Hi, in the testcase I don't really know how to put into testsuite since it needs DSO there is issue with LTO not merging external declaration with body. This is because logic in symtab_real_symbol_p that really applies only to LTO symbol table output not to the symbol merging.
Bootstrapped/regtested x86_64-linux and tested with Mozilla build. Honza PR lto/54728 * cgraph.h (symtab_real_symbol_p): Drop code looking for external functions. * lto-streamer-out.c (output_symbol_p): New function. (produce_symtab) Use it. Index: cgraph.h =================================================================== *** cgraph.h (revision 194605) --- cgraph.h (working copy) *************** static inline bool *** 1357,1363 **** symtab_real_symbol_p (symtab_node node) { struct cgraph_node *cnode; - struct ipa_ref *ref; if (!is_a <cgraph_node> (node)) return true; --- 1357,1362 ---- *************** symtab_real_symbol_p (symtab_node node) *** 1366,1376 **** return false; if (cnode->abstract_and_needed) return false; - /* We keep virtual clones in symtab. */ - if (!cnode->analyzed - || DECL_EXTERNAL (cnode->symbol.decl)) - return (cnode->callers - || ipa_ref_list_referring_iterate (&cnode->symbol.ref_list, 0, ref)); return true; } #endif /* GCC_CGRAPH_H */ --- 1365,1370 ---- Index: lto-streamer-out.c =================================================================== *** lto-streamer-out.c (revision 194605) --- lto-streamer-out.c (working copy) *************** write_symbol (struct streamer_tree_cache *** 1257,1262 **** --- 1257,1282 ---- lto_output_data_stream (stream, &slot_num, 4); } + /* Return true if NODE should appear in the plugin symbol table. */ + + bool + output_symbol_p (symtab_node node) + { + struct cgraph_node *cnode; + struct ipa_ref *ref; + + if (!symtab_real_symbol_p (node)) + return false; + /* We keep external functions in symtab for sake of inlining + and devirtualization. We do not want to see them in symbol table as + references. */ + cnode = dyn_cast <cgraph_node> (node); + if (cnode && DECL_EXTERNAL (cnode->symbol.decl)) + return (cnode->callers + || ipa_ref_list_referring_iterate (&cnode->symbol.ref_list, 0, ref)); + return true; + } + /* Write an IL symbol table to OB. SET and VSET are cgraph/varpool node sets we are outputting. */ *************** produce_symtab (struct output_block *ob) *** 1285,1291 **** { symtab_node node = lsei_node (lsei); ! if (!symtab_real_symbol_p (node) || DECL_EXTERNAL (node->symbol.decl)) continue; write_symbol (cache, &stream, node->symbol.decl, seen, false); } --- 1305,1311 ---- { symtab_node node = lsei_node (lsei); ! if (!output_symbol_p (node) || DECL_EXTERNAL (node->symbol.decl)) continue; write_symbol (cache, &stream, node->symbol.decl, seen, false); } *************** produce_symtab (struct output_block *ob) *** 1294,1300 **** { symtab_node node = lsei_node (lsei); ! if (!symtab_real_symbol_p (node) || !DECL_EXTERNAL (node->symbol.decl)) continue; write_symbol (cache, &stream, node->symbol.decl, seen, false); } --- 1314,1320 ---- { symtab_node node = lsei_node (lsei); ! if (!output_symbol_p (node) || !DECL_EXTERNAL (node->symbol.decl)) continue; write_symbol (cache, &stream, node->symbol.decl, seen, false); }