From: Mark Wooding <mdw@distorted.org.uk>
Date: Fri, 9 Aug 2019 10:55:20 +0000 (+0100)
Subject: configure.ac, Makefile.am, pcre.c, regexp.c: Overhaul conditional building.
X-Git-Url: https://git.distorted.org.uk/~mdw/anag/commitdiff_plain/7c2b74abc8bbc3b009a233b65d4f8aa23219892d

configure.ac, Makefile.am, pcre.c, regexp.c: Overhaul conditional building.

Use Automake conditions rather than `#ifdef'.  Use `pkgconfig' to find
PCRE.  Tidy up the code a little.
---

diff --git a/Makefile.am b/Makefile.am
index 6374697..9425a68 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -30,6 +30,11 @@ SUFFIXES		 =
 bin_PROGRAMS		 =
 bin_SCRIPTS		 =
 
+LDADD			 =
+if HAVE_PCRE
+  LDADD			+= $(PCRE_LIBS)
+endif
+
 ###--------------------------------------------------------------------------
 ### Making substitutions.
 
@@ -54,8 +59,12 @@ anag_SOURCES		 = anag.c anag.h util.c
 anag_SOURCES		+= anagram.c
 anag_SOURCES		+= longest.c
 anag_SOURCES		+= mono.c
-anag_SOURCES		+= pcre.c
-anag_SOURCES		+= regexp.c
+if HAVE_PCRE
+  anag_SOURCES		+= pcre.c
+endif
+if HAVE_REGCOMP
+  anag_SOURCES		+= regexp.c
+endif
 anag_SOURCES		+= trackword.c
 anag_SOURCES		+= wildcard.c
 
diff --git a/anag.h b/anag.h
index 0223c54..6763d0f 100644
--- a/anag.h
+++ b/anag.h
@@ -95,8 +95,12 @@ extern node *subgram(const char *const */*av*/);
 extern node *wildcard(const char *const */*av*/);
 extern node *trackword(const char *const */*av*/);
 extern node *mono(const char *const */*av*/);
-extern node *regexp(const char *const */*av*/);
-extern node *pcrenode(const char *const */*av*/);
+#ifdef HAVE_REGCOMP
+  extern node *regexp(const char *const */*av*/);
+#endif
+#ifdef HAVE_PCRE
+  extern node *pcrenode(const char *const */*av*/);
+#endif
 extern node *longest(const char *const */*av*/);
 extern node *shortest(const char *const */*av*/);
 
diff --git a/configure.ac b/configure.ac
index f1cac47..272fe9c 100644
--- a/configure.ac
+++ b/configure.ac
@@ -40,9 +40,15 @@ dnl--------------------------------------------------------------------------
 dnl C programming environment.
 
 AC_CHECK_FUNCS([regcomp])
-
-AC_SEARCH_LIBS([pcre_fullinfo], [pcre],
-  [AC_DEFINE([HAVE_PCRE], [1], [Define if you have libpcre available.])])
+AM_CONDITIONAL([HAVE_REGCOMP], [test $ac_cv_func_regcomp = yes])
+
+mdw_have_pcre2=nil mdw_have_pcre=nil
+PKG_CHECK_MODULES([PCRE], [libpcre],
+  [mdw_have_pcre=t AM_CFLAGS="$AM_CFLAGS $PCRE_CFLAGS"], [])
+AM_CONDITIONAL([HAVE_PCRE], [test $mdw_have_pcre = t])
+case $mdw_have_pcre in
+  t) AC_DEFINE([HAVE_PCRE], [1], [PCRE library is available.]) ;;
+esac
 
 dnl--------------------------------------------------------------------------
 dnl Java.
diff --git a/pcre.c b/pcre.c
index f15e37a..5c5994c 100644
--- a/pcre.c
+++ b/pcre.c
@@ -26,15 +26,8 @@
 
 /*----- Header files ------------------------------------------------------*/
 
-#ifdef HAVE_CONFIG_H
-#  include "config.h"
-#endif
-
-#ifndef HAVE_PCRE
-  extern int dummy;
-#else
-
 #include "anag.h"
+
 #include <pcre.h>
 
