 # If the defaults will not work for your platform, you need only change the
 # variables that won't work, i.e., you do not need to explicitly set a
@@ -66,7 +71,7 @@ case "${host_cpu}" in
   alpha*)
     try_cpu=alpha
     ;;
-  athlon* | i586 | i686 | i786 | x86_64)
+  i[567]86 | x86_64)
     try_cpu=i486
     ;;
   hppa*)
Index: config/linker-map.gnu
===================================================================
RCS file: /cvs/gcc/gcc/libstdc++-v3/config/linker-map.gnu,v
retrieving revision 1.41
diff -u -3 -p -r1.41 linker-map.gnu
--- config/linker-map.gnu	5 Jul 2003 04:05:26 -0000	1.41
+++ config/linker-map.gnu	6 Jul 2003 03:56:58 -0000
@@ -1,4 +1,4 @@
-## Linker script for GNU ld 2.11.94+ only.
+## Linker script for GNU ld 2.13.91+ only.
 ##
 ## Copyright (C) 2002, 2003 Free Software Foundation, Inc.
 ##
@@ -25,7 +25,6 @@ GLIBCXX_3.4 {
   global:
 
     # Names inside the 'extern' block are demangled names.
-    # All but the last are terminated with a semicolon.
     extern "C++"
     {
       std::[A-Za-k]*;
@@ -56,7 +55,7 @@ GLIBCXX_3.4 {
       std::__num_base::_S_format_int*;
       std::__num_base::_S_atoms_in;
       std::__num_base::_S_atoms_out;
-      std::__numpunct_cache*
+      std::__numpunct_cache*;
     };
 
     # Names not in an 'extern' block are mangled names.
@@ -168,6 +167,8 @@ GLIBCXX_3.4 {
     _ZN9__gnu_cxx17_Atomic_add_mutexE;
     _ZN9__gnu_cxx22_Atomic_add_mutex_onceE;
     _ZN9__gnu_cxx31__gthread_atomic_add_mutex_onceEv;
+
+  # DO NOT DELETE THIS LINE.  Port-specific symbols, if any, will be here.
 
   local:
     *;
Index: docs/html/17_intro/porting.texi
===================================================================
RCS file: /cvs/gcc/gcc/libstdc++-v3/docs/html/17_intro/porting.texi,v
retrieving revision 1.11
diff -u -3 -p -r1.11 porting.texi
--- docs/html/17_intro/porting.texi	18 Apr 2003 09:53:42 -0000	1.11
+++ docs/html/17_intro/porting.texi	6 Jul 2003 03:56:59 -0000
@@ -9,7 +9,7 @@
 @setchapternewpage odd
 
 @copying
-Copyright @copyright{} 2000, 2001, 2002 Free Software Foundation, Inc.
+Copyright @copyright{} 2000, 2001, 2002, 2003 Free Software Foundation, Inc.
 
 Permission is granted to copy, distribute and/or modify this document
 under the terms of the GNU Free Documentation License, Version 1.2 or
@@ -74,6 +74,9 @@ In addition, you should try to verify th
 works.  It is difficult to test the C++ compiler without a working
 library, but you should at least try some minimal test cases.
 
+(Note that what we think of as a ``target,'' the library refers to as
+a ``host.''  The comment at the top of @file{configure.in} explains why.)
+
 Here are the primary steps required to port the library:
 
 @menu
@@ -106,7 +109,7 @@ directory.  The important information is
 directory under @file{config/os} to store the files for your operating
 system.
 
-You might have to change the @file{configure.target} file to ensure that
+You might have to change the @file{configure.host} file to ensure that
 your new directory is activated.  Look for the switch statement that sets
 @code{os_include_dir}, and add a pattern to handle your operating system
 if the default will not suffice.  The switch statement switches on only
@@ -150,45 +153,42 @@ need to define.  You will need to add th
 target.  It will not work to simply define these macros in
 @file{os_defines.h}.
 
-At this time, there are a few libstdc++-v3-specific macro which may be
-defined.  @code{_G_USING_THUNKS} may be defined to 0 to express that the
-port doesn't use thunks (although it is unclear that this is still
-useful since libio support isn't currently working and the g++ v3 ABI
-invalidates the assumption that some ports don't use thunks).
+At this time, there are a few libstdc++-v3-specific macros which may be
+defined:
 
-@code{_GLIBCPP_USE_C99_CHECK} may be defined to 1 to check C99
+@code{_GLIBCXX_USE_C99_CHECK} may be defined to 1 to check C99
 function declarations (which are not covered by specialization below)
 found in system headers against versions found in the library headers
 derived from the standard.
 
