Use char_span for return type of location_get_source_line
location_get_source_line returns a const char * that isn't 0-terminated,
writing back a length through an int * param.
This is error-prone, as all call-sites have to take into account the
lack of 0-termination, and respect the length of the buffer.
It's cleaner to bundle together this pointer+length state into a class,
so this patch does so, reusing the "char_span" class that I introduced
in r250187 (as part of the fix for PR c/81405).
The patch also adds assertions to all access to the char_span.
gcc/c-family/ChangeLog:
* c-format.c (get_corrected_substring): Update for
location_get_source_line returning a char_span. Use a char_span
when handling the prefix of the correction.
* c-indentation.c (get_visual_column): Update for
location_get_source_line returning a char_span.
(get_first_nws_vis_column): Likewise.
gcc/ChangeLog:
* diagnostic-show-locus.c (layout::layout): Update for
location_get_source_line returning a char_span.
(struct char_span): Move to input.h.
(struct correction): Update for fields in char_span becoming
private.
(struct source_line): Update for location_get_source_line
returning a char_span.
(layout::print_line): Likewise.
* edit-context.c (edited_file::print_content): Likewise.
(edited_file::print_diff_hunk): Likewise.
(edited_file::print_run_of_changed_lines): Likewise.
(edited_file::get_num_lines): Likewise.
(edited_line::edited_line): Likewise.
* final.c (asm_show_source): Likewise.
* input.c (location_get_source_line): Convert return type
from const char * to char_span, losing the final "line_len"
param.
(dump_location_info): Update for the above.
(get_substring_ranges_for_loc): Likewise. Use a char_span
when handling the literal within the line.
(test_reading_source_line): Update for location_get_source_line
returning a char_span.
* input.h (class char_span): Move here from
diagnostic-show-locus.c, converting from a struct to a class.
Make data members private.
(char_span::operator bool): New.
(char_span::length): New.
(char_span::get_buffer): New.
(char_span::operator[]): New.
(char_span::subspan): Make const.
(char_span::xstrdup): New.
(location_get_source_line): Convert return type from const char *
to char_span, losing the final "line_size" param.
gcc/testsuite/ChangeLog:
* gcc.dg/plugin/diagnostic_plugin_test_show_locus.c
(test_show_locus): Update for location_get_source_line returning a
char_span. Use char_span for handling words in the
"test_many_nested_locations" fix-it example.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@259768 138bc75d-0d04-0410-961f-82ee72b054a4