Add default extensions to .include, .library

assemble.c

@@ -502,6 +502,7 @@ O    75                                         .endc
                             return 0;
                         }
 
+                        name = defext (name, "MAC");
                         my_searchenv(name, "INCLUDE", hitfile, sizeof(hitfile));
 
                         if (hitfile[0] == '\0') {
@@ -569,6 +570,7 @@ O    75                                         .endc
                         char            hitfile[FILENAME_MAX];
                         char           *name = getstring_fn(cp, &cp);
 
+                        name = defext (name, "MLB");
                         my_searchenv(name, "MCALL", hitfile, sizeof(hitfile));
 
                         if (hitfile[0]) {

util.c

@@ -314,3 +314,21 @@ void padto(
         *str++ = ' ', needspace--;
     *str = 0;
 }
+
+/* defext adds the supplied extension to the file name if it doesn't
+   already have one.  "ext" is the desired extension, without the
+   period.  The file name must be in a malloc'ed buffer.  The
+   resulting string address is returned. */
+char *defext (char *fn, const char *ext)
+{
+    char *ret;
+    
+    if (strchr (fn, '.'))
+        return fn;
+    ret = realloc (fn, strlen (fn) + strlen (ext) + 2);
+    if (ret == NULL)
+        return ret;
+    strcat (ret, ".");
+    strcat (ret, ext);
+    return ret;
+}

util.h

@@ -87,5 +87,6 @@ void            padto(
 void           *memcheck(
     void *ptr);
 
+char *defext (char *fn, const char *ext);
 
 #endif /* UTIL__H */