Adding upstream version 3.4.23.upstream/3.4.23upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 928 insertions, 0 deletions

diff --git a/src/util/dict_pcre.c b/src/util/dict_pcre.c
new file mode 100644
index 0000000..38c0ec3
--- /dev/null
+++ b/src/util/dict_pcre.c
@@ -0,0 +1,928 @@
+/*++
+/* NAME
+/*	dict_pcre 3
+/* SUMMARY
+/*	dictionary manager interface to PCRE regular expression library
+/* SYNOPSIS
+/*	#include <dict_pcre.h>
+/*
+/*	DICT	*dict_pcre_open(name, dummy, dict_flags)
+/*	const char *name;
+/*	int	dummy;
+/*	int	dict_flags;
+/* DESCRIPTION
+/*	dict_pcre_open() opens the named file and compiles the contained
+/*	regular expressions. The result object can be used to match strings
+/*	against the table.
+/* SEE ALSO
+/*	dict(3) generic dictionary manager
+/* AUTHOR(S)
+/*	Andrew McNamara
+/*	andrewm@connect.com.au
+/*	connect.com.au Pty. Ltd.
+/*	Level 3, 213 Miller St
+/*	North Sydney, NSW, Australia
+/*
+/*	Wietse Venema
+/*	IBM T.J. Watson Research
+/*	P.O. Box 704
+/*	Yorktown Heights, NY 10598, USA
+/*
+/*	Wietse Venema
+/*	Google, Inc.
+/*	111 8th Avenue
+/*	New York, NY 10011, USA
+/*--*/
+
+#include "sys_defs.h"
+
+#ifdef HAS_PCRE
+
+/* System library. */
+
+#include <sys/stat.h>
+#include <stdio.h>			/* sprintf() prototype */
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <ctype.h>
+
+#ifdef STRCASECMP_IN_STRINGS_H
+#include <strings.h>
+#endif
+
+/* Utility library. */
+
+#include "mymalloc.h"
+#include "msg.h"
+#include "safe.h"
+#include "vstream.h"
+#include "vstring.h"
+#include "stringops.h"
+#include "readlline.h"
+#include "dict.h"
+#include "dict_pcre.h"
+#include "mac_parse.h"
+#include "pcre.h"
+#include "warn_stat.h"
+#include "mvect.h"
+
+ /*
+  * Backwards compatibility.
+  */
+#ifdef PCRE_STUDY_JIT_COMPILE
+#define DICT_PCRE_FREE_STUDY(x)	pcre_free_study(x)
+#else
+#define DICT_PCRE_FREE_STUDY(x)	pcre_free((char *) (x))
+#endif
+
+ /*
+  * Support for IF/ENDIF based on an idea by Bert Driehuis.
+  */
+#define DICT_PCRE_OP_MATCH    1		/* Match this regexp */
+#define DICT_PCRE_OP_IF       2		/* Increase if/endif nesting on match */
+#define DICT_PCRE_OP_ENDIF    3		/* Decrease if/endif nesting on match */
+
+ /*
+  * Max strings captured by regexp - essentially the max number of (..)
+  */
+#define PCRE_MAX_CAPTURE	99
+
+ /*
+  * Regular expression before and after compilation.
+  */
+typedef struct {
+    char   *regexp;			/* regular expression */
+    int     options;			/* options */
+    int     match;			/* positive or negative match */
+} DICT_PCRE_REGEXP;
+
+typedef struct {
+    pcre   *pattern;			/* the compiled pattern */
+    pcre_extra *hints;			/* hints to speed pattern execution */
+} DICT_PCRE_ENGINE;
+
+ /*
+  * Compiled generic rule, and subclasses that derive from it.
+  */
+typedef struct DICT_PCRE_RULE {
+    int     op;				/* DICT_PCRE_OP_MATCH/IF/ENDIF */
+    int     lineno;			/* source file line number */
+    struct DICT_PCRE_RULE *next;	/* next rule in dict */
+} DICT_PCRE_RULE;
+
+typedef struct {
+    DICT_PCRE_RULE rule;		/* generic part */
+    pcre   *pattern;			/* compiled pattern */
+    pcre_extra *hints;			/* hints to speed pattern execution */
+    char   *replacement;		/* replacement string */
+    int     match;			/* positive or negative match */
+    size_t  max_sub;			/* largest $number in replacement */
+} DICT_PCRE_MATCH_RULE;
+
+typedef struct {
+    DICT_PCRE_RULE rule;		/* generic members */
+    pcre   *pattern;			/* compiled pattern */
+    pcre_extra *hints;			/* hints to speed pattern execution */
+    int     match;			/* positive or negative match */
+    struct DICT_PCRE_RULE *endif_rule;	/* matching endif rule */
+} DICT_PCRE_IF_RULE;
+
+ /*
+  * PCRE map.
