| Age | Commit message (Collapse) | Author | Files | Lines |
|---|
|
potential_constant_expression for CALL_EXPR tests FUNCTION_POINTER_TYPE_P
on the callee rather than on the type of the callee, which means we
always pass want_rval=any when recursing and so may fail to identify a
non-constant function pointer callee as such. Fixing this turns out to
further work around PR111703.
PR c++/111703
PR c++/107939
gcc/cp/ChangeLog:
* constexpr.cc (potential_constant_expression_1) <case CALL_EXPR>:
Fix FUNCTION_POINTER_TYPE_P test.
gcc/testsuite/ChangeLog:
* g++.dg/cpp2a/concepts-fn8.C: Extend test.
* g++.dg/diagnostic/constexpr4.C: New test.
|
|
potential_constant_expression was incorrectly treating most local
variables from a constexpr function as constant because it wasn't
considering the 'now' parameter. This patch fixes this by relaxing
its var_in_maybe_constexpr_fn checks accordingly, which turns out to
partially fix two recently reported regressions:
PR111703 is a regression caused by r11-550-gf65a3299a521a4 for restricting
constexpr evaluation during warning-dependent folding. The mechanism is
intended to restrict only constant evaluation of the instantiated
non-dependent expression, but it also ends up restricting constant
evaluation occurring during instantiation of the expression, in particular
when instantiating the converted argument 'x' (a VIEW_CONVERT_EXPR) into
a copy constructor call. This seems like a flaw in the mechanism, though
I don't know if we want to fix the mechanism or get rid of it completely
since the original testcases which motivated the mechanism are fixed more
simply by r13-1225-gb00b95198e6720. In any case, this patch partially
fixes this by making us correctly treat 'x' as non-constant which prevents
the problematic warning-dependent folding from occurring at all.
PR112269 is caused by r14-4796-g3e3d73ed5e85e7 for merging tsubst_copy
into tsubst_copy_and_build. tsubst_copy used to exit early when 'args'
was empty, behavior which that commit deliberately didn't preserve.
This early exit masked the fact that COMPLEX_EXPR wasn't handled by
tsubst at all, and is a tree code that apparently we could see during
warning-dependent folding on some targets. A complete fix is to add
handling for this tree code in tsubst_expr, but this patch should fix
the reported testsuite failures since the COMPLEX_EXPRs that crop up
in <complex> are considered non-constant expressions after this patch.
PR c++/111703
PR c++/112269
gcc/cp/ChangeLog:
* constexpr.cc (potential_constant_expression_1) <case VAR_DECL>:
Only consider var_in_maybe_constexpr_fn if 'now' is false.
<case INDIRECT_REF>: Likewise.
gcc/testsuite/ChangeLog:
* g++.dg/cpp2a/concepts-fn8.C: New test.
|
|
This tree code dates all the way back to r69130[1] which implemented
typing of non-dependent expressions. Its motivation was never clear (to
me at least) since its documentation in e.g. cp-tree.def doesn't seem
accurate anymore. build_non_dependent_expr has since gained a bunch of
edge cases about whether or how to wrap certain templated trees, making
it hard to reason about in general.
So this patch removes this tree code, and temporarily turns
build_non_dependent_expr into the identity function. The subsequent
patch will remove build_non_dependent_expr and adjust its callers
appropriately.
We now need to more thoroughly handle templated (sub)trees in a couple
of places which previously didn't need to since they didn't look through
NON_DEPENDENT_EXPR.
[1]: https://gcc.gnu.org/pipermail/gcc-patches/2003-July/109355.html
gcc/c-family/ChangeLog:
* c-warn.cc (check_address_or_pointer_of_packed_member): Handle
type-dependent callee of CALL_EXPR.
gcc/cp/ChangeLog:
* class.cc (instantiate_type): Remove NON_DEPENDENT_EXPR
handling.
* constexpr.cc (cxx_eval_constant_expression): Likewise.
(potential_constant_expression_1): Likewise.
* coroutines.cc (coro_validate_builtin_call): Don't
expect ALIGNOF_EXPR to be wrapped in NON_DEPENDENT_EXPR.
* cp-objcp-common.cc (cp_common_init_ts): Remove
NON_DEPENDENT_EXPR handling.
* cp-tree.def (NON_DEPENDENT_EXPR): Remove.
* cp-tree.h (build_non_dependent_expr): Temporarily redefine as
the identity function.
* cvt.cc (maybe_warn_nodiscard): Handle type-dependent and
variable callee of CALL_EXPR.
* cxx-pretty-print.cc (cxx_pretty_printer::expression): Remove
NON_DEPENDENT_EXPR handling.
* error.cc (dump_decl): Likewise.
(dump_expr): Likewise.
* expr.cc (mark_use): Likewise.
(mark_exp_read): Likewise.
* pt.cc (build_non_dependent_expr): Remove.
* tree.cc (lvalue_kind): Remove NON_DEPENDENT_EXPR handling.
(cp_stabilize_reference): Likewise.
* typeck.cc (warn_for_null_address): Likewise.
(cp_build_binary_op): Handle type-dependent SIZEOF_EXPR operands.
(cp_build_unary_op) <case TRUTH_NOT_EXPR>: Don't fold inside a
template.
gcc/testsuite/ChangeLog:
* g++.dg/concepts/var-concept3.C: Adjust expected diagnostic
for attempting to call a variable concept.
Reviewed-by: Jason Merrill <jason@redhat.com>
|
|
This patch adds checks for attempting to change the active member of a
union by methods other than a member access expression.
To be able to properly distinguish `*(&u.a) = ` from `u.a = `, this
patch redoes the solution for c++/59950 to avoid extranneous *&; it
seems that the only case that needed the workaround was when copying
empty classes.
This patch also ensures that constructors for a union field mark that
field as the active member before entering the call itself; this ensures
that modifications of the field within the constructor's body don't
cause false positives (as these will not appear to be member access
expressions). This means that we no longer need to start the lifetime of
empty union members after the constructor body completes.
As a drive-by fix, this patch also ensures that value-initialised unions
are considered to have activated their initial member for the purpose of
checking stores and accesses, which catches some additional mistakes
pre-C++20.
PR c++/101631
PR c++/102286
gcc/cp/ChangeLog:
* call.cc (build_over_call): Fold more indirect refs for trivial
assignment op.
* class.cc (type_has_non_deleted_trivial_default_ctor): Create.
* constexpr.cc (cxx_eval_call_expression): Start lifetime of
union member before entering constructor.
(cxx_eval_component_reference): Check against first member of
value-initialised union.
(cxx_eval_store_expression): Activate member for
value-initialised union. Check for accessing inactive union
member indirectly.
* cp-tree.h (type_has_non_deleted_trivial_default_ctor):
Forward declare.
gcc/testsuite/ChangeLog:
* g++.dg/cpp1y/constexpr-89336-3.C: Fix union initialisation.
* g++.dg/cpp1y/constexpr-union6.C: New test.
* g++.dg/cpp1y/constexpr-union7.C: New test.
* g++.dg/cpp2a/constexpr-union2.C: New test.
* g++.dg/cpp2a/constexpr-union3.C: New test.
* g++.dg/cpp2a/constexpr-union4.C: New test.
* g++.dg/cpp2a/constexpr-union5.C: New test.
