diff --git a/src/backend/regex/regc_nfa.c b/src/backend/regex/regc_nfa.c
index ecc91a8ede9657c7e968b6a3d2df114d0d8f9196..fe8a4a12d1783a870e782667fb5cfb055bdd5b9b 100644
--- a/src/backend/regex/regc_nfa.c
+++ b/src/backend/regex/regc_nfa.c
@@ -63,7 +63,6 @@ newnfa(struct vars * v,
nfa->nstates = 0;
nfa->cm = cm;
nfa->v = v;
- nfa->size = 0;
nfa->bos[0] = nfa->bos[1] = COLORLESS;
nfa->eos[0] = nfa->eos[1] = COLORLESS;
nfa->parent = parent; /* Precedes newfstate so parent is valid. */
@@ -92,57 +91,6 @@ newnfa(struct vars * v,
return nfa;
}
-/*
- * TooManyStates - checks if the max states exceeds the compile-time value
- */
-static int
-TooManyStates(struct nfa * nfa)
-{
- struct nfa *parent = nfa->parent;
- size_t sz = nfa->size;
-
- while (parent != NULL)
- {
- sz = parent->size;
- parent = parent->parent;
- }
- if (sz > REG_MAX_STATES)
- return 1;
- return 0;
-}
-
-/*
- * IncrementSize - increases the tracked size of the NFA and its parents.
- */
-static void
-IncrementSize(struct nfa * nfa)
-{
- struct nfa *parent = nfa->parent;
-
- nfa->size++;
- while (parent != NULL)
- {
- parent->size++;
- parent = parent->parent;
- }
-}
-
-/*
- * DecrementSize - decreases the tracked size of the NFA and its parents.
- */
-static void
-DecrementSize(struct nfa * nfa)
-{
- struct nfa *parent = nfa->parent;
-
- nfa->size--;
- while (parent != NULL)
- {
- parent->size--;
- parent = parent->parent;
- }
-}
-
/*
* freenfa - free an entire NFA
*/
@@ -188,12 +136,6 @@ newstate(struct nfa * nfa)
return NULL;
}
- if (TooManyStates(nfa))
- {
- NERR(REG_ETOOBIG);
- return NULL;
- }
-
if (nfa->free != NULL)
{
s = nfa->free;
@@ -201,12 +143,18 @@ newstate(struct nfa * nfa)
}
else
{
+ if (nfa->v->spaceused >= REG_MAX_COMPILE_SPACE)
+ {
+ NERR(REG_ETOOBIG);
+ return NULL;
+ }
s = (struct state *) MALLOC(sizeof(struct state));
if (s == NULL)
{
NERR(REG_ESPACE);
return NULL;
}
+ nfa->v->spaceused += sizeof(struct state);
s->oas.next = NULL;
s->free = NULL;
s->noas = 0;
@@ -230,8 +178,6 @@ newstate(struct nfa * nfa)
}
s->prev = nfa->slast;
nfa->slast = s;
- /* track the current size and the parent size */
- IncrementSize(nfa);
return s;
}
@@ -294,7 +240,6 @@ freestate(struct nfa * nfa,
s->prev = NULL;
s->next = nfa->free; /* don't delete it, put it on the free list */
nfa->free = s;
- DecrementSize(nfa);
}
/*
@@ -312,11 +257,13 @@ destroystate(struct nfa * nfa,
{
abnext = ab->next;
FREE(ab);
+ nfa->v->spaceused -= sizeof(struct arcbatch);
}
s->ins = NULL;
s->outs = NULL;
s->next = NULL;
FREE(s);
+ nfa->v->spaceused -= sizeof(struct state);
}
/*
@@ -437,12 +384,18 @@ allocarc(struct nfa * nfa,
struct arcbatch *newAb;
int i;
+ if (nfa->v->spaceused >= REG_MAX_COMPILE_SPACE)
+ {
+ NERR(REG_ETOOBIG);
+ return NULL;
+ }
newAb = (struct arcbatch *) MALLOC(sizeof(struct arcbatch));
if (newAb == NULL)
{
NERR(REG_ESPACE);
return NULL;
}
+ nfa->v->spaceused += sizeof(struct arcbatch);
newAb->next = s->oas.next;
s->oas.next = newAb;
diff --git a/src/backend/regex/regcomp.c b/src/backend/regex/regcomp.c
index 6b031075e7551299feaaba062989b6c4a1524ab4..324fea5ffb0e52c1360c2c1c8e5f8467875fcf31 100644
