Add asserts to bimapset manipulation functions

New asserts validate that arguments are really bitmapsets.  This should help
to early detect accesses to dangling pointers.

Discussion: https://postgr.es/m/CAMbWs4_wJthNtYBL%2BSsebpgF-5L2r5zFFk6xYbS0A78GKOTFHw%40mail.gmail.com
Reviewed-by: Richard Guo, Andres Freund, Ashutosh Bapat, Andrei Lepikhov

diff --git a/src/backend/nodes/bitmapset.c b/src/backend/nodes/bitmapset.c
index 704879f56605048c23b61482f62b7c50f81c6317..1627922ef7ad1877f123d03d74d9b518ab2433e1 100644 (file)
--- a/src/backend/nodes/bitmapset.c
+++ b/src/backend/nodes/bitmapset.c
@@ -84,6 +84,7 @@ bms_copy(const Bitmapset *a)
 
    if (a == NULL)
        return NULL;
+   Assert(IsA(a, Bitmapset));
    size = BITMAPSET_SIZE(a->nwords);
    result = (Bitmapset *) palloc(size);
    memcpy(result, a, size);
@@ -98,8 +99,8 @@ bms_equal(const Bitmapset *a, const Bitmapset *b)
 {
    int         i;
 
-   Assert(a == NULL || a->words[a->nwords - 1] != 0);
-   Assert(b == NULL || b->words[b->nwords - 1] != 0);
+   Assert(a == NULL || (IsA(a, Bitmapset) && a->words[a->nwords - 1] != 0));
+   Assert(b == NULL || (IsA(b, Bitmapset) && b->words[b->nwords - 1] != 0));
 
    /* Handle cases where either input is NULL */
    if (a == NULL)
@@ -139,8 +140,8 @@ bms_compare(const Bitmapset *a, const Bitmapset *b)
 {
    int         i;
 
-   Assert(a == NULL || a->words[a->nwords - 1] != 0);
-   Assert(b == NULL || b->words[b->nwords - 1] != 0);
+   Assert(a == NULL || (IsA(a, Bitmapset) && a->words[a->nwords - 1] != 0));
+   Assert(b == NULL || (IsA(b, Bitmapset) && b->words[b->nwords - 1] != 0));
 
    /* Handle cases where either input is NULL */
    if (a == NULL)
@@ -215,6 +216,9 @@ bms_union(const Bitmapset *a, const Bitmapset *b)
    int         otherlen;
    int         i;
 
+   Assert(a == NULL || IsA(a, Bitmapset));
+   Assert(b == NULL || IsA(b, Bitmapset));
+
    /* Handle cases where either input is NULL */
    if (a == NULL)
        return bms_copy(b);
@@ -253,6 +257,9 @@ bms_intersect(const Bitmapset *a, const Bitmapset *b)
    int         resultlen;
    int         i;
 
+   Assert(a == NULL || IsA(a, Bitmapset));
+   Assert(b == NULL || IsA(b, Bitmapset));
+
    /* Handle cases where either input is NULL */
    if (a == NULL || b == NULL)
        return NULL;
@@ -299,8 +306,8 @@ bms_difference(const Bitmapset *a, const Bitmapset *b)
    Bitmapset  *result;
    int         i;
 
-   Assert(a == NULL || a->words[a->nwords - 1] != 0);
-   Assert(b == NULL || b->words[b->nwords - 1] != 0);
+   Assert(a == NULL || (IsA(a, Bitmapset) && a->words[a->nwords - 1] != 0));
+   Assert(b == NULL || (IsA(b, Bitmapset) && b->words[b->nwords - 1] != 0));
 
    /* Handle cases where either input is NULL */
    if (a == NULL)
@@ -308,6 +315,8 @@ bms_difference(const Bitmapset *a, const Bitmapset *b)
    if (b == NULL)
        return bms_copy(a);
 
+   Assert(IsA(a, Bitmapset) && IsA(b, Bitmapset));
+
    /*
     * In Postgres' usage, an empty result is a very common case, so it's
     * worth optimizing for that by testing bms_nonempty_difference().  This
@@ -364,8 +373,8 @@ bms_is_subset(const Bitmapset *a, const Bitmapset *b)
 {
    int         i;
 