* g++.dg/cpp2a/constexpr-union6.C: New test.
Signed-off-by: Nathaniel Shead <nathanieloshead@gmail.com>
Reviewed-by: Jason Merrill <jason@redhat.com>
|
|
This patch improves the errors given when casting from void* in C++26 to
include the expected type if the types of the pointed-to objects were
not similar. It also ensures (for all standard modes) that void* casts
are checked even for DECL_ARTIFICIAL declarations, such as
lifetime-extended temporaries, and is only ignored for cases where we
know it's OK (e.g. source_location::current) or have no other choice
(heap-allocated data).
gcc/cp/ChangeLog:
* constexpr.cc (is_std_source_location_current): New.
(cxx_eval_constant_expression): Only ignore cast from void* for
specific cases and improve other diagnostics.
gcc/testsuite/ChangeLog:
* g++.dg/cpp0x/constexpr-cast4.C: New test.
Signed-off-by: Nathaniel Shead <nathanieloshead@gmail.com>
Reviewed-by: Marek Polacek <polacek@redhat.com>
Reviewed-by: Jason Merrill <jason@redhat.com>
|
|
gcc/cp/ChangeLog:
* constexpr.cc (cxx_eval_dynamic_cast_fn): Add missing
auto_diagnostic_group.
(cxx_eval_call_expression): Likewise.
(diag_array_subscript): Likewise.
(outside_lifetime_error): Likewise.
(potential_constant_expression_1): Likewise.
Signed-off-by: Nathaniel Shead <nathanieloshead@gmail.com>
Reviewed-by: Marek Polacek <polacek@redhat.com>
|
|
In C++23, since P2448, a constexpr function F that calls a non-constexpr
function N is OK as long as we don't actually call F in a constexpr
context. So instead of giving an error in maybe_save_constexpr_fundef,
we only give an error when evaluating the call. Unfortunately, as shown
in this PR, the diagnostic can be truncated:
z.C:10:13: note: 'constexpr Jam::Jam()' is not usable as a 'constexpr' function because:
10 | constexpr Jam() { ft(); }
| ^~~
...because what? With this patch, we say:
z.C:10:13: note: 'constexpr Jam::Jam()' is not usable as a 'constexpr' function because:
10 | constexpr Jam() { ft(); }
| ^~~
z.C:10:23: error: call to non-'constexpr' function 'int Jam::ft()'
10 | constexpr Jam() { ft(); }
| ~~^~
z.C:8:7: note: 'int Jam::ft()' declared here
8 | int ft() { return 42; }
| ^~
Like maybe_save_constexpr_fundef, explain_invalid_constexpr_fn should
also check the body of a constructor, not just the mem-initializer.
PR c++/111272
gcc/cp/ChangeLog:
* constexpr.cc (explain_invalid_constexpr_fn): Also check the body of
a constructor in C++14 and up.
gcc/testsuite/ChangeLog:
* g++.dg/cpp1y/constexpr-diag1.C: New test.
|
|
Switching to default constructors for poly_int exposed some
unused variables that weren't previously diagnosed.
gcc/
* dwarf2out.cc (mem_loc_descriptor): Remove unused variables.
* tree-affine.cc (expr_to_aff_combination): Likewise.
gcc/cp/
* constexpr.cc (cxx_fold_indirect_ref): Remove unused variables.
gcc/rust/
* backend/rust-constexpr.cc (rs_fold_indirect_ref): Remove unused
variables.
|
|
The change of active member being non-constant (before C++20) results in a
CONSTRUCTOR with a null value for the first field, don't crash.
gcc/cp/ChangeLog:
* constexpr.cc (free_constructor): Handle null ce->value.
gcc/testsuite/ChangeLog:
* g++.dg/cpp2a/constexpr-union7.C: New test.
|
|
In the review of P2564:
<https://gcc.gnu.org/pipermail/gcc-patches/2023-August/628747.html>
it turned out that in order to correctly handle an example in the paper,
we should stop doing immediate evaluation in build_over_call and
bot_replace, and instead do it in cp_fold_r. This patch does that.
Another benefit is that this is a pretty significant simplification, at
least in my opinion. Also, this fixes the c++/110997 ICE (but the test
doesn't compile yet).
The main drawback seems to be that cp_fold_r doesn't process
uninstantiated templates. We still have to handle things like
"false ? foo () : 1". To that end, I've added cp_fold_immediate, called
on dead branches in cxx_eval_conditional_expression.
You'll see that I've reintroduced ADDR_EXPR_DENOTES_CALL_P here. This
is to detect
*(&foo)) ()
(s.*&S::foo) ()
which were deemed ill-formed.
gcc/cp/ChangeLog:
* call.cc (build_over_call): Set ADDR_EXPR_DENOTES_CALL_P. Don't handle
immediate_invocation_p here.
* constexpr.cc (cxx_eval_call_expression): Use mce_true for
DECL_IMMEDIATE_FUNCTION_P.
(cxx_eval_conditional_expression): Call cp_fold_immediate.
* cp-gimplify.cc (enum fold_flags): Add ff_fold_immediate.
(maybe_replace_decl): Make static.
(cp_fold_r): Expand immediate invocations.
(cp_fold_immediate_r): New.
(cp_fold_immediate): New.
* cp-tree.h (ADDR_EXPR_DENOTES_CALL_P): Define.
(cp_fold_immediate): Declare.
* tree.cc (bot_replace): Don't handle immediate invocations here.
libstdc++-v3/ChangeLog:
* testsuite/20_util/allocator/105975.cc: Add dg-error.
gcc/testsuite/ChangeLog:
* g++.dg/cpp23/consteval-if2.C: Add xfail.
* g++.dg/cpp2a/consteval-memfn1.C: Adjust.
* g++.dg/cpp2a/consteval11.C: Remove dg-message.
* g++.dg/cpp2a/consteval3.C: Remove dg-message and dg-error.
* g++.dg/cpp2a/consteval9.C: Remove dg-message.
* g++.dg/cpp2a/consteval32.C: New test.
* g++.dg/cpp2a/consteval33.C: New test.
* g++.dg/cpp2a/consteval34.C: New test.
* g++.dg/cpp2a/consteval35.C: New test.
|
|
When verify_constant complains, it's pretty terse. Consider
void test ()
{
constexpr int i = 42;
constexpr const int *p = &i;
}
where it says "'& i' is not a constant expression". OK, but why?
With this patch, we say:
b.C:5:28: error: '& i' is not a constant expression
5 | constexpr const int *p = &i;
| ^~
b.C:5:28: note: pointer to 'i' is not a constant expression
b.C:4:17: note: address of non-static constexpr variable 'i' may differ on each invocation of the enclosing function; add 'static' to give it a constant address
4 | constexpr int i = 42;
| ^
| static
which brings g++ on par with clang++.
PR c++/91483
gcc/cp/ChangeLog:
* constexpr.cc (verify_constant_explain_r): New.
(verify_constant): Call it.
gcc/testsuite/ChangeLog:
* g++.dg/diagnostic/constexpr3.C: New test.
|
|
In order to detect invalid jumps in and out of intervening code in
imperfectly-nested loops, the front ends need to insert some sort of
marker to identify the structured block sequences that they push into
the inner body of the loop. The error checking happens in the
diagnose_omp_blocks pass, between gimplification and OMP lowering, so
we need both GENERIC and GIMPLE representations of these markers.
