On Thu, Mar 02, 2023 at 11:48:04AM -0500, Jason Merrill wrote: > > The stmtexpr19.C testcase used to be rejected as it has a static > > variable in statement expression in constexpr context, but as that > > static variable is initialized by constant expression, when P2647R1 > > was implemented we agreed to make it valid. > > > > Now, as reported, the testcase compiles fine, but doesn't actually link > > because the static variable isn't defined anywhere, and with -flto ICEs > > because of this problem. This is because we never > > varpool_node::finalize_decl those vars, the constant expression in which > > the DECL_EXPR is present for the static VAR_DECL is folded (constant > > evaluated) into just the address of the VAR_DECL. > > Would it make sense to define it when we see the DECL_EXPR in constant > evaluation?
So like this? Passes GXX_TESTSUITE_STDS=98,11,14,17,20,2b make check-g++ so far. 2023-03-03 Jakub Jelinek <ja...@redhat.com> PR c++/108702 * constexpr.cc: Include toplev.h. (cxx_eval_constant_expression) <case DECL_EXPR>: When seeing a local static initialized by constant expression outside of a constexpr function which has been deferred by make_rtl_for_nonlocal_decl, call rest_of_decl_compilation on it. * g++.dg/ext/stmtexpr19.C: Use dg-do link rather than dg-do compile. --- gcc/cp/constexpr.cc.jj 2023-03-03 00:34:44.113679918 +0100 +++ gcc/cp/constexpr.cc 2023-03-03 13:26:57.602871900 +0100 @@ -40,6 +40,7 @@ along with GCC; see the file COPYING3. #include "attribs.h" #include "fold-const.h" #include "intl.h" +#include "toplev.h" static bool verify_constant (tree, bool, bool *, bool *); #define VERIFY_CONSTANT(X) \ @@ -7127,6 +7128,24 @@ cxx_eval_constant_expression (const cons break; } + /* make_rtl_for_nonlocal_decl could have deferred emission of + a local static var, but if it appears in a statement expression + which is constant expression evaluated to e.g. just the address + of the variable, its DECL_EXPR will never be seen during + gimple lowering's record_vars_into as the statement expression + will not be in the IL at all. */ + if (VAR_P (r) + && TREE_STATIC (r) + && !DECL_REALLY_EXTERN (r) + && DECL_FUNCTION_SCOPE_P (r) + && !var_in_maybe_constexpr_fn (r) + && decl_constant_var_p (r)) + { + varpool_node *node = varpool_node::get (r); + if (node == NULL || !node->definition) + rest_of_decl_compilation (r, 0, at_eof); + } + if (AGGREGATE_TYPE_P (TREE_TYPE (r)) || VECTOR_TYPE_P (TREE_TYPE (r))) { --- gcc/testsuite/g++.dg/ext/stmtexpr19.C.jj 2023-02-09 15:52:29.623359240 +0100 +++ gcc/testsuite/g++.dg/ext/stmtexpr19.C 2023-03-03 12:24:20.217186735 +0100 @@ -1,6 +1,6 @@ // PR c++/81073 // { dg-options "" } -// { dg-do compile { target c++11 } } +// { dg-do link { target c++11 } } struct test { const int *addr; }; Jakub