https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78551
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Keywords| |ice-on-invalid-code
Known to work| |4.9.4
Target Milestone|--- |5.5
Summary|Internal compiler error |[5/6/7 Regression] Internal
|with constexpr |compiler error with
|initialization of union |constexpr initialization of
| |union
Known to fail| |5.4.0, 6.2.0, 7.0
--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
ICEs in
t.C:20:53: internal compiler error: in output_constructor_regular_field, at
varasm.c:4968
constexpr std::array<A, 2> array({"long", "longer"});
^
GCC 4.9 rejects it, so does clang++:
> clang++ t.C -S -std=gnu++14
t.C:20:28: error: constexpr variable 'array' must be initialized by a constant
expression
constexpr std::array<A, 2> array({"long", "longer"});
^~~~~~~~~~~~~~~~~~~~~~~~~
t.C:14:22: note: assignment to member 'buff' of union with active member 's' is
not allowed in a constant expression
buff[i] = str[i];
^
t.C:20:35: note: in call to 'A(&"long"[0])'
constexpr std::array<A, 2> array({"long", "longer"});
^
1 error generated.
Backtrace from GCC 6 branch head:
> /space/rguenther/install/gcc-6.2/bin/g++ t.ii -B /abuild/rguenther/gcc6-g/gcc
t.C:20:53: internal compiler error: in output_constructor_regular_field, at
varasm.c:4968
constexpr std::array<A, 2> array({"long", "longer"});
^
0x14386b5 output_constructor_regular_field
/space/rguenther/src/svn/gcc-6-branch/gcc/varasm.c:4968
0x14394c1 output_constructor
/space/rguenther/src/svn/gcc-6-branch/gcc/varasm.c:5276
0x1437f16 output_constant
/space/rguenther/src/svn/gcc-6-branch/gcc/varasm.c:4803
0x143897b output_constructor_regular_field
/space/rguenther/src/svn/gcc-6-branch/gcc/varasm.c:5006
0x14394c1 output_constructor
/space/rguenther/src/svn/gcc-6-branch/gcc/varasm.c:5276
0x1437f16 output_constant
/space/rguenther/src/svn/gcc-6-branch/gcc/varasm.c:4803
0x143897b output_constructor_regular_field
/space/rguenther/src/svn/gcc-6-branch/gcc/varasm.c:5006
0x14394c1 output_constructor
/space/rguenther/src/svn/gcc-6-branch/gcc/varasm.c:5276
0x1437bd8 output_constant
/space/rguenther/src/svn/gcc-6-branch/gcc/varasm.c:4773
0x143897b output_constructor_regular_field
/space/rguenther/src/svn/gcc-6-branch/gcc/varasm.c:5006
0x14394c1 output_constructor
/space/rguenther/src/svn/gcc-6-branch/gcc/varasm.c:5276
0x1437f16 output_constant
/space/rguenther/src/svn/gcc-6-branch/gcc/varasm.c:4803
0x142f4d9 assemble_variable_contents
/space/rguenther/src/svn/gcc-6-branch/gcc/varasm.c:2062
0x142fe82 assemble_variable(tree_node*, int, int, int)
/space/rguenther/src/svn/gcc-6-branch/gcc/varasm.c:2238
0x1447096 varpool_node::assemble_decl()
/space/rguenther/src/svn/gcc-6-branch/gcc/varpool.c:582
0xbb40d9 output_in_order
/space/rguenther/src/svn/gcc-6-branch/gcc/cgraphunit.c:2231
0xbb4784 symbol_table::compile()
/space/rguenther/src/svn/gcc-6-branch/gcc/cgraphunit.c:2468
0xbb49c3 symbol_table::finalize_compilation_unit()
/space/rguenther/src/svn/gcc-6-branch/gcc/cgraphunit.c:2564
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