From 994e0ad41529f5518fd013474a657968807d9ca5 Mon Sep 17 00:00:00 2001 From: Jakub Jelinek Date: Fri, 14 Feb 2020 00:11:24 +0100 Subject: [PATCH] c++: Emit DFP typeinfos even when DFP is disabled [PR92906] 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. 2020-02-14 Jakub Jelinek 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/ChangeLog | 12 ++++++++++++ gcc/cp/cp-tree.h | 10 ++++++++++ gcc/cp/mangle.c | 6 +++--- gcc/cp/rtti.c | 14 ++++++++++++++ 4 files changed, 39 insertions(+), 3 deletions(-) diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog index 793e4afffcb..11acab7008e 100644 --- a/gcc/cp/ChangeLog +++ b/gcc/cp/ChangeLog @@ -1,3 +1,15 @@ +2020-02-14 Jakub Jelinek + + 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. + 2020-02-13 Jason Merrill PR c++/93713 diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h index 53de2b0afe7..c1aafa1de3a 100644 --- a/gcc/cp/cp-tree.h +++ b/gcc/cp/cp-tree.h @@ -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_MAX]; #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" diff --git a/gcc/cp/mangle.c b/gcc/cp/mangle.c index 23baa382ed9..a0e888fde62 100644 --- a/gcc/cp/mangle.c +++ b/gcc/cp/mangle.c @@ -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 (); diff --git a/gcc/cp/rtti.c b/gcc/cp/rtti.c index 36c1b4ed7bc..f20941c413b 100644 --- a/gcc/cp/rtti.c +++ b/gcc/cp/rtti.c @@ -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; } -- 2.30.2