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Re: [PATCH 4/6] C++ify badness_vector, fix leaks
- From: Pedro Alves <palves at redhat dot com>
- To: Simon Marchi <simon dot marchi at ericsson dot com>, "gdb-patches at sourceware dot org" <gdb-patches at sourceware dot org>
- Date: Wed, 21 Nov 2018 12:47:31 +0000
- Subject: Re: [PATCH 4/6] C++ify badness_vector, fix leaks
- References: <20181015151115.6356-1-palves@redhat.com> <20181015151115.6356-5-palves@redhat.com> <00ee88d8-857d-d85a-db78-b7a05b62ea0b@ericsson.com>
On 10/17/2018 06:44 PM, Simon Marchi wrote:
> LGTM, just a tiny comment:
>
> On 2018-10-15 11:11 a.m., Pedro Alves wrote:
>> @@ -2848,7 +2842,7 @@ find_overload_match (gdb::array_view<value *> args,
>> contained in QUALIFIED_NAME until it either finds a good match or
>> runs out of namespaces. It stores the overloaded functions in
>> *OLOAD_SYMS, and the badness vector in *OLOAD_CHAMP_BV. The
>> - calling function is responsible for freeing *OLOAD_SYMS and
>> + calling function is responsible for clearing *OLOAD_SYMS and
>> *OLOAD_CHAMP_BV. If NO_ADL, argument dependent lookup is not
>> performned. */
>
> The previous comment meant that the caller was responsible to free the data
> after this function is called. From what I understand, the new comment means
> the caller is responsible to pass empty vectors as inputs, is that right? If
> so, it would be clearer to say "the calling function is responsible for passing
> empty vectors for *OLOAD_SYMS and *OLOAD_CHAMP_BV".
Yeah. I just removed that sentence, since it wasn't really adding anything
anymore.
>
> I know the opposite wouldn't really make sense (asking the caller to clear the
> vector after the call), but like this it sounds ambiguous.
Here's what I pushed.
>From fa7819ae688b390009353bdf7dec15ece3ade159 Mon Sep 17 00:00:00 2001
From: Pedro Alves <palves@redhat.com>
Date: Wed, 21 Nov 2018 11:55:14 +0000
Subject: [PATCH 4/6] C++ify badness_vector, fix leaks
badness_vector is currently an open coded vector. This reimplements
it as a std::vector.
This fixes a few leaks as well:
- find_oload_champ is leaking every badness vector calculated bar the
one returned.
- bv->rank is always leaked, since callers of rank_function only
xfree the badness_vector pointer, not bv->rank.
gdb/ChangeLog:
2018-11-21 Pedro Alves <palves@redhat.com>
* gdbtypes.c (compare_badness): Change type of parameters to const
reference. Adjust to badness_vector being a std::vector now.
(rank_function): Adjust to badness_vector being a std::vector now.
* gdbtypes.h (badness_vector): Now a typedef to std::vector.
(LENGTH_MATCH): Delete.
(compare_badness): Change type of parameters to const reference.
(rank_function): Return a badness_vector by value now.
(find_overload_match): Adjust to badness_vector being a
std::vector now. Remove cleanups.
(find_oload_champ_namespace): 'oload_champ_bv' parameter now a
badness_vector pointer.
(find_oload_champ_namespace_loop): 'oload_champ_bv' parameter now
a badness_vector pointer. Adjust to badness_vector being a
std::vector now. Remove cleanups.
(find_oload_champ): 'oload_champ_bv' parameter now
a badness_vector pointer. Adjust to badness_vector being a
std::vector now. Remove cleanups.
---
gdb/ChangeLog | 20 +++++++++++++++
gdb/gdbtypes.c | 43 ++++++++++++++++----------------
gdb/gdbtypes.h | 17 +++++--------
gdb/valops.c | 78 ++++++++++++++++++++--------------------------------------
4 files changed, 74 insertions(+), 84 deletions(-)
diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index e808dd5dab..5ae9ae7b1b 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,23 @@
+2018-11-21 Pedro Alves <palves@redhat.com>
+
+ * gdbtypes.c (compare_badness): Change type of parameters to const
+ reference. Adjust to badness_vector being a std::vector now.
+ (rank_function): Adjust to badness_vector being a std::vector now.
