On Fri, 2022-11-04 at 09:44 -0400, Lewis Hyatt via Gcc-patches wrote:
> The result of linemap_resolve_location() can be an ad-hoc location,
> if that is
> what was stored in a relevant macro map.
> maybe_unwind_expanded_macro_loc()
> did not previously handle this case, causing it to print the wrong
> tracking
> information for an example such as the new testcase macro-trace-1.c.
> Fix that
> by checking for ad-hoc locations where needed.
Thanks; looks good to me.
Dave
>
> gcc/ChangeLog:
>
> * tree-diagnostic.cc (maybe_unwind_expanded_macro_loc):
> Handle ad-hoc
> location in return value of linemap_resolve_location().
>
> gcc/testsuite/ChangeLog:
>
> * c-c++-common/cpp/macro-trace-1.c: New test.
> ---
> gcc/testsuite/c-c++-common/cpp/macro-trace-1.c | 4 ++++
> gcc/tree-diagnostic.cc | 7 +++++--
> 2 files changed, 9 insertions(+), 2 deletions(-)
> create mode 100644 gcc/testsuite/c-c++-common/cpp/macro-trace-1.c
>
> diff --git a/gcc/testsuite/c-c++-common/cpp/macro-trace-1.c
> b/gcc/testsuite/c-c++-common/cpp/macro-trace-1.c
> new file mode 100644
> index 00000000000..34cfbb3dad3
> --- /dev/null
> +++ b/gcc/testsuite/c-c++-common/cpp/macro-trace-1.c
> @@ -0,0 +1,4 @@
> +/* This token is long enough to require an ad-hoc location. Make
> sure that
> + the macro trace still prints properly. */
> +#define X "0123456789012345678901234567689" /* { dg-error {expected
> .* before string constant} } */
> +X /* { dg-note {in expansion of macro 'X'} } */
> diff --git a/gcc/tree-diagnostic.cc b/gcc/tree-diagnostic.cc
> index 0d79fe3c3c1..5cf3a1c17d2 100644
> --- a/gcc/tree-diagnostic.cc
> +++ b/gcc/tree-diagnostic.cc
> @@ -190,14 +190,17 @@ maybe_unwind_expanded_macro_loc
> (diagnostic_context *context,
> location_t l =
> linemap_resolve_location (line_table, resolved_def_loc,
> LRK_SPELLING_LOCATION, &m);
> - if (l < RESERVED_LOCATION_COUNT || LINEMAP_SYSP (m))
> + location_t l0 = l;
> + if (IS_ADHOC_LOC (l0))
> + l0 = get_location_from_adhoc_loc (line_table, l0);
> + if (l0 < RESERVED_LOCATION_COUNT || LINEMAP_SYSP (m))
> continue;
>
> /* We need to print the context of the macro definition only
> when the locus of the first displayed diagnostic
> (displayed
> before this trace) was inside the definition of the
> macro. */
> - int resolved_def_loc_line = SOURCE_LINE (m, l);
> + const int resolved_def_loc_line = SOURCE_LINE (m, l0);
> if (ix == 0 && saved_location_line != resolved_def_loc_line)
> {
> diagnostic_append_note (context, resolved_def_loc,
>