+  */
+typedef struct {
+    DICT    dict;			/* generic members */
+    DICT_PCRE_RULE *head;
+    VSTRING *expansion_buf;		/* lookup result */
+} DICT_PCRE;
+
+static int dict_pcre_init = 0;		/* flag need to init pcre library */
+
+/*
+ * Context for $number expansion callback.
+ */
+typedef struct {
+    DICT_PCRE *dict_pcre;		/* the dictionary handle */
+    DICT_PCRE_MATCH_RULE *match_rule;	/* the rule we matched */
+    const char *lookup_string;		/* string against which we match */
+    int     offsets[PCRE_MAX_CAPTURE * 3];	/* Cut substrings */
+    int     matches;			/* Count of cuts */
+} DICT_PCRE_EXPAND_CONTEXT;
+
+ /*
+  * Context for $number pre-scan callback.
+  */
+typedef struct {
+    const char *mapname;		/* name of regexp map */
+    int     lineno;			/* where in file */
+    size_t  max_sub;			/* Largest $n seen */
+    char   *literal;			/* constant result, $$ -> $ */
+} DICT_PCRE_PRESCAN_CONTEXT;
+
+ /*
+  * Compatibility.
+  */
+#ifndef MAC_PARSE_OK
+#define MAC_PARSE_OK 0
+#endif
+
+ /*
+  * Macros to make dense code more accessible.
+  */
+#define NULL_STARTOFFSET	(0)
+#define NULL_EXEC_OPTIONS 	(0)
+#define NULL_OVECTOR		((int *) 0)
+#define NULL_OVECTOR_LENGTH	(0)
+
+/* dict_pcre_expand - replace $number with matched text */
+
+static int dict_pcre_expand(int type, VSTRING *buf, void *ptr)
+{
+    DICT_PCRE_EXPAND_CONTEXT *ctxt = (DICT_PCRE_EXPAND_CONTEXT *) ptr;
+    DICT_PCRE_MATCH_RULE *match_rule = ctxt->match_rule;
+    DICT_PCRE *dict_pcre = ctxt->dict_pcre;
+    const char *pp;
+    int     n;
+    int     ret;
+
+    /*
+     * Replace $0-${99} with strings cut from matched text.
+     */
+    if (type == MAC_PARSE_VARNAME) {
+	n = atoi(vstring_str(buf));
+	ret = pcre_get_substring(ctxt->lookup_string, ctxt->offsets,
+				 ctxt->matches, n, &pp);
+	if (ret < 0) {
+	    if (ret == PCRE_ERROR_NOSUBSTRING)
+		return (MAC_PARSE_UNDEF);
+	    else
+		msg_fatal("pcre map %s, line %d: pcre_get_substring error: %d",
+			dict_pcre->dict.name, match_rule->rule.lineno, ret);
+	}
+	if (*pp == 0) {
+	    myfree((void *) pp);
+	    return (MAC_PARSE_UNDEF);
+	}
+	vstring_strcat(dict_pcre->expansion_buf, pp);
+	myfree((void *) pp);
+	return (MAC_PARSE_OK);
+    }
+
+    /*
+     * Straight text - duplicate with no substitution.
