https://gcc.gnu.org/g:8e4107a1b3d430f5d3938c8068c6cd512f661e95
commit r16-6696-g8e4107a1b3d430f5d3938c8068c6cd512f661e95 Author: Michal Jires <[email protected]> Date: Fri Dec 19 17:09:16 2025 +0100 lto: Fix SegFault in ICF caused by missing body During LTO symbol merging, weak symbols may be resolved to external definition. We reset the symbol, so the body might be released in unreachability pass. But we didn't mark the symbol with body_removed, so ICF assumed the body was still there causing SegFault. gcc/lto/ChangeLog: * lto-symtab.cc (lto_symtab_merge_symbols): Set body_removed for symbols resolved outside of IR. gcc/testsuite/ChangeLog: * gcc.dg/lto/attr-weakref-2_0.c: New test. * gcc.dg/lto/attr-weakref-2_1.c: New test. Diff: --- gcc/lto/lto-symtab.cc | 1 + gcc/testsuite/gcc.dg/lto/attr-weakref-2_0.c | 11 +++++++++++ gcc/testsuite/gcc.dg/lto/attr-weakref-2_1.c | 3 +++ 3 files changed, 15 insertions(+) diff --git a/gcc/lto/lto-symtab.cc b/gcc/lto/lto-symtab.cc index b8759a7fef55..b458462dc237 100644 --- a/gcc/lto/lto-symtab.cc +++ b/gcc/lto/lto-symtab.cc @@ -1043,6 +1043,7 @@ lto_symtab_merge_symbols (void) node->analyzed = node->definition = false; node->remove_all_references (); } + node->body_removed = true; } DECL_EXTERNAL (node->decl) = 1; } diff --git a/gcc/testsuite/gcc.dg/lto/attr-weakref-2_0.c b/gcc/testsuite/gcc.dg/lto/attr-weakref-2_0.c new file mode 100644 index 000000000000..a55ef28bd131 --- /dev/null +++ b/gcc/testsuite/gcc.dg/lto/attr-weakref-2_0.c @@ -0,0 +1,11 @@ +/* { dg-lto-do link } */ +/* { dg-lto-options {{-O2 -flto}} } */ + +#define __weak __attribute__((__weak__)) +void __weak other() {} +void __weak fn() {} + +int main() { + fn(); + other(); +} diff --git a/gcc/testsuite/gcc.dg/lto/attr-weakref-2_1.c b/gcc/testsuite/gcc.dg/lto/attr-weakref-2_1.c new file mode 100644 index 000000000000..639093fba466 --- /dev/null +++ b/gcc/testsuite/gcc.dg/lto/attr-weakref-2_1.c @@ -0,0 +1,3 @@ +/* { dg-options {{-fno-lto}} } */ + +void fn() {}
