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() {

[Nick Bray, 2012/05/22 23:46:31]

Name: NaClGetValidatorInterface?  "Create" seems wrong.

[pasko-google - do not use, 2012/05/23 14:28:11]

I want to emphasize that this needs to be called only once on program startup
since it may one time have side effects like memory allocation. Also, checking
an environment variable is not something we want to do prior to every validation
step.

The prefix "Create" makes a nice hint about possible unpleasant side effects.

+#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
+}