+     */
+    else {
+	vstring_strcat(dict_pcre->expansion_buf, vstring_str(buf));
+	return (MAC_PARSE_OK);
+    }
+}
+
+/* dict_pcre_exec_error - report matching error */
+
+static void dict_pcre_exec_error(const char *mapname, int lineno, int errval)
+{
+    switch (errval) {
+	case 0:
+	msg_warn("pcre map %s, line %d: too many (...)",
+		 mapname, lineno);
+	return;
+    case PCRE_ERROR_NULL:
+    case PCRE_ERROR_BADOPTION:
+	msg_warn("pcre map %s, line %d: bad args to re_exec",
+		 mapname, lineno);
+	return;
+    case PCRE_ERROR_BADMAGIC:
+    case PCRE_ERROR_UNKNOWN_NODE:
+	msg_warn("pcre map %s, line %d: corrupt compiled regexp",
+		 mapname, lineno);
+	return;
+#ifdef PCRE_ERROR_NOMEMORY
+    case PCRE_ERROR_NOMEMORY:
+	msg_warn("pcre map %s, line %d: out of memory",
+		 mapname, lineno);
+	return;
+#endif
+#ifdef PCRE_ERROR_MATCHLIMIT
+    case PCRE_ERROR_MATCHLIMIT:
+	msg_warn("pcre map %s, line %d: backtracking limit exceeded",
+		 mapname, lineno);
+	return;
+#endif
+#ifdef PCRE_ERROR_BADUTF8
+    case PCRE_ERROR_BADUTF8:
+	msg_warn("pcre map %s, line %d: bad UTF-8 sequence in search string",
+		 mapname, lineno);
+	return;
+#endif
+#ifdef PCRE_ERROR_BADUTF8_OFFSET
+    case PCRE_ERROR_BADUTF8_OFFSET:
+	msg_warn("pcre map %s, line %d: bad UTF-8 start offset in search string",
+		 mapname, lineno);
+	return;
+#endif
+    default:
+	msg_warn("pcre map %s, line %d: unknown pcre_exec error: %d",
+		 mapname, lineno, errval);
+	return;
+    }
+}
+
+ /*
+  * Inlined to reduce function call overhead in the time-critical loop.
+  */
+#define DICT_PCRE_EXEC(ctxt, map, line, pattern, hints, match, str, len) \
+    ((ctxt).matches = pcre_exec((pattern), (hints), (str), (len), \
+				NULL_STARTOFFSET, NULL_EXEC_OPTIONS, \
+				(ctxt).offsets, PCRE_MAX_CAPTURE * 3), \
+     (ctxt).matches > 0 ? (match) : \
+     (ctxt).matches == PCRE_ERROR_NOMATCH ? !(match) : \
+     (dict_pcre_exec_error((map), (line), (ctxt).matches), 0))
+
+/* dict_pcre_lookup - match string and perform optional substitution */
+
+static const char *dict_pcre_lookup(DICT *dict, const char *lookup_string)
+{
+    DICT_PCRE *dict_pcre = (DICT_PCRE *) dict;
+    DICT_PCRE_RULE *rule;
+    DICT_PCRE_IF_RULE *if_rule;
+    DICT_PCRE_MATCH_RULE *match_rule;
+    int     lookup_len = strlen(lookup_string);
+    DICT_PCRE_EXPAND_CONTEXT ctxt;
+
+    dict->error = 0;
+
+    if (msg_verbose)
+	msg_info("dict_pcre_lookup: %s: %s", dict->name, lookup_string);
+
+    /*
+     * Optionally fold the key.
+     */
+    if (dict->flags & DICT_FLAG_FOLD_MUL) {
+	if (dict->fold_buf == 0)
+	    dict->fold_buf = vstring_alloc(10);
+	vstring_strcpy(dict->fold_buf, lookup_string);
+	lookup_string = lowercase(vstring_str(dict->fold_buf));
+    }
+    for (rule = dict_pcre->head; rule; rule = rule->next) {
+
+	switch (rule->op) {
+
+	    /*
+	     * Search for a matching expression.
+	     */
+	case DICT_PCRE_OP_MATCH:
+	    match_rule = (DICT_PCRE_MATCH_RULE *) rule;
+	    if (!DICT_PCRE_EXEC(ctxt, dict->name, rule->lineno,
+				match_rule->pattern, match_rule->hints,
+			      match_rule->match, lookup_string, lookup_len))
+		continue;
+
+	    /*
+	     * Skip $number substitutions when the replacement text contains
+	     * no $number strings, as learned during the compile time
+	     * pre-scan. The pre-scan already replaced $$ by $.
+	     */
+	    if (match_rule->max_sub == 0)
+		return match_rule->replacement;
+
+	    /*
+	     * We've got a match. Perform substitution on replacement string.
+	     */
+	    if (dict_pcre->expansion_buf == 0)
+		dict_pcre->expansion_buf = vstring_alloc(10);
+	    VSTRING_RESET(dict_pcre->expansion_buf);
+	    ctxt.dict_pcre = dict_pcre;
+	    ctxt.match_rule = match_rule;
+	    ctxt.lookup_string = lookup_string;
+
+	    if (mac_parse(match_rule->replacement, dict_pcre_expand,
+			  (void *) &ctxt) & MAC_PARSE_ERROR)
+		msg_fatal("pcre map %s, line %d: bad replacement syntax",
+			  dict->name, rule->lineno);
+
+	    VSTRING_TERMINATE(dict_pcre->expansion_buf);
+	    return (vstring_str(dict_pcre->expansion_buf));
+
+	    /*
+	     * Conditional. XXX We provide space for matched substring info
+	     * because PCRE uses part of it as workspace for backtracking.
