From af4fa23fba220c1b26bb3c8a7996b406dcc181cc Mon Sep 17 00:00:00 2001 From: Alan Modra Date: Fri, 17 May 2019 19:09:42 +0930 Subject: [PATCH] PR24567, assertion failure in ldlang.c:6868 when compiling with -flto As the existing comment said: "a common ought to be overridden by a def in a -flto object". This patch makes the code actually do that, rather than allowing a normal object file common to override a -flto defined symbol. PR 24567 * plugin.c (plugin_notice): Do not let a common symbol override a non-common definition in IR. --- ld/ChangeLog | 6 ++++++ ld/plugin.c | 42 ++++++++++++++++++++++++------------------ 2 files changed, 30 insertions(+), 18 deletions(-) diff --git a/ld/ChangeLog b/ld/ChangeLog index 9ca4a4ed51a..90216dae56d 100644 --- a/ld/ChangeLog +++ b/ld/ChangeLog @@ -1,3 +1,9 @@ +2019-05-17 Alan Modra + + PR 24567 + * plugin.c (plugin_notice): Do not let a common symbol override + a non-common definition in IR. + 2019-05-09 Dimitar Dimitrov * scripttempl/pru.sc (__init_array_begin, __init_array_begin): diff --git a/ld/plugin.c b/ld/plugin.c index e3ca3240693..fcd864a117c 100644 --- a/ld/plugin.c +++ b/ld/plugin.c @@ -1406,30 +1406,36 @@ plugin_notice (struct bfd_link_info *info, ref = TRUE; } - /* Otherwise, it must be a new def. */ - else + + /* A common symbol should be merged with other commons or + defs with the same name. In particular, a common ought + to be overridden by a def in a -flto object. In that + sense a common is also a ref. */ + else if (bfd_is_com_section (section)) { - /* Ensure any symbol defined in an IR dummy BFD takes on a - new value from a real BFD. Weak symbols are not normally - overridden by a new weak definition, and strong symbols - will normally cause multiple definition errors. Avoid - this by making the symbol appear to be undefined. */ - if (((h->type == bfd_link_hash_defweak - || h->type == bfd_link_hash_defined) - && is_ir_dummy_bfd (sym_bfd = h->u.def.section->owner)) - || (h->type == bfd_link_hash_common - && is_ir_dummy_bfd (sym_bfd = h->u.c.p->section->owner))) + if (h->type == bfd_link_hash_common + && is_ir_dummy_bfd (sym_bfd = h->u.c.p->section->owner)) { h->type = bfd_link_hash_undefweak; h->u.undef.abfd = sym_bfd; } + ref = TRUE; + } - /* A common symbol should be merged with other commons or - defs with the same name. In particular, a common ought - to be overridden by a def in a -flto object. In that - sense a common is also a ref. */ - if (bfd_is_com_section (section)) - ref = TRUE; + /* Otherwise, it must be a new def. + Ensure any symbol defined in an IR dummy BFD takes on a + new value from a real BFD. Weak symbols are not normally + overridden by a new weak definition, and strong symbols + will normally cause multiple definition errors. Avoid + this by making the symbol appear to be undefined. */ + else if (((h->type == bfd_link_hash_defweak + || h->type == bfd_link_hash_defined) + && is_ir_dummy_bfd (sym_bfd = h->u.def.section->owner)) + || (h->type == bfd_link_hash_common + && is_ir_dummy_bfd (sym_bfd = h->u.c.p->section->owner))) + { + h->type = bfd_link_hash_undefweak; + h->u.undef.abfd = sym_bfd; } if (ref) -- 2.30.2