 /*----- Data structures ---------------------------------------------------*/
@@ -58,12 +51,9 @@ static int n_pcre(node *nn, const char *p, size_t sz)
   int e;
 
   e = pcre_exec(n->rx, n->rx_study, p, sz, 0, 0, n->ovec, n->ovecsz);
-  if (e >= 0)
-    return (1);
-  if (e == PCRE_ERROR_NOMATCH)
-    return (0);
+  if (e >= 0) return (1);
+  if (e == PCRE_ERROR_NOMATCH) return (0);
   die("unexpected PCRE error code %d", e);
-  return (-1);
 }
 
 /* --- Node creation --- */
@@ -76,17 +66,16 @@ node *pcrenode(const char *const *av)
   int c;
 
   n->n.func = n_pcre;
-  if ((n->rx = pcre_compile(av[0], PCRE_CASELESS, &e, &eo, 0)) == 0)
-    die("bad regular expression `%s': %s", av[0], e);
+
+  n->rx = pcre_compile(av[0], PCRE_CASELESS, &e, &eo, 0);
+  if (!n->rx) die("bad regular expression `%s': %s", av[0], e);
   n->rx_study = pcre_study(n->rx, 0, &e);
-  if (e)
-    die("error studying pattern `%s': %s", av[0], e);
-  pcre_fullinfo(n->rx, n->rx_study, PCRE_INFO_BACKREFMAX, &c);
-  n->ovecsz = c * 2;
-  n->ovec = xmalloc(n->ovecsz * sizeof(*n->ovec));
+  if (e) die("error studying pattern `%s': %s", av[0], e);
+  pcre_fullinfo(n->rx, n->rx_study, PCRE_INFO_CAPTURECOUNT, &c);
+  n->ovecsz = 2*c;
+  n->ovec = xmalloc(n->ovecsz*sizeof(*n->ovec));
+
   return (&n->n);
 }
 
 /*----- That's all, folks -------------------------------------------------*/
-
-#endif
diff --git a/regexp.c b/regexp.c
index c930ea5..cd12f15 100644
--- a/regexp.c
+++ b/regexp.c
@@ -26,15 +26,8 @@
 
 /*----- Header files ------------------------------------------------------*/
 
-#ifdef HAVE_CONFIG_H
-#  include "config.h"
-#endif
-
-#ifndef HAVE_REGCOMP
-  extern int dummy;
-#else
-
 #include "anag.h"
+
 #include <regex.h>
 
 /*----- Data structures ---------------------------------------------------*/
@@ -52,19 +45,17 @@ typedef struct node_regexp {
 static int n_regexp(node *nn, const char *p, size_t sz)
 {
   node_regexp *n = (node_regexp *)nn;
+  char buf[256];
   int e;
 
   switch (e = regexec(&n->rx, p, 0, 0, 0)) {
-    case 0:
-      return 1;
-    case REG_NOMATCH:
-      return 0;
-    default: {
-      char buf[256];
+    case 0: return 1;
+    case REG_NOMATCH: return 0;
+    default:
       regerror(e, &n->rx, buf, sizeof(buf));
       die("error matching regexp `%s' against `%s': %s",
 	  n->s, p, buf);
-    } break;
+      break;
   }
   return (0);
 }
@@ -74,11 +65,12 @@ static int n_regexp(node *nn, const char *p, size_t sz)
 node *regexp(const char *const *av)
 {
   node_regexp *n = xmalloc(sizeof(*n));
+  char buf[256];
   int e;
+
   n->n.func = n_regexp;
   if ((e = regcomp(&n->rx, av[0],
 		   REG_EXTENDED | REG_ICASE | REG_NOSUB)) != 0) {
-    char buf[256];
     regerror(e, &n->rx, buf, sizeof(buf));
     die("bad regular expression `%s': %s", av[0], buf);
   }
@@ -86,5 +78,3 @@ node *regexp(const char *const *av)
 }
 
 /*----- That's all, folks -------------------------------------------------*/
-
-#endif