+	     * PCRE will allocate memory if it runs out of backtracking
+	     * storage.
+	     */
+	case DICT_PCRE_OP_IF:
+	    if_rule = (DICT_PCRE_IF_RULE *) rule;
+	    if (DICT_PCRE_EXEC(ctxt, dict->name, rule->lineno,
+			       if_rule->pattern, if_rule->hints,
+			       if_rule->match, lookup_string, lookup_len))
+		continue;
+	    /* An IF without matching ENDIF has no "endif" rule. */
+	    if ((rule = if_rule->endif_rule) == 0)
+		return (0);
+	    /* FALLTHROUGH */
+
+	    /*
+	     * ENDIF after IF.
+	     */
+	case DICT_PCRE_OP_ENDIF:
+	    continue;
+
+	default:
+	    msg_panic("dict_pcre_lookup: impossible operation %d", rule->op);
+	}
+    }
+    return (0);
+}
+
+/* dict_pcre_close - close pcre dictionary */
+
+static void dict_pcre_close(DICT *dict)
+{
+    DICT_PCRE *dict_pcre = (DICT_PCRE *) dict;
+    DICT_PCRE_RULE *rule;
+    DICT_PCRE_RULE *next;
+    DICT_PCRE_MATCH_RULE *match_rule;
+    DICT_PCRE_IF_RULE *if_rule;
+
+    for (rule = dict_pcre->head; rule; rule = next) {
+	next = rule->next;
+	switch (rule->op) {
+	case DICT_PCRE_OP_MATCH:
+	    match_rule = (DICT_PCRE_MATCH_RULE *) rule;
+	    if (match_rule->pattern)
+		myfree((void *) match_rule->pattern);
+	    if (match_rule->hints)
+		DICT_PCRE_FREE_STUDY(match_rule->hints);
+	    if (match_rule->replacement)
+		myfree((void *) match_rule->replacement);
+	    break;
+	case DICT_PCRE_OP_IF:
+	    if_rule = (DICT_PCRE_IF_RULE *) rule;
+	    if (if_rule->pattern)
+		myfree((void *) if_rule->pattern);
+	    if (if_rule->hints)
+		DICT_PCRE_FREE_STUDY(if_rule->hints);
+	    break;
+	case DICT_PCRE_OP_ENDIF:
+	    break;
+	default:
+	    msg_panic("dict_pcre_close: unknown operation %d", rule->op);
+	}
+	myfree((void *) rule);
+    }
+    if (dict_pcre->expansion_buf)
+	vstring_free(dict_pcre->expansion_buf);
+    if (dict->fold_buf)
+	vstring_free(dict->fold_buf);
+    dict_free(dict);
+}
+
+/* dict_pcre_get_pattern - extract pattern from rule */
+
+static int dict_pcre_get_pattern(const char *mapname, int lineno, char **bufp,
+				         DICT_PCRE_REGEXP *pattern)
+{
+    char   *p = *bufp;
+    char    re_delimiter;
+
+    /*
+     * Process negation operators.
+     */
+    pattern->match = 1;
+    for (;;) {
+	if (*p == '!')
+	    pattern->match = !pattern->match;
+	else if (!ISSPACE(*p))
+	    break;
+	p++;
+    }
+    if (*p == 0) {
+	msg_warn("pcre map %s, line %d: no regexp: skipping this rule",
+		 mapname, lineno);
+	return (0);
+    }
+    re_delimiter = *p++;
+    pattern->regexp = p;
+
+    /*
+     * Search for second delimiter, handling backslash escape.
+     */
+    while (*p) {
+	if (*p == '\\') {
+	    ++p;
+	    if (*p == 0)
+		break;
+	} else if (*p == re_delimiter)
+	    break;
+	++p;
+    }
+
+    if (!*p) {
+	msg_warn("pcre map %s, line %d: no closing regexp delimiter \"%c\": "
+		 "ignoring this rule", mapname, lineno, re_delimiter);
+	return (0);
+    }
+    *p++ = 0;					/* Null term the regexp */
+
+    /*
+     * Parse any regexp options.
