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| author | Marek Polacek <polacek@redhat.com> | 2024-11-25 09:45:13 -0500 |
|---|---|---|
| committer | Marek Polacek <polacek@redhat.com> | 2025-01-24 12:22:10 -0500 |
| commit | 10850f92b2a618ef1b1ad399530943ef4847823d (patch) | |
| tree | 2bbd1a6ac3b3beaa625ebd29971dcd2d3e69ea53 | |
| parent | 41a6d4f8aa659dd88fce2d831306affc91ba4d53 (diff) | |
| download | gcc-10850f92b2a618ef1b1ad399530943ef4847823d.zip gcc-10850f92b2a618ef1b1ad399530943ef4847823d.tar.gz gcc-10850f92b2a618ef1b1ad399530943ef4847823d.tar.bz2 | |
c++: ICE with nested anonymous union [PR117153]
In a template, for
union {
union {
T d;
};
};
build_anon_union_vars crates a malformed COMPONENT_REF: we have no
DECL_NAME for the nested anon union so we create something like "object.".
Most of the front end doesn't seem to care, but if such a tree gets to
potential_constant_expression, it can cause a crash.
We can use FIELD directly for the COMPONENT_REF's member. tsubst_stmt
should build up a proper one in:
if (VAR_P (decl) && !DECL_NAME (decl)
&& ANON_AGGR_TYPE_P (TREE_TYPE (decl)))
/* Anonymous aggregates are a special case. */
finish_anon_union (decl);
PR c++/117153
gcc/cp/ChangeLog:
* decl2.cc (build_anon_union_vars): Use FIELD for the second operand
of a COMPONENT_REF.
gcc/testsuite/ChangeLog:
* g++.dg/other/anon-union6.C: New test.
* g++.dg/other/anon-union7.C: New test.
Reviewed-by: Jason Merrill <jason@redhat.com>
| -rw-r--r-- | gcc/cp/decl2.cc | 2 | ||||
| -rw-r--r-- | gcc/testsuite/g++.dg/other/anon-union6.C | 13 | ||||
| -rw-r--r-- | gcc/testsuite/g++.dg/other/anon-union7.C | 16 |
3 files changed, 30 insertions, 1 deletions
diff --git a/gcc/cp/decl2.cc b/gcc/cp/decl2.cc index ffe1aa3..9e61afd 100644 --- a/gcc/cp/decl2.cc +++ b/gcc/cp/decl2.cc @@ -2032,7 +2032,7 @@ build_anon_union_vars (tree type, tree object) if (processing_template_decl) ref = build_min_nt_loc (UNKNOWN_LOCATION, COMPONENT_REF, object, - DECL_NAME (field), NULL_TREE); + field, NULL_TREE); else ref = build_class_member_access_expr (object, field, NULL_TREE, false, tf_warning_or_error); diff --git a/gcc/testsuite/g++.dg/other/anon-union6.C b/gcc/testsuite/g++.dg/other/anon-union6.C new file mode 100644 index 0000000..d1cde30 --- /dev/null +++ b/gcc/testsuite/g++.dg/other/anon-union6.C @@ -0,0 +1,13 @@ +// PR c++/117153 +// { dg-do compile } + +template<typename T> +void f() { + union { + union { + T d; + }; + }; + (void) (d + 0); +} +template void f<double>(); diff --git a/gcc/testsuite/g++.dg/other/anon-union7.C b/gcc/testsuite/g++.dg/other/anon-union7.C new file mode 100644 index 0000000..e89334a --- /dev/null +++ b/gcc/testsuite/g++.dg/other/anon-union7.C @@ -0,0 +1,16 @@ +// PR c++/117153 +// { dg-do compile { target c++11 } } + +using U = union { union { int a; }; }; + +U +foo () +{ + return {}; +} + +void +g () +{ + [[maybe_unused]] auto u = foo (); +} |