From 96572464234a88949ebfc07207ae2ae04c63e53b Mon Sep 17 00:00:00 2001 From: Marek Polacek Date: Tue, 18 Feb 2025 12:18:31 -0500 Subject: c++: fix rejects-valid and ICE with constexpr NSDMI [PR110822] Since r10-7718 the attached tests produce an ICE in verify_address: error: constant not recomputed when 'ADDR_EXPR' changed but before that we wrongly rejected the tests with "is not a constant expression". This patch fixes both problems. Since r10-7718 replace_decl_r can replace {._M_dataplus=&._M_local_buf, ._M_local_buf=0} with {._M_dataplus=&HelloWorld._M_local_buf, ._M_local_buf=0} The initial &._M_local_buf was not constant, but since HelloWorld is a static VAR_DECL, the resulting &HelloWorld._M_local_buf should have been marked as TREE_CONSTANT. And since we're taking its address, the whole thing should be TREE_ADDRESSABLE. PR c++/114913 PR c++/110822 gcc/cp/ChangeLog: * constexpr.cc (replace_decl_r): If we've replaced something inside of an ADDR_EXPR, call cxx_mark_addressable and recompute_tree_invariant_for_addr_expr on the resulting ADDR_EXPR. gcc/testsuite/ChangeLog: * g++.dg/cpp0x/constexpr-nsdmi4.C: New test. * g++.dg/cpp0x/constexpr-nsdmi5.C: New test. Reviewed-by: Jason Merrill --- gcc/testsuite/g++.dg/cpp0x/constexpr-nsdmi4.C | 19 +++++++++++++++++++ gcc/testsuite/g++.dg/cpp0x/constexpr-nsdmi5.C | 15 +++++++++++++++ 2 files changed, 34 insertions(+) create mode 100644 gcc/testsuite/g++.dg/cpp0x/constexpr-nsdmi4.C create mode 100644 gcc/testsuite/g++.dg/cpp0x/constexpr-nsdmi5.C (limited to 'gcc/testsuite/g++.dg/cpp0x') diff --git a/gcc/testsuite/g++.dg/cpp0x/constexpr-nsdmi4.C b/gcc/testsuite/g++.dg/cpp0x/constexpr-nsdmi4.C new file mode 100644 index 0000000..360470d --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp0x/constexpr-nsdmi4.C @@ -0,0 +1,19 @@ +// PR c++/114913 +// { dg-do compile { target c++11 } } + +struct strt { + char *_M_dataplus; + char _M_local_buf = 0; + constexpr strt() + : _M_dataplus(&_M_local_buf) {} + constexpr strt(const strt &) + : _M_dataplus(&_M_local_buf) {} +}; + +constexpr strt +f () +{ + return {}; +} +constexpr strt HelloWorld = f(); +const char *a() { return HelloWorld._M_dataplus; } diff --git a/gcc/testsuite/g++.dg/cpp0x/constexpr-nsdmi5.C b/gcc/testsuite/g++.dg/cpp0x/constexpr-nsdmi5.C new file mode 100644 index 0000000..0a0acaa --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp0x/constexpr-nsdmi5.C @@ -0,0 +1,15 @@ +// PR c++/110822 +// { dg-do compile { target c++11 } } + +void __ostream_insert(const char*); +struct basic_string { + const char* _M_p; + char _M_local_buf[16] = {}; + constexpr basic_string() : _M_p(_M_local_buf) {} + const char *data() const { return _M_p; } +}; +constexpr basic_string f() { return {}; } +constexpr basic_string text = f(); +int main() { + __ostream_insert(text._M_p); +} -- cgit v1.1