--- a/src/backend/regex/regcomp.c
+++ b/src/backend/regex/regcomp.c
@@ -248,6 +248,7 @@ struct vars
struct cvec *cv2; /* utility cvec */
struct subre *lacons; /* lookahead-constraint vector */
int nlacons; /* size of lacons */
+ size_t spaceused; /* approx. space used for compilation */
};
/* parsing macros; most know that `v' is the struct vars pointer */
@@ -363,6 +364,7 @@ pg_regcomp(regex_t *re,
v->cv2 = NULL;
v->lacons = NULL;
v->nlacons = 0;
+ v->spaceused = 0;
re->re_magic = REMAGIC;
re->re_info = 0; /* bits get set during parse */
re->re_csize = sizeof(chr);
diff --git a/src/include/regex/regerrs.h b/src/include/regex/regerrs.h
index 809b511266047a32b403ac05f0f3b22d3437b5dc..41e25f7ff00e5cae1e2f07555653ce6db017dead 100644
--- a/src/include/regex/regerrs.h
+++ b/src/include/regex/regerrs.h
@@ -75,7 +75,7 @@
},
{
- REG_ETOOBIG, "REG_ETOOBIG", "nfa has too many states"
+ REG_ETOOBIG, "REG_ETOOBIG", "regular expression is too complex"
},
{
diff --git a/src/include/regex/regex.h b/src/include/regex/regex.h
index 3020b0ff0f76d1a6fc520062803f28f43822cca0..5e1b692d26c130d09cbe4f7e3150ba6cbba6f66a 100644
--- a/src/include/regex/regex.h
+++ b/src/include/regex/regex.h
@@ -152,7 +152,7 @@ typedef struct
#define REG_INVARG 16 /* invalid argument to regex function */
#define REG_MIXED 17 /* character widths of regex and string differ */
#define REG_BADOPT 18 /* invalid embedded option */
-#define REG_ETOOBIG 19 /* nfa has too many states */
+#define REG_ETOOBIG 19 /* regular expression is too complex */
#define REG_ECOLORS 20 /* too many colors */
#define REG_CANCEL 21 /* operation cancelled */
/* two specials for debugging and testing */
diff --git a/src/include/regex/regguts.h b/src/include/regex/regguts.h
index 357891aa254847f9eba290b9e4f749ff59cd2bd9..19fe991c74faa5213261ce3b060071a8c7f2eec2 100644
--- a/src/include/regex/regguts.h
+++ b/src/include/regex/regguts.h
@@ -334,9 +334,6 @@ struct nfa
struct colormap *cm; /* the color map */
color bos[2]; /* colors, if any, assigned to BOS and BOL */
color eos[2]; /* colors, if any, assigned to EOS and EOL */
- size_t size; /* Current NFA size; differs from nstates as
- * it also counts the number of states in
- * children of this NFA. */
struct vars *v; /* simplifies compile error reporting */
struct nfa *parent; /* parent NFA, if any */
};
@@ -384,10 +381,16 @@ struct cnfa
#define NULLCNFA(cnfa) ((cnfa).nstates == 0)
/*
- * Used to limit the maximum NFA size to something sane. [Tcl Bug 1810264]
+ * This symbol limits the transient heap space used by the regex compiler,
+ * and thereby also the maximum complexity of NFAs that we'll deal with.
+ * Currently we only count NFA states and arcs against this; the other
+ * transient data is generally not large enough to notice compared to those.
+ * Note that we do not charge anything for the final output data structures
+ * (the compacted NFA and the colormap).
*/
-#ifndef REG_MAX_STATES
-#define REG_MAX_STATES 100000
+#ifndef REG_MAX_COMPILE_SPACE
+#define REG_MAX_COMPILE_SPACE \
+ (100000 * sizeof(struct state) + 100000 * sizeof(struct arcbatch))
#endif
/*