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| author | Jakub Jelinek <jakub@redhat.com> | 2023-01-19 23:27:34 +0100 |
|---|---|---|
| committer | Jakub Jelinek <jakub@redhat.com> | 2023-01-19 23:27:34 +0100 |
| commit | 9b9a989adc042b304572fd6d4ade46b47be6ccb8 (patch) | |
| tree | f863fb6cccd9ccd4a333c89b7a0d9c40a0314fb6 | |
| parent | c81e68a9cdbb5411dce1f1da3b35854212305c7c (diff) | |
| download | gcc-9b9a989adc042b304572fd6d4ade46b47be6ccb8.zip gcc-9b9a989adc042b304572fd6d4ade46b47be6ccb8.tar.gz gcc-9b9a989adc042b304572fd6d4ade46b47be6ccb8.tar.bz2 | |
c++: Fix up handling of references to anon union members in initializers [PR53932]
For anonymous union members we create artificial VAR_DECLs which
have DECL_VALUE_EXPR for the actual COMPONENT_REF. That works
just fine inside of functions (including global dynamic constructors),
because during gimplification such VAR_DECLs are gimplified as
their DECL_VALUE_EXPR. This is also done during regimplification.
But references to these artificial vars in DECL_INITIAL expressions
aren't ever replaced by the DECL_VALUE_EXPRs, so we end up either
with link failures like on the testcase below, or worse ICEs with
LTO.
The following patch fixes those during cp_fully_fold_init where we
already walk all the trees (!data->genericize means that
function rather than cp_fold_function).
2023-01-19 Jakub Jelinek <jakub@redhat.com>
PR c++/53932
* cp-gimplify.cc (cp_fold_r): During cp_fully_fold_init replace
DECL_ANON_UNION_VAR_P VAR_DECLs with their corresponding
DECL_VALUE_EXPR.
* g++.dg/init/pr53932.C: New test.
| -rw-r--r-- | gcc/cp/cp-gimplify.cc | 10 | ||||
| -rw-r--r-- | gcc/testsuite/g++.dg/init/pr53932.C | 25 |
2 files changed, 35 insertions, 0 deletions
diff --git a/gcc/cp/cp-gimplify.cc b/gcc/cp/cp-gimplify.cc index a282156..340b464 100644 --- a/gcc/cp/cp-gimplify.cc +++ b/gcc/cp/cp-gimplify.cc @@ -1010,6 +1010,16 @@ 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/init/pr53932.C b/gcc/testsuite/g++.dg/init/pr53932.C new file mode 100644 index 0000000..3b129e7 --- /dev/null +++ b/gcc/testsuite/g++.dg/init/pr53932.C @@ -0,0 +1,25 @@ +// PR c++/53932 +// { dg-do link } + +static union { int i; }; +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 () +{ +} |