gc.c: unit suffix

* gc.c (get_envparam_size): accept unit suffix 'k', 'm', and 'g'.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@44936 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

gc.c

@@ -5663,16 +5663,39 @@ get_envparam_size(const char *name, size_t *default_value, size_t lower_bound)
     ssize_t val;
 
     if (ptr != NULL && *ptr) {
+	size_t unit = 0;
 	char *end;
 #if SIZEOF_SIZE_T == SIZEOF_LONG_LONG
 	val = strtoll(ptr, &end, 0);
 #else
 	val = strtol(ptr, &end, 0);
 #endif
-	if (!*ptr || *end) {
+	switch (*end) {
+	  case 'k': case 'K':
+	    unit = 1024;
+	    ++end;
+	    break;
+	  case 'm': case 'M':
+	    unit = 1024*1024;
+	    ++end;
+	    break;
+	  case 'g': case 'G':
+	    unit = 1024*1024*1024;
+	    ++end;
+	    break;
+	}
+	while (*end && isspace(*end)) end++;
+	if (*end) {
 	    if (RTEST(ruby_verbose)) fprintf(stderr, "invalid string for %s: %s\n", name, ptr);
 	    return 0;
 	}
+	if (unit > 0) {
+	    if (val < -(ssize_t)(SIZE_MAX / 2 / unit) || (ssize_t)(SIZE_MAX / 2 / unit) < val) {
+		if (RTEST(ruby_verbose)) fprintf(stderr, "%s=%s is ignored because it overflows\n", name, ptr);
+		return 0;
+	    }
+	    val *= unit;
+	}
 	if (val > 0 && (size_t)val > lower_bound) {
 	    if (RTEST(ruby_verbose)) {
 		fprintf(stderr, "%s=%"PRIdSIZE" (default value: %"PRIdSIZE")\n", name, val, *default_value);