On 12/02/20 12:31 +0100, Jakub Jelinek wrote:
Hi!
Before Joseph's changes when compiling
libstdc++-v3/libsupc++/fundamental_type_info.cc
we were emitting
_ZTIPDd, _ZTIPDe, _ZTIPDf, _ZTIPKDd, _ZTIPKDe, _ZTIPKDf, _ZTIDd, _ZTIDe, _ZTIDf
symbols even when DFP wasn't usable, but now we don't and thus those 9
symbols @@CXXABI_1.3.4 are gone from libstdc++. While nothing could
probably use it (except perhaps dlsym etc.), various tools don't really like
symbols disappearing from symbol versioned shared libraries with stable ABI.
Adding those in assembly would be possible, but would be a portability
nightmare (the PR has something Red Hat uses in libstdc++_nonshared.a, but that
can handle only a handful of linux ELF targets we care about).
So, instead this patch hacks up the FE, so that it emits those, but in a way
that won't make the DFP types available again on targets that don't support
them.
Bootstrapped/regtested on x86_64-linux and i686-linux (where it doesn't
change anything, because DFP is supported), aarch64-linux (where it fixed
FAIL: libstdc++-abi/abi_check
) and armv7hl-linux (where abi_check didn't fail because we don't have
baseline file, but comparing abilist of unpatched and patched libstdc++.so.6
shows:
+_ZTIDd@@CXXABI_1.3.4 OBJECT WEAK DEFAULT 8
+_ZTIDe@@CXXABI_1.3.4 OBJECT WEAK DEFAULT 8
+_ZTIDf@@CXXABI_1.3.4 OBJECT WEAK DEFAULT 8
+_ZTIPDd@@CXXABI_1.3.4 OBJECT WEAK DEFAULT 16
+_ZTIPDe@@CXXABI_1.3.4 OBJECT WEAK DEFAULT 16
+_ZTIPDf@@CXXABI_1.3.4 OBJECT WEAK DEFAULT 16
+_ZTIPKDd@@CXXABI_1.3.4 OBJECT WEAK DEFAULT 16
+_ZTIPKDe@@CXXABI_1.3.4 OBJECT WEAK DEFAULT 16
+_ZTIPKDf@@CXXABI_1.3.4 OBJECT WEAK DEFAULT 16
). Ok for trunk?
It seems less hacky than the aliases that would be needed in
libstdc++.so to solve it purely in the library.