They are removed in OMP lowering so no subsequent passes need to know
about them.
This patch doesn't include any front-end changes to generate the new
data structures.
gcc/cp/ChangeLog
* constexpr.cc (cxx_eval_constant_expression): Handle
OMP_STRUCTURED_BLOCK.
* pt.cc (tsubst_expr): Likewise.
gcc/ChangeLog
* doc/generic.texi (OpenMP): Document OMP_STRUCTURED_BLOCK.
* doc/gimple.texi (GIMPLE instruction set): Add
GIMPLE_OMP_STRUCTURED_BLOCK.
(GIMPLE_OMP_STRUCTURED_BLOCK): New subsection.
* gimple-low.cc (lower_stmt): Error on GIMPLE_OMP_STRUCTURED_BLOCK.
* gimple-pretty-print.cc (dump_gimple_omp_block): Handle
GIMPLE_OMP_STRUCTURED_BLOCK.
(pp_gimple_stmt_1): Likewise.
* gimple-walk.cc (walk_gimple_stmt): Likewise.
* gimple.cc (gimple_build_omp_structured_block): New.
* gimple.def (GIMPLE_OMP_STRUCTURED_BLOCK): New.
* gimple.h (gimple_build_omp_structured_block): Declare.
(gimple_has_substatements): Handle GIMPLE_OMP_STRUCTURED_BLOCK.
(CASE_GIMPLE_OMP): Likewise.
* gimplify.cc (is_gimple_stmt): Handle OMP_STRUCTURED_BLOCK.
(gimplify_expr): Likewise.
* omp-expand.cc (GIMPLE_OMP_STRUCTURED_BLOCK): Error on
GIMPLE_OMP_STRUCTURED_BLOCK.
* omp-low.cc (scan_omp_1_stmt): Handle GIMPLE_OMP_STRUCTURED_BLOCK.
(lower_omp_1): Likewise.
(diagnose_sb_1): Likewise.
(diagnose_sb_2): Likewise.
* tree-inline.cc (remap_gimple_stmt): Handle
GIMPLE_OMP_STRUCTURED_BLOCK.
(estimate_num_insns): Likewise.
* tree-nested.cc (convert_nonlocal_reference_stmt): Likewise.
(convert_local_reference_stmt): Likewise.
(convert_gimple_call): Likewise.
* tree-pretty-print.cc (dump_generic_node): Handle
OMP_STRUCTURED_BLOCK.
* tree.def (OMP_STRUCTURED_BLOCK): New.
* tree.h (OMP_STRUCTURED_BLOCK_BODY): New.
|
|
Now that init_subob_ctx no longer sets new_ctx.ctor for a subobject of
empty type, it seems we need to ensure its callers also consistently
omit entries in the parent ctx->ctor for such subobjects. We also need
to allow cxx_eval_array_reference to synthesize an empty subobject even
if the array CONSTRUCTOR has CONSTRUCTOR_NO_CLEARING set.
PR c++/110197
gcc/cp/ChangeLog:
* constexpr.cc (cxx_eval_array_reference): Allow synthesizing an
empty subobject even if CONSTRUCTOR_NO_CLEARING is set.
(cxx_eval_bare_aggregate): Set 'no_slot' to true more generally
whenever new_ctx.ctor is set to NULL_TREE by init_subob_ctx,
i.e. whenever initializing an subobject of empty type.
(cxx_eval_vec_init_1): Define 'no_slot' as above and use it
accordingly.
gcc/testsuite/ChangeLog:
* g++.dg/cpp0x/constexpr-empty18.C: New test.
* g++.dg/cpp0x/constexpr-empty19.C: New test.
|
|
This adds rudimentary lifetime tracking in C++ constexpr contexts,
allowing the compiler to report errors with using values after their
backing has gone out of scope. We don't yet handle other ways of
accessing values outside their lifetime (e.g. following explicit
destructor calls).
PR c++/96630
PR c++/98675
PR c++/70331
gcc/cp/ChangeLog:
* constexpr.cc (constexpr_global_ctx::is_outside_lifetime): New
function.
(constexpr_global_ctx::get_value): Don't return expired values.
(constexpr_global_ctx::get_value_ptr): Likewise.
(constexpr_global_ctx::remove_value): Mark value outside
lifetime.
(outside_lifetime_error): New function.
(cxx_eval_call_expression): No longer track save_exprs.
(cxx_eval_loop_expr): Likewise.
(cxx_eval_constant_expression): Add checks for outside lifetime
values. Remove local variables at end of bind exprs, and
temporaries after cleanup points.
gcc/testsuite/ChangeLog:
* g++.dg/cpp1y/constexpr-lifetime1.C: New test.
* g++.dg/cpp1y/constexpr-lifetime2.C: New test.
* g++.dg/cpp1y/constexpr-lifetime3.C: New test.
* g++.dg/cpp1y/constexpr-lifetime4.C: New test.
* g++.dg/cpp1y/constexpr-lifetime5.C: New test.
* g++.dg/cpp1y/constexpr-lifetime6.C: New test.
Signed-off-by: Nathaniel Shead <nathanieloshead@gmail.com>
|
|
This patch updates 'input_location' during constant evaluation to ensure
that errors in subexpressions that lack location information still
provide accurate diagnostics.
By itself this change causes some small regressions in diagnostic
quality for circumstances where errors used 'input_location' but the
location of the parent subexpression doesn't make sense, so this patch
also includes a small diagnostic improvement to fix the most egregious
case.
gcc/cp/ChangeLog:
* constexpr.cc (modifying_const_object_error): Find the source
location of the const object's declaration.
(cxx_eval_constant_expression): Update input_location to the
location of the currently evaluated expression, if possible.
libstdc++-v3/ChangeLog:
* testsuite/25_algorithms/equal/constexpr_neg.cc: Update diagnostic
locations.
* testsuite/26_numerics/gcd/105844.cc: Likewise.
* testsuite/26_numerics/lcm/105844.cc: Likewise.
gcc/testsuite/ChangeLog:
* g++.dg/cpp0x/constexpr-48089.C: Update diagnostic locations.
* g++.dg/cpp0x/constexpr-70323.C: Likewise.
* g++.dg/cpp0x/constexpr-70323a.C: Likewise.
* g++.dg/cpp0x/constexpr-delete2.C: Likewise.
* g++.dg/cpp0x/constexpr-diag3.C: Likewise.
* g++.dg/cpp0x/constexpr-ice20.C: Likewise.
* g++.dg/cpp0x/constexpr-mutable3.C: Likewise.
* g++.dg/cpp0x/constexpr-recursion.C: Likewise.
* g++.dg/cpp0x/overflow1.C: Likewise.
* g++.dg/cpp1y/constexpr-89285.C: Likewise.
* g++.dg/cpp1y/constexpr-89481.C: Likewise.
* g++.dg/cpp1y/constexpr-tracking-const14.C: Likewise.
* g++.dg/cpp1y/constexpr-tracking-const16.C: Likewise.
* g++.dg/cpp1y/constexpr-tracking-const18.C: Likewise.
* g++.dg/cpp1y/constexpr-tracking-const19.C: Likewise.
* g++.dg/cpp1y/constexpr-tracking-const21.C: Likewise.
* g++.dg/cpp1y/constexpr-tracking-const22.C: Likewise.
