From 60b6f5c0a334db3f8f6dffaf0b9aab42fd5c54a2 Mon Sep 17 00:00:00 2001 From: Jakub Jelinek Date: Fri, 10 Mar 2023 20:38:13 +0100 Subject: [PATCH] c++: Don't clear TREE_READONLY for -fmerge-all-constants for non-aggregates [PR107558] The following testcase ICEs, because OpenMP lowering for shared clause on l variable with REFERENCE_TYPE creates POINTER_TYPE to REFERENCE_TYPE. The reason is that the automatic variable has non-trivial construction (reference to a lambda) and -fmerge-all-constants is on and so TREE_READONLY isn't set - omp-low will handle automatic TREE_READONLY vars in shared specially and only copy to the construct and not back, while !TREE_READONLY are assumed to be changeable. The PR91529 change rationale was that the gimplification can change some non-addressable automatic variables to TREE_STATIC with -fmerge-all-constants and therefore TREE_READONLY on them is undesirable. But, the gimplifier does that only for aggregate variables: switch (TREE_CODE (type)) { case RECORD_TYPE: case UNION_TYPE: case QUAL_UNION_TYPE: case ARRAY_TYPE: and not for anything else. So, I think clearing TREE_READONLY for automatic integral or reference or pointer etc. vars for -fmerge-all-constants only is unnecessary. 2023-03-10 Jakub Jelinek PR c++/107558 * decl.cc (cp_finish_decl): Don't clear TREE_READONLY on automatic non-aggregate variables just because of -fmerge-all-constants. * g++.dg/gomp/pr107558.C: New test. --- gcc/cp/decl.cc | 6 ++++-- gcc/testsuite/g++.dg/gomp/pr107558.C | 14 ++++++++++++++ 2 files changed, 18 insertions(+), 2 deletions(-) create mode 100644 gcc/testsuite/g++.dg/gomp/pr107558.C diff --git a/gcc/cp/decl.cc b/gcc/cp/decl.cc index 51199bb..1d1ae02 100644 --- a/gcc/cp/decl.cc +++ b/gcc/cp/decl.cc @@ -8685,8 +8685,10 @@ cp_finish_decl (tree decl, tree init, bool init_const_expr_p, if (var_definition_p /* With -fmerge-all-constants, gimplify_init_constructor - might add TREE_STATIC to the variable. */ - && (TREE_STATIC (decl) || flag_merge_constants >= 2)) + might add TREE_STATIC to aggregate variables. */ + && (TREE_STATIC (decl) + || (flag_merge_constants >= 2 + && AGGREGATE_TYPE_P (type)))) { /* If a TREE_READONLY variable needs initialization at runtime, it is no longer readonly and we need to diff --git a/gcc/testsuite/g++.dg/gomp/pr107558.C b/gcc/testsuite/g++.dg/gomp/pr107558.C new file mode 100644 index 0000000..8a6b8d4 --- /dev/null +++ b/gcc/testsuite/g++.dg/gomp/pr107558.C @@ -0,0 +1,14 @@ +// PR c++/107558 +// { dg-do compile { target c++11 } } +// { dg-additional-options "-fmerge-all-constants" } +// { dg-additional-options "-flto" { target lto } } + +int a = 15; + +void +foo () +{ + auto &&l = [&]() { return a; }; +#pragma omp target parallel + l (); +} -- 2.7.4