Modify enuminsts to be able to communicate matched instructions accross

src/trusted/validator/x86/testing/enuminsts/input_tester.c

Index: src/trusted/validator/x86/testing/enuminsts/input_tester.c
===================================================================
--- src/trusted/validator/x86/testing/enuminsts/input_tester.c	(revision 0)
+++ src/trusted/validator/x86/testing/enuminsts/input_tester.c	(revision 0)
@@ -0,0 +1,213 @@
+/*
+ * 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.
+ */
+
+/*
+ * input_tester.c
+ * Implements a decoder that matches the input enumeration fed into stdin.
+ */
+
+#include "native_client/src/trusted/validator/x86/testing/enuminsts/input_tester.h"
+
+#include <stdio.h>
+#include <string.h>
+
+#include "native_client/src/trusted/validator/types_memory_model.h"
+#include "native_client/src/trusted/validator/x86/ncinstbuffer.h"
+#include "native_client/src/trusted/validator/x86/testing/enuminsts/str_utils.h"
+#include "native_client/src/trusted/validator/x86/testing/enuminsts/text2hex.h"
+
+#define kBufferSize 1024
+
+/* Defines the virtual table for the input decoder. */
+static struct {
+  /* The virtual table that implements this decoder. */
+  NaClEnumeratorDecoder base_;
+  /* The iput text line. */
+  char line_[kBufferSize];
+  /* The number of bytes in the last instruction read from the
+   * input stream.
+   */
+  int num_bytes_;
+  /* The input line number associated with the last instruction
+   * read from the input stream.
+   */
+  int line_number_;
+  /* The specified pc address when parsing. */
+  NaClPcAddress pc_address_;
+  /* The instruction mnemonic, if defined. */
+  char* mnemonic_;
+  /* The instruction arguments, if defined. */
+  char* operands_;
+  /* Buffer used to hold mnemonic name and operands. */
+  char buffer_[kBufferSize];
+  /* Boolean flag defining if we have processed the first
+   * line of input, which specifies how to configure the
+   * the input decoder.
+   */
+  Bool configured_;
+} input_decoder;
+
+/* Defines the function to parse the first instruction in the enumerator
+ * text. Since we are accepting the input that was set up the input
+ * enumeration, there is nothing to do.
+ */
+static void ParseInst(NaClEnumerator* enumerator, int pc_address) {

[Brad Chen, 2012/03/28 17:26:43]

const int pc_address?

What is the enumerator for? It looks like it's getting passed all over the place
in this file but nobody is using it.

[Karl, 2012/03/28 18:25:28]

It is there because of the API expected by callers. The enumerator construct has
data (i.e. the text to parse) that is used by other decoders. Only this decoder,
which circumvents this (because it is acting as a surrogate for a decoder in a
different process). That is why you don't see it being used in this file.

+  input_decoder.pc_address_ = pc_address;
+  input_decoder.mnemonic_ = NULL;
+  input_decoder.operands_ = NULL;
+}
+
+/* Finds the instruction mnemonic, by looking at the end of the
+ * input line. Looks for a comment of the form '#mnemonic operands'
+ */
+static void AssembleDesc(NaClEnumerator* enumerator) {

[Brad Chen, 2012/03/28 17:26:43]

Please make these parameters const if they are not written.

[Karl, 2012/03/28 18:25:28]

At one time, API functions updated the enumerator. However, since this is no
longer true, I'll change the API to assume all parameters are constants.