+ * gdbtypes.h (badness_vector): Now a typedef to std::vector.
+ (LENGTH_MATCH): Delete.
+ (compare_badness): Change type of parameters to const reference.
+ (rank_function): Return a badness_vector by value now.
+ (find_overload_match): Adjust to badness_vector being a
+ std::vector now. Remove cleanups.
+ (find_oload_champ_namespace): 'oload_champ_bv' parameter now a
+ badness_vector pointer.
+ (find_oload_champ_namespace_loop): 'oload_champ_bv' parameter now
+ a badness_vector pointer. Adjust to badness_vector being a
+ std::vector now. Remove cleanups.
+ (find_oload_champ): 'oload_champ_bv' parameter now
+ a badness_vector pointer. Adjust to badness_vector being a
+ std::vector now. Remove cleanups.
+
2018-11-21 Pedro Alves <palves@redhat.com>
* cp-support.c (sym_return_val_size, sym_return_val_index)
diff --git a/gdb/gdbtypes.c b/gdb/gdbtypes.c
index 4160d996de..39b7a99017 100644
--- a/gdb/gdbtypes.c
+++ b/gdb/gdbtypes.c
@@ -3426,21 +3426,21 @@ compare_ranks (struct rank a, struct rank b)
3 => A is worse than B */
int
-compare_badness (struct badness_vector *a, struct badness_vector *b)
+compare_badness (const badness_vector &a, const badness_vector &b)
{
int i;
int tmp;
short found_pos = 0; /* any positives in c? */
short found_neg = 0; /* any negatives in c? */
- /* differing lengths => incomparable */
- if (a->length != b->length)
+ /* differing sizes => incomparable */
+ if (a.size () != b.size ())
return 1;
/* Subtract b from a */
- for (i = 0; i < a->length; i++)
+ for (i = 0; i < a.size (); i++)
{
- tmp = compare_ranks (b->rank[i], a->rank[i]);
+ tmp = compare_ranks (b[i], a[i]);
if (tmp > 0)
found_pos = 1;
else if (tmp < 0)
@@ -3465,19 +3465,16 @@ compare_badness (struct badness_vector *a, struct badness_vector *b)
}
/* Rank a function by comparing its parameter types (PARMS), to the
- types of an argument list (ARGS). Return a pointer to a badness
- vector. This has ARGS.size() + 1 entries. */
+ types of an argument list (ARGS). Return the badness vector. This
+ has ARGS.size() + 1 entries. */
-struct badness_vector *
+badness_vector
rank_function (gdb::array_view<type *> parms,
gdb::array_view<value *> args)
{
- int i;
- struct badness_vector *bv = XNEW (struct badness_vector);
- size_t min_len = std::min (parms.size (), args.size ());
-
- bv->length = args.size () + 1; /* add 1 for the length-match rank. */
- bv->rank = XNEWVEC (struct rank, args.size () + 1);
+ /* add 1 for the length-match rank. */
+ badness_vector bv;
+ bv.reserve (1 + args.size ());
/* First compare the lengths of the supplied lists.
