We weren't replacing PLACEHOLDER_EXPR in the following testcase, leading to a crash in the gimplifier. The fix seems to be to use replace_placeholders, the question is where. These three functions have it: cp_gimplify_init_expr store_init_value build_new_1 But we call neither so I tried adding the call to build_over_call, right after we create the MODIFY_EXPR with the NSDMI, and that seemed to work out.
Bootstrapped/regtested on x86_64-linux, ok for trunk? 2017-03-03 Marek Polacek <pola...@redhat.com> PR c++/79796 - ICE with NSDMI and this pointer * call.c (build_over_call): Handle NSDMI with a 'this' by calling replace_placeholders. * g++.dg/cpp0x/nsdmi13.C: New test. diff --git gcc/cp/call.c gcc/cp/call.c index dc629b96..b821224 100644 --- gcc/cp/call.c +++ gcc/cp/call.c @@ -8047,6 +8047,9 @@ build_over_call (struct z_candidate *cand, int flags, tsubst_flags_t complain) { arg = cp_build_indirect_ref (arg, RO_NULL, complain); val = build2 (MODIFY_EXPR, TREE_TYPE (to), to, arg); + if (cxx_dialect >= cxx14) + /* Handle NSDMI that refer to the object being initialized. */ + replace_placeholders (arg, to); } else { diff --git gcc/testsuite/g++.dg/cpp0x/nsdmi13.C gcc/testsuite/g++.dg/cpp0x/nsdmi13.C index e69de29..2751da3 100644 --- gcc/testsuite/g++.dg/cpp0x/nsdmi13.C +++ gcc/testsuite/g++.dg/cpp0x/nsdmi13.C @@ -0,0 +1,13 @@ +// PR c++/79796 +// { dg-do compile { target c++11 } } + +struct A +{ + A* p = this; +}; + +void foo() +{ + A a; + a = A({}); +} Marek