Refactor the process of choosing validators.

src/trusted/validator/validator_init.c

+/*
+ * 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
+}