Reimplement apropos -s NUM -S ARCH EXPR by internally converting it to

apropos \( EXPR \) -a 'sec~^NUM$' -a 'arch~^(ARCH|any)$'
in preparation for removal of sec and arch from the mpage table.

Almost no functional change except for the following bonus:
This also makes sure that for cross-section and cross-arch MLINKs,
all of the following work:
apropos -s 1 encrypt
apropos -s 8 encrypt
apropos -s 1 makekey
apropos -s 8 makekey

While here, print error messages about invalid regexps to stderr.

2 files changed, 55 insertions, 23 deletions

diff --git a/mandocdb.c b/mandocdb.c
index c6680163..4b5d8fdb 100644
--- a/mandocdb.c
+++ b/mandocdb.c
@@ -1025,14 +1025,16 @@ mpages_merge(struct mchars *mc, struct mparse *mp, int check_reachable)
 			    mandoc_strdup(mpage->mlinks->name);
 		}
 		putkey(mpage, mpage->sec, TYPE_sec);
-		putkey(mpage, mpage->arch, TYPE_arch);
+		putkey(mpage, '\0' == *mpage->arch ?
+		    "any" : mpage->arch, TYPE_arch);
 
 		for (mlink = mpage->mlinks; mlink; mlink = mlink->next) {
 			if ('\0' != *mlink->dsec)
 				putkey(mpage, mlink->dsec, TYPE_sec);
 			if ('\0' != *mlink->fsec)
 				putkey(mpage, mlink->fsec, TYPE_sec);
-			putkey(mpage, mlink->arch, TYPE_arch);
+			putkey(mpage, '\0' == *mlink->arch ?
+			    "any" : mlink->arch, TYPE_arch);
 			putkey(mpage, mlink->name, TYPE_Nm);
 		}
 
diff --git a/mansearch.c b/mansearch.c
index 6db43e4e..a9c7a2d4 100644
--- a/mansearch.c
+++ b/mansearch.c
@@ -135,6 +135,8 @@ static	void		*hash_halloc(size_t, void *);
 static	struct expr	*exprcomp(const struct mansearch *, 
 				int, char *[]);
 static	void		 exprfree(struct expr *);
+static	struct expr	*exprspec(struct expr *, uint64_t,
+				 const char *, const char *);
 static	struct expr	*exprterm(const struct mansearch *, char *, int);
 static	void		 sql_append(char **sql, size_t *sz,
 				const char *newstr, int count);
@@ -142,8 +144,7 @@ static	void		 sql_match(sqlite3_context *context,
 				int argc, sqlite3_value **argv);
 static	void		 sql_regexp(sqlite3_context *context,
 				int argc, sqlite3_value **argv);
-static	char		*sql_statement(const struct expr *,
-				const char *, const char *);
+static	char		*sql_statement(const struct expr *);
 
 int
 mansearch(const struct mansearch *search,
@@ -211,7 +212,7 @@ mansearch(const struct mansearch *search,
 		goto out;
 	}
 
-	sql = sql_statement(e, search->arch, search->sec);
+	sql = sql_statement(e);
 
 	/*
 	 * Loop over the directories (containing databases) for us to
@@ -258,11 +259,6 @@ mansearch(const struct mansearch *search,
 		if (SQLITE_OK != c)
 			fprintf(stderr, "%s\n", sqlite3_errmsg(db));
 
-		if (NULL != search->arch)
-			SQL_BIND_TEXT(db, s, j, search->arch);
-		if (NULL != search->sec)
-			SQL_BIND_TEXT(db, s, j, search->sec);
-
 		for (ep = e; NULL != ep; ep = ep->next) {
 			if (NULL == ep->substr) {
 				SQL_BIND_BLOB(db, s, j, ep->regexp);
@@ -480,7 +476,7 @@ sql_append(char **sql, size_t *sz, const char *newstr, int count)
  * Prepare the search SQL statement.
  */
 static char *
-sql_statement(const struct expr *e, const char *arch, const char *sec)
+sql_statement(const struct expr *e)
 {
 	char		*sql;
 	size_t		 sz;
@@ -489,12 +485,6 @@ sql_statement(const struct expr *e, const char *arch, const char *sec)
 	sql = mandoc_strdup("SELECT * FROM mpages WHERE ");
 	sz = strlen(sql);
 
