From 5a752e3f7920c1d72c130096e0e0fea023cf8ffc Mon Sep 17 00:00:00 2001 From: Nathan Sidwell Date: Thu, 18 Jan 2018 11:53:50 +0000 Subject: [PATCH] PR c++/83160] local ref to capture https://gcc.gnu.org/ml/gcc-patches/2018-01/msg01638.html PR c++/83160 * cp-tree.h (mark_use): Declare. * expr.c (mark_use): Make extern. * call.c (direct_reference_binding): Set inner conv's rvaluedness_matches_p, if it is an identity. (convert_like_real): Mark lvalue or rvalue use for identity as rvaledness_matches_p demands. PR c++/83160 * g++.dg/cpp0x/pr83160.C: New. From-SVN: r256842 --- gcc/cp/ChangeLog | 10 +++++++++ gcc/cp/call.c | 12 ++++++++-- gcc/cp/cp-tree.h | 3 +++ gcc/cp/expr.c | 2 +- gcc/testsuite/ChangeLog | 5 +++++ gcc/testsuite/g++.dg/cpp0x/pr83160.C | 33 ++++++++++++++++++++++++++++ 6 files changed, 62 insertions(+), 3 deletions(-) create mode 100644 gcc/testsuite/g++.dg/cpp0x/pr83160.C diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog index 998e0b9925e..0cacefa674d 100644 --- a/gcc/cp/ChangeLog +++ b/gcc/cp/ChangeLog @@ -1,3 +1,13 @@ +2018-01-18 Nathan Sidwell + + PR c++/83160 + * cp-tree.h (mark_use): Declare. + * expr.c (mark_use): Make extern. + * call.c (direct_reference_binding): Set inner conv's + rvaluedness_matches_p, if it is an identity. + (convert_like_real): Mark lvalue or rvalue use for identity as + rvaledness_matches_p demands. + 2018-01-18 Jakub Jelinek PR c++/83824 diff --git a/gcc/cp/call.c b/gcc/cp/call.c index 1f326d5c1ad..e08622ce9c2 100644 --- a/gcc/cp/call.c +++ b/gcc/cp/call.c @@ -102,7 +102,8 @@ struct conversion { being bound to an lvalue expression or an rvalue reference is being bound to an rvalue expression. If KIND is ck_rvalue, true when we are treating an lvalue as an rvalue (12.8p33). If - KIND is ck_base, always false. */ + KIND is ck_base, always false. If ck_identity, we will be + binding a reference directly. */ BOOL_BITFIELD rvaluedness_matches_p: 1; BOOL_BITFIELD check_narrowing: 1; /* The type of the expression resulting from the conversion. */ @@ -1476,6 +1477,10 @@ direct_reference_binding (tree type, conversion *conv) t = TREE_TYPE (type); + if (conv->kind == ck_identity) + /* Mark the identity conv as to not decay to rvalue. */ + conv->rvaluedness_matches_p = true; + /* [over.ics.rank] When a parameter of reference type binds directly @@ -1501,6 +1506,7 @@ direct_reference_binding (tree type, conversion *conv) That way, convert_like knows not to generate a temporary. */ conv->need_temporary_p = false; } + return build_conv (ck_ref_bind, type, conv); } @@ -6800,7 +6806,9 @@ convert_like_real (conversion *convs, tree expr, tree fn, int argnum, else gcc_unreachable (); } - expr = mark_rvalue_use (expr); + expr = mark_use (expr, /*rvalue_p=*/!convs->rvaluedness_matches_p, + /*read_p=*/true, UNKNOWN_LOCATION, + /*reject_builtin=*/true); if (type_unknown_p (expr)) expr = instantiate_type (totype, expr, complain); diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h index 4300d9217a8..a8a5ab18342 100644 --- a/gcc/cp/cp-tree.h +++ b/gcc/cp/cp-tree.h @@ -6328,6 +6328,9 @@ extern tree create_try_catch_expr (tree, tree); /* in expr.c */ extern tree cplus_expand_constant (tree); +extern tree mark_use (tree expr, bool rvalue_p, bool read_p, + location_t = UNKNOWN_LOCATION, + bool reject_builtin = true); extern tree mark_rvalue_use (tree, location_t = UNKNOWN_LOCATION, bool reject_builtin = true); diff --git a/gcc/cp/expr.c b/gcc/cp/expr.c index 49a17a62424..2e679868970 100644 --- a/gcc/cp/expr.c +++ b/gcc/cp/expr.c @@ -89,7 +89,7 @@ cplus_expand_constant (tree cst) /* We've seen an actual use of EXPR. Possibly replace an outer variable reference inside with its constant value or a lambda capture. */ -static tree +tree mark_use (tree expr, bool rvalue_p, bool read_p, location_t loc /* = UNKNOWN_LOCATION */, bool reject_builtin /* = true */) diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 3cc5bda0454..df64bb05b76 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2018-01-18 Nathan Sidwell + + PR c++/83160 + * g++.dg/cpp0x/pr83160.C: New. + 2018-01-18 Richard Biener PR tree-optimization/83887 diff --git a/gcc/testsuite/g++.dg/cpp0x/pr83160.C b/gcc/testsuite/g++.dg/cpp0x/pr83160.C new file mode 100644 index 00000000000..b3b97c70c3d --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp0x/pr83160.C @@ -0,0 +1,33 @@ +// { dg-do run { target c++11 } } +// PR c++/83160 failed to capture as lvalue + +int main () +{ + const int a = 0; + + if (![&a] (const int *p) + { + const int &b = a; + // We should bind to the outer a + return &b == p; + } (&a)) + return 1; + + if (![&] (const int *p) + { + const int &b = a; + // We should bind to the outer a + return &b == p; + } (&a)) + return 2; + + if ([=] (const int *p) + { + const int &b = a; + // We should bind to the captured instance + return &b == p; + }(&a)) + return 3; + + return 0; +} -- 2.30.2