mirror of git://gcc.gnu.org/git/gcc.git
b9f4757f8e
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. From-SVN: r244292 |
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| .. | ||
| include | ||
| po | ||
| ChangeLog | ||
| ChangeLog.jit | ||
| Makefile.in | ||
| aclocal.m4 | ||
| charset.c | ||
| config.in | ||
| configure | ||
| configure.ac | ||
| directives-only.c | ||
| directives.c | ||
| errors.c | ||
| expr.c | ||
| files.c | ||
| identifiers.c | ||
| init.c | ||
| internal.h | ||
| lex.c | ||
| line-map.c | ||
| location-example.txt | ||
| macro.c | ||
| makeucnid.c | ||
| mkdeps.c | ||
| pch.c | ||
| symtab.c | ||
| system.h | ||
| traditional.c | ||
| ucnid.h | ||
| ucnid.tab | ||