From 477e1843fd13958fbecafeb540a8876146a61e3a Mon Sep 17 00:00:00 2001 From: Jason Merrill Date: Thu, 28 Mar 2013 14:20:30 -0400 Subject: [PATCH] re PR c++/56728 (ICE using constexpr initialization and arrays) PR c++/56728 * semantics.c (potential_constant_expression_1) [NOP_EXPR]: Reject conversion from integer to pointer. (cxx_eval_constant_expression): Likewise. (cxx_eval_indirect_ref): Use the folded operand if we still think this might be constant. From-SVN: r197209 --- gcc/cp/ChangeLog | 9 +++++ gcc/cp/semantics.c | 21 +++++++++++ .../g++.dg/cpp0x/constexpr-reinterpret1.C | 37 +++++++++++++++++++ 3 files changed, 67 insertions(+) create mode 100644 gcc/testsuite/g++.dg/cpp0x/constexpr-reinterpret1.C diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog index ecc5503f37c..164c79700ca 100644 --- a/gcc/cp/ChangeLog +++ b/gcc/cp/ChangeLog @@ -1,3 +1,12 @@ +2013-03-28 Jason Merrill + + PR c++/56728 + * semantics.c (potential_constant_expression_1) [NOP_EXPR]: Reject + conversion from integer to pointer. + (cxx_eval_constant_expression): Likewise. + (cxx_eval_indirect_ref): Use the folded operand if we still think + this might be constant. + 2013-03-28 Paolo Carlini Manuel Lopez-Ibanez diff --git a/gcc/cp/semantics.c b/gcc/cp/semantics.c index 72b884ef2e4..0b8e2f74888 100644 --- a/gcc/cp/semantics.c +++ b/gcc/cp/semantics.c @@ -7661,6 +7661,8 @@ cxx_eval_indirect_ref (const constexpr_call *call, tree t, if (r == NULL_TREE) { + if (addr && op0 != orig_op0) + return build1 (INDIRECT_REF, TREE_TYPE (t), op0); if (!addr) VERIFY_CONSTANT (t); return t; @@ -8056,6 +8058,16 @@ cxx_eval_constant_expression (const constexpr_call *call, tree t, non_constant_p, overflow_p); if (*non_constant_p) return t; + if (POINTER_TYPE_P (TREE_TYPE (t)) + && TREE_CODE (op) == INTEGER_CST + && !integer_zerop (op)) + { + if (!allow_non_constant) + error_at (EXPR_LOC_OR_HERE (t), + "reinterpret_cast from integer to pointer"); + *non_constant_p = true; + return t; + } if (op == oldop) /* We didn't fold at the top so we could check for ptr-int conversion. */ @@ -8452,6 +8464,15 @@ potential_constant_expression_1 (tree t, bool want_rval, tsubst_flags_t flags) may change to something more specific to type-punning (DR 1312). */ { tree from = TREE_OPERAND (t, 0); + if (POINTER_TYPE_P (TREE_TYPE (t)) + && TREE_CODE (from) == INTEGER_CST + && !integer_zerop (from)) + { + if (flags & tf_error) + error_at (EXPR_LOC_OR_HERE (t), + "reinterpret_cast from integer to pointer"); + return false; + } return (potential_constant_expression_1 (from, TREE_CODE (t) != VIEW_CONVERT_EXPR, flags)); } diff --git a/gcc/testsuite/g++.dg/cpp0x/constexpr-reinterpret1.C b/gcc/testsuite/g++.dg/cpp0x/constexpr-reinterpret1.C new file mode 100644 index 00000000000..69db98bc772 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp0x/constexpr-reinterpret1.C @@ -0,0 +1,37 @@ +// PR c++/56728 +// { dg-require-effective-target c++11 } + +class B { +public: + static B instance; + class Inner + { + public: + class Wuzi + { + unsigned int m; + } m_Class[3]; + unsigned m_Int[4]; + }; + + constexpr static Inner & getInner() + { + /* I am surprised this is considered a constexpr */ + return *((Inner *)4); + } // { dg-error "reinterpret_cast" } +}; + +B B::instance; + +class A +{ +public: + constexpr A(B &bridge, B::Inner &bridge2, unsigned char index) + : m_Bridge(bridge), m_Wuz(bridge2.m_Class[index]) + {} + + B &m_Bridge; + B::Inner::Wuzi &m_Wuz; +}; +A works{B::instance, B::getInner(), 3}; +A crashnkill[1]{{B::instance, B::getInner(), 3}}; -- 2.30.2