+  char* desc;
+  char* end;
+  /* Start by looking for description. */
+  desc = (char*) strip(strskip(input_decoder.line_, "#"));
+  if (desc == NULL) {
+    /* Not found, fill in a default value. */
+    input_decoder.mnemonic_ = "???";
+    input_decoder.operands_ = "";
+    return;
+  }
+  /* Copy the description into the buffer, and then extract the needed parts. */
+  cstrncpy(input_decoder.buffer_, desc, kBufferSize);
+  input_decoder.mnemonic_ = input_decoder.buffer_;
+  end = (char*) strfind(input_decoder.buffer_, " ");
+  if (end == NULL) {
+    /* No operands, clean up mnemonic. */
+    rstrip(input_decoder.buffer_);
+    input_decoder.operands_ = "";
+    return;
+  }
+  /* Has mnemonic and operands. Separate out parts. */
+  *end = '\0';
+  input_decoder.operands_ = (char*) strip(end + 1);
+  rstrip(input_decoder.operands_);
+}
+
+/* Finds the instruction mnemonic, by looking at the end of the
+ * input line. Looks for a comment of the form '#mnemonic operands'
+ */
+static const char* GetInstMnemonic(NaClEnumerator* enumerator) {
+  if (input_decoder.mnemonic_ != NULL) return input_decoder.mnemonic_;
+  AssembleDesc(enumerator);
+  return input_decoder.mnemonic_;
+}
+
+/* Finst the instruction operands, by looking at the end of the
+ * input line. Looks for a comment of the form '#mnemonic operands'
+ */
+static const char* GetInstOperandsText(NaClEnumerator* enumerator) {
+  if (input_decoder.operands_ != NULL) return input_decoder.operands_;
+  AssembleDesc(enumerator);
+  return input_decoder.operands_;
+}
+
+
+/* Prints out the disassembled instruction. */
+static void PrintInst(NaClEnumerator* enumerator) {
+  size_t i;
+  const char* desc;
+  size_t num_bytes;
+  printf("   IN: %"NACL_PRIxNaClPcAddressAll": ", input_decoder.pc_address_);
+  for (i = 0; i < input_decoder.num_bytes_; ++i) {
+    printf("%02x ", enumerator->_itext[i]);
+  }
+  for (i = input_decoder.num_bytes_; i < MAX_INST_LENGTH; ++i) {
+    printf("   ");
+  }
+
+  /* Print out decoding if included on the input line. */
+  if (NULL == input_decoder.base_._get_inst_mnemonic_fn) {
+    printf("\n");
+  } else {
+    printf("%s %s\n", GetInstMnemonic(enumerator),
+           GetInstOperandsText(enumerator));
+  }
+}
+
+/* Returns true if the instruction parsed a legal instruction. */
+static Bool IsInstLegal(NaClEnumerator* enumerator) {
+  return TRUE;
+}
+
+static size_t InstLength(NaClEnumerator* enumerator) {
+  return (size_t) input_decoder.num_bytes_;
+}
+
+static void InstallFlag(NaClEnumerator* enumerator,
+                        const char* flag_name,
+                        void* flag_address) {
+}
+
+
+/* Defines the registry function that creates a input decoder, and returns
+ * the decoder to be registered.
+ */
+NaClEnumeratorDecoder* RegisterInputDecoder() {
+  input_decoder.base_._id_name = "in";
+  input_decoder.base_._legal_only = TRUE;
+  input_decoder.base_._parse_inst_fn = ParseInst;
+  input_decoder.base_._inst_length_fn = InstLength;
+  input_decoder.base_._print_inst_fn = PrintInst;
+  /* Initially assume that the input doesn't get information on
+   * mnemonic and operand text. Change (in InstallFlag) above if
+   * specified on command line.
+   */
+  input_decoder.base_._get_inst_mnemonic_fn = NULL;
+  input_decoder.base_._get_inst_num_operands_fn = NULL;
+  input_decoder.base_._get_inst_operands_text_fn = NULL;
+  input_decoder.base_._writes_to_reserved_reg_fn = NULL;
+  input_decoder.base_._is_inst_legal_fn = IsInstLegal;
+  input_decoder.base_._maybe_inst_validates_fn = NULL;
+  input_decoder.base_._segment_validates_fn = NULL;
+  input_decoder.base_._install_flag_fn = InstallFlag;
+  input_decoder.base_._usage_message = "Defines legal instructions from stdin";
+  input_decoder.num_bytes_ = 0;
+  input_decoder.line_number_ = 0;
+  input_decoder.pc_address_ = 0;
+  input_decoder.mnemonic_ = NULL;
+  input_decoder.operands_ = NULL;
+  input_decoder.configured_ = FALSE;
+  return &input_decoder.base_;
+}
+
+int ReadAnInstruction(uint8_t ibytes[NACL_ENUM_MAX_INSTRUCTION_BYTES]) {

[Brad Chen, 2012/03/28 17:26:43]

Would a typedef for this array make this code cleaner?

[Karl, 2012/03/28 18:25:28]

Done.

+  input_decoder.num_bytes_ = 0;
+  while (input_decoder.num_bytes_ == 0) {
+    ++input_decoder.line_number_;
+    if (fgets(input_decoder.line_, kBufferSize, stdin) == NULL) return 0;
+
+    /* If the line specifies that the input has opcode sequences plus
+     * descriptions, then install the virtuals to handle the input.
+     */
+    if (!input_decoder.configured_) {
+      if (input_decoder.line_ ==
+          strstr(input_decoder.line_, "#OPCODEPLUSDESC#")) {
+        input_decoder.base_._get_inst_mnemonic_fn = GetInstMnemonic;
+        input_decoder.base_._get_inst_operands_text_fn = GetInstOperandsText;
+      }
+      input_decoder.configured_ = TRUE;
+    }
+
+    /* If the line is a progress line, print out the corresponding progress
+     * message.
+     */
+    if (input_decoder.line_ == strstr(input_decoder.line_, "#PROGRESS#")) {
+      printf("%s", &input_decoder.line_[strlen("#PROGRESS#")]);
+    }
+
+    /* Finally, convert the input into the corresponding sequence of bytes
+     * that defines the instruction.
+     */
+    input_decoder.num_bytes_ =
+        Text2Bytes(ibytes, input_decoder.line_, "stdin",
+                   input_decoder.line_number_);
+  }
+  return input_decoder.num_bytes_;
+}