* g++.dg/cpp1y/constexpr-tracking-const3.C: Likewise.
* g++.dg/cpp1y/constexpr-tracking-const4.C: Likewise.
* g++.dg/cpp1y/constexpr-tracking-const7.C: Likewise.
* g++.dg/cpp1y/constexpr-union5.C: Likewise.
* g++.dg/cpp1y/pr68180.C: Likewise.
* g++.dg/cpp1z/constexpr-lambda6.C: Likewise.
* g++.dg/cpp1z/constexpr-lambda8.C: Likewise.
* g++.dg/cpp2a/bit-cast11.C: Likewise.
* g++.dg/cpp2a/bit-cast12.C: Likewise.
* g++.dg/cpp2a/bit-cast14.C: Likewise.
* g++.dg/cpp2a/constexpr-98122.C: Likewise.
* g++.dg/cpp2a/constexpr-dynamic17.C: Likewise.
* g++.dg/cpp2a/constexpr-init1.C: Likewise.
* g++.dg/cpp2a/constexpr-new12.C: Likewise.
* g++.dg/cpp2a/constexpr-new3.C: Likewise.
* g++.dg/cpp2a/constinit10.C: Likewise.
* g++.dg/cpp2a/is-corresponding-member4.C: Likewise.
* g++.dg/ext/constexpr-vla2.C: Likewise.
* g++.dg/ext/constexpr-vla3.C: Likewise.
* g++.dg/ubsan/pr63956.C: Likewise.
Signed-off-by: Nathaniel Shead <nathanieloshead@gmail.com>
|
|
This code in cxx_eval_array_reference has been hard to get right.
In r12-2304 I added some code; in r13-5693 I removed some of it.
Here the problematic line is "S s = arr[0];" which causes a crash
on the assert in verify_ctor_sanity:
gcc_assert (!ctx->object || !DECL_P (ctx->object)
|| ctx->global->get_value (ctx->object) == ctx->ctor);
ctx->object is the VAR_DECL 's', which is correct here. The second
line points to the problem: we replaced ctx->ctor in
cxx_eval_array_reference:
new_ctx.ctor = build_constructor (elem_type, NULL); // #1
which I think we shouldn't have; the CONSTRUCTOR we created in
cxx_eval_constant_expression/DECL_EXPR
new_ctx.ctor = build_constructor (TREE_TYPE (r), NULL);
had the right type.
We still need #1 though. E.g., in constexpr-96241.C, we never
set ctx.ctor/object before calling cxx_eval_array_reference, so
we have to build a CONSTRUCTOR there. And in constexpr-101371-2.C
we have a ctx.ctor, but it has the wrong type, so we need a new one.
We can fix the problem by always clearing the object, and, as an
optimization, only create/free a new ctor when actually needed.
PR c++/110382
gcc/cp/ChangeLog:
* constexpr.cc (cxx_eval_array_reference): Create a new constructor
only when we don't already have a matching one. Clear the object
when the type is non-scalar.
gcc/testsuite/ChangeLog:
* g++.dg/cpp1y/constexpr-110382.C: New test.
|
|
is_really_empty_class is liable to crash when it gets an incomplete
or dependent type. Since r11-557, we pass the yet-uninstantiated
class type S<0> of the PARM_DECL s to is_really_empty_class -- because
of the potential_rvalue_constant_expression -> is_rvalue_constant_expression
change in cp_parser_constant_expression. Here we're not parsing
a template so we did not check COMPLETE_TYPE_P as we should.
It should work to complete the type before checking COMPLETE_TYPE_P.
PR c++/110106
gcc/cp/ChangeLog:
* constexpr.cc (potential_constant_expression_1): Try to complete the
type when !processing_template_decl.
gcc/testsuite/ChangeLog:
* g++.dg/cpp0x/noexcept80.C: New test.
|
|
The change to only cache constexpr calls that are
reduced_constant_expression_p tripped on bit-cast3.C, which failed that
predicate due to the presence of an empty field in the result of
native_interpret_aggregate, which reduced_constant_expression_p rejects to
avoid confusing output_constructor.
This patch proposes to skip such fields in native_interpret_aggregate, since
they aren't actually involved in the value representation.
gcc/ChangeLog:
* fold-const.cc (native_interpret_aggregate): Skip empty fields.
gcc/cp/ChangeLog:
* constexpr.cc (cxx_eval_bit_cast): Check that the result of
native_interpret_aggregate doesn't need more evaluation.
|
|
In reviewing Nathaniel's patch for PR70331, it occurred to me that instead
of looking for various specific problematic things in the result of a
constexpr call to decide whether to cache it, we should use
reduced_constant_expression_p.
The change to that function is to avoid crashing on uninitialized objects of
non-class type.
In a trial version of this patch I checked to see what cases this stopped
caching; most were instances of partially-initialized return values, which
seem fine to not cache. Some were returning pointers to expiring local
variables, which we definitely want not to cache. And one was bit-cast3.C,
which will be handled in a follow-up patch.
gcc/cp/ChangeLog:
* constexpr.cc (cxx_eval_call_expression): Only cache
reduced_constant_expression_p results.
(reduced_constant_expression_p): Handle CONSTRUCTOR of scalar type.
(cxx_eval_constant_expression): Fold vectors here.
(cxx_eval_bare_aggregate): Not here.
|
|
At this point r == t, but it makes more sense to refer to t like all the
other cases do.
gcc/cp/ChangeLog:
* constexpr.cc (cxx_eval_constant_expression): Pass t to get_value.
Signed-off-by: Nathaniel Shead <nathanieloshead@gmail.com>
|
|
Apparently I wasn't actually running the testsuite in C++26 mode like I
thought I was, so there were some failures I wasn't seeing.
The constexpr hunk fixes regressions with the P2738 implementation; we still
need to use the old handling for casting from void pointers to heap
variables.
PR c++/110344
gcc/cp/ChangeLog:
* constexpr.cc (cxx_eval_constant_expression): Move P2738 handling
after heap handling.
* name-lookup.cc (get_cxx_dialect_name): Add C++26.
gcc/testsuite/ChangeLog:
* g++.dg/cpp0x/constexpr-cast2.C: Adjust for P2738.
* g++.dg/ipa/devirt-45.C: Handle -fimplicit-constexpr.
|
|
P2768 allows static_cast from void* to ob* in constant evaluation if the
pointer does in fact point to an object of the appropriate type.
cxx_fold_indirect_ref already does the work of finding such an object if it
happens to be a subobject rather than the outermost object at that address,
as in constexpr-voidptr2.C.
P2768
PR c++/110344
gcc/c-family/ChangeLog:
* c-cppbuiltin.cc (c_cpp_builtins): Update __cpp_constexpr.
gcc/cp/ChangeLog:
* constexpr.cc (cxx_eval_constant_expression): In C++26, allow cast
from void* to the type of a pointed-to object.
gcc/testsuite/ChangeLog:
* g++.dg/cpp26/constexpr-voidptr1.C: New test.
* g++.dg/cpp26/constexpr-voidptr2.C: New test.
* g++.dg/cpp26/feat-cxx26.C: New test.
|
|
I previously applied this change in r13-4565 but reverted it due to
PR108071. That PR was then fixed by r13-4712, but I didn't re-apply this
change then because we weren't making the array static; since r14-1500 for
PR110070 we now make the initializer array static, so let's bring this back.
