Fix warnings when building jam.

Sorry for the included whitespace cleanup.

jam/execunix.c

@@ -50,6 +50,10 @@
 # include <process.h>
 # endif
 
+# ifdef unix
+# include <unistd.h>
+# endif
+
 # ifdef OS_NT
 # define USE_EXECNT
 # include <process.h>
@@ -231,7 +235,7 @@ execcmd(
 # else
 	if ((pid = vfork()) == 0)
    	{
-	    execvp( argv[0], argv );
+	    execvp( argv[0], (char* const*)argv );
 	    _exit(127);
 	}
 # endif

jam/hcache.c

@@ -42,7 +42,7 @@
  * */
 
 struct hcachedata {
-    char		*boundname;
+    const char	*boundname;
     time_t		time;
     LIST		*includes;
     LIST		*hdrscan; /* the HDRSCAN value for this target */
@@ -70,10 +70,10 @@ static int hits = 0;
  * We cache the result so the user can't change the cache file during
  * header scanning.
  */
-static char*
+static const char*
 cache_name(void)
 {
-    static char* name = 0;
+    static const char* name = 0;
     if (!name) {
 	LIST *hcachevar = var_get("HCACHEFILE");
 
@@ -116,7 +116,7 @@ cache_maxage(void)
  * ASCII 0.  The returned value is as returned by newstr(), so it need
  * not be freed.
  */
-char*
+const char*
 read_netstring(FILE* f)
 {
     unsigned long len;
@@ -168,10 +168,10 @@ void
 hcache_init()
 {
     HCACHEDATA  cachedata, *c;
-    FILE	*f;
-    char	*version;
-    int		header_count = 0;
-    char*	hcachename;
+    FILE		*f;
+    const char	*version;
+    int			header_count = 0;
+    const char*	hcachename;
 
     hcachehash = hashinit (sizeof (HCACHEDATA), "hcache");
 
@@ -189,11 +189,11 @@ hcache_init()
 
     while (1)
     {
-	char* record_type;
-	char *time_str;
-	char *age_str;
-	char *includes_count_str;
-	char *hdrscan_count_str;
+	const char* record_type;
+	const char *time_str;
+	const char *age_str;
+	const char *includes_count_str;
+	const char *hdrscan_count_str;
 	int i, count;
 	LIST *l;
 
@@ -230,7 +230,7 @@ hcache_init()
 
 	count = atoi(includes_count_str);
 	for (l = 0, i = 0; i < count; i++) {
-	    char* s = read_netstring(f);
+	    const char* s = read_netstring(f);
 	    if (!s) {
 		fprintf(stderr, "invalid %s\n", hcachename);
 		goto bail;
@@ -248,7 +248,7 @@ hcache_init()
 
 	count = atoi(hdrscan_count_str);
 	for (l = 0, i = 0; i < count; i++) {
-	    char* s = read_netstring(f);
+	    const char* s = read_netstring(f);
 	    if (!s) {
 		fprintf(stderr, "invalid %s\n", hcachename);
 		goto bail;
@@ -280,11 +280,11 @@ hcache_init()
 void
 hcache_done()
 {
-    FILE	*f;
+    FILE		*f;
     HCACHEDATA  *c;
-    int 	header_count = 0;
-    char*	hcachename;
-    int		maxage;
+    int 		header_count = 0;
+    const char*	hcachename;
+    int			maxage;
 
     if (!hcachehash)
 	return;

jam/pathunix.c

@@ -38,9 +38,7 @@
 
 # ifdef USE_PATHUNIX
 
-# if defined( OS_MACOSX )
-/* need unistd for the prototype for getcwd to avoid defaulting return to int on 64bit */
-/* XXX: others too ? */
+# if defined( unix )
 # include <unistd.h>
 # endif