-   Assert(a == NULL || a->words[a->nwords - 1] != 0);
-   Assert(b == NULL || b->words[b->nwords - 1] != 0);
+   Assert(a == NULL || (IsA(a, Bitmapset) && a->words[a->nwords - 1] != 0));
+   Assert(b == NULL || (IsA(b, Bitmapset) && b->words[b->nwords - 1] != 0));
 
    /* Handle cases where either input is NULL */
    if (a == NULL)
@@ -373,6 +382,8 @@ bms_is_subset(const Bitmapset *a, const Bitmapset *b)
    if (b == NULL)
        return false;
 
+   Assert(IsA(a, Bitmapset) && IsA(b, Bitmapset));
+
    /* 'a' can't be a subset of 'b' if it contains more words */
    if (a->nwords > b->nwords)
        return false;
@@ -399,8 +410,8 @@ bms_subset_compare(const Bitmapset *a, const Bitmapset *b)
    int         shortlen;
    int         i;
 
-   Assert(a == NULL || a->words[a->nwords - 1] != 0);
-   Assert(b == NULL || b->words[b->nwords - 1] != 0);
+   Assert(a == NULL || (IsA(a, Bitmapset) && a->words[a->nwords - 1] != 0));
+   Assert(b == NULL || (IsA(b, Bitmapset) && b->words[b->nwords - 1] != 0));
 
    /* Handle cases where either input is NULL */
    if (a == NULL)
@@ -411,6 +422,9 @@ bms_subset_compare(const Bitmapset *a, const Bitmapset *b)
    }
    if (b == NULL)
        return BMS_SUBSET2;
+
+   Assert(IsA(a, Bitmapset) && IsA(b, Bitmapset));
+
    /* Check common words */
    result = BMS_EQUAL;         /* status so far */
    shortlen = Min(a->nwords, b->nwords);
@@ -467,6 +481,9 @@ bms_is_member(int x, const Bitmapset *a)
        elog(ERROR, "negative bitmapset member not allowed");
    if (a == NULL)
        return false;
+
+   Assert(IsA(a, Bitmapset));
+
    wordnum = WORDNUM(x);
    bitnum = BITNUM(x);
    if (wordnum >= a->nwords)
@@ -495,6 +512,8 @@ bms_member_index(Bitmapset *a, int x)
    if (!bms_is_member(x, a))
        return -1;
 
+   Assert(IsA(a, Bitmapset));
+
    wordnum = WORDNUM(x);
    bitnum = BITNUM(x);
 
@@ -529,6 +548,9 @@ bms_overlap(const Bitmapset *a, const Bitmapset *b)
    int         shortlen;
    int         i;
 
+   Assert(a == NULL || IsA(a, Bitmapset));
+   Assert(b == NULL || IsA(b, Bitmapset));
+
    /* Handle cases where either input is NULL */
    if (a == NULL || b == NULL)
        return false;
@@ -553,6 +575,8 @@ bms_overlap_list(const Bitmapset *a, const List *b)
    int         wordnum,
                bitnum;
 
+   Assert(a == NULL || IsA(a, Bitmapset));
+
    if (a == NULL || b == NIL)
        return false;
 
@@ -582,8 +606,8 @@ bms_nonempty_difference(const Bitmapset *a, const Bitmapset *b)
 {
    int         i;
 
-   Assert(a == NULL || a->words[a->nwords - 1] != 0);
-   Assert(b == NULL || b->words[b->nwords - 1] != 0);
+   Assert(a == NULL || (IsA(a, Bitmapset) && a->words[a->nwords - 1] != 0));
+   Assert(b == NULL || (IsA(b, Bitmapset) && b->words[b->nwords - 1] != 0));
 