If there is a mismatch, set it to a high value. */
@@ -3486,18 +3483,20 @@ rank_function (gdb::array_view<type *> parms,
arguments and ellipsis parameter lists, we should consider those
and rank the length-match more finely. */
- LENGTH_MATCH (bv) = (args.size () != parms.size ())
- ? LENGTH_MISMATCH_BADNESS
- : EXACT_MATCH_BADNESS;
+ bv.push_back ((args.size () != parms.size ())
+ ? LENGTH_MISMATCH_BADNESS
+ : EXACT_MATCH_BADNESS);
/* Now rank all the parameters of the candidate function. */
- for (i = 1; i <= min_len; i++)
- bv->rank[i] = rank_one_type (parms[i - 1], value_type (args[i - 1]),
- args[i - 1]);
+ size_t min_len = std::min (parms.size (), args.size ());
+
+ for (size_t i = 0; i < min_len; i++)
+ bv.push_back (rank_one_type (parms[i], value_type (args[i]),
+ args[i]));
/* If more arguments than parameters, add dummy entries. */
- for (i = min_len + 1; i <= args.size (); i++)
- bv->rank[i] = TOO_FEW_PARAMS_BADNESS;
+ for (size_t i = min_len; i < args.size (); i++)
+ bv.push_back (TOO_FEW_PARAMS_BADNESS);
return bv;
}
diff --git a/gdb/gdbtypes.h b/gdb/gdbtypes.h
index 731b18d082..f0adec7a20 100644
--- a/gdb/gdbtypes.h
+++ b/gdb/gdbtypes.h
@@ -1095,13 +1095,9 @@ struct rank
short subrank;
};
-/* * Struct used for ranking a function for overload resolution. */
+/* * Used for ranking a function for overload resolution. */
-struct badness_vector
- {
- int length;
- struct rank *rank;
- };
+typedef std::vector<rank> badness_vector;
/* * GNAT Ada-specific information for various Ada types. */
@@ -1983,8 +1979,6 @@ extern int is_unique_ancestor (struct type *, struct value *);
/* Overload resolution */
-#define LENGTH_MATCH(bv) ((bv)->rank[0])
-
/* * Badness if parameter list length doesn't match arg list length. */
extern const struct rank LENGTH_MISMATCH_BADNESS;
@@ -2043,10 +2037,11 @@ extern const struct rank NS_INTEGER_POINTER_CONVERSION_BADNESS;
extern struct rank sum_ranks (struct rank a, struct rank b);
extern int compare_ranks (struct rank a, struct rank b);
-extern int compare_badness (struct badness_vector *, struct badness_vector *);
+extern int compare_badness (const badness_vector &,
+ const badness_vector &);
-extern struct badness_vector *rank_function (gdb::array_view<type *> parms,
- gdb::array_view<value *> args);
+extern badness_vector rank_function (gdb::array_view<type *> parms,
+ gdb::array_view<value *> args);
extern struct rank rank_one_type (struct type *, struct type *,
struct value *);
diff --git a/gdb/valops.c b/gdb/valops.c
index 7fbedd77bb..1b4a8e123c 100644
--- a/gdb/valops.c
+++ b/gdb/valops.c
@@ -57,27 +57,26 @@ static struct value *search_struct_method (const char *, struct value **,
static int find_oload_champ_namespace (gdb::array_view<value *> args,
const char *, const char *,
std::vector<symbol *> *oload_syms,
- struct badness_vector **,
+ badness_vector *,
const int no_adl);
static int find_oload_champ_namespace_loop (gdb::array_view<value *> args,
const char *, const char *,
int, std::vector<symbol *> *oload_syms,
- struct badness_vector **, int *,
+ badness_vector *, int *,
const int no_adl);
static int find_oload_champ (gdb::array_view<value *> args, int,
struct fn_field *,
const std::vector<xmethod_worker_up> *,
- struct symbol **, struct badness_vector **);
+ struct symbol **, badness_vector *);
static int oload_method_static_p (struct fn_field *, int);
enum oload_classification { STANDARD, NON_STANDARD, INCOMPATIBLE };
-static enum
-oload_classification classify_oload_match (struct badness_vector *,
- int, int);
+static enum oload_classification classify_oload_match
+ (const badness_vector &, int, int);
static struct value *value_struct_elt_for_reference (struct type *,
int, struct type *,
@@ -2508,10 +2507,10 @@ find_overload_match (gdb::array_view<value *> args,
int ext_method_oload_champ = -1;
/* The measure for the current best match. */
- struct badness_vector *method_badness = NULL;
- struct badness_vector *func_badness = NULL;
- struct badness_vector *ext_method_badness = NULL;
- struct badness_vector *src_method_badness = NULL;
+ badness_vector method_badness;
+ badness_vector func_badness;
+ badness_vector ext_method_badness;
+ badness_vector src_method_badness;
struct value *temp = obj;
/* For methods, the list of overloaded methods. */
@@ -2584,8 +2583,6 @@ find_overload_match (gdb::array_view<value *> args,
src_method_match_quality = classify_oload_match