In situations where the maybe_init_list_as_range optimization isn't viable,
we can build an initializer_list<string> with a loop over a constant array
of string literals.
This is represented using a VEC_INIT_EXPR, which required adjusting a couple
of places that expected the initializer array to have the same type as the
target array and fixing build_vec_init not to undo our efforts.
PR c++/105838
gcc/cp/ChangeLog:
* call.cc (convert_like_internal) [ck_list]: Use
maybe_init_list_as_array.
* constexpr.cc (cxx_eval_vec_init_1): Init might have
a different type.
* tree.cc (build_vec_init_elt): Likewise.
* init.cc (build_vec_init): Handle from_array from a
TARGET_EXPR. Retain TARGET_EXPR of a different type.
gcc/testsuite/ChangeLog:
* g++.dg/tree-ssa/initlist-opt5.C: New test.
|
|
In this other testcase from PR110122, during regeneration of the generic
lambda with V=Bar{}, substitution followed by coerce_template_parms for
A<V>'s template argument naturally yields a copy of V in terms of Bar's
(implicitly) defaulted copy constructor.
This however happens inside a template context so although we introduced
a use of the copy constructor, mark_used didn't actually synthesize it,
which causes subsequent constant evaluation of the template argument to
fail with:
nontype-class59.C: In instantiation of ‘void f() [with Bar V = Bar{Foo()}]’:
nontype-class59.C:22:11: required from here
nontype-class59.C:18:18: error: ‘constexpr Bar::Bar(const Bar&)’ used before its definition
We already make sure to instantiate templated constexpr functions needed
for constant evaluation (as per P0859R0). So this patch fixes this by
making us synthesize defaulted constexpr functions needed for constant
evaluation as well.
PR c++/110122
gcc/cp/ChangeLog:
* constexpr.cc (cxx_eval_call_expression): Synthesize defaulted
functions needed for constant evaluation.
(instantiate_cx_fn_r): Likewise.
gcc/testsuite/ChangeLog:
* g++.dg/cpp2a/nontype-class59.C: New test.
|
|
DR 2543 clarifies that constinit variables should follow the language, and
diagnose non-constant initializers (according to [expr.const]) even if they
can actually initialize the variables statically.
DR 2543
gcc/cp/ChangeLog:
* constexpr.cc (cxx_eval_outermost_constant_expr): Preserve
TARGET_EXPR flags.
(potential_constant_expression_1): Check TARGET_EXPR_ELIDING_P.
* typeck2.cc (store_init_value): Diagnose constinit sooner.
gcc/testsuite/ChangeLog:
* g++.dg/DRs/dr2543.C: New test.
|
|
The restriction on the "permitted result of a constant expression" to not
refer to an immediate function applies regardless of context. The previous
code tried to only check in cases where we wouldn't get the check in
cp_fold_r, but with the next patch I would need to add another case and it
shouldn't be a problem to always check.
We also shouldn't talk about immediate evaluation when we aren't dealing
with one.
gcc/cp/ChangeLog:
* constexpr.cc (cxx_eval_outermost_constant_expr): Always check
for address of immediate fn.
(maybe_constant_init_1): Evaluate PTRMEM_CST.
gcc/testsuite/ChangeLog:
* g++.dg/DRs/dr2478.C: Handle -fimplicit-constexpr.
* g++.dg/cpp23/consteval-if12.C: Adjust diagnostics.
* g++.dg/cpp2a/consteval20.C: Likewise.
* g++.dg/cpp2a/consteval24.C: Likewise.
* g++.dg/cpp2a/srcloc20.C: Likewise.
|
|
Here we're incorrectly deeming the templated call a.g() inside b's
initializer as potentially constant, despite g being non-constexpr,
which leads to us needlessly instantiating the initializer ahead of time
and which subsequently triggers a bug in access checking deferral (to be
fixed by the follow-up patch).
This patch fixes this by calling get_fns earlier during CALL_EXPR
potentiality checking so that when we extract a FUNCTION_DECL out of a
templated member function call (whose overall callee is typically a
COMPONENT_REF) we do the usual constexpr-eligibility checking for it.
In passing, I noticed the nearby special handling of the object argument
of a non-static member function call is effectively the same as the
generic argument handling a few lines below. So this patch just gets
rid of this special handling; otherwise we'd have to adapt it to handle
templated versions of such calls.
PR c++/109480
gcc/cp/ChangeLog:
* constexpr.cc (potential_constant_expression_1) <case CALL_EXPR>:
Reorganize to call get_fns sooner. Remove special handling of
the object argument of a non-static member function call. Remove
dead store to 'fun'.
gcc/testsuite/ChangeLog:
* g++.dg/cpp0x/noexcept59.C: Make e() constexpr so that the
expected "without object" diagnostic isn't replaced by a
"call to non-constexpr function" diagnostic.
* g++.dg/template/non-dependent25.C: New test.
|
|
While looking at the empty base handling for 109678, it occurred to me that
we ought to be able to look for an empty base at a specific offset, not just
in general.
PR c++/109678
gcc/cp/ChangeLog:
* cp-tree.h (lookup_base): Add offset parm.
* constexpr.cc (cxx_fold_indirect_ref_1): Pass it.
* search.cc (struct lookup_base_data_s): Add offset.
(dfs_lookup_base): Handle it.
(lookup_base): Pass it.
|
|
Here, when dealing with a class with a complex subobject structure, we would
try and fail to find the relevant FIELD_DECL for an empty base before giving
up. And we would do this at each level, in a combinatorially problematic
way. Instead, we should check for an empty base first.
PR c++/109678
gcc/cp/ChangeLog:
* constexpr.cc (cxx_fold_indirect_ref_1): Handle empty base first.
gcc/testsuite/ChangeLog:
* g++.dg/cpp1z/variant1.C: New test.
|
|
We were assuming that the result of evaluation of TARGET_EXPR_INITIAL would
always be the new value of the temporary, but that's not necessarily true
when the initializer is complex (i.e. target_expr_needs_replace). In that
case evaluating the initializer initializes the temporary as a side-effect.
PR c++/109357
gcc/cp/ChangeLog:
* constexpr.cc (cxx_eval_constant_expression) [TARGET_EXPR]:
Check for complex initializer.
gcc/testsuite/ChangeLog:
* g++.dg/cpp2a/constexpr-dtor15.C: New test.
|
|
This testcase in this PR (already fixed by r13-6526-ge4692319fd5fc7)
demonstrates that maybe_constant_init can be called on an unevaluated
operand (e.g. from massage_init_elt) so this entry point should also
limit constant evaluation in that case, like maybe_constant_value does.
PR c++/109030
gcc/cp/ChangeLog:
* constexpr.cc (maybe_constant_init_1): For an unevaluated
non-manifestly-constant operand, don't constant evaluate
and instead call fold_to_constant as in maybe_constant_value.
gcc/testsuite/ChangeLog:
* g++.dg/cpp2a/constexpr-inst2.C: New test.
|
|
We crash here since r10-3661, the store_init_value hunk in particular.
Before, we called cp_fully_fold_init, so e.g.