    /* Handle cases where either input is NULL */
    if (a == NULL)
@@ -617,6 +641,9 @@ bms_singleton_member(const Bitmapset *a)
 
    if (a == NULL)
        elog(ERROR, "bitmapset is empty");
+
+   Assert(IsA(a, Bitmapset));
+
    nwords = a->nwords;
    wordnum = 0;
    do
@@ -657,6 +684,7 @@ bms_get_singleton_member(const Bitmapset *a, int *member)
 
    if (a == NULL)
        return false;
+   Assert(IsA(a, Bitmapset));
    nwords = a->nwords;
    wordnum = 0;
    do
@@ -690,6 +718,7 @@ bms_num_members(const Bitmapset *a)
 
    if (a == NULL)
        return 0;
+   Assert(IsA(a, Bitmapset));
    nwords = a->nwords;
    wordnum = 0;
    do
@@ -717,6 +746,7 @@ bms_membership(const Bitmapset *a)
 
    if (a == NULL)
        return BMS_EMPTY_SET;
+   Assert(IsA(a, Bitmapset));
    nwords = a->nwords;
    wordnum = 0;
    do
@@ -759,6 +789,7 @@ bms_add_member(Bitmapset *a, int x)
        elog(ERROR, "negative bitmapset member not allowed");
    if (a == NULL)
        return bms_make_singleton(x);
+   Assert(IsA(a, Bitmapset));
    wordnum = WORDNUM(x);
    bitnum = BITNUM(x);
 
@@ -799,6 +830,9 @@ bms_del_member(Bitmapset *a, int x)
        elog(ERROR, "negative bitmapset member not allowed");
    if (a == NULL)
        return NULL;
+
+   Assert(IsA(a, Bitmapset));
+
    wordnum = WORDNUM(x);
    bitnum = BITNUM(x);
 
@@ -839,6 +873,9 @@ bms_add_members(Bitmapset *a, const Bitmapset *b)
    int         otherlen;
    int         i;
 
+   Assert(a == NULL || IsA(a, Bitmapset));
+   Assert(b == NULL || IsA(b, Bitmapset));
+
    /* Handle cases where either input is NULL */
    if (a == NULL)
        return bms_copy(b);
@@ -884,6 +921,8 @@ bms_add_range(Bitmapset *a, int lower, int upper)
                ushiftbits,
                wordnum;
 
+   Assert(a == NULL || IsA(a, Bitmapset));
+
    /* do nothing if nothing is called for, without further checking */
    if (upper < lower)
        return a;
@@ -954,6 +993,9 @@ bms_int_members(Bitmapset *a, const Bitmapset *b)
    int         shortlen;
    int         i;
 
+   Assert(a == NULL || IsA(a, Bitmapset));
+   Assert(b == NULL || IsA(b, Bitmapset));
+
    /* Handle cases where either input is NULL */
    if (a == NULL)
        return NULL;
@@ -994,8 +1036,8 @@ bms_del_members(Bitmapset *a, const Bitmapset *b)
 {
    int         i;
 
-   Assert(a == NULL || a->words[a->nwords - 1] != 0);
-   Assert(b == NULL || b->words[b->nwords - 1] != 0);
+   Assert(a == NULL || (IsA(a, Bitmapset) && a->words[a->nwords - 1] != 0));
+   Assert(b == NULL || (IsA(b, Bitmapset) && b->words[b->nwords - 1] != 0));
 
    /* Handle cases where either input is NULL */
    if (a == NULL)
@@ -1055,6 +1097,9 @@ bms_join(Bitmapset *a, Bitmapset *b)
    int         otherlen;
    int         i;
 
+   Assert(a == NULL || IsA(a, Bitmapset));
+   Assert(b == NULL || IsA(b, Bitmapset));
+
    /* Handle cases where either input is NULL */
    if (a == NULL)
        return b;
@@ -1109,6 +1154,8 @@ bms_next_member(const Bitmapset *a, int prevbit)
    int         wordnum;
    bitmapword  mask;
 
+   Assert(a == NULL || IsA(a, Bitmapset));
+
    if (a == NULL)
        return -2;
    nwords = a->nwords;
@@ -1168,6 +1215,8 @@ bms_prev_member(const Bitmapset *a, int prevbit)
    int         ushiftbits;
    bitmapword  mask;
 
+   Assert(a == NULL || IsA(a, Bitmapset));
+
    /*
     * If set is NULL or if there are no more bits to the right then we've
     * nothing to do.