* doc/libtool.texi (Invoking libtool): Mention --tag=TAG.

(Tags, Trace interface): New nodes. * m4/libtool.m4 (LT_SUPPORTED_TAG): New macro. (_LT_LANG): Call it. * tests/tagtrace.test: New file. * tests/Makefile.am (TESTS): Add tagtrace.test. * tests/defs: Define AUTOCONF.
2025-02-17 15:10:02 +08:00 · 2004-05-17 17:42:44 +00:00 · 2004-05-17 17:42:44 +00:00 · 639afd859e
commit 639afd859e
parent 74e63154f4
5 changed files with 103 additions and 13 deletions
--- a/11
+++ b/11
@ -1,3 +1,14 @@
+2004-05-16  Alexandre Duret-Lutz  <adl@gnu.org>
+
+	* doc/libtool.texi (Invoking libtool): Mention --tag=TAG.
+	(Tags, Trace interface): New nodes.
+	* m4/libtool.m4 (LT_SUPPORTED_TAG): New macro.
+	(_LT_LANG): Call it.
+	* tests/tagtrace.test: New file.
+	* tests/Makefile.am
+	(TESTS): Add tagtrace.test.
+	* tests/defs: Define AUTOCONF.
+
 2004-05-14  Mike Gorchak  <lestat@i.com.ua>

 	* ltmain.in: Add new qnx version type support.
--- a/doc/libtool.texi
+++ b/doc/libtool.texi
@ -92,6 +92,7 @@ version @value{VERSION}.
 * Inter-library dependencies::  Libraries that depend on other libraries.
 * Dlopened modules::            @code{dlopen}ing libtool-created libraries.
 * Using libltdl::               Libtool's portable @code{dlopen} wrapper library.
+* Trace interface::             Libtool's trace interface.
 * Troubleshooting::             When libtool doesn't work as advertised.
 * Maintaining::                 Information used by the libtool maintainer.
 * GNU Free Documentation License:: License for this manual.
@ -141,7 +142,12 @@ Configuring libtool
 Including libtool in your package

 * Invoking libtoolize::         @code{libtoolize} command line options.
-* Autoconf and LTLIBOBJS::      Autoconf automates LTLIBOBJ generation.
+* Autoconf and LTLIBOBJS::      Autoconf automates LTLIBOBJS generation.
+
+Using libtool with other languages
+
+* C++ libraries::
+* Tags::                        Using Tags.

 Library interface versions

@ -165,15 +171,11 @@ Using libltdl

 * Libltdl interface::           How to use libltdl in your programs.
 * Modules for libltdl::         Creating modules that can be @code{dlopen}ed.
-* Thread Saftey in libltdl::	Registering callbacks for multi-thread safety.
+* Thread Safety in libltdl::    Registering callbacks for multi-thread safety.
 * User defined module data::    Associating data with loaded modules.
 * Module loaders for libltdl::  Creating user defined module loaders.
 * Distributing libltdl::        How to distribute libltdl with your package.

-Using libtool with other languages
-
-* C++ libraries::
-
 Troubleshooting

 * Libtool test suite::          Libtool's self-tests.
@ -202,7 +204,7 @@ Platform quirks
 * References::                  Finding more information.
 * Compilers::                   Creating object files from source files.
 * Reloadable objects::          Binding object files together.
-* Multiple dependencies::	Removing duplicate dependent libraries.
+* Multiple dependencies::       Removing duplicate dependent libraries.
 * Archivers::                   Programs that create static archives.

@end detailmenu
@ -1148,6 +1150,9 @@ Delete installed libraries or executables.
 Delete uninstalled libraries or executables.
@end table

+@item --tag=@var{tag}
+Use configuration variables from tag @var{tag} (@pxref{Tags}).
+
@item --preserve-dup-deps
 Do not remove duplicate dependencies in libraries.  When building packages
 with static libraries, the libraries may depend circularly on each other
@ -2167,6 +2172,7 @@ and what special considerations you need to make if you do not use C.

@menu
 * C++ libraries::
+* Tags::
@end menu

@node C++ libraries
@ -2206,6 +2212,44 @@ some instances the @code{main()} function of a program must also be
 compiled with the C++ compiler for static C++ objects to be properly
 initialized.

+@node Tags
+@section Tags
+@cindex tag names
+@cindex language names
+@cindex inferring tags
+
+Libtool supports multiple languages through the use of tags.  Technically
+a tag corresponds to a set of configuration variables associated with a
+language.  These variables tell @command{libtool} how it should create
+objects and libraries for each language.
+
+Tags are defined at @command{configure}-time for each language activated
+in the package (see @code{LT_LANG} in @ref{LT_INIT}).  Here is the
+correspondence between language names and tags names.
+
+@multitable {Windows Resource} {Tag name}
+@item Language name    @tab Tag name
+@item C                @tab
+@item C++              @tab CXX
+@item Java             @tab GCJ
+@item Fortran 77       @tab F77
+@item Windows Resource @tab RC
+@end multitable
+
+@command{libtool} tries to automatically infer which tag to use from
+the compiler command being used to compile or link.  If it can't infer
+a tag, then it defaults to the configuration for the @code{C} language.
+
+The tag can also be specified using @command{libtool}'s
+@code{--tag=@var{tag}} option (@pxref{Invoking libtool}).  It is a good
+idea to do so in @file{Makefile} rules, because that will allow users to
+substitute the compiler without relying on @command{libtool} inference
+heuristics.  Note that there is no tag for @code{C} because that is
+the default configuration.
+
+Finally, the set of tags available in a particular project can be
+retrieved by tracing for the @code{LT_SUPPORTED_TAG} macro (@pxref{Trace
+interface}).

