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?
2020-02-12 Jakub Jelinek <ja...@redhat.com>
PR libstdc++/92906
* cp-tree.h (enum cp_tree_index): Add CPTI_FALLBACK_DFLOAT32_TYPE,
CPTI_FALLBACK_DFLOAT64_TYPE and CPTI_FALLBACK_DFLOAT128_TYPE.
(fallback_dfloat32_type, fallback_dfloat64_type,
fallback_dfloat128_type): Define.
* mangle.c (write_builtin_type): Handle fallback_dfloat*_type like
dfloat*_type_node.
* rtti.c (emit_support_tinfos): Emit DFP typeinfos even when dfp
is disabled for compatibility.
--- gcc/cp/cp-tree.h.jj 2020-02-10 15:02:05.031846484 +0100
+++ gcc/cp/cp-tree.h 2020-02-11 23:00:25.561410042 +0100
@@ -206,6 +206,10 @@ enum cp_tree_index
CPTI_SOURCE_LOCATION_IMPL,
+ CPTI_FALLBACK_DFLOAT32_TYPE,
+ CPTI_FALLBACK_DFLOAT64_TYPE,
+ CPTI_FALLBACK_DFLOAT128_TYPE,
+
CPTI_MAX
};
@@ -366,6 +370,12 @@ extern GTY(()) tree cp_global_trees[CPTI
#define access_default_node null_node
+/* Variant of dfloat{32,64,128}_type_node only used for fundamental
+ rtti purposes if DFP is disabled. */
+#define fallback_dfloat32_type
cp_global_trees[CPTI_FALLBACK_DFLOAT32_TYPE]
+#define fallback_dfloat64_type
cp_global_trees[CPTI_FALLBACK_DFLOAT64_TYPE]
+#define fallback_dfloat128_type
cp_global_trees[CPTI_FALLBACK_DFLOAT128_TYPE]
+
#include "name-lookup.h"
--- gcc/cp/mangle.c.jj 2020-01-21 09:13:43.339634944 +0100
+++ gcc/cp/mangle.c 2020-02-11 22:59:28.466265009 +0100
@@ -2569,11 +2569,11 @@ write_builtin_type (tree type)
write_char ('d');
else if (type == long_double_type_node)
write_char ('e');
- else if (type == dfloat32_type_node)
+ else if (type == dfloat32_type_node || type == fallback_dfloat32_type)
write_string ("Df");
- else if (type == dfloat64_type_node)
+ else if (type == dfloat64_type_node || type == fallback_dfloat64_type)
write_string ("Dd");
- else if (type == dfloat128_type_node)
+ else if (type == dfloat128_type_node || type == fallback_dfloat128_type)
write_string ("De");
else
gcc_unreachable ();
--- gcc/cp/rtti.c.jj 2020-01-21 09:13:43.359634642 +0100
+++ gcc/cp/rtti.c 2020-02-11 22:59:28.467264994 +0100
@@ -1588,6 +1588,20 @@ emit_support_tinfos (void)
}
for (tree t = registered_builtin_types; t; t = TREE_CHAIN (t))
emit_support_tinfo_1 (TREE_VALUE (t));
+ /* For compatibility, emit DFP typeinfos even when DFP isn't enabled,
+ because we've emitted that in the past. */
+ if (!targetm.decimal_float_supported_p ())
+ {
+ gcc_assert (dfloat32_type_node == NULL_TREE
+ && dfloat64_type_node == NULL_TREE
+ && dfloat128_type_node == NULL_TREE);
+ fallback_dfloat32_type = make_node (REAL_TYPE);
+ fallback_dfloat64_type = make_node (REAL_TYPE);
+ fallback_dfloat128_type = make_node (REAL_TYPE);
+ emit_support_tinfo_1 (fallback_dfloat32_type);
+ emit_support_tinfo_1 (fallback_dfloat64_type);
+ emit_support_tinfo_1 (fallback_dfloat128_type);
+ }
input_location = saved_loc;
}
Jakub
