validator_ragel: Link into TCB, use under env var

src/trusted/validator_ragel/unreviewed/dfa_validate_32.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.
+ */
+
+/* Implement the ApplyDfaValidator API for the x86-32 architecture. */
+#include <assert.h>
+#include "native_client/src/shared/platform/nacl_log.h"
+#include "native_client/src/trusted/validator/ncvalidate.h"
+#include "native_client/src/trusted/validator/validation_cache.h"
+#include "native_client/src/trusted/validator_ragel/unreviewed/validator.h"
+
+/* Be sure the correct compile flags are defined for this. */
+#if NACL_ARCH(NACL_TARGET_ARCH) != NACL_x86
+# error("Can't compile, target is for x86-32")
+#else
+# if NACL_TARGET_SUBARCH != 32
+#  error("Can't compile, target is for x86-32")
+# endif
+#endif
+
+
+static void ProcessError(const uint8_t *ptr, void *userdata) {
+  UNREFERENCED_PARAMETER(ptr);
+  UNREFERENCED_PARAMETER(userdata);
+}
+
+NaClValidationStatus NACL_SUBARCH_NAME(ApplyDfaValidator, x86, 32) (
+    enum NaClSBKind sb_kind,
+    uintptr_t guest_addr,
+    uint8_t *data,
+    size_t size,
+    int stubout_mode,
+    int readonly_text,
+    const NaClCPUFeaturesX86 *cpu_features,
+    struct NaClValidationCache *cache) {
+  UNREFERENCED_PARAMETER(guest_addr);
+  UNREFERENCED_PARAMETER(readonly_text);

[Nick Bray, 2012/04/19 23:11:08]

I'd check if readonly_text and error if it's requested, see the ARM validator.

[pasko-google - do not use, 2012/04/20 14:30:38]

Done.

+  UNREFERENCED_PARAMETER(cache);
+
+  if (stubout_mode || sb_kind != NACL_SB_DEFAULT) {

[Nick Bray, 2012/04/19 23:11:08]

Keep the checks separate, it makes it easier to refactor.

[pasko-google - do not use, 2012/04/20 14:30:38]

Code should be optimized for readability, not for refactoring pleasures.
Besides, I do not see how your suggestion makes refactoring easier. Do you mean
it would make conflicts more likely? I think returning NotImplemented in one
condition makes the code more clear because the reader does not have to look
through multiple conditionals and hunt for differences in returned codes that
are lengthy words looking similarly.

Not a big deal. If you insist I can put conditions on different lines.

+    return NaClValidationFailedNotImplemented;
+  }
+  if (!NaClArchSupported(cpu_features)) {
+    return NaClValidationFailedCpuNotSupported;
+  }
+  if (!ValidateChunkIA32(data, size, ProcessError, 0)) {

[Nick Bray, 2012/04/19 23:11:08]

Nit: == 0?  This would make it clearer that you're expecting an "error code"
return rather than a true / false return.

[pasko-google - do not use, 2012/04/20 14:30:38]

Good nit. Done.

+    return NaClValidationSucceeded;
+  }
+  return NaClValidationFailed;
+}