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| author | Marek Polacek <polacek@redhat.com> | 2022-03-17 14:39:37 -0400 |
|---|---|---|
| committer | Marek Polacek <polacek@redhat.com> | 2022-03-24 16:59:57 -0400 |
| commit | 9fdac7e16c940fb6264e6ddaf99c761f1a64a054 (patch) | |
| tree | 33fae8fdc94ade66fe5fc55a1204b17dfbeb4159 /gcc/cp | |
| parent | 346ab5a54a831ad9c78afcbd8dfe98e0e07e3070 (diff) | |
| download | gcc-9fdac7e16c940fb6264e6ddaf99c761f1a64a054.zip gcc-9fdac7e16c940fb6264e6ddaf99c761f1a64a054.tar.gz gcc-9fdac7e16c940fb6264e6ddaf99c761f1a64a054.tar.bz2 | |
c++: ICE with template code in constexpr [PR104284]
Since r9-6073 cxx_eval_store_expression preevaluates the value to
be stored, and that revealed a crash where a template code (here,
code=IMPLICIT_CONV_EXPR) leaks into cxx_eval*.
It happens because we're performing build_vec_init while processing
a template, which calls get_temp_regvar which creates an INIT_EXPR.
This INIT_EXPR's RHS contains an rvalue conversion so we create an
IMPLICIT_CONV_EXPR. Its operand is not type-dependent and the whole
INIT_EXPR is not type-dependent. So we call build_non_dependent_expr
which, with -fchecking=2, calls fold_non_dependent_expr. At this
point the expression still has an IMPLICIT_CONV_EXPR, which ought to
be handled in instantiate_non_dependent_expr_internal. However,
tsubst_copy_and_build doesn't handle INIT_EXPR; it will just call
tsubst_copy which does nothing when args is null. So we fail to
replace the IMPLICIT_CONV_EXPR and ICE.
The problem is that we call build_vec_init in a template in the
first place. We can avoid doing so by checking p_t_d before
calling build_aggr_init in check_initializer.
PR c++/104284
gcc/cp/ChangeLog:
* decl.cc (check_initializer): Don't call build_aggr_init in
a template.
gcc/testsuite/ChangeLog:
* g++.dg/cpp1y/constexpr-104284-1.C: New test.
* g++.dg/cpp1y/constexpr-104284-2.C: New test.
* g++.dg/cpp1y/constexpr-104284-3.C: New test.
* g++.dg/cpp1y/constexpr-104284-4.C: New test.
Diffstat (limited to 'gcc/cp')
| -rw-r--r-- | gcc/cp/decl.cc | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/gcc/cp/decl.cc b/gcc/cp/decl.cc index 68741bbf..69f60a6 100644 --- a/gcc/cp/decl.cc +++ b/gcc/cp/decl.cc @@ -7332,6 +7332,10 @@ check_initializer (tree decl, tree init, int flags, vec<tree, va_gc> **cleanups) && !(init && BRACE_ENCLOSED_INITIALIZER_P (init) && CP_AGGREGATE_TYPE_P (type) && (CLASS_TYPE_P (type) + /* The call to build_aggr_init below could end up + calling build_vec_init, which may break when we + are processing a template. */ + || processing_template_decl || !TYPE_NEEDS_CONSTRUCTING (type) || type_has_extended_temps (type)))) || (DECL_DECOMPOSITION_P (decl) && TREE_CODE (type) == ARRAY_TYPE)) |