d21252de6c
In the first testcase below, expand_aggr_init_1 sets up t's default constructor such that the ctor first zero-initializes the entire base b, followed by calling b's default constructor, the latter of which just default-initializes the array member b::m via a VEC_INIT_EXPR. So upon constexpr evaluation of this latter VEC_INIT_EXPR, ctx->ctor is nonempty due to the prior zero-initialization, and we proceed in cxx_eval_vec_init to append new constructor_elts to the end of ctx->ctor without first checking if a matching constructor_elt already exists. This leads to ctx->ctor having two matching constructor_elts for each index. This patch fixes this issue by truncating a zero-initialized array CONSTRUCTOR in cxx_eval_vec_init_1 before we begin appending array elements to it. We propagate its zeroed out state during evaluation by clearing CONSTRUCTOR_NO_CLEARING on each new appended aggregate element. gcc/cp/ChangeLog: PR c++/96282 * constexpr.c (cxx_eval_vec_init_1): Truncate ctx->ctor and then clear CONSTRUCTOR_NO_CLEARING on each appended element initializer if we're initializing a previously zero-initialized array object. gcc/testsuite/ChangeLog: PR c++/96282 * g++.dg/cpp0x/constexpr-array26.C: New test. * g++.dg/cpp0x/constexpr-array27.C: New test. * g++.dg/cpp2a/constexpr-init18.C: New test. Co-authored-by: Jason Merrill <jason@redhat.com>
14 lines
243 B
C
14 lines
243 B
C
// PR c++/96282
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// { dg-do compile { target c++11 } }
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struct e { bool v = true; e *p = this; };
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template<int N>
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struct b { e m[N][N]; };
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template<int N>
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struct t : b<N> { constexpr t() : b<N>() {} };
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constexpr t<1> h1;
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constexpr t<42> h2;
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