https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116741
Bug ID: 116741
Summary: ICE with invalid cast from void* in constexpr
Product: gcc
Version: 15.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: nshead at gcc dot gnu.org
Target Milestone: ---
The following sample:
struct S {
int foo;
};
constexpr float f() {
S s;
void* p = &s.foo;
return *static_cast<float*>(p);
}
constexpr auto x = f();
fails on trunk (-std=c++26) with:
test.cpp:11:21: in ‘constexpr’ expansion of ‘f()’
test.cpp:8:11: error: cast from ‘void*’ is not allowed in a constant expression
because pointed-to type ‘int’ is not similar to ‘float’
8 | return *static_cast<float*>(p);
| ^~~~~~~~~~~~~~~~~~~~~~
test.cpp:8:11: internal compiler error: tree check: expected tree that contains
‘decl minimal’ structure, have ‘component_ref’ in cxx_eval_constant_expression,
at cp/constexpr.cc:8203
0x3ad6512 internal_error(char const*, ...)
../../gcc/gcc/diagnostic-global-context.cc:517
0x2098f8c tree_contains_struct_check_failed(tree_node const*,
tree_node_structure_enum, char const*, int, char const*)
../../gcc/gcc/tree.cc:9177
0xe39100 contains_struct_check(tree_node*, tree_node_structure_enum, char
const*, int, char const*)
../../gcc/gcc/tree.h:3779
0xed6f78 cxx_eval_constant_expression
../../gcc/gcc/cp/constexpr.cc:8203
0xecd1b4 cxx_eval_indirect_ref
../../gcc/gcc/cp/constexpr.cc:5926
0xed5b9a cxx_eval_constant_expression
../../gcc/gcc/cp/constexpr.cc:7849
0xecf2a4 cxx_eval_store_expression
../../gcc/gcc/cp/constexpr.cc:6238
0xed53c6 cxx_eval_constant_expression
../../gcc/gcc/cp/constexpr.cc:7719
0xed54b5 cxx_eval_constant_expression
../../gcc/gcc/cp/constexpr.cc:7731
0xed2408 cxx_eval_statement_list
../../gcc/gcc/cp/constexpr.cc:6991
0xed8144 cxx_eval_constant_expression
../../gcc/gcc/cp/constexpr.cc:8362
0xed827f cxx_eval_constant_expression
../../gcc/gcc/cp/constexpr.cc:8371
0xec1e63 cxx_eval_call_expression
../../gcc/gcc/cp/constexpr.cc:3300
0xed4622 cxx_eval_constant_expression
../../gcc/gcc/cp/constexpr.cc:7566
0xeda8e7 cxx_eval_outermost_constant_expr
../../gcc/gcc/cp/constexpr.cc:8852
0xedc479 maybe_constant_init_1
../../gcc/gcc/cp/constexpr.cc:9363
0xedc537 cxx_constant_init(tree_node*, tree_node*)
../../gcc/gcc/cp/constexpr.cc:9389
0x12eda97 store_init_value(tree_node*, tree_node*, vec<tree_node*, va_gc,
vl_embed>**, int)
../../gcc/gcc/cp/typeck2.cc:909
0xf79ee0 check_initializer
../../gcc/gcc/cp/decl.cc:7870
0xf80ccc cp_finish_decl(tree_node*, tree_node*, bool, tree_node*, int,
cp_decomp*)
../../gcc/gcc/cp/decl.cc:8918
Please submit a full bug report, with preprocessed source (by using
-freport-bug).
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.
