On 2/10/25 11:58 PM, Nathaniel Shead wrote:
Bootstrapped and regtested on x86_64-pc-linux-gnu (and additionally passed modules.exp with a checking=all build), OK for trunk?-- >8 -- When instantiating a friend function, we call register_specialization which adds it to the DECL_TEMPLATE_INSTANTIATIONS of the template. However, in some circumstances we might immediately call pushdecl and find an existing specialisation. In this case, when reregistering the specialisation we also need to update the DECL_TEMPLATE_INSTANTIATIONS list so that we don't try to access the freed spec again later. PR c++/118807 gcc/cp/ChangeLog: * pt.cc (reregister_specialization): Remove spec from DECL_TEMPLATE_INSTANTIATIONS. gcc/testsuite/ChangeLog: * g++.dg/modules/pr118807.C: New test. Signed-off-by: Nathaniel Shead <nathanielosh...@gmail.com> --- gcc/cp/pt.cc | 11 +++++++++++ gcc/testsuite/g++.dg/modules/pr118807.C | 11 +++++++++++ 2 files changed, 22 insertions(+) create mode 100644 gcc/testsuite/g++.dg/modules/pr118807.C diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc index 39232b5e67f..e1764743597 100644 --- a/gcc/cp/pt.cc +++ b/gcc/cp/pt.cc @@ -1985,6 +1985,17 @@ reregister_specialization (tree spec, tree tinfo, tree new_spec) gcc_assert (entry->spec == spec || entry->spec == new_spec); gcc_assert (new_spec != NULL_TREE); entry->spec = new_spec; + + /* We need to also remove the old specialisation from
Let's say "spec" instead of "old specialisation", old and new are kind of confusing here since in duplicate_decls, new_spec is olddecl and spec is newdecl.
OK with that tweak.
+ DECL_TEMPLATE_INSTANTIATIONS if it was placed there. */ + for (tree *inst = &DECL_TEMPLATE_INSTANTIATIONS (elt.tmpl); + *inst; inst = &TREE_CHAIN (*inst)) + if (TREE_VALUE (*inst) == spec) + { + *inst = TREE_CHAIN (*inst); + break; + } + return 1; }diff --git a/gcc/testsuite/g++.dg/modules/pr118807.C b/gcc/testsuite/g++.dg/modules/pr118807.Cnew file mode 100644 index 00000000000..a97afb92699 --- /dev/null +++ b/gcc/testsuite/g++.dg/modules/pr118807.C @@ -0,0 +1,11 @@ +// PR c++/118807 +// { dg-additional-options "-fmodules --param=ggc-min-expand=0 --param=ggc-min-heapsize=0 -Wno-global-module" } + +module; +template <typename> class basic_streambuf; +template <typename> struct basic_streambuf { + friend void __istream_extract(); +}; +template class basic_streambuf<char>; +template class basic_streambuf<wchar_t>; +export module M;
