Comment 46 for bug 1890435

seen on the gcc-10 branch and trunk 20201003 on arm-linux-gnueabihf. Omitting -g works around the issue.

$ cat signal.i
typedef int a __attribute__((aligned(2)));
a b[1];

$ gcc -c -g -O0 signal.i
signal.i:2:1: error: 'TYPE_CANONICAL' is not compatible
    2 | a b[1];
      | ^
 <array_type 0xf751d7e0
    type <integer_type 0xf7a4f3c0 int public SI
        size <integer_cst 0xf7426e58 constant 32>
        unit-size <integer_cst 0xf7426e70 constant 4>
        align:32 warn_if_not_align:0 symtab:-144899760 alias-set -1 canonical-type 0xf7a4f3c0 precision:32 min <integer_cst 0xf74370a8 -2147483648> max <integer_cst 0xf74370c0 2147483647>
        pointer_to_this <pointer_type 0xf7a4ff00>>
    SI size <integer_cst 0xf7426e58 32> unit-size <integer_cst 0xf7426e70 4>
    align:32 warn_if_not_align:0 symtab:0 alias-set -1 canonical-type 0xf751d7e0
    domain <integer_type 0xf751d6c0
        type <integer_type 0xf7a4f060 sizetype public unsigned SI size <integer_cst 0xf7426e58 32> unit-size <integer_cst 0xf7426e70 4>
            align:32 warn_if_not_align:0 symtab:0 alias-set -1 canonical-type 0xf7a4f060 precision:32 min <integer_cst 0xf7426e88 0> max <integer_cst 0xf7426000 4294967295>>
        SI size <integer_cst 0xf7426e58 32> unit-size <integer_cst 0xf7426e70 4>
        align:32 warn_if_not_align:0 symtab:0 alias-set -1 canonical-type 0xf751d6c0 precision:32 min <integer_cst 0xf7426e88 0> max <integer_cst 0xf7426e88 0>>>
signal.i:2:1: error: 'TYPE_MODE' of 'TYPE_CANONICAL' is not compatible
 <array_type 0xf751d7e0
    type <integer_type 0xf7a4f3c0 int public SI
        size <integer_cst 0xf7426e58 constant 32>
        unit-size <integer_cst 0xf7426e70 constant 4>
        align:32 warn_if_not_align:0 symtab:-144899760 alias-set -1 canonical-type 0xf7a4f3c0 precision:32 min <integer_cst 0xf74370a8 -2147483648> max <integer_cst 0xf74370c0 2147483647>
        pointer_to_this <pointer_type 0xf7a4ff00>>
    SI size <integer_cst 0xf7426e58 32> unit-size <integer_cst 0xf7426e70 4>
    align:32 warn_if_not_align:0 symtab:0 alias-set -1 canonical-type 0xf751d7e0
    domain <integer_type 0xf751d6c0
        type <integer_type 0xf7a4f060 sizetype public unsigned SI size <integer_cst 0xf7426e58 32> unit-size <integer_cst 0xf7426e70 4>
            align:32 warn_if_not_align:0 symtab:0 alias-set -1 canonical-type 0xf7a4f060 precision:32 min <integer_cst 0xf7426e88 0> max <integer_cst 0xf7426000 4294967295>>
        SI size <integer_cst 0xf7426e58 32> unit-size <integer_cst 0xf7426e70 4>
        align:32 warn_if_not_align:0 symtab:0 alias-set -1 canonical-type 0xf751d6c0 precision:32 min <integer_cst 0xf7426e88 0> max <integer_cst 0xf7426e88 0>>>
 <array_type 0xf751d600
    type <integer_type 0xf751d660 a SI
        size <integer_cst 0xf7426e58 constant 32>
        unit-size <integer_cst 0xf7426e70 constant 4>
        user align:16 warn_if_not_align:0 symtab:-144899808 alias-set -1 canonical-type 0xf7a4f3c0 precision:32 min <integer_cst 0xf74370a8 -2147483648> max <integer_cst 0xf74370c0 2147483647>>
    no-force-blk BLK size <integer_cst 0xf7426e58 32> unit-size <integer_cst 0xf7426e70 4>
    user align:16 warn_if_not_align:0 symtab:0 alias-set -1 canonical-type 0xf751d7e0
    domain <integer_type 0xf751d6c0
        type <integer_type 0xf7a4f060 sizetype public unsigned SI size <integer_cst 0xf7426e58 32> unit-size <integer_cst 0xf7426e70 4>
            align:32 warn_if_not_align:0 symtab:0 alias-set -1 canonical-type 0xf7a4f060 precision:32 min <integer_cst 0xf7426e88 0> max <integer_cst 0xf7426000 4294967295>>
        SI size <integer_cst 0xf7426e58 32> unit-size <integer_cst 0xf7426e70 4>
        align:32 warn_if_not_align:0 symtab:0 alias-set -1 canonical-type 0xf751d6c0 precision:32 min <integer_cst 0xf7426e88 0> max <integer_cst 0xf7426e88 0>>>
signal.i:2:1: internal compiler error: 'verify_type' failed
0x980721 verify_type(tree_node const*)
        ../../src/gcc/tree.c:14727
0x3969e3 gen_type_die_with_usage
        ../../src/gcc/dwarf2out.c:25498
0x397fe9 gen_type_die
        ../../src/gcc/dwarf2out.c:25728
0x393fd5 gen_decl_die
        ../../src/gcc/dwarf2out.c:26399
0x394aed dwarf2out_decl
        ../../src/gcc/dwarf2out.c:26908
0x394f8f dwarf2out_early_global_decl
        ../../src/gcc/dwarf2out.c:26565
0x1c59b1 finish_decl(tree_node*, unsigned int, tree_node*, tree_node*, tree_node*)
        ../../src/gcc/c/c-decl.c:5453
0x223611 c_parser_declaration_or_fndef
        ../../src/gcc/c/c-parser.c:2336
0x22bbdf c_parser_external_declaration
        ../../src/gcc/c/c-parser.c:1745
0x22c451 c_parser_translation_unit
        ../../src/gcc/c/c-parser.c:1618
0x22c451 c_parse_file()
        ../../src/gcc/c/c-parser.c:21752
0x279abd c_common_parse_file()
        ../../src/gcc/c-family/c-opts.c:1190
Please submit a full bug report,
with preprocessed source if appropriate.

gcc is configured with

--with-arch=armv7-a --with-fpu=vfpv3-d16 --with-float=hard --with-mode=thumb
--enable-checking=yes,extra,rtl
--enable-default-pie

a gcc configured with --enable-checking=release doesn't show this, however segfaults in an unreproducible way in other places.