@node Versioning
@chapter Library interface versions
@ -2928,7 +2972,7 @@ distribution terms that you use for the rest of that program.
@menu
 * Libltdl interface::           How to use libltdl in your programs.
 * Modules for libltdl::         Creating modules that can be @code{dlopen}ed.
-* Thread Saftey in libltdl::	Registering callbacks for multi-thread safety.
+* Thread Safety in libltdl::    Registering callbacks for multi-thread safety.
 * User defined module data::    Associating data with loaded modules.
 * Module loaders for libltdl::  Creating user defined module loaders.
 * Distributing libltdl::        How to distribute libltdl with your package.
@ -2960,7 +3004,7 @@ your application in order to use this version of libltdl.

@noindent
 Note that libltdl is not well tested in a multithreaded environment,
-though the intention is that it should work (@pxref{Thread Saftey
+though the intention is that it should work (@pxref{Thread Safety
 in libltdl, , Using libtldl in a multi threaded environment}).  It was
 reported that @sc{gnu}/Linux's glibc 2.0's @code{dlopen} with
@samp{RTLD_LAZY} (which libltdl uses by default) is not thread-safe,
@ -3251,7 +3295,7 @@ foo1_la_LDFLAGS = -module
@end example


-@node Thread Saftey in libltdl
+@node Thread Safety in libltdl
@section Using libtldl in a multi threaded environment

 Libltdl provides a wrapper around whatever dynamic run-time object
@ -3785,6 +3829,31 @@ myprog_DEPENDENCIES = $(LIBLTDL) foo1.la
@end example


+@node Trace interface
+@chapter Libtool's trace interface
+@cindex trace interface
+@cindex autoconf traces
+
+This section describes macros whose sole purpose is to be traced using
+Autoconf's @code{--trace} option (@pxref{autoconf Invocation, , The
+Autoconf Manual, autoconf, The Autoconf Manual}) to query the Libtool
+configuration of a project.  These macros are called by Libtool
+internals and should never be called by user code; they should only be
+traced.
+
+@defmac LT_SUPPORTED_TAG (@var{tag})
+This macro is called once for each language enabled in the package.  Its
+only argument, @var{tag}, is the tag-name corresponding to the language
+(@pxref{Tags}).
+
+You can therefore retrieve the list of all tags enabled in a project
+using the following command:
+@example
+autoconf --trace 'LT_SUPPORTED_TAG:$1'
+@end example
+@end defmac
+
+
@node Troubleshooting
@chapter Troubleshooting
@cindex troubleshooting
@ -4270,7 +4339,7 @@ write your own.
 * References::                  Finding more information.
 * Compilers::                   Creating object files from source files.
 * Reloadable objects::          Binding object files together.
-* Multiple dependencies::	Removing duplicate dependent libraries.
+* Multiple dependencies::       Removing duplicate dependent libraries.
 * Archivers::                   Programs that create static archives.
@end menu

--- a/m4/libtool.m4
+++ b/m4/libtool.m4
@ -554,6 +554,14 @@ _LT_EOF
 ])# _LT_CONFIG


+# LT_SUPPORTED_TAG(TAG)
+# ---------------------
+# Trace this macro to discover what tags are supported by the libtool
+# --tag option, using:
+#    autoconf --trace 'LT_SUPPORTED_TAG:$1'
+AC_DEFUN([LT_SUPPORTED_TAG], [])
+
+
 # C support is built-in for now
 m4_define([_LT_LANG_C_enabled], [])
 m4_define([_LT_TAGS], [])
@ -577,7 +585,8 @@ AC_DEFUN([LT_LANG],
 # ------------------
 m4_define([_LT_LANG],
 [m4_ifdef([_LT_LANG_]$1[_enabled], [],
-  [m4_append([_LT_TAGS], [$1 ])dnl
+  [LT_SUPPORTED_TAG([$1])dnl
+  m4_append([_LT_TAGS], [$1 ])dnl
  m4_define([_LT_LANG_]$1[_enabled], [])dnl
  _LT_LANG_$1_CONFIG($1)])dnl
 ])# _LT_LANG
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@ -12,7 +12,7 @@ F77_TESTS = \

 COMMON_TESTS = \
 	assign.test link.test link-2.test nomode.test \
-	quote.test sh.test suffix.test \
+	quote.test sh.test suffix.test tagtrace.test \
 	cdemo-static.test cdemo-make.test cdemo-exec.test \
 	demo-static.test demo-make.test demo-exec.test \
 	demo-inst.test demo-unst.test \
--- a/tests/defs
+++ b/tests/defs
@ -19,6 +19,7 @@ prefix="./_inst"
 make="${MAKE-make}"
 SHELL="${CONFIG_SHELL-/bin/sh}"
 MKDIR="${MKDIR-mkdir}"
+AUTOCONF="${AUTOCONF-autoconf}"

 if echo a | (grep -E '(a|b)') >/dev/null 2>&1; then
  EGREP='grep -E'