The first aspect of this patch is to add some checking of fix-it hints.
The idea is to put this checking within the rich_location machinery,
rather than requiring every diagnostic to implement it for itself.
The fixits within a rich_location are "atomic": all must be valid for
any to be applicable.
We reject any fixits involving locations above
LINE_MAP_MAX_LOCATION_WITH_COLS.
There's no guarantee that it's sane to modify a macro, so we reject
any fix-its that touch them.
For example, note the attempt to provide a fix-it for the definition
of the macro FIELD:
spellcheck-fields-2.c: In function ‘test_macro’:
spellcheck-fields-2.c:26:15: error: ‘union u’ has no member named ‘colour’; did you mean ‘color’?
#define FIELD colour
^
color
spellcheck-fields-2.c:27:15: note: in expansion of macro ‘FIELD’
return ptr->FIELD;
^~~~~
After this patch, the fixit is not displayed:
spellcheck-fields-2.c: In function ‘test_macro’:
spellcheck-fields-2.c:26:15: error: ‘union u’ has no member named ‘colour’; did you mean ‘color’?
#define FIELD colour
^
spellcheck-fields-2.c:27:15: note: in expansion of macro ‘FIELD’
return ptr->FIELD;
^~~~~
We might want some way for a diagnostic to opt-in to fix-its that
affect macros, but for now it's simplest to reject them.
The other aspect of this patch is fix-it consolidation: in some cases
neighboring fix-its can be merged. For example, in a diagnostic to
modernize old-style struct initializers from:
struct s example = {
- foo: 1,
+ .foo = 1,
};
one approach would be to replace the "foo" with ".foo" and the ":"
with " =". This would give two "replace" fix-its:
foo: 1,
--- FIXIT 1
.foo
- FIXIT 2
=
This patch allows them to be consolidated into a single "replace" fix-it:
foo: 1,
----
.foo =
gcc/ChangeLog:
* diagnostic-show-locus.c
(selftest::test_fixit_consolidation): New function.
(selftest::diagnostic_show_locus_c_tests): Call it.
* gcc-rich-location.h (gcc_rich_location): Eliminate unused
constructor based on source_range.
gcc/testsuite/ChangeLog:
* gcc.dg/spellcheck-fields-2.c (test): Move
dg-begin/end-multiline-output within function body.
(test_macro): New function.
libcpp/ChangeLog:
* include/line-map.h (rich_location): Eliminate unimplemented
constructor based on source_range.
(rich_location::get_last_fixit_hint): New method.
(rich_location::reject_impossible_fixit): New method.
(rich_location): Add fields m_line_table and
m_seen_impossible_fixit.
(fixit_hint::maybe_append_replace): New pure virtual function.
(fixit_insert::maybe_append_replace): New function.
(fixit_replace::maybe_append_replace): New function.
* line-map.c (rich_location::rich_location): Initialize
m_line_table and m_seen_impossible_fixit.
(rich_location::add_fixit_insert): Call
reject_impossible_fixit and bail out if true.
(column_before_p): New function.
(rich_location::add_fixit_replace): Call reject_impossible_fixit
and bail out if true. Attempt to consolidate with neighboring
fixits.
(rich_location::get_last_fixit_hint): New method.
(rich_location::reject_impossible_fixit): New method.
(fixit_insert::maybe_append_replace): New method.
(fixit_replace::maybe_append_replace): New method.
From-SVN: r239789
ee90851679