https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113492
Bug ID: 113492
Summary: [14 Regression] ICE: in composite_type_internal, at
c/c-typeck.cc:557 with -std=c2x -funsigned-bitfields
Product: gcc
Version: 14.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: zsojka at seznam dot cz
Target Milestone: ---
Host: x86_64-pc-linux-gnu
Target: x86_64-pc-linux-gnu
Created attachment 57147
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=57147&action=edit
reduced testcase (from gcc.dg/c23-tag-composite-3.c)
Compiler output:
$ x86_64-pc-linux-gnu-gcc -std=c2x -funsigned-bitfields testcase.c
testcase.c: In function 'foo':
testcase.c:11:3: internal compiler error: in composite_type_internal, at
c/c-typeck.cc:557
11 | 1 ? a : c;
| ^
0x6eabe7 composite_type_internal(tree_node*, tree_node*, composite_cache*)
/repo/gcc-trunk/gcc/c/c-typeck.cc:557
0xe267e0 composite_type(tree_node*, tree_node*)
/repo/gcc-trunk/gcc/c/c-typeck.cc:748
0xe267e0 build_conditional_expr(unsigned int, tree_node*, bool, tree_node*,
tree_node*, unsigned int, tree_node*, tree_node*, unsigned int)
/repo/gcc-trunk/gcc/c/c-typeck.cc:5733
0xe59a26 c_parser_conditional_expression
/repo/gcc-trunk/gcc/c/c-parser.cc:9238
0xe59d64 c_parser_expr_no_commas
/repo/gcc-trunk/gcc/c/c-parser.cc:9072
0xe5a1c1 c_parser_expression
/repo/gcc-trunk/gcc/c/c-parser.cc:12762
0xe5a697 c_parser_expression_conv
/repo/gcc-trunk/gcc/c/c-parser.cc:12802
0xe7c5ef c_parser_statement_after_labels
/repo/gcc-trunk/gcc/c/c-parser.cc:7761
0xe516c6 c_parser_compound_statement_nostart
/repo/gcc-trunk/gcc/c/c-parser.cc:7248
0xe78d44 c_parser_compound_statement
/repo/gcc-trunk/gcc/c/c-parser.cc:6533
0xe7b058 c_parser_declaration_or_fndef
/repo/gcc-trunk/gcc/c/c-parser.cc:3017
0xe84c9b c_parser_external_declaration
/repo/gcc-trunk/gcc/c/c-parser.cc:2046
0xe85683 c_parser_translation_unit
/repo/gcc-trunk/gcc/c/c-parser.cc:1900
0xe85683 c_parse_file()
/repo/gcc-trunk/gcc/c/c-parser.cc:26815
0xefb1b1 c_common_parse_file()
/repo/gcc-trunk/gcc/c-family/c-opts.cc:1301
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.
I would even say that with -funsigned-bitfields, the code is valid, but I am
not a language lawyer.
gcc-13, or gcc-14 without -std=2x, rejects the code though. On the other hand,
changing the "unsigned" to "signed", makes the code to be accepted, with the
default "signed" bitfields, so "int" and "signed" bitfield types are equal;
maybe my understanding of the "-funsigned-bitfields" as "any plain 'int'
bitfield is 'unsigned'" is incorrect.
$ x86_64-pc-linux-gnu-gcc -v
Using built-in specs.
COLLECT_GCC=/repo/gcc-trunk/binary-latest-amd64/bin/x86_64-pc-linux-gnu-gcc
COLLECT_LTO_WRAPPER=/repo/gcc-trunk/binary-trunk-r14-8251-20240118071416-g48c8d26d771-checking-yes-rtl-df-extra-nobootstrap-amd64/bin/../libexec/gcc/x86_64-pc-linux-gnu/14.0.1/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: /repo/gcc-trunk//configure --enable-languages=c,c++
--enable-valgrind-annotations --disable-nls --enable-checking=yes,rtl,df,extra
--disable-bootstrap --with-cloog --with-ppl --with-isl
--build=x86_64-pc-linux-gnu --host=x86_64-pc-linux-gnu
--target=x86_64-pc-linux-gnu --with-ld=/usr/bin/x86_64-pc-linux-gnu-ld
--with-as=/usr/bin/x86_64-pc-linux-gnu-as --disable-libstdcxx-pch
--prefix=/repo/gcc-trunk//binary-trunk-r14-8251-20240118071416-g48c8d26d771-checking-yes-rtl-df-extra-nobootstrap-amd64
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 14.0.1 20240118 (experimental) (GCC)