+     */
+    pattern->options = PCRE_CASELESS | PCRE_DOTALL;
+    while (*p && !ISSPACE(*p)) {
+	switch (*p) {
+	case 'i':
+	    pattern->options ^= PCRE_CASELESS;
+	    break;
+	case 'm':
+	    pattern->options ^= PCRE_MULTILINE;
+	    break;
+	case 's':
+	    pattern->options ^= PCRE_DOTALL;
+	    break;
+	case 'x':
+	    pattern->options ^= PCRE_EXTENDED;
+	    break;
+	case 'A':
+	    pattern->options ^= PCRE_ANCHORED;
+	    break;
+	case 'E':
+	    pattern->options ^= PCRE_DOLLAR_ENDONLY;
+	    break;
+	case 'U':
+	    pattern->options ^= PCRE_UNGREEDY;
+	    break;
+	case 'X':
+	    pattern->options ^= PCRE_EXTRA;
+	    break;
+	default:
+	    msg_warn("pcre map %s, line %d: unknown regexp option \"%c\": "
+		     "skipping this rule", mapname, lineno, *p);
+	    return (0);
+	}
+	++p;
+    }
+    *bufp = p;
+    return (1);
+}
+
+/* dict_pcre_prescan - sanity check $number instances in replacement text */
+
+static int dict_pcre_prescan(int type, VSTRING *buf, void *context)
+{
+    DICT_PCRE_PRESCAN_CONTEXT *ctxt = (DICT_PCRE_PRESCAN_CONTEXT *) context;
+    size_t  n;
+
+    /*
+     * Keep a copy of literal text (with $$ already replaced by $) if and
+     * only if the replacement text contains no $number expression. This way
+     * we can avoid having to scan the replacement text at lookup time.
+     */
+    if (type == MAC_PARSE_VARNAME) {
+	if (ctxt->literal) {
+	    myfree(ctxt->literal);
+	    ctxt->literal = 0;
+	}
+	if (!alldig(vstring_str(buf))) {
+	    msg_warn("pcre map %s, line %d: non-numeric replacement index \"%s\"",
+		     ctxt->mapname, ctxt->lineno, vstring_str(buf));
+	    return (MAC_PARSE_ERROR);
+	}
+	n = atoi(vstring_str(buf));
+	if (n < 1) {
+	    msg_warn("pcre map %s, line %d: out of range replacement index \"%s\"",
+		     ctxt->mapname, ctxt->lineno, vstring_str(buf));
+	    return (MAC_PARSE_ERROR);
+	}
+	if (n > ctxt->max_sub)
+	    ctxt->max_sub = n;
+    } else if (type == MAC_PARSE_LITERAL && ctxt->max_sub == 0) {
+	if (ctxt->literal)
+	    msg_panic("pcre map %s, line %d: multiple literals but no $number",
+		      ctxt->mapname, ctxt->lineno);
+	ctxt->literal = mystrdup(vstring_str(buf));
+    }
+    return (MAC_PARSE_OK);
+}
+
+/* dict_pcre_compile - compile pattern */
+
+static int dict_pcre_compile(const char *mapname, int lineno,
+			             DICT_PCRE_REGEXP *pattern,
+			             DICT_PCRE_ENGINE *engine)
+{
+    const char *error;
+    int     errptr;
+
+    engine->pattern = pcre_compile(pattern->regexp, pattern->options,
+				   &error, &errptr, NULL);
+    if (engine->pattern == 0) {
+	msg_warn("pcre map %s, line %d: error in regex at offset %d: %s",
+		 mapname, lineno, errptr, error);
+	return (0);
+    }
+    engine->hints = pcre_study(engine->pattern, 0, &error);
+    if (error != 0) {
+	msg_warn("pcre map %s, line %d: error while studying regex: %s",
+		 mapname, lineno, error);
+	myfree((void *) engine->pattern);
+	return (0);
+    }
+    return (1);
+}
+
+/* dict_pcre_rule_alloc - fill in a generic rule structure */
+
+static DICT_PCRE_RULE *dict_pcre_rule_alloc(int op, int lineno, size_t size)
+{
+    DICT_PCRE_RULE *rule;
+
+    rule = (DICT_PCRE_RULE *) mymalloc(size);
+    rule->op = op;
+    rule->lineno = lineno;
+    rule->next = 0;
+
+    return (rule);
+}
+
+/* dict_pcre_parse_rule - parse and compile one rule */
+
+static DICT_PCRE_RULE *dict_pcre_parse_rule(DICT *dict, const char *mapname,
+					            int lineno, char *line,
+					            int nesting)
+{
+    char   *p;
+    int     actual_sub;
+
+    p = line;
+
+    /*
+     * An ordinary match rule takes one pattern and replacement text.
