Refactor the process of choosing validators.

src/trusted/validator/validator_init.c

Index: src/trusted/validator/validator_init.c
diff --git a/src/trusted/validator/validator_init.c b/src/trusted/validator/validator_init.c
new file mode 100644
index 0000000000000000000000000000000000000000..7ab1eba4a59b9f12aef83b886c56e35ab18bbb70
--- /dev/null
+++ b/src/trusted/validator/validator_init.c
@@ -0,0 +1,43 @@
+/*
+ * Copyright (c) 2012 The Native Client Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "native_client/src/trusted/validator/ncvalidate.h"
+
+int NaClUseDfaValidator() {
+  if (getenv("NACL_DANGEROUS_USE_DFA_VALIDATOR") != NULL) {
+    return 1;
+  }
+  return 0;
+}
+
+const struct NaClValidatorInterface* NaClCreateValidator() {
+#if defined(__arm__)
+  return NaClValidatorCreateArm();
+#elif NACL_ARCH(NACL_TARGET_ARCH) != NACL_x86
+#error("No validator available for this architecture!")
+#elif NACL_TARGET_SUBARCH == 32 && defined(NACL_STANDALONE)
+  if (NaClUseDfaValidator()) {
+    fprintf(stderr, "DANGER! USING THE EXPERIMENTAL DFA VALIDATOR!\n");
+    return NaClDfaValidatorCreate_x86_32();
+  } else {
+    return NaClValidatorCreate_x86_32();
+  }
+#elif NACL_TARGET_SUBARCH == 32
+  return NaClValidatorCreate_x86_32();
+#elif NACL_TARGET_SUBARCH == 64 && defined(NACL_STANDALONE)
+  if (NaClUseDfaValidator()) {
+    fprintf(stderr, "DANGER! USING THE EXPERIMENTAL DFA VALIDATOR!\n");
+    return NaClDfaValidatorCreate_x86_64();
+  } else {
+    return NaClValidatorCreate_x86_64();
+  }
+#elif NACL_TARGET_SUBARCH == 64
+  return NaClValidatorCreate_x86_64();
+#endif
+}