Fix for PR preprocessor/78680
PR preprocessor/78680 identifies a crash when attempting to issue
a -Wformat warning, where the format string includes a string token
split across multiple physical source lines via backslash-continued
lines.
The issue is that libcpp is generating bogus range information for
such tokens.
For example, in:
void fn1() {
__builtin_printf("\
%ld.\n\
2\n"); };
the range of the string token is printed as:
__builtin_printf("\
^~
whereas the range ought to be:
__builtin_printf("\
^~
%ld.\n\
~~~~~~~
2\n"); };
~~~~
The root cause is that the line notes expressing the update
of the buffer in lex.c aren't yet updated when the end-point of
the token is computed
3095 tok_range.m_finish
3096 = linemap_position_for_column (pfile->line_table,
3097 CPP_BUF_COLUMN (buffer, buffer->cur));
so that the physical line is still regarded as that of the start
of the token, and, where CPP_BUF_COLUMN uses (BUF)->line_base,
line_base is still the location of the first physical line in the
and hence the column information is too large (as if it were the
offset in the *logical* line).
(the printed range is somewhat misleading; the actual buggy range
extends beyond the "\ in the line, but within diagnostic-show-locus.c
layout::print_annotation_line only prints up to the xbound set by
layout::print_source_line and so truncates most of the buggy range).
The fix is to ensure that line notes are handled before calculating
the end-point of the token range.
This leads to the range for the string token being correctly
computed, as:
__builtin_printf("\
^~
%ld.\n\
~~~~~~~
2\n"); };
~~~~
and this leads to get_substring_ranges_for_loc failing gracefully,
rather than crashing.
gcc/testsuite/ChangeLog:
PR preprocessor/78680
* gcc.dg/format/pr78680.c: New test case.
* gcc.dg/plugin/diagnostic-test-expressions-1.c
(test_multiline_token): New function.
* gcc.dg/plugin/diagnostic-test-string-literals-1.c
(test_backslash_continued_logical_lines): New function.
libcpp/ChangeLog:
PR preprocessor/78680
* lex.c (_cpp_lex_direct): Ensure line notes are processed before
computing the end-point of the token.
From-SVN: r243567
470a60b2c4