+     */
+    if (!ISALNUM(*p)) {
+	DICT_PCRE_REGEXP regexp;
+	DICT_PCRE_ENGINE engine;
+	DICT_PCRE_PRESCAN_CONTEXT prescan_context;
+	DICT_PCRE_MATCH_RULE *match_rule;
+
+	/*
+	 * Get the pattern string and options.
+	 */
+	if (dict_pcre_get_pattern(mapname, lineno, &p, &regexp) == 0)
+	    return (0);
+
+	/*
+	 * Get the replacement text.
+	 */
+	while (*p && ISSPACE(*p))
+	    ++p;
+	if (!*p)
+	    msg_warn("pcre map %s, line %d: no replacement text: "
+		     "using empty string", mapname, lineno);
+
+	/*
+	 * Sanity check the $number instances in the replacement text.
+	 */
+	prescan_context.mapname = mapname;
+	prescan_context.lineno = lineno;
+	prescan_context.max_sub = 0;
+	prescan_context.literal = 0;
+
+	/*
+	 * The optimizer will eliminate code duplication and/or dead code.
+	 */
+#define CREATE_MATCHOP_ERROR_RETURN(rval) do { \
+	if (prescan_context.literal) \
+	    myfree(prescan_context.literal); \
+	return (rval); \
+    } while (0)
+
+	if (dict->flags & DICT_FLAG_SRC_RHS_IS_FILE) {
+	    VSTRING *base64_buf;
+	    char   *err;
+
+	    if ((base64_buf = dict_file_to_b64(dict, p)) == 0) {
+		err = dict_file_get_error(dict);
+		msg_warn("pcre map %s, line %d: %s: skipping this rule",
+			 mapname, lineno, err);
+		myfree(err);
+		CREATE_MATCHOP_ERROR_RETURN(0);
+	    }
+	    p = vstring_str(base64_buf);
+	}
+	if (mac_parse(p, dict_pcre_prescan, (void *) &prescan_context)
+	    & MAC_PARSE_ERROR) {
+	    msg_warn("pcre map %s, line %d: bad replacement syntax: "
+		     "skipping this rule", mapname, lineno);
+	    CREATE_MATCHOP_ERROR_RETURN(0);
+	}
+
+	/*
+	 * Substring replacement not possible with negative regexps.
+	 */
+	if (prescan_context.max_sub > 0 && regexp.match == 0) {
+	    msg_warn("pcre map %s, line %d: $number found in negative match "
+		   "replacement text: skipping this rule", mapname, lineno);
+	    CREATE_MATCHOP_ERROR_RETURN(0);
+	}
+	if (prescan_context.max_sub > 0 && (dict->flags & DICT_FLAG_NO_REGSUB)) {
+	    msg_warn("pcre map %s, line %d: "
+		     "regular expression substitution is not allowed: "
+		     "skipping this rule", mapname, lineno);
+	    CREATE_MATCHOP_ERROR_RETURN(0);
+	}
+
+	/*
+	 * Compile the pattern.
+	 */
+	if (dict_pcre_compile(mapname, lineno, &regexp, &engine) == 0)
+	    CREATE_MATCHOP_ERROR_RETURN(0);
+#ifdef PCRE_INFO_CAPTURECOUNT
+	if (pcre_fullinfo(engine.pattern, engine.hints,
+			  PCRE_INFO_CAPTURECOUNT,
+			  (void *) &actual_sub) != 0)
+	    msg_panic("pcre map %s, line %d: pcre_fullinfo failed",
+		      mapname, lineno);
+	if (prescan_context.max_sub > actual_sub) {
+	    msg_warn("pcre map %s, line %d: out of range replacement index \"%d\": "
+		     "skipping this rule", mapname, lineno,
+		     (int) prescan_context.max_sub);
+	    if (engine.pattern)
+		myfree((void *) engine.pattern);
+	    if (engine.hints)
+		DICT_PCRE_FREE_STUDY(engine.hints);
+	    CREATE_MATCHOP_ERROR_RETURN(0);
+	}
+#endif
+
+	/*
+	 * Save the result.
