Hi!
On 2021-09-02T15:59:14+0200, I wrote:
> On 2016-08-05T14:16:58-0400, David Malcolm <dmalc...@redhat.com> wrote:
>> Committed to trunk as r239175; I'm attaching the final version of the
>> patch for reference.
>
> David, you've added here 'gcc/input.h:struct location_hash' (see quoted
> below), which will be useful elsewhere, so:
>
>> --- a/gcc/input.c
>> +++ b/gcc/input.c
>
>> +/* Internal function. Canonicalize LOC into a form suitable for
>> + use as a key within the database, stripping away macro expansion,
>> + ad-hoc information, and range information, using the location of
>> + the start of LOC within an ordinary linemap. */
>> +
>> +location_t
>> +string_concat_db::get_key_loc (location_t loc)
>> +{
>> + loc = linemap_resolve_location (line_table, loc, LRK_SPELLING_LOCATION,
>> + NULL);
>> +
>> + loc = get_range_from_loc (line_table, loc).m_start;
>> +
>> + return loc;
>> +}
>
> OK to push the attached
> "Harden 'gcc/input.c:string_concat_db::get_key_loc'"? (This fell out of
> my analysis for development work elsewhere.)
My suggested patch was:
--- a/gcc/input.c
+++ b/gcc/input.c
@@ -1483,6 +1483,9 @@ string_concat_db::get_key_loc (location_t loc)
loc = get_range_from_loc (line_table, loc).m_start;
+ /* Ascertain that 'loc' is valid as a key in 'm_table'. */
+ gcc_checking_assert (!RESERVED_LOCATION_P (loc));
+
return loc;
}
Uh, I should've looked at the correct test logs... This change actually
does regress 'c-c++-common/substring-location-PR-87721.c' and
'gcc.dg/plugin/diagnostic-test-string-literals-1.c': for these, we do see
'BUILTINS_LOCATION' (via 'string_concat_db::record_string_concatenation').
Unless someone tell me that's unexpected (I'm completely lost in this
code...), I shall change/generalize my changes to provide both a
'location_hash' only using 'UNKNOWN_LOCATION' as a spare value for
'Empty' (as currently used here) and another variant additionally using
'BUILTINS_LOCATION' as spare value for 'Deleted'.
Grüße
Thomas
>> --- a/gcc/input.h
>> +++ b/gcc/input.h
>
>> +struct location_hash : int_hash <location_t, UNKNOWN_LOCATION> { };
>> +
>> +class GTY(()) string_concat_db
>> +{
>> +[...]
>> + hash_map <location_hash, string_concat *> *m_table;
>> +};
>
> OK to push the attached
> "Generalize 'gcc/input.h:struct location_hash'"?
My suggested patch was:
> Subject: [PATCH 2/2] Generalize 'gcc/input.h:struct location_hash'
>
> This is currently only used here ('gcc/input.h:class string_concat_db'), but
> is
> actually generally useful, so advertize it as such.
>
> Per the rationale given, we may use 'BUILTINS_LOCATION' as spare value for
> 'Deleted', in addition to the existing use of 'UNKNOWN_LOCATION' as spare
> value
> for 'Empty'.
>
> gcc/
> * input.h (location_hash): Use 'BUILTINS_LOCATION' as spare value
> for 'Deleted'. Turn into a '#define'.
> ---
> gcc/input.h | 21 +++++++++++++++++++--
> 1 file changed, 19 insertions(+), 2 deletions(-)
>
> diff --git a/gcc/input.h b/gcc/input.h
> index e6881072c5f..46971a2684c 100644
> --- a/gcc/input.h
> +++ b/gcc/input.h
> @@ -36,6 +36,25 @@ extern GTY(()) class line_maps *saved_line_table;
> both UNKNOWN_LOCATION and BUILTINS_LOCATION fit into that. */
> STATIC_ASSERT (BUILTINS_LOCATION < RESERVED_LOCATION_COUNT);
>
> +/* Hasher for 'location_t' values satisfying '!RESERVED_LOCATION_P', thus
> able
> + to use 'UNKNOWN_LOCATION'/'BUILTINS_LOCATION' as spare values for
> + 'Empty'/'Deleted'. */
> +/* If the following is used more than once, 'gengtype' generates duplicate
> + functions (thus: "error: redefinition of 'void gt_ggc_mx(location_hash&)'"
> + etc.):
> +
> + struct location_hash
> + : int_hash<location_t, UNKNOWN_LOCATION, BUILTINS_LOCATION> {};
> +
> + Likewise for this:
> +
> + typedef int_hash<location_t, UNKNOWN_LOCATION, BUILTINS_LOCATION>
> + location_hash;
> +
> + Thus, use a plain ol' '#define':
> +*/
> +#define location_hash int_hash<location_t, UNKNOWN_LOCATION,
> BUILTINS_LOCATION>
> +
> extern bool is_location_from_builtin_token (location_t);
> extern expanded_location expand_location (location_t);
>
> @@ -230,8 +249,6 @@ public:
> location_t * GTY ((atomic)) m_locs;
> };
>
> -struct location_hash : int_hash <location_t, UNKNOWN_LOCATION> { };
> -
> class GTY(()) string_concat_db
> {
> public:
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