Add documentation for the dynamic code modifications.

src/trusted/validator_ragel/unreviewed/validator.h

 /*
  * 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.
  */
 
 #ifndef NATIVE_CLIENT_SRC_TRUSTED_VALIDATOR_RAGEL_VALIDATOR_H_
 #define NATIVE_CLIENT_SRC_TRUSTED_VALIDATOR_RAGEL_VALIDATOR_H_
 
 #include "native_client/src/trusted/validator_ragel/unreviewed/decoder.h"
 
 EXTERN_C_BEGIN
 
 enum validation_callback_info {
-  /* validation_error & IMMEDIATES_INFO will give you immediates size.  */
-  IMMEDIATES_SIZE               = 0x0000000f,
+  /* Anyfield info mask: you can use to parse information about anyfields.  */
+  ANYFIELD_INFO_MASK            = 0x000000ff,
   /* Immediate sizes (immediates always come at the end of instruction).  */
+  IMMEDIATES_SIZE_MASK          = 0x0000000f,
   IMMEDIATE_8BIT                = 0x00000001,
   IMMEDIATE_16BIT               = 0x00000002,
   IMMEDIATE_32BIT               = 0x00000004,
   IMMEDIATE_64BIT               = 0x00000008,
   /* Second 8bit immediate is only used in "extrq/insertq" instructions.  */
   SECOND_IMMEDIATE_8BIT         = 0x00000011,
   /* Second 16bit immediate is only used in "enter" instruction.  */
   SECOND_IMMEDIATE_16BIT        = 0x00000012,
   /* Displacement sizes (displacements come at the end - before immediates).  */
+  DISPLACEMENT_SIZE_MASK        = 0x00000060,
   DISPLACEMENT_8BIT             = 0x00000021,
   DISPLACEMENT_16BIT            = 0x00000042,
   DISPLACEMENT_32BIT            = 0x00000064,
   /* Relative size (relative fields always come at the end if instriction).  */
   RELATIVE_8BIT                 = 0x00000081,
   RELATIVE_16BIT                = 0x00000082,
   RELATIVE_32BIT                = 0x00000084,
   /* Not a normal immediate: only two bits can be changed.  */
   IMMEDIATE_2BIT                = 0x20000010,
   /* Last restricted register.  */
   RESTRICTED_REGISTER_MASK      = 0x00001f00,
   RESTRICTED_REGISTER_SHIFT     =          8,
   /* Was restricted from previous instruction used in the current one?  */
   RESTRICTED_REGISTER_USED      = 0x00002000,
   /* Mask to select all validation errors.  */
-  VALIDATION_ERRORS             = 0x03ffc000,
+  VALIDATION_ERRORS_MASK        = 0x03ffc000,
   /* Unrecognized instruction: fatal error, processing stops here.  */
   UNRECOGNIZED_INSTRUCTION      = 0x00004000,
   /* Direct jump to unaligned address outside of given region.  */
   DIRECT_JUMP_OUT_OF_RANGE      = 0x00008000,
   /* Instruction is not allowed on current CPU.  */
   CPUID_UNSUPPORTED_INSTRUCTION = 0x00010000,
   /* Base register can be one of: %r15, %rbp, %rip, %rsp.  */
   FORBIDDEN_BASE_REGISTER       = 0x00020000,
   /* Index must be restricted if present.  */
   UNRESTRICTED_INDEX_REGISTER   = 0x00040000,
@@ skipping 54 matching lines @@
 
 Bool ValidateChunkIA32(const uint8_t *data, size_t size,
                        enum validation_options options,
                        const NaClCPUFeaturesX86 *cpu_features,
                        validation_callback_func user_callback,
                        void *callback_data);
 
 EXTERN_C_END
 
 #endif  /* NATIVE_CLIENT_SRC_TRUSTED_VALIDATOR_RAGEL_VALIDATOR_H_ */