(src_method_badness, args.size (),
oload_method_static_p (fns_ptr, src_method_oload_champ));
-
- make_cleanup (xfree, src_method_badness);
}
if (!xm_worker_vec.empty ())
@@ -2594,7 +2591,6 @@ find_overload_match (gdb::array_view<value *> args,
NULL, &ext_method_badness);
ext_method_match_quality = classify_oload_match (ext_method_badness,
args.size (), 0);
- make_cleanup (xfree, ext_method_badness);
}
if (src_method_oload_champ >= 0 && ext_method_oload_champ >= 0)
@@ -2716,8 +2712,6 @@ find_overload_match (gdb::array_view<value *> args,
if (func_oload_champ >= 0)
func_match_quality = classify_oload_match (func_badness,
args.size (), 0);
-
- make_cleanup (xfree, func_badness);
}
/* Did we find a match ? */
@@ -2847,17 +2841,15 @@ find_overload_match (gdb::array_view<value *> args,
/* Find the best overload match, searching for FUNC_NAME in namespaces
contained in QUALIFIED_NAME until it either finds a good match or
runs out of namespaces. It stores the overloaded functions in
- *OLOAD_SYMS, and the badness vector in *OLOAD_CHAMP_BV. The
- calling function is responsible for freeing *OLOAD_SYMS and
- *OLOAD_CHAMP_BV. If NO_ADL, argument dependent lookup is not
- performned. */
+ *OLOAD_SYMS, and the badness vector in *OLOAD_CHAMP_BV. If NO_ADL,
+ argument dependent lookup is not performned. */
static int
find_oload_champ_namespace (gdb::array_view<value *> args,
const char *func_name,
const char *qualified_name,
std::vector<symbol *> *oload_syms,
- struct badness_vector **oload_champ_bv,
+ badness_vector *oload_champ_bv,
const int no_adl)
{
int oload_champ;
@@ -2876,10 +2868,7 @@ find_oload_champ_namespace (gdb::array_view<value *> args,
how deep we've looked for namespaces, and the champ is stored in
OLOAD_CHAMP. The return value is 1 if the champ is a good one, 0
if it isn't. Other arguments are the same as in
- find_oload_champ_namespace
-
- It is the caller's responsibility to free *OLOAD_SYMS and
- *OLOAD_CHAMP_BV. */
+ find_oload_champ_namespace. */
static int
find_oload_champ_namespace_loop (gdb::array_view<value *> args,
@@ -2887,15 +2876,13 @@ find_oload_champ_namespace_loop (gdb::array_view<value *> args,
const char *qualified_name,
int namespace_len,
std::vector<symbol *> *oload_syms,
- struct badness_vector **oload_champ_bv,
+ badness_vector *oload_champ_bv,
int *oload_champ,
const int no_adl)
{
int next_namespace_len = namespace_len;
int searched_deeper = 0;
- struct cleanup *old_cleanups;
int new_oload_champ;
- struct badness_vector *new_oload_champ_bv;
char *new_namespace;
if (next_namespace_len != 0)
@@ -2906,9 +2893,6 @@ find_oload_champ_namespace_loop (gdb::array_view<value *> args,
next_namespace_len +=
cp_find_first_component (qualified_name + next_namespace_len);
- /* Initialize these to values that can safely be xfree'd. */
- *oload_champ_bv = NULL;
-
/* First, see if we have a deeper namespace we can search in.
If we get a good match there, use it. */
@@ -2934,7 +2918,6 @@ find_oload_champ_namespace_loop (gdb::array_view<value *> args,
because this overload mechanism only gets called if there's a
function symbol to start off with.) */
- old_cleanups = make_cleanup (xfree, *oload_champ_bv);
new_namespace = (char *) alloca (namespace_len + 1);
strncpy (new_namespace, qualified_name, namespace_len);
new_namespace[namespace_len] = '\0';
@@ -2958,6 +2941,7 @@ find_oload_champ_namespace_loop (gdb::array_view<value *> args,
&new_oload_syms);
}
+ badness_vector new_oload_champ_bv;
new_oload_champ = find_oload_champ (args, new_oload_syms.size (),
NULL, NULL, new_oload_syms.data (),
&new_oload_champ_bv);
@@ -2974,22 +2958,18 @@ find_oload_champ_namespace_loop (gdb::array_view<value *> args,
{
*oload_syms = std::move (new_oload_syms);
*oload_champ = new_oload_champ;
- *oload_champ_bv = new_oload_champ_bv;
- do_cleanups (old_cleanups);
+ *oload_champ_bv = std::move (new_oload_champ_bv);
return 1;
}
else if (searched_deeper)
{
- xfree (new_oload_champ_bv);
- discard_cleanups (old_cleanups);
return 0;
}
else
{
*oload_syms = std::move (new_oload_syms);
*oload_champ = new_oload_champ;
- *oload_champ_bv = new_oload_champ_bv;
- do_cleanups (old_cleanups);
+ *oload_champ_bv = std::move (new_oload_champ_bv);
return 0;
}
}
@@ -3003,20 +2983,18 @@ find_oload_champ_namespace_loop (gdb::array_view<value *> args,
or OLOAD_SYMS (whichever is non-NULL) is specified in NUM_FNS.