-@code{_GLIBCPP_USE_C99_DYNAMIC} may be defined to an expression that
+@code{_GLIBCXX_USE_C99_DYNAMIC} may be defined to an expression that
 yields 0 if and only if the system headers are exposing proper support
 for C99 functions (which are not covered by specialization below).  If
 defined, it must be 0 while bootstrapping the compiler/rebuilding the
 library.
 
-@code{_GLIBCPP_USE_C99_LONG_LONG_CHECK} may be defined to 1 to check
+@code{_GLIBCXX_USE_C99_LONG_LONG_CHECK} may be defined to 1 to check
 the set of C99 long long function declarations found in system headers
 against versions found in the library headers derived from the
 standard.
 
-@code{_GLIBCPP_USE_C99_LONG_LONG_DYNAMIC} may be defined to an
+@code{_GLIBCXX_USE_C99_LONG_LONG_DYNAMIC} may be defined to an
 expression that yields 0 if and only if the system headers are
 exposing proper support for the set of C99 long long functions.  If
 defined, it must be 0 while bootstrapping the compiler/rebuilding the
 library.
 
-@code{_GLIBCPP_USE_C99_FP_MACROS_DYNAMIC} may be defined to an
+@code{_GLIBCXX_USE_C99_FP_MACROS_DYNAMIC} may be defined to an
 expression that yields 0 if and only if the system headers
 are exposing proper support for the related set of macros.  If defined,
 it must be 0 while bootstrapping the compiler/rebuilding the library.
 
-@code{_GLIBCPP_USE_C99_FLOAT_TRANSCENDENTALS_CHECK} may be defined
+@code{_GLIBCXX_USE_C99_FLOAT_TRANSCENDENTALS_CHECK} may be defined
 to 1 to check the related set of function declarations found in system
 headers against versions found in the library headers derived from
 the standard.
 
-@code{_GLIBCPP_USE_C99_FLOAT_TRANSCENDENTALS_DYNAMIC} may be defined
+@code{_GLIBCXX_USE_C99_FLOAT_TRANSCENDENTALS_DYNAMIC} may be defined
 to an expression that yields 0 if and only if the system headers
 are exposing proper support for the related set of functions.  If defined,
 it must be 0 while bootstrapping the compiler/rebuilding the library.
@@ -197,8 +197,8 @@ Finally, you should bracket the entire f
 this:
 
 @example
-#ifndef _GLIBCPP_OS_DEFINES
-#define _GLIBCPP_OS_DEFINES
+#ifndef _GLIBCXX_OS_DEFINES
+#define _GLIBCXX_OS_DEFINES
 ...
 #endif
 @end example
@@ -222,14 +222,14 @@ setup files without explicit help.
 
 We recommend that for a target triplet @code{<CPU>-<vendor>-<OS>}, you
 name your configuration directory @file{config/cpu/<CPU>}.  If you do this,
-the configury will find the directory itself.  Otherwise you will need to
-edit the @file{configure.target} file and, in the switch statement that sets
+the configury will find the directory by itself.  Otherwise you will need to
+edit the @file{configure.host} file and, in the switch statement that sets
 @code{cpu_include_dir}, add a pattern to handle your chip.
 
 Note that some chip families share a single configuration directory, for
 example, @code{alpha}, @code{alphaev5}, and @code{alphaev6} all use the
 @file{config/cpu/alpha} directory, and there is an entry in the
-@file{configure.target} switch statement to handle this.
+@file{configure.host} switch statement to handle this.
 
 The @code{cpu_include_dir} sets default locations for the files controlling
 @ref{Thread safety} and @ref{Numeric limits}, if the defaults are not
@@ -474,14 +474,14 @@ see the @file{atomicity.h} file for IRIX
 Alternatively, if the primitives are more closely related to the OS
 than they are to the CPU, you can put the @file{atomicity.h} file in
 the @ref{Operating system} directory instead.  In this case, you must
-edit @file{configure.target}, and in the switch statement that handles
+edit @file{configure.host}, and in the switch statement that handles
 operating systems, override the @code{ATOMICITYH} variable to point to
 the appropriate @code{os_include_dir}.  For examples of this approach,
 see the @file{atomicity.h} file for AIX.
 
 With those bits out of the way, you have to actually write
 @file{atomicity.h} itself.  This file should be wrapped in an
-include guard named @code{_BITS_ATOMICITY_H}.  It should define one
+include guard named @code{_GLIBCXX_ATOMICITY_H}.  It should define one
 type, and two functions.  
 
