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..ce38bfb19d2fe5bcaa016ea578bf46377a46179b
--- /dev/null
+++ b/src/trusted/validator/validator_init.c
@@ -0,0 +1,41 @@
+/*
+ * 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 "native_client/src/shared/platform/nacl_log.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 NACL_ARCH(NACL_BUILD_ARCH) == NACL_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()) {
+    NaClLog(LOG_WARNING, "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()) {
+    NaClLog(LOG_WARNING, "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
+}