{.str=VIEW_CONVERT_EXPR<char[8]>("")}
was folded into
{.str=""}
but now we don't fold and keep the VCE around, and it causes trouble in
cxx_eval_store_expression: in the !refs->is_empty () loop we descend on
.str's initializer but since it's wrapped in a VCE, we skip the STRING_CST
check and then crash on the CONSTRUCTOR_NO_CLEARING.
PR c++/107280
gcc/cp/ChangeLog:
* constexpr.cc (cxx_eval_store_expression): Strip location wrappers.
gcc/testsuite/ChangeLog:
* g++.dg/cpp1z/constexpr-lambda28.C: New test.
|
|
When processing a noexcept, constructors aren't elided: build_over_call
has
/* It's unsafe to elide the constructor when handling
a noexcept-expression, it may evaluate to the wrong
value (c++/53025). */
&& (force_elide || cp_noexcept_operand == 0))
so the assert I added recently needs to be relaxed a little bit.
PR c++/109030
gcc/cp/ChangeLog:
* constexpr.cc (cxx_eval_call_expression): Relax assert.
gcc/testsuite/ChangeLog:
* g++.dg/cpp0x/noexcept77.C: New test.
|
|
Similarly to PR107938, this also started with r11-557, whereby cp_finish_decl
can call check_initializer even in a template for a constexpr initializer.
Here we are rejecting
extern const Q q;
template<int>
constexpr auto p = q(0);
even though q has a constexpr operator(). It's deemed non-const by
decl_maybe_constant_var_p because even though 'q' is const it is not
of integral/enum type.
If fun is not a function pointer, we don't know if we're using it as an
lvalue or rvalue, so with this patch we pass 'any' for want_rval. With
that, p_c_e/VAR_DECL doesn't flat out reject the underlying VAR_DECL.
PR c++/107939
gcc/cp/ChangeLog:
* constexpr.cc (potential_constant_expression_1) <case CALL_EXPR>: Pass
'any' when recursing on a VAR_DECL and not a pointer to function.
gcc/testsuite/ChangeLog:
* g++.dg/cpp1y/var-templ74.C: Remove dg-error.
* g++.dg/cpp1y/var-templ77.C: New test.
|
|
The stmtexpr19.C testcase used to be rejected as it has a static
variable in statement expression in constexpr context, but as that
static variable is initialized by constant expression, when P2647R1
was implemented we agreed to make it valid.
Now, as reported, the testcase compiles fine, but doesn't actually link
because the static variable isn't defined anywhere, and with -flto ICEs
because of this problem. This is because we never
varpool_node::finalize_decl those vars, the constant expression in which
the DECL_EXPR is present for the static VAR_DECL is folded (constant
evaluated) into just the address of the VAR_DECL.
Now, similar testcase included below (do we want to include it in the
testsuite too?) works fine, because in
cp_finish_decl -> make_rtl_for_nonlocal_decl
we have since PR70353 fix:
/* We defer emission of local statics until the corresponding
DECL_EXPR is expanded. But with constexpr its function might never
be expanded, so go ahead and tell cgraph about the variable now. */
defer_p = ((DECL_FUNCTION_SCOPE_P (decl)
&& !var_in_maybe_constexpr_fn (decl))
|| DECL_VIRTUAL_P (decl));
and so don't defer them in constexpr/consteval functions. The following
patch calls rest_of_decl_compilation which make_rtl_for_nonlocal_decl didn't
call when encountering DECL_EXPRs of such vars during constant evaluation
if they weren't finalized yet.
2023-03-04 Jakub Jelinek <jakub@redhat.com>
PR c++/108702
* constexpr.cc: Include toplev.h.
(cxx_eval_constant_expression) <case DECL_EXPR>: When seeing a local
static initialized by constant expression outside of a constexpr
function which has been deferred by make_rtl_for_nonlocal_decl,
call rest_of_decl_compilation on it.
* g++.dg/ext/stmtexpr19.C: Use dg-do link rather than dg-do compile.
|
|
According to [basic.start.static]/2 and [expr.const]/2, a variable
with static storage duration initialized with a constant initializer
has constant initialization, and such an initializer is manifestly
constant-evaluated.
For copy initialization, we're already getting this right because in
that case check_initializer would consistently call store_init_value,
which for TREE_STATIC variables calls fold_non_dependent_init with
m_c_e=true.
But for direct (or default) initialization, check_initializer doesn't
always call store_init_value. We instead however always call
maybe_constant_init from expand_default_init[1], albeit with m_c_e=false
which means we don't get the "manifestly constant-evaluated" part right
for non-copy-init.
This patch fixes this by setting m_c_e=true in maybe_constant_init for
static storage duration variables, mainly for benefit of the call
to maybe_constant_init from expand_default_init.
[1]: this maybe_constant_init call isn't reached in the copy-init
case because there init is a CONSTRUCTOR rather than a TREE_LIST,
and so we exit early from expand_default_init, returning an INIT_EXPR.
This INIT_EXPR is ultimately what causes us to consistently hit the
store_init_value code path from check_initializer in the copy-init case.
PR c++/108243
gcc/cp/ChangeLog:
* constexpr.cc (maybe_constant_init_1): Override
manifestly_const_eval to true if is_static.
gcc/testsuite/ChangeLog:
* g++.dg/cpp2a/is-constant-evaluated14.C: New test.
|
|
Here we're attempting to evaluate a PTRMEM_CST in a class that hasn't
been completed yet, but that doesn't work:
/* We can't lower this until the class is complete. */
if (!COMPLETE_TYPE_P (DECL_CONTEXT (member)))
return cst;
and then this unlowered PTRMEM_CST is used as EXPR in
tree op1 = build_nop (ptrdiff_type_node, expr);
and we crash in a subsequent cp_fold_convert which gets type=ptrdiff_type_node,
expr=PTRMEM_CST and does
else if (TREE_CODE (expr) == PTRMEM_CST
&& same_type_p (TYPE_PTRMEM_CLASS_TYPE (type),
PTRMEM_CST_CLASS (expr)))
where TYPE_PTRMEM_CLASS_TYPE (type) is going to crash since the type
is ptrdiff_type_node. We could just add a TYPE_PTRMEM_P check before
accessing TYPE_PTRMEM_CLASS_TYPE but I think it's nicer to explain why
we couldn't evaluate the expression.
PR c++/107574
gcc/cp/ChangeLog:
* constexpr.cc (cxx_eval_constant_expression): Emit an error when
a PTRMEM_CST cannot be evaluated.
gcc/testsuite/ChangeLog:
* g++.dg/cpp0x/ptrmem-cst1.C: New test.
|
|
Here we're mishandling the unevaluated array new-expressions due to a
supposed non-constant array size ever since r12-5253-g4df7f8c79835d569
made us no longer perform constant evaluation of non-manifestly-constant
expressions within unevaluated contexts. This shouldn't make a difference
here since the array sizes are constant literals, except they're expressed
as NON_LVALUE_EXPR location wrappers around INTEGER_CST, wrappers which
used to get stripped as part of constant evaluation and now no longer do.
Moreover it means build_vec_init can't constant fold the MINUS_EXPR
'maxindex' passed from build_new_1 when in an unevaluated context (since
it tries reducing it via maybe_constant_value called with mce_unknown).
This patch fixes these issues by making maybe_constant_value (and
fold_non_dependent_expr) try folding an unevaluated non-manifestly-constant
operand via fold(), as long as it simplifies to a simple constant, rather
than doing no simplification at all. This covers e.g. simple arithmetic
and casts including stripping of location wrappers around INTEGER_CST.