-	if (NULL != arch)
-		sql_append(&sql, &sz, "arch = ? AND ", 1);
-	if (NULL != sec)
-		sql_append(&sql, &sz, "sec = ? AND ", 1);
-	sql_append(&sql, &sz, "(", 1);
-
 	for (needop = 0; NULL != e; e = e->next) {
 		if (e->and)
 			sql_append(&sql, &sz, " AND ", 1);
@@ -511,7 +501,6 @@ sql_statement(const struct expr *e, const char *arch, const char *sec)
 			sql_append(&sql, &sz, ")", e->close);
 		needop = 1;
 	}
-	sql_append(&sql, &sz, ")", 1);
 
 	return(sql);
 }
@@ -528,7 +517,8 @@ exprcomp(const struct mansearch *search, int argc, char *argv[])
 	struct expr	*first, *next, *cur;
 
 	first = cur = NULL;
-	toopen = logic = igncase = toclose = 0;
+	logic = igncase = toclose = 0;
+	toopen = 1;
 
 	for (i = 0; i < argc; i++) {
 		if (0 == strcmp("(", argv[i])) {
@@ -572,8 +562,15 @@ exprcomp(const struct mansearch *search, int argc, char *argv[])
 			cur = first = next;
 		toopen = logic = igncase = 0;
 	}
-	if ( ! (toopen || logic || igncase || toclose))
-		return(first);
+	if (toopen || logic || igncase || toclose)
+		goto fail;
+
+	cur->close++;
+	cur = exprspec(cur, TYPE_arch, search->arch, "^(%s|any)$");
+	exprspec(cur, TYPE_sec, search->sec, "^%s$");
+
+	return(first);
+
 fail:
 	if (NULL != first)
 		exprfree(first);
@@ -581,11 +578,42 @@ fail:
 }
 
 static struct expr *
+exprspec(struct expr *cur, uint64_t key, const char *value,
+		const char *format)
+{
+	char	 errbuf[BUFSIZ];
+	char	*cp;
+	int	 irc;
+
+	if (NULL == value)
+		return(cur);
+
+	if (-1 == asprintf(&cp, format, value)) {
+		perror(0);
+		exit((int)MANDOCLEVEL_SYSERR);
+	}
+	cur->next = mandoc_calloc(1, sizeof(struct expr));
+	cur = cur->next;
+	cur->and = 1;
+	cur->bits = key;
+	if (0 != (irc = regcomp(&cur->regexp, cp,
+	    REG_EXTENDED | REG_NOSUB | REG_ICASE))) {
+		regerror(irc, &cur->regexp, errbuf, sizeof(errbuf));
+		fprintf(stderr, "regcomp: %s\n", errbuf);
+		cur->substr = value;
+	}
+	free(cp);
+	return(cur);
+}
+
+static struct expr *
 exprterm(const struct mansearch *search, char *buf, int cs)
 {
+	char		 errbuf[BUFSIZ];
 	struct expr	*e;
 	char		*key, *v;
 	size_t		 i;
+	int		 irc;
 
 	if ('\0' == *buf)
 		return(NULL);
@@ -614,8 +642,10 @@ exprterm(const struct mansearch *search, char *buf, int cs)
 		e->bits = search->deftype;
 
 	if ('~' == *v++) {
-		if (regcomp(&e->regexp, v,
-		    REG_EXTENDED | REG_NOSUB | (cs ? 0 : REG_ICASE))) {
+		if (0 != (irc = regcomp(&e->regexp, v,
+		    REG_EXTENDED | REG_NOSUB | (cs ? 0 : REG_ICASE)))) {
+			regerror(irc, &e->regexp, errbuf, sizeof(errbuf));
+			fprintf(stderr, "regcomp: %s\n", errbuf);
 			free(e);
 			return(NULL);
 		}