 The type is @code{_Atomic_word}.  Here is the version used on IRIX:
Index: src/Makefile.am
===================================================================
RCS file: /cvs/gcc/gcc/libstdc++-v3/src/Makefile.am,v
retrieving revision 1.125
diff -u -3 -p -r1.125 Makefile.am
--- src/Makefile.am	5 Jul 2003 04:05:41 -0000	1.125
+++ src/Makefile.am	6 Jul 2003 03:56:59 -0000
@@ -37,9 +37,16 @@ toolexeclib_LTLIBRARIES = libstdc++.la
 
 # Symbol versioning for shared libraries.
 if GLIBCXX_BUILD_VERSIONED_SHLIB
+port_specific_symbol_file = @port_specific_symbol_file@
 version_arg = -Wl,--version-script=libstdc++-symbol.ver
 libstdc++-symbol.ver:  ${glibcxx_srcdir}/@SYMVER_MAP@
-	@LN_S@  ${glibcxx_srcdir}/@SYMVER_MAP@ ./libstdc++-symbol.ver || true
+	cp ${glibcxx_srcdir}/@SYMVER_MAP@ ./libstdc++-symbol.ver
+	if test "x${port_specific_symbol_file}" != x; then \
+	  sed -n '1,/DO NOT DELETE/p' $@ > tmp.top; \
+	  sed -n '/DO NOT DELETE/,$$p' $@ > tmp.bottom; \
+	  cat tmp.top $(port_specific_symbol_file) tmp.bottom > $@; \
+	  rm tmp.top tmp.bottom; \
+	fi
 else
 version_arg =
 libstdc++-symbol.ver:
@@ -106,7 +113,7 @@ time_members.cc: ${glibcxx_srcdir}/@CTIM
 # particular host, but with ad hoc naming rules.
 host_sources_extra = \
 	basic_file.cc \
-	c++locale.cc 
+	c++locale.cc
 
 c++locale.cc: ${glibcxx_srcdir}/@CLOCALE_CC@
 	@LN_S@ ${glibcxx_srcdir}/@CLOCALE_CC@ ./$@ || true
@@ -157,7 +164,7 @@ libstdc___la_DEPENDENCIES = libstdc++-sy
 
 libstdc___la_LDFLAGS = \
 	-version-info @libtool_VERSION@ ${version_arg} \
-	-lm @LIBUNWIND_FLAG@ 
+	-lm @LIBUNWIND_FLAG@
 
 
 # Use special rules for the deprecated source files so that they find
@@ -188,13 +195,13 @@ demangle.o: demangle.cc
 # modified in a per-library or per-sub-library way.  Need to manually
 # set this option because CONFIG_CXXFLAGS has to be after
 # OPTIMIZE_CXXFLAGS on the compile line so that -O2 can be overridden
-# as the occasion call for it. 
+# as the occasion calls for it.
 AM_CXXFLAGS = \
 	-fno-implicit-templates \
 	$(LIBSUPCXX_CXXFLAGS) \
 	$(WARN_CXXFLAGS) \
 	$(OPTIMIZE_CXXFLAGS) \
-	$(CONFIG_CXXFLAGS)  
+	$(CONFIG_CXXFLAGS)
 
 
 # libstdc++ libtool notes
@@ -216,7 +223,7 @@ AM_CXXFLAGS = \
 # CXXLINK, just after $(LIBTOOL), so that libtool doesn't have to
 # attempt to infer which configuration to use
 LTCXXCOMPILE = $(LIBTOOL) --tag CXX --mode=compile $(CXX) $(INCLUDES) \
-	       $(AM_CPPFLAGS) $(CPPFLAGS) $(CXXFLAGS) $(AM_CXXFLAGS) 
+	       $(AM_CPPFLAGS) $(CPPFLAGS) $(CXXFLAGS) $(AM_CXXFLAGS)
 
 # 3) We'd have a problem when building the shared libstdc++ object if
 # the rules automake generates would be used.  We cannot allow g++ to
@@ -234,13 +241,13 @@ all-local: build_debug
 install-data-local: install_debug
 else
 all-local:
-install-data-local: 
+install-data-local:
 endif
 
 debugdir = debug
 
 # Build parallel set of debug objects here.
-stamp-debug: 
+stamp-debug:
 	if test ! -d ${debugdir}; then \
 	  mkdir -p ${debugdir}; \
 	  (cd ${debugdir}; \
@@ -251,12 +258,12 @@ stamp-debug: 
 	      -e 's/install-data-local: install_debug/install-data-local:/' \
 	  < ../Makefile > Makefile) ; \
 	fi; \
-	echo `date` > stamp-debug; 
+	echo `date` > stamp-debug;
 
 build_debug: stamp-debug
 	(cd ${debugdir} && $(MAKE) CXXFLAGS='@DEBUG_FLAGS@' all)
 
 # Install debug library here.
-install_debug: 
+install_debug:
 	(cd ${debugdir} && $(MAKE) \
 	toolexeclibdir=@glibcxx_toolexeclibdir@/debug install)