From b84e21115700523b4d0ac44275443f7b9c670344 Mon Sep 17 00:00:00 2001 From: Jakub Jelinek Date: Tue, 24 Jan 2023 11:28:00 +0100 Subject: [PATCH] c++: Handle structured bindings like anon unions in initializers [PR108474] As reported by Andrew Pinski, structured bindings (with the exception of the ones using std::tuple_{size,element} and get which are really standalone variables in addition to the binding one) also use DECL_VALUE_EXPR and needs the same treatment in static initializers. On Sun, Jan 22, 2023 at 07:19:07PM -0500, Jason Merrill wrote: > Though, actually, why not instead fix expand_expr_real_1 (and staticp) to > look through DECL_VALUE_EXPR? Doing it when emitting the initializers seems to be too late to me, we in various spots try to put parts of the static var DECL_INITIAL expressions into the IL, or e.g. for varpool purposes remember which vars are referenced there. This patch moves it to record_reference, which is called from varpool_node::analyze and so about the same time as gimplification of the bodies which also replaces DECL_VALUE_EXPRs. 2023-01-24 Jakub Jelinek PR c++/108474 * cgraphbuild.cc: Include gimplify.h. (record_reference): Replace VAR_DECLs with DECL_HAS_VALUE_EXPR_P with their corresponding DECL_VALUE_EXPR expressions after unsharing. * cp-gimplify.cc (cp_fold_r): Revert 2023-01-19 changes. * g++.dg/cpp1z/decomp57.C: New test. * g++.dg/cpp1z/decomp58.C: New test. --- gcc/cgraphbuild.cc | 12 +++++++++++ gcc/cp/cp-gimplify.cc | 10 --------- gcc/testsuite/g++.dg/cpp1z/decomp57.C | 27 ++++++++++++++++++++++++ gcc/testsuite/g++.dg/cpp1z/decomp58.C | 39 +++++++++++++++++++++++++++++++++++ 4 files changed, 78 insertions(+), 10 deletions(-) create mode 100644 gcc/testsuite/g++.dg/cpp1z/decomp57.C create mode 100644 gcc/testsuite/g++.dg/cpp1z/decomp58.C diff --git a/gcc/cgraphbuild.cc b/gcc/cgraphbuild.cc index f13abca..597831e 100644 --- a/gcc/cgraphbuild.cc +++ b/gcc/cgraphbuild.cc @@ -31,6 +31,7 @@ along with GCC; see the file COPYING3. If not see #include "gimple-walk.h" #include "ipa-utils.h" #include "except.h" +#include "gimplify.h" /* Context of record_reference. */ struct record_reference_ctx @@ -79,6 +80,17 @@ record_reference (tree *tp, int *walk_subtrees, void *data) if (VAR_P (decl)) { + /* Replace vars with their DECL_VALUE_EXPR if any. + This is normally done during gimplification, but + static var initializers are never gimplified. */ + if (DECL_HAS_VALUE_EXPR_P (decl)) + { + tree *p; + for (p = tp; *p != decl; p = &TREE_OPERAND (*p, 0)) + ; + *p = unshare_expr (DECL_VALUE_EXPR (decl)); + return record_reference (tp, walk_subtrees, data); + } varpool_node *vnode = varpool_node::get_create (decl); ctx->varpool_node->create_reference (vnode, IPA_REF_ADDR); } diff --git a/gcc/cp/cp-gimplify.cc b/gcc/cp/cp-gimplify.cc index 92cd309..a35cedd 100644 --- a/gcc/cp/cp-gimplify.cc +++ b/gcc/cp/cp-gimplify.cc @@ -1035,16 +1035,6 @@ cp_fold_r (tree *stmt_p, int *walk_subtrees, void *data_) } break; - case VAR_DECL: - /* In initializers replace anon union artificial VAR_DECLs - with their DECL_VALUE_EXPRs, as nothing will do it later. */ - if (DECL_ANON_UNION_VAR_P (stmt) && !data->genericize) - { - *stmt_p = stmt = unshare_expr (DECL_VALUE_EXPR (stmt)); - break; - } - break; - default: break; } diff --git a/gcc/testsuite/g++.dg/cpp1z/decomp57.C b/gcc/testsuite/g++.dg/cpp1z/decomp57.C new file mode 100644 index 0000000..923862e --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp1z/decomp57.C @@ -0,0 +1,27 @@ +// PR c++/108474 +// { dg-do link { target c++17 } } + +struct T { int i, j; }; +T h; +auto [i, j] = h; +int &r = i; +int s = i; +int *t = &i; + +void +foo (int **p, int *q) +{ + static int &u = i; + static int v = i; + static int *w = &i; + int &x = i; + int y = i; + int *z = &i; + *p = &i; + *q = i; +} + +int +main () +{ +} diff --git a/gcc/testsuite/g++.dg/cpp1z/decomp58.C b/gcc/testsuite/g++.dg/cpp1z/decomp58.C new file mode 100644 index 0000000..b260437 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp1z/decomp58.C @@ -0,0 +1,39 @@ +// PR c++/108474 +// { dg-do link { target c++17 } } + +namespace std { + template struct tuple_size; + template struct tuple_element; +} + +struct A { + int i; + template int& get() { return i; } +}; + +template <> struct std::tuple_size { static const int value = 2; }; +template struct std::tuple_element { using type = int; }; + +struct A a; +auto [i, j] = a; +int &r = i; +int s = i; +int *t = &i; + +void +foo (int **p, int *q) +{ + static int &u = i; + static int v = i; + static int *w = &i; + int &x = i; + int y = i; + int *z = &i; + *p = &i; + *q = i; +} + +int +main () +{ +} -- 2.7.4