https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80226
Bug ID: 80226
Summary: ICE gimple-expr.c:474 on Go function returning
multiple empty struct/array values
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: go
Assignee: ian at airs dot com
Reporter: thanm at google dot com
CC: cmang at google dot com
Target Milestone: ---
Compiling the attached test case with gccgo results in an ICE. Example:
$ go build -compiler gccgo repro.go
# command-line-arguments
In function ‘repro.Test36’:
go1: internal compiler error: in create_tmp_var, at gimple-expr.c:474
0xc2ace4 create_tmp_var(tree_node*, char const*)
../../gcc-trunk/gcc/gimple-expr.c:474
0x8f5f37 Gcc_backend::return_statement(Bfunction*, std::vector<Bexpression*,
std::allocator<Bexpression*> > const&, Location)
../../gcc-trunk/gcc/go/go-gcc.cc:2135
0x96f3b9 Return_statement::do_get_backend(Translate_context*)
../../gcc-trunk/gcc/go/gofrontend/statements.cc:2838
0x968480 Statement::get_backend(Translate_context*)
../../gcc-trunk/gcc/go/gofrontend/statements.cc:142
0x91b0f2 Block::get_backend(Translate_context*)
../../gcc-trunk/gcc/go/gofrontend/gogo.cc:6026
0x96c772 Block_statement::do_get_backend(Translate_context*)
../../gcc-trunk/gcc/go/gofrontend/statements.cc:1850
0x968480 Statement::get_backend(Translate_context*)
../../gcc-trunk/gcc/go/gofrontend/statements.cc:142
0x91b0f2 Block::get_backend(Translate_context*)
../../gcc-trunk/gcc/go/gofrontend/gogo.cc:6026
0x96ff8e If_statement::do_get_backend(Translate_context*)
../../gcc-trunk/gcc/go/gofrontend/statements.cc:3178
0x968480 Statement::get_backend(Translate_context*)
../../gcc-trunk/gcc/go/gofrontend/statements.cc:142
0x91b0f2 Block::get_backend(Translate_context*)
../../gcc-trunk/gcc/go/gofrontend/gogo.cc:6026
0x96c772 Block_statement::do_get_backend(Translate_context*)
../../gcc-trunk/gcc/go/gofrontend/statements.cc:1850
0x968480 Statement::get_backend(Translate_context*)
../../gcc-trunk/gcc/go/gofrontend/statements.cc:142
0x91b0f2 Block::get_backend(Translate_context*)
../../gcc-trunk/gcc/go/gofrontend/gogo.cc:6026
0x9198ef Function::build(Gogo*, Named_object*)
../../gcc-trunk/gcc/go/gofrontend/gogo.cc:5629
0x91ebf0 Named_object::get_backend(Gogo*, std::vector<Bexpression*,
std::allocator<Bexpression*> >&, std::vector<Btype*, std::allocator<Btype*> >&,
std::vector<Bfunction*, std::allocator<Bfunction*> >&)
../../gcc-trunk/gcc/go/gofrontend/gogo.cc:7411
0x90cad1 Gogo::write_globals()
../../gcc-trunk/gcc/go/gofrontend/gogo.cc:1322
0x90679e go_write_globals()
../../gcc-trunk/gcc/go/gofrontend/go.cc:174
0x8fd2e1 go_langhook_parse_file
../../gcc-trunk/gcc/go/go-lang.c:318
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.
This is with trunk gccgo:
$ gccgo --version
gccgo (GCC) 7.0.1 20170322 (experimental)
$
Excerpt from the function:
func Test36(p0 uint64, p1 StructF36S0, p2 uint8, p3 int32, p4 StructF36S1) (r0
StructF36S2, r1 ArrayF36S0E0, r2 ArrayF36S1E0) {
rc0 := StructF36S2{}
rc1 := ArrayF36S0E0{}
rc2 := ArrayF36S1E0{}
if p0 == 0 {
return rc0, rc1, rc2
}
where r0/r1/r2 are all zero-sized arrays or empty structures.
I spent a little while poking around -- from what I can tell there is code
already in Gcc_backend::return_statement designed to catch this case (returning
empty-sized stuff), however it doesn't appear to be working correctly. Line is
if (int_size_in_bytes(TREE_TYPE(result)) == 0)
however this call is returning -1 in this case (since TREE_TYPE(result) is the
void type).
I will work on a fix.