In passing, this patch also fixes maybe_constant_value to avoid constant
evaluating an unevaluated operand when called with mce_false, by adjusting
the early exit test appropriately.
Co-authored-by: Jason Merrill <jason@redhat.com>
PR c++/108219
PR c++/108218
gcc/cp/ChangeLog:
* constexpr.cc (fold_to_constant): Define.
(maybe_constant_value): Move up early exit test for unevaluated
operands. Try reducing an unevaluated operand to a constant via
fold_to_constant.
(fold_non_dependent_expr_template): Add early exit test for
CONSTANT_CLASS_P nodes. Try reducing an unevaluated operand
to a constant via fold_to_constant.
* cp-tree.h (fold_to_constant): Declare.
gcc/testsuite/ChangeLog:
* g++.dg/cpp0x/new6.C: New test.
* g++.dg/cpp2a/concepts-new1.C: New test.
|
|
The r13-2965-g73d9b0e5947e16 change changed the line touched in this patch
from
return RECUR (tmp, want_rval);
to
return RECUR (DECL_INITIAL (tmp), want_rval);
This is on DECL_EXPR handling code, where tmp can be lots of different
trees and DECL_INITIAL unfortunately also means different things on
different trees.
It is the initializer on VAR_DECL, DECL_ARG_TYPE on PARM_DECLs (though
those are unlikely to have DECL_EXPRs), for FUNCTION_DECLs the body,
..., USING_DECL_DECLS on USING_DECLs and DECL_FRIENDLIST on TYPE_DECLs.
The testcase below ICEs because we have a DECL_EXPR for TYPE_DECL
which has non-NULL DECL_FRIENDLIST and we certainly can't recurse on
the friend list.
The following patch will RECUR on DECL_INITIAL only for VAR_DECLs and
for anything else just return true.
2023-03-01 Jakub Jelinek <jakub@redhat.com>
PR c++/108606
* constexpr.cc (potential_constant_expression_1) <case DECL_EXPR>:
Only recurse on DECL_INITIAL (tmp) if tmp is a VAR_DECL, otherwise
just return true.
* g++.dg/cpp1y/pr108606.C: New test.
|
|
In constexpr-nsdmi3.C, with -fno-elide-constructors, we don't elide
the Y::Y(const Y&) call used to initialize o.c. So store_init_value
-> cxx_constant_init must constexpr-evaluate the call to Y::Y(const Y&)
in cxx_eval_call_expression. It's a trivial function, so we do the
"Shortcut trivial constructor/op=" code and rather than evaluating
the function, we just create an assignment
o.c = *(const struct Y &) (const struct Y *) &(&<PLACEHOLDER_EXPR struct X>)->b
which is a MODIFY_EXPR, so the preeval code in cxx_eval_store_expression
clears .ctor and .object, therefore we can't replace the PLACEHOLDER_EXPR
whereupon we crash at
/* A placeholder without a referent. We can get here when
checking whether NSDMIs are noexcept, or in massage_init_elt;
just say it's non-constant for now. */
gcc_assert (ctx->quiet);
The PLACEHOLDER_EXPR can also be on the LHS as in constexpr-nsdmi10.C.
I don't think we can do much here, but I noticed that the whole
trivial_fn_p (fun) block is only entered when -fno-elide-constructors.
This is true since GCC 9; it wasn't easy to bisect what changes made it
so, but r240845 is probably one of them. -fno-elide-constructors is an
option for experiments only so it's not clear to me why we'd still want
to shortcut trivial constructor/op=. I propose to remove the code and
add a checking assert to make sure we're not getting a trivial_fn_p
unless -fno-elide-constructors.
PR c++/101073
gcc/cp/ChangeLog:
* constexpr.cc (cxx_eval_call_expression): Replace shortcutting trivial
constructor/op= with a checking assert.
gcc/testsuite/ChangeLog:
* g++.dg/cpp0x/constexpr-nsdmi3.C: New test.
* g++.dg/cpp1y/constexpr-nsdmi10.C: New test.
|
|
This patch converts the constexpr machinery's manifestly_const_eval flag
into a tri-state enum to allow us to express wanting to fold
__builtin_is_constant_evaluated to false via speculative constexpr
evaluation. For now, only the maybe_constant_value entry point is
changed to take this enum; the others continue to take bool. The
subsequent patch will teach cp_fold (which uses maybe_constant_value) to
fold the builtin to false when called from cp_fold_function and
cp_fully_fold_init.
gcc/cp/ChangeLog:
* constexpr.cc (constexpr_call::manifestly_const_eval): Give
it type int instead of bool.
(constexpr_ctx::manifestly_const_eval): Give it type mce_value
instead of bool.
(cxx_eval_builtin_function_call): Adjust after making
manifestly_const_eval tri-state.
(cxx_eval_call_expression): Likewise.
(cxx_eval_binary_expression): Likewise.
(cxx_eval_conditional_expression): Likewise.
(cxx_eval_constant_expression): Likewise.
(cxx_eval_outermost_constant_expr): Likewise.
(cxx_constant_value): Likewise.
(cxx_constant_dtor): Likewise.
(maybe_constant_value): Give manifestly_const_eval parameter
type mce_value instead of bool and adjust accordingly.
(fold_non_dependent_expr_template): Adjust call
to cxx_eval_outermost_constant_expr.
(fold_non_dependent_expr): Likewise.
(maybe_constant_init_1): Likewise.
* constraint.cc (satisfy_atom): Adjust call to
maybe_constant_value.
* cp-tree.h (enum class mce_value): Define.
(maybe_constant_value): Adjust manifestly_const_eval parameter
type and default argument.
* decl.cc (compute_array_index_type_loc): Adjust call to
maybe_constant_value.
* pt.cc (convert_nontype_argument): Likewise.
|
|
In this test case, we find ourselves evaluating 't' which is
((const struct carray *) this)->data_[VIEW_CONVERT_EXPR<long int>(index)]
in cxx_eval_array_reference. ctx->object is non-null, a RESULT_DECL, so
we replace it with 't':
new_ctx.object = t; // result_decl replaced
and then we go to cxx_eval_constant_expression to evaluate an
AGGR_INIT_EXPR, where we end up evaluating an INIT_EXPR (which is in the
body of the constructor for seed_or_index):
((struct seed_or_index *) this)->value_ = NON_LVALUE_EXPR <0>
whereupon in cxx_eval_store_expression we go to the probe loop
where the 'this' is evaluated to
ze_set.tables_.first_table_.data_[0]
so the 'object' is ze_set, but that isn't in ctx->global->get_value_ptr
so we fail with a bogus error. ze_set is not there because it comes
from a different constexpr context (it's not in cv_cache either).
The problem started with r12-2304 where I added the new_ctx.object
replacement. That was to prevent a type mismatch: the type of 't'
and ctx.object were different.
It seems clear that we shouldn't have replaced ctx.object here.
The cxx_eval_array_reference I mentioned earlier is called from
cxx_eval_store_expression:
6257 init = cxx_eval_constant_expression (&new_ctx, init, vc_prvalue,
6258 non_constant_p, overflow_p);
which already created a new context, whose .object we should be
using unless, for instance, INIT contained a.b and we're evaluating
the 'a' part, which I think was the case for r12-2304; in that case
ctx.object has to be something different.