+	 */
+	match_rule = (DICT_PCRE_MATCH_RULE *)
+	    dict_pcre_rule_alloc(DICT_PCRE_OP_MATCH, lineno,
+				 sizeof(DICT_PCRE_MATCH_RULE));
+	match_rule->match = regexp.match;
+	match_rule->max_sub = prescan_context.max_sub;
+	if (prescan_context.literal)
+	    match_rule->replacement = prescan_context.literal;
+	else
+	    match_rule->replacement = mystrdup(p);
+	match_rule->pattern = engine.pattern;
+	match_rule->hints = engine.hints;
+	return ((DICT_PCRE_RULE *) match_rule);
+    }
+
+    /*
+     * The IF operator takes one pattern but no replacement text.
+     */
+    else if (strncasecmp(p, "IF", 2) == 0 && !ISALNUM(p[2])) {
+	DICT_PCRE_REGEXP regexp;
+	DICT_PCRE_ENGINE engine;
+	DICT_PCRE_IF_RULE *if_rule;
+
+	p += 2;
+
+	/*
+	 * Get the pattern.
+	 */
+	while (*p && ISSPACE(*p))
+	    p++;
+	if (!dict_pcre_get_pattern(mapname, lineno, &p, &regexp))
+	    return (0);
+
+	/*
+	 * Warn about out-of-place text.
+	 */
+	while (*p && ISSPACE(*p))
+	    ++p;
+	if (*p) {
+	    msg_warn("pcre map %s, line %d: ignoring extra text after "
+		     "IF statement: \"%s\"", mapname, lineno, p);
+	    msg_warn("pcre map %s, line %d: do not prepend whitespace"
+		     " to statements between IF and ENDIF", mapname, lineno);
+	}
+
+	/*
+	 * Compile the pattern.
+	 */
+	if (dict_pcre_compile(mapname, lineno, &regexp, &engine) == 0)
+	    return (0);
+
+	/*
+	 * Save the result.
+	 */
+	if_rule = (DICT_PCRE_IF_RULE *)
+	    dict_pcre_rule_alloc(DICT_PCRE_OP_IF, lineno,
+				 sizeof(DICT_PCRE_IF_RULE));
+	if_rule->match = regexp.match;
+	if_rule->pattern = engine.pattern;
+	if_rule->hints = engine.hints;
+	if_rule->endif_rule = 0;
+	return ((DICT_PCRE_RULE *) if_rule);
+    }
+
+    /*
+     * The ENDIF operator takes no patterns and no replacement text.
+     */
+    else if (strncasecmp(p, "ENDIF", 5) == 0 && !ISALNUM(p[5])) {
+	DICT_PCRE_RULE *rule;
+
+	p += 5;
+
+	/*
+	 * Warn about out-of-place ENDIFs.
+	 */
+	if (nesting == 0) {
+	    msg_warn("pcre map %s, line %d: ignoring ENDIF without matching IF",
+		     mapname, lineno);
+	    return (0);
+	}
+
+	/*
+	 * Warn about out-of-place text.
+	 */
+	while (*p && ISSPACE(*p))
+	    ++p;
+	if (*p)
+	    msg_warn("pcre map %s, line %d: ignoring extra text after ENDIF",
+		     mapname, lineno);
+
+	/*
+	 * Save the result.
+	 */
+	rule = dict_pcre_rule_alloc(DICT_PCRE_OP_ENDIF, lineno,
+				    sizeof(DICT_PCRE_RULE));
+	return (rule);
+    }
+
+    /*
+     * Unrecognized input.
+     */
+    else {
+	msg_warn("pcre map %s, line %d: ignoring unrecognized request",
+		 mapname, lineno);
+	return (0);
+    }
+}
+
+/* dict_pcre_open - load and compile a file containing regular expressions */
+
+DICT   *dict_pcre_open(const char *mapname, int open_flags, int dict_flags)
+{
+    const char myname[] = "dict_pcre_open";
+    DICT_PCRE *dict_pcre;
+    VSTREAM *map_fp = 0;
+    struct stat st;
+    VSTRING *line_buffer = 0;
+    DICT_PCRE_RULE *last_rule = 0;
+    DICT_PCRE_RULE *rule;
+    int     last_line = 0;
+    int     lineno;
+    int     nesting = 0;
+    char   *p;
+    DICT_PCRE_RULE **rule_stack = 0;
+    MVECT   mvect;
+
+    /*
+     * Let the optimizer worry about eliminating redundant code.
