Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look OK for trunk/13?
-- >8 -- cp_fold is neglecting to propagate CONSTRUCTOR_MUTABLE_POISON when folding a CONSTRUCTOR initializer, which for the below testcase causes us to fail to reject a mutable member access of a constexpr variable during constexpr evaluation. PR c++/110463 gcc/cp/ChangeLog: * cp-gimplify.cc (cp_fold) <case CONSTRUCTOR>: Propagate CONSTRUCTOR_MUTABLE_POISON. gcc/testsuite/ChangeLog: * g++.dg/cpp0x/constexpr-mutable6.C: New test. --- gcc/cp/cp-gimplify.cc | 2 ++ .../g++.dg/cpp0x/constexpr-mutable6.C | 18 ++++++++++++++++++ 2 files changed, 20 insertions(+) create mode 100644 gcc/testsuite/g++.dg/cpp0x/constexpr-mutable6.C diff --git a/gcc/cp/cp-gimplify.cc b/gcc/cp/cp-gimplify.cc index 853b1e44236..f5734197774 100644 --- a/gcc/cp/cp-gimplify.cc +++ b/gcc/cp/cp-gimplify.cc @@ -3079,6 +3079,8 @@ cp_fold (tree x, fold_flags_t flags) x = build_constructor (TREE_TYPE (x), nelts); CONSTRUCTOR_PLACEHOLDER_BOUNDARY (x) = CONSTRUCTOR_PLACEHOLDER_BOUNDARY (org_x); + CONSTRUCTOR_MUTABLE_POISON (x) + = CONSTRUCTOR_MUTABLE_POISON (org_x); } if (VECTOR_TYPE_P (TREE_TYPE (x))) x = fold (x); diff --git a/gcc/testsuite/g++.dg/cpp0x/constexpr-mutable6.C b/gcc/testsuite/g++.dg/cpp0x/constexpr-mutable6.C new file mode 100644 index 00000000000..2c946e388ab --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp0x/constexpr-mutable6.C @@ -0,0 +1,18 @@ +// PR c++/110463 +// { dg-do compile { target c++11 } } + +struct U { + mutable int x = 1; +}; + +struct V { + mutable int y = 1+1; +}; + +int main() { + constexpr U u = {}; + constexpr int x = u.x; // { dg-error "mutable" } + + constexpr V v = {}; + constexpr int y = v.y; // { dg-error "mutable" } +} -- 2.41.0.199.ga9e066fa63