Following test-case was accidentally created as a secondary product of a test-case reduction. The code is very crappy, but causes an ICE: $ g++ linemap-ice2.ii ... linemap-ice2.ii:1:4063: error: expected ‘;’ at end of member declaration linemap-ice2.ii:1:4095: internal compiler error: in linemap_position_for_loc_and_offset, at libcpp/line-map.c:907 :const_iterator, bool> result = cobject_info_set.insert(co); return *(result.first); } inline void basic_oarchive_impl::save_object( basic_oarchive & ar const void *t const basic_oserializer & bos ) inline void basic_oarchive_implsave_pointer } ^ 0x1591bd3 linemap_position_for_loc_and_offset(line_maps*, unsigned int, unsigned int) ../../libcpp/line-map.c:907 0x7922d9 cp_parser_class_specifier_1 ../../gcc/cp/parser.c:21810 0x794221 cp_parser_class_specifier ../../gcc/cp/parser.c:21961 0x794221 cp_parser_type_specifier ../../gcc/cp/parser.c:16102 0x7a82e9 cp_parser_decl_specifier_seq ../../gcc/cp/parser.c:13019 0x7bc7b5 cp_parser_member_declaration ../../gcc/cp/parser.c:22696 0x791c88 cp_parser_member_specification_opt ../../gcc/cp/parser.c:22548 0x791c88 cp_parser_class_specifier_1 ../../gcc/cp/parser.c:21712 0x794221 cp_parser_class_specifier ../../gcc/cp/parser.c:21961 0x794221 cp_parser_type_specifier ../../gcc/cp/parser.c:16102 0x7a82e9 cp_parser_decl_specifier_seq ../../gcc/cp/parser.c:13019 0x7b2691 cp_parser_simple_declaration ../../gcc/cp/parser.c:12546 0x7b2ada cp_parser_block_declaration ../../gcc/cp/parser.c:12493 0x7bacfe cp_parser_declaration ../../gcc/cp/parser.c:12390 0x7bb156 cp_parser_declaration_seq_opt ../../gcc/cp/parser.c:12266 0x7bb8d8 cp_parser_namespace_body ../../gcc/cp/parser.c:17940 0x7bb8d8 cp_parser_namespace_definition ../../gcc/cp/parser.c:17916 0x7bae17 cp_parser_declaration ../../gcc/cp/parser.c:12374 0x7bb156 cp_parser_declaration_seq_opt ../../gcc/cp/parser.c:12266 0x7bb488 cp_parser_translation_unit ../../gcc/cp/parser.c:4360 Started to ICE with r238008.
Created attachment 39792 [details] Test-case
Confirmed. I'll take a peek.
Caused by: commit b65b8df248d4eb4801cbe16287cf32eda9325dec Author: dmalcolm <dmalcolm@138bc75d-0d04-0410-961f-82ee72b054a4> Date: Tue Jul 5 15:50:54 2016 +0000 PR c++/62314: add fixit hint for "expected ';' after class definition" gcc/cp/ChangeLog: PR c++/62314 * parser.c (cp_parser_class_specifier_1): When reporting missing semicolons, use a fixit-hint to suggest insertion of a semicolon immediately after the closing brace, offsetting the reported column accordingly. gcc/testsuite/ChangeLog: PR c++/62314 * gcc/testsuite/g++.dg/parse/error5.C: Update column number of missing semicolon error. * g++.dg/pr62314-2.C: New test case. git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@238008 138bc75d-0d04-0410-96 1f-82ee72b054a4
Author: dmalcolm Date: Tue Jan 10 21:54:09 2017 New Revision: 244292 URL: https://gcc.gnu.org/viewcvs?rev=244292&root=gcc&view=rev Log: Fix issues with unrepresentable column numbers (PR c++/77949) PR c++/77949 identifies an ICE when the C++ frontend attempts to emit a fix-it hint inserting a missing semicolon at column 4097 of a source file. This column value exceeds LINE_MAP_MAX_COLUMN_NUMBER and hence isn't representable using a location_t. Attempting to do so leads to these problems, which this patch fixes: (a) when encountering a column number > LINE_MAP_MAX_COLUMN_NUMBER we create a new linemap with m_column_and_range_bits == 0, but linemap_position_for_column doesn't check for this, and hence can emit a bogus location_t value that's calculated relative to the previous linemap start, but which will be decoded relative to the new linemap, leading to very large incorrect line values. (b) when encountering a column number that can't be represented, and for which the linemap was pre-existing, the code would hit this assertion: if (linemap_assert_fails (column < (1u << map->m_column_and_range_bits))) around a bail-out condition. The patch replaces this assertion with a simple conditional, to stop the ICE when this occurs, and fixes the bit count (effective column bits, vs column+range bits) (c) the C++ frontend wasn't checking for failure of linemap_position_for_loc_and_offset when considering emitting the fix-it hint. The patch adds a conditional, so that no fix-it hint is emitted if the location is bogus. gcc/cp/ChangeLog: PR c++/77949 * parser.c (cp_parser_class_specifier_1): Only suggest inserting a missing semicolon if we have a valid insertion location for the fix-it hint. gcc/ChangeLog: PR c++/77949 * input.c (selftest::test_accessing_ordinary_linemaps): Verify that we correctly handle column numbers greater than LINE_MAP_MAX_COLUMN_NUMBER. gcc/testsuite/ChangeLog: PR c++/77949 * g++.dg/diagnostic/pr77949.C: New test case. libcpp/ChangeLog: PR c++/77949 * line-map.c (linemap_position_for_column): When calling linemap_start_line, detect if a new linemap was created with 0 column bits, and bail out early if this is the case. (linemap_position_for_loc_and_offset): Replace overzealous linemap_assert_fails with a simple conditional; use correct bit count. Added: trunk/gcc/testsuite/g++.dg/diagnostic/pr77949.C Modified: trunk/gcc/ChangeLog trunk/gcc/cp/ChangeLog trunk/gcc/cp/parser.c trunk/gcc/input.c trunk/gcc/testsuite/ChangeLog trunk/libcpp/ChangeLog trunk/libcpp/line-map.c
Should be fixed by r244292; closing.