It no longer seems necessary to replace new_ctx.object (likely due to
changes in empty class handling).
PR c++/108158
gcc/cp/ChangeLog:
* constexpr.cc (cxx_eval_array_reference): Don't replace
new_ctx.object.
gcc/testsuite/ChangeLog:
* g++.dg/cpp1y/constexpr-108158.C: New test.
|
|
evaluation [PR108607]
While potential_constant_expression_1 handled most of OMP_* codes (by saying that
they aren't potential constant expressions), OMP_SCOPE was missing in that list.
I've also added OMP_SCAN, though that is less important (similarly to OMP_SECTION
it ought to appear solely inside of OMP_{FOR,SIMD} resp. OMP_SECTIONS).
As the testcase shows, it isn't enough, potential_constant_expression_1
can catch only some cases, as soon as one uses switch or ifs where at least
one of the possible paths could be constant expression, we can run into the
same codes during cxx_eval_constant_expression, so this patch handles those
there as well.
2023-02-01 Jakub Jelinek <jakub@redhat.com>
PR c++/108607
* constexpr.cc (cxx_eval_constant_expression): Handle OMP_*
and OACC_* constructs as non-constant.
(potential_constant_expression_1): Handle OMP_SCAN and OMP_SCOPE.
* g++.dg/gomp/pr108607.C: New test.
|
|
|
|
cxx_eval_call_expression requests an INSERT even in cases when it
would later decide not to insert. This could break double-hashing
chains. Arrange for it to use NO_INSERT when the insertion would not
be completed.
for gcc/cp/ChangeLog
* constexpr.cc (cxx_eval_call_expression): Do not request an
INSERT that would not be completed.
|
|
Here during ahead of time checking of C{}, we indirectly call get_nsdmi
for C::m from finish_compound_literal, which in turn calls
break_out_target_exprs for C::m's (non-templated) initializer, during
which we build a call to A::~A and check expr_noexcept_p for it (from
build_vec_delete_1). But this is all done with processing_template_decl
set, so the built A::~A call is templated (whose form was recently
changed by r12-6897-gdec8d0e5fa00ceb2) which expr_noexcept_p doesn't
expect, and we crash.
This patch fixes this by clearing processing_template_decl before
the call to break_out_target_exprs from get_nsdmi. And since it more
generally seems we shouldn't be seeing (or producing) non-templated
trees in break_out_target_exprs, this patch also adds an assert to
that effect.
PR c++/108116
gcc/cp/ChangeLog:
* constexpr.cc (maybe_constant_value): Clear
processing_template_decl before calling break_out_target_exprs.
* init.cc (get_nsdmi): Likewise.
* tree.cc (break_out_target_exprs): Assert processing_template_decl
is cleared.
gcc/testsuite/ChangeLog:
* g++.dg/cpp0x/nsdmi-template24.C: New test.
|
|
We currently declare __builtin_source_location with a const void* return
type instead of the actual type const std::source_location::__impl*, and
later when folding this builtin we obtain the actual type via name lookup.
But the below testcase demonstrates this approach seems to interact
poorly with modules, since we may import an entity that uses
std::source_location::current() in its default argument (or DMI) without
necessarily importing <source_location>, and thus the name lookup for
std::source_location will fail at the call site (when using the default
argument) unless we also import <source_location>.
This patch fixes this by instead initially declaring the builtin with an
auto return type and updating it appropriately upon its first use (in
standard code the first/only use would be in the definition of
std::source_location). Thus when folding calls to this builtin we can
get at its return type through the type of the CALL_EXPR and avoid
needing to do a name lookup.
PR c++/100881
gcc/cp/ChangeLog:
* constexpr.cc (cxx_eval_builtin_function_call): Adjust calls
to fold_builtin_source_location.
* cp-gimplify.cc (cp_gimplify_expr): Likewise.
(cp_fold): Likewise.
(get_source_location_impl_type): Remove location_t parameter and
adjust accordingly. No longer static.
(fold_builtin_source_location): Take a CALL_EXPR tree instead of a
location and obtain the impl type from its return type.
* cp-tree.h (enum cp_tree_index): Remove CPTI_SOURCE_LOCATION_IMPL
enumerator.
(source_location_impl): Remove.
(fold_builtin_source_location): Adjust parameter type.
(get_source_location_impl_type): Declare.
* decl.cc (cxx_init_decl_processing): Declare
__builtin_source_location with auto return type instead of
const void*.
(require_deduced_type): Update the return type of
__builtin_source_location.
gcc/testsuite/ChangeLog:
* g++.dg/cpp2a/srcloc3.C: Adjust expected note s/evaluating/using.
* g++.dg/cpp2a/srcloc4.C: Likewise.
* g++.dg/cpp2a/srcloc5.C: Likewise.
* g++.dg/cpp2a/srcloc6.C: Likewise.
* g++.dg/cpp2a/srcloc7.C: Likewise.
* g++.dg/cpp2a/srcloc8.C: Likewise.
* g++.dg/cpp2a/srcloc9.C: Likewise.
* g++.dg/cpp2a/srcloc10.C: Likewise.
* g++.dg/cpp2a/srcloc11.C: Likewise.
* g++.dg/cpp2a/srcloc12.C: Likewise.
* g++.dg/cpp2a/srcloc13.C: Likewise.
* g++.dg/modules/pr100881_a.C: New test.
* g++.dg/modules/pr100881_b.C: New test.
|
|
This patch broke a couple of different patterns; reverting while I work on a
fix.
PR c++/108701
This reverts commit bd0485f20f4794f9787237706a6308473a8e9415.
|
|
The previous patch avoided building an initializer_list<string> at all when
building a vector<string>, but in situations where that isn't possible, we
could still build the initializer_list with a loop over a constant array.
This is represented using a VEC_INIT_EXPR, which required adjusting a couple
of places that expected the initializer array to have the same type as the
target array and fixing build_vec_init not to undo our efforts.
PR c++/105838
gcc/cp/ChangeLog:
* call.cc (convert_like_internal) [ck_list]: Use
maybe_init_list_as_array.
* constexpr.cc (cxx_eval_vec_init_1): Init might have
a different type.
* tree.cc (build_vec_init_elt): Likewise.
* init.cc (build_vec_init): Handle from_array from a
TARGET_EXPR. Retain TARGET_EXPR of a different type.
gcc/testsuite/ChangeLog:
* g++.dg/tree-ssa/initlist-opt2.C: New test.
|
|
In this PR, initializing the array of std::string to pass to the vector
initializer_list constructor gets very confusing to the optimizers as the
number of elements increases, primarily because of all the std::allocator
temporaries passed to all the string constructors. Instead of creating one
for each string, let's share an allocator between all the strings; we can do
this safely because we know that std::allocator is stateless and that string
doesn't care about the object identity of its allocator parameter.
PR c++/105838
gcc/cp/ChangeLog:
* cp-tree.h (is_std_allocator): Declare.
* constexpr.cc (is_std_allocator): Split out from...
(is_std_allocator_allocate): ...here.
* init.cc (find_temps_r): New.
(find_allocator_temp): New.
(build_vec_init): Use it.
gcc/testsuite/ChangeLog:
* g++.dg/tree-ssa/allocator-opt1.C: New test.
|
