Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk/13? -- >8 -- We evaluate constexpr functions on the original, pre-genericization bodies. That means that the function body we're evaluating will not have gone through cp_genericize_r's "Map block scope extern declarations to visible declarations with the same name and type in outer scopes if any". Here:
constexpr bool bar() { return true; } // #1 constexpr bool foo() { constexpr bool bar(void); // #2 return bar(); } it means that we: 1) register_constexpr_fundef (#1) 2) cp_genericize (#1) nothing interesting happens 3) register_constexpr_fundef (foo) does copy_fn, so we have two copies of the BIND_EXPR 4) cp_genericize (foo) this remaps #2 to #1, but only on one copy of the BIND_EXPR 5) retrieve_constexpr_fundef (foo) we find it, no problem 6) retrieve_constexpr_fundef (#2) and here #2 isn't found in constexpr_fundef_table, because we're working on the BIND_EXPR copy where #2 wasn't mapped to #1 so we fail. We've only registered #1. It should work to use DECL_LOCAL_DECL_ALIAS (which used to be extern_decl_map). We evaluate constexpr functions on pre-cp_fold bodies to avoid diagnostic problems, but the remapping I'm proposing should not interfere with diagnostics. This is not a problem for a global scope redeclaration; there we go through duplicate_decls which keeps the DECL_UID: DECL_UID (olddecl) = olddecl_uid; and DECL_UID is what constexpr_fundef_hasher::hash uses. PR c++/111132 gcc/cp/ChangeLog: * constexpr.cc (get_function_named_in_call): If there's a DECL_LOCAL_DECL_ALIAS, use it. gcc/testsuite/ChangeLog: * g++.dg/cpp0x/constexpr-redeclaration3.C: New test. * g++.dg/cpp0x/constexpr-redeclaration4.C: New test. --- gcc/cp/constexpr.cc | 19 +++++++++++++++---- .../g++.dg/cpp0x/constexpr-redeclaration3.C | 13 +++++++++++++ .../g++.dg/cpp0x/constexpr-redeclaration4.C | 14 ++++++++++++++ 3 files changed, 42 insertions(+), 4 deletions(-) create mode 100644 gcc/testsuite/g++.dg/cpp0x/constexpr-redeclaration3.C create mode 100644 gcc/testsuite/g++.dg/cpp0x/constexpr-redeclaration4.C diff --git a/gcc/cp/constexpr.cc b/gcc/cp/constexpr.cc index fa346fe01c9..b47f0e984c0 100644 --- a/gcc/cp/constexpr.cc +++ b/gcc/cp/constexpr.cc @@ -702,15 +702,26 @@ build_constexpr_constructor_member_initializers (tree type, tree body) /* We have an expression tree T that represents a call, either CALL_EXPR or AGGR_INIT_EXPR. If the call is lexically to a named function, - retrun the _DECL for that function. */ + return the _DECL for that function. */ static tree get_function_named_in_call (tree t) { tree fun = cp_get_callee (t); - if (fun && TREE_CODE (fun) == ADDR_EXPR - && TREE_CODE (TREE_OPERAND (fun, 0)) == FUNCTION_DECL) - fun = TREE_OPERAND (fun, 0); + if (fun) + { + if (TREE_CODE (fun) == ADDR_EXPR + && TREE_CODE (TREE_OPERAND (fun, 0)) == FUNCTION_DECL) + fun = TREE_OPERAND (fun, 0); + /* We evaluate constexpr functions on the original, pre-genericization + bodies. So block-scope extern declarations have not been mapped to + declarations in outer scopes. Use the namespace-scope declaration, + if any, so that retrieve_constexpr_fundef can find it (PR111132). */ + if (TREE_CODE (fun) == FUNCTION_DECL && DECL_LOCAL_DECL_P (fun)) + if (tree alias = DECL_LOCAL_DECL_ALIAS (fun)) + if (alias != error_mark_node) + fun = alias; + } return fun; } diff --git a/gcc/testsuite/g++.dg/cpp0x/constexpr-redeclaration3.C b/gcc/testsuite/g++.dg/cpp0x/constexpr-redeclaration3.C new file mode 100644 index 00000000000..2b41b456fc3 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp0x/constexpr-redeclaration3.C @@ -0,0 +1,13 @@ +// PR c++/111132 +// { dg-do compile { target c++11 } } + +constexpr bool bar(void) { + return true; +} + +constexpr bool foo() { + constexpr bool bar(void); + return bar(); +} + +static_assert(foo(), ""); diff --git a/gcc/testsuite/g++.dg/cpp0x/constexpr-redeclaration4.C b/gcc/testsuite/g++.dg/cpp0x/constexpr-redeclaration4.C new file mode 100644 index 00000000000..c58247218c6 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp0x/constexpr-redeclaration4.C @@ -0,0 +1,14 @@ +// PR c++/111132 +// { dg-do compile { target c++11 } } + +constexpr bool bar(void) { + return true; +} + +constexpr bool bar(void); + +constexpr bool foo() { + return bar(); +} + +static_assert(foo(), ""); base-commit: 0e64bbb8823f7b3757befc878ed177dfb59943d1 -- 2.44.0