From d78201d30c7c5a8f15f0265d64386233e134fb7d Mon Sep 17 00:00:00 2001 From: Jason Merrill Date: Tue, 23 Jan 2018 16:23:53 -0500 Subject: [PATCH] PR c++/83947 - ICE with auto declarations. * pt.c (do_auto_deduction): Don't deduce from an auto decl. * decl.c (undeduced_auto_decl): Limit to vars and fns. From-SVN: r257000 --- gcc/cp/ChangeLog | 6 ++++++ gcc/cp/decl.c | 8 +++++--- gcc/cp/pt.c | 4 ++++ gcc/testsuite/g++.dg/cpp1y/auto-fn46.C | 6 ++++++ 4 files changed, 21 insertions(+), 3 deletions(-) create mode 100644 gcc/testsuite/g++.dg/cpp1y/auto-fn46.C diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog index 1f26155ddf1..9c2cba99121 100644 --- a/gcc/cp/ChangeLog +++ b/gcc/cp/ChangeLog @@ -1,3 +1,9 @@ +2018-01-23 Jason Merrill + + PR c++/83947 - ICE with auto declarations. + * pt.c (do_auto_deduction): Don't deduce from an auto decl. + * decl.c (undeduced_auto_decl): Limit to vars and fns. + 2018-01-23 David Malcolm PR c++/83974 diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c index 5f197ef68d8..1970865f367 100644 --- a/gcc/cp/decl.c +++ b/gcc/cp/decl.c @@ -16195,15 +16195,17 @@ fndecl_declared_return_type (tree fn) return TREE_TYPE (TREE_TYPE (fn)); } -/* Returns true iff DECL was declared with an auto type and it has - not yet been deduced to a real type. */ +/* Returns true iff DECL is a variable or function declared with an auto type + that has not yet been deduced to a real type. */ bool undeduced_auto_decl (tree decl) { if (cxx_dialect < cxx11) return false; - return type_uses_auto (TREE_TYPE (decl)); + return ((VAR_OR_FUNCTION_DECL_P (decl) + || TREE_CODE (decl) == TEMPLATE_DECL) + && type_uses_auto (TREE_TYPE (decl))); } /* Complain if DECL has an undeduced return type. */ diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c index fe64b0647b0..d39b54ed408 100644 --- a/gcc/cp/pt.c +++ b/gcc/cp/pt.c @@ -25884,6 +25884,10 @@ do_auto_deduction (tree type, tree init, tree auto_node, from ahead of time isn't worth the trouble. */ return type; + /* Similarly, we can't deduce from another undeduced decl. */ + if (init && undeduced_auto_decl (init)) + return type; + if (tree tmpl = CLASS_PLACEHOLDER_TEMPLATE (auto_node)) /* C++17 class template argument deduction. */ return do_class_deduction (type, tmpl, init, flags, complain); diff --git a/gcc/testsuite/g++.dg/cpp1y/auto-fn46.C b/gcc/testsuite/g++.dg/cpp1y/auto-fn46.C new file mode 100644 index 00000000000..120a4dd9e7c --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp1y/auto-fn46.C @@ -0,0 +1,6 @@ +// PR c++/83947 +// { dg-do compile { target c++14 } } + +auto f (); +template < int > auto g (f); // { dg-error "before deduction" } +auto h = g < 0 > (); -- 2.30.2