+     */
+#define DICT_PCRE_OPEN_RETURN(d) do { \
+	DICT *__d = (d); \
+	if (map_fp != 0) \
+	    vstream_fclose(map_fp); \
+	if (line_buffer != 0) \
+	    vstring_free(line_buffer); \
+	return (__d); \
+    } while (0)
+
+    /*
+     * Sanity checks.
+     */
+    if (open_flags != O_RDONLY)
+	DICT_PCRE_OPEN_RETURN(dict_surrogate(DICT_TYPE_PCRE, mapname,
+					     open_flags, dict_flags,
+				  "%s:%s map requires O_RDONLY access mode",
+					     DICT_TYPE_PCRE, mapname));
+
+    /*
+     * Open the configuration file.
+     */
+    if ((map_fp = vstream_fopen(mapname, O_RDONLY, 0)) == 0)
+	DICT_PCRE_OPEN_RETURN(dict_surrogate(DICT_TYPE_PCRE, mapname,
+					     open_flags, dict_flags,
+					     "open %s: %m", mapname));
+    if (fstat(vstream_fileno(map_fp), &st) < 0)
+	msg_fatal("fstat %s: %m", mapname);
+
+    line_buffer = vstring_alloc(100);
+
+    dict_pcre = (DICT_PCRE *) dict_alloc(DICT_TYPE_PCRE, mapname,
+					 sizeof(*dict_pcre));
+    dict_pcre->dict.lookup = dict_pcre_lookup;
+    dict_pcre->dict.close = dict_pcre_close;
+    dict_pcre->dict.flags = dict_flags | DICT_FLAG_PATTERN;
+    if (dict_flags & DICT_FLAG_FOLD_MUL)
+	dict_pcre->dict.fold_buf = vstring_alloc(10);
+    dict_pcre->head = 0;
+    dict_pcre->expansion_buf = 0;
+
+    if (dict_pcre_init == 0) {
+	pcre_malloc = (void *(*) (size_t)) mymalloc;
+	pcre_free = (void (*) (void *)) myfree;
+	dict_pcre_init = 1;
+    }
+    dict_pcre->dict.owner.uid = st.st_uid;
+    dict_pcre->dict.owner.status = (st.st_uid != 0);
+
+    /*
+     * Parse the pcre table.
+     */
+    while (readllines(line_buffer, map_fp, &last_line, &lineno)) {
+	p = vstring_str(line_buffer);
+	trimblanks(p, 0)[0] = 0;		/* Trim space at end */
+	if (*p == 0)
+	    continue;
+	rule = dict_pcre_parse_rule(&dict_pcre->dict, mapname, lineno,
+				    p, nesting);
+	if (rule == 0)
+	    continue;
+	if (rule->op == DICT_PCRE_OP_IF) {
+	    if (rule_stack == 0)
+		rule_stack = (DICT_PCRE_RULE **) mvect_alloc(&mvect,
+					   sizeof(*rule_stack), nesting + 1,
+						(MVECT_FN) 0, (MVECT_FN) 0);
+	    else
+		rule_stack =
+		    (DICT_PCRE_RULE **) mvect_realloc(&mvect, nesting + 1);
+	    rule_stack[nesting] = rule;
+	    nesting++;
+	} else if (rule->op == DICT_PCRE_OP_ENDIF) {
+	    DICT_PCRE_IF_RULE *if_rule;
+
+	    if (nesting-- <= 0)
+		/* Already handled in dict_pcre_parse_rule(). */
+		msg_panic("%s: ENDIF without IF", myname);
+	    if (rule_stack[nesting]->op != DICT_PCRE_OP_IF)
+		msg_panic("%s: unexpected rule stack element type %d",
+			  myname, rule_stack[nesting]->op);
+	    if_rule = (DICT_PCRE_IF_RULE *) rule_stack[nesting];
+	    if_rule->endif_rule = rule;
+	}
+	if (last_rule == 0)
+	    dict_pcre->head = rule;
+	else
+	    last_rule->next = rule;
+	last_rule = rule;
+    }
+
+    while (nesting-- > 0)
+	msg_warn("pcre map %s, line %d: IF has no matching ENDIF",
+		 mapname, rule_stack[nesting]->lineno);
+
+    if (rule_stack)
+	(void) mvect_free(&mvect);
+
+    dict_file_purge_buffers(&dict_pcre->dict);
+    DICT_PCRE_OPEN_RETURN(DICT_DEBUG (&dict_pcre->dict));
+}
+
+#endif					/* HAS_PCRE */