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We currently list P2115R0 as implemented, but only the modules changes had been done. This patch implements the linkage changes so that unnamed unscoped enums will use the name of the first enumerator for linkage purposes. This is (strictly speaking) a breaking change, as code that previously relied on unnamed enumerations being internal linkage may have overloads using those types become exposed and clash with other functions in a different TU that have been similarly exposed. As such this feature is only implemented for C++20. No ABI flag warning is provided, partly because C++20 is still an experimental standard, but also because any affected functions could not have been part of an ABI until this change anyway. A number of testcases that are testing for behaviour of no-linkage types are adjusted to use an enumeration with no values, so that the pre-C++20 and post-C++20 behaviour is equivalently tested. In terms of implementation, I had originally considered adjusting the DECL_NAME of the enum, as with 'name_unnamed_type', but this ended up being more complicated as it had unwanted interactions with the existing modules streaming and with name lookup and diagnostic messages. This patch instead uses a new function to derive this case. The standard says that ([dcl.enum] p11) such an enum "...is denoted, for linkage purposes, by its underlying type and its first enumerator", so we need to add a new mangling production as well to handle this. PR c++/120503 PR c++/120824 gcc/cp/ChangeLog: * cp-tree.h (TYPE_UNNAMED_P): Adjust for enums with enumerators for linkage purposes. (enum_with_enumerator_for_linkage_p): Declare. * decl.cc (name_unnamed_type): Adjust assertions to handle enums with enumerators for linkage purposes. (grokdeclarator): Use a typedef name for enums with enumerators for linkage purposes. (enum_with_enumerator_for_linkage_p): New function. (finish_enum_value_list): Reset type linkage for enums with enumerators for linkage purposes. * mangle.cc (write_unnamed_enum_name): New function. (write_unqualified_name): Handle enums with enumerators for linkage purposes. * tree.cc (decl_linkage): Fixup unnamed enums. gcc/testsuite/ChangeLog: * g++.dg/abi/mangle32.C: Remove enumerator list. * g++.dg/cpp0x/linkage2.C: Likewise. * g++.dg/ext/vector26.C: Likewise. * g++.dg/other/anon3.C: Likewise. * g++.dg/abi/mangle83.C: New test. * g++.dg/modules/enum-15_a.C: New test. * g++.dg/modules/enum-15_b.C: New test. include/ChangeLog: * demangle.h (enum demangle_component_type): Add enumeration DEMANGLE_COMPONENT_UNNAMED_ENUM. libiberty/ChangeLog: * cp-demangle.c (d_unnamed_enum): New function. (d_unqualified_name): Call it. (cplus_demangle_type): Handle unscoped unnamed types (Ue, Ul, etc.) (d_count_templates_scopes): Handle unnamed enums. (d_find_pack): Likewise. (d_print_comp_inner): Print unnamed enums. * testsuite/demangle-expected: Add tests. Signed-off-by: Nathaniel Shead <nathanieloshead@gmail.com> Reviewed-by: Jason Merrill <jason@redhat.com>
This directory contains the -liberty library of free software.
It is a collection of subroutines used by various GNU programs.
Current members include:
getopt -- get options from command line
obstack -- stacks of arbitrarily-sized objects
strerror -- error message strings corresponding to errno
strtol -- string-to-long conversion
strtoul -- string-to-unsigned-long conversion
We expect many of the GNU subroutines that are floating around to
eventually arrive here.
The library must be configured from the top source directory. Don't
try to run configure in this directory. Follow the configuration
instructions in ../README.
Please report bugs to https://gcc.gnu.org/bugzilla/ and send fixes to
"gcc-patches@gcc.gnu.org". Thank you.
ADDING A NEW FILE
=================
There are two sets of files: Those that are "required" will be
included in the library for all configurations, while those
that are "optional" will be included in the library only if "needed."
To add a new required file, edit Makefile.in to add the source file
name to CFILES and the object file to REQUIRED_OFILES.
To add a new optional file, it must provide a single function, and the
name of the function must be the same as the name of the file.
* Add the source file name to CFILES in Makefile.in and the object
file to CONFIGURED_OFILES.
* Add the function to name to the funcs shell variable in
configure.ac.
* Add the function to the AC_CHECK_FUNCS lists just after the
setting of the funcs shell variable. These AC_CHECK_FUNCS calls
are never executed; they are there to make autoheader work
better.
* Consider the special cases of building libiberty; as of this
writing, the special cases are newlib and VxWorks. If a
particular special case provides the function, you do not need
to do anything. If it does not provide the function, add the
object file to LIBOBJS, and add the function name to the case
controlling whether to define HAVE_func.
Finally, in the build directory of libiberty, configure with
"--enable-maintainer-mode", run "make maint-deps" to update
Makefile.in, and run 'make stamp-functions' to regenerate
functions.texi.
The optional file you've added (e.g. getcwd.c) should compile and work
on all hosts where it is needed. It does not have to work or even
compile on hosts where it is not needed.
ADDING A NEW CONFIGURATION
==========================
On most hosts you should be able to use the scheme for automatically
figuring out which files are needed. In that case, you probably
don't need a special Makefile stub for that configuration.
If the fully automatic scheme doesn't work, you may be able to get
by with defining EXTRA_OFILES in your Makefile stub. This is
a list of object file names that should be treated as required
for this configuration - they will be included in libiberty.a,
regardless of whatever might be in the C library.