Return the index of the best match; store an indication of the
- quality of the match in OLOAD_CHAMP_BV.
-
- It is the caller's responsibility to free *OLOAD_CHAMP_BV. */
+ quality of the match in OLOAD_CHAMP_BV. */
static int
find_oload_champ (gdb::array_view<value *> args,
int num_fns, struct fn_field *fns_ptr,
const std::vector<xmethod_worker_up> *xm_worker_vec,
struct symbol **oload_syms,
- struct badness_vector **oload_champ_bv)
+ badness_vector *oload_champ_bv)
{
int ix;
/* A measure of how good an overloaded instance is. */
- struct badness_vector *bv;
+ badness_vector bv;
/* Index of best overloaded function. */
int oload_champ = -1;
/* Current ambiguity state for overload resolution. */
@@ -3029,8 +3007,6 @@ find_oload_champ (gdb::array_view<value *> args,
gdb_assert ((fns_ptr != NULL) + (oload_syms != NULL) + (xm_worker_vec != NULL)
== 1);
- *oload_champ_bv = NULL;
-
int fn_count = xm_worker_vec != NULL ? xm_worker_vec->size () : num_fns;
/* Consider each candidate in turn. */
@@ -3073,9 +3049,9 @@ find_oload_champ (gdb::array_view<value *> args,
bv = rank_function (parm_types,
args.slice (static_offset));
- if (!*oload_champ_bv)
+ if (oload_champ_bv->empty ())
{
- *oload_champ_bv = bv;
+ *oload_champ_bv = std::move (bv);
oload_champ = 0;
}
else /* See whether current candidate is better or worse than
@@ -3089,7 +3065,7 @@ find_oload_champ (gdb::array_view<value *> args,
oload_ambiguous = 2;
break;
case 2: /* New champion, record details. */
- *oload_champ_bv = bv;
+ *oload_champ_bv = std::move (bv);
oload_ambiguous = 0;
oload_champ = ix;
break;
@@ -3116,7 +3092,7 @@ find_oload_champ (gdb::array_view<value *> args,
for (jj = 0; jj < args.size () - static_offset; jj++)
fprintf_filtered (gdb_stderr,
"...Badness @ %d : %d\n",
- jj, bv->rank[jj].rank);
+ jj, bv[jj].rank);
fprintf_filtered (gdb_stderr, "Overload resolution "
"champion is %d, ambiguous? %d\n",
oload_champ, oload_ambiguous);
@@ -3141,7 +3117,7 @@ oload_method_static_p (struct fn_field *fns_ptr, int index)
/* Check how good an overload match OLOAD_CHAMP_BV represents. */
static enum oload_classification
-classify_oload_match (struct badness_vector *oload_champ_bv,
+classify_oload_match (const badness_vector &oload_champ_bv,
int nargs,
int static_offset)
{
@@ -3152,12 +3128,12 @@ classify_oload_match (struct badness_vector *oload_champ_bv,
{
/* If this conversion is as bad as INCOMPATIBLE_TYPE_BADNESS
or worse return INCOMPATIBLE. */
- if (compare_ranks (oload_champ_bv->rank[ix],
+ if (compare_ranks (oload_champ_bv[ix],
INCOMPATIBLE_TYPE_BADNESS) <= 0)
return INCOMPATIBLE; /* Truly mismatched types. */
/* Otherwise If this conversion is as bad as
NS_POINTER_CONVERSION_BADNESS or worse return NON_STANDARD. */
- else if (compare_ranks (oload_champ_bv->rank[ix],
+ else if (compare_ranks (oload_champ_bv[ix],
NS_POINTER_CONVERSION_BADNESS) <= 0)
worst = NON_STANDARD; /* Non-standard type conversions
needed. */
--
2.14.4