Working stand-alone preparser.

preparser/preparser-process.cc

+// Copyright 2010 the V8 project authors. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+//       notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+//       copyright notice, this list of conditions and the following
+//       disclaimer in the documentation and/or other materials provided
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#include <stdarg.h>
+#include "../include/v8stdint.h"
+#include "globals.h"
+#include "checks.h"
+#include "allocation.h"
+#include "utils.h"
+#include "list.h"
+#include "smart-pointer.h"
+#include "scanner-base.h"
+#include "preparse-data.h"
+#include "preparser.h"
+
+enum ResultCode { kSuccess = 0, kErrorReading = 1, kErrorWriting = 2 };
+
+namespace v8 {
+namespace internal {
+
+// THIS FILE IS PROOF-OF-CONCEPT ONLY.
+// The final goal is a stand-alone preparser library.
+
+// UTF16Buffer based on an UTF-8 string in memory.
+class UTF8UTF16Buffer : public UTF16Buffer {
+ public:
+  UTF8UTF16Buffer(uint8_t* buffer, size_t length)
+      : UTF16Buffer(),
+        buffer_(buffer),
+        offset_(0),
+        end_offset_(static_cast<int>(length)) { }
+
+  virtual void PushBack(uc32 ch) {
+    // Pushback assumes that the character pushed back is the
+    // one that was most recently read, and jumps back in the
+    // UTF-8 stream by the length of that character's encoding.
+    offset_ -= unibrow::Utf8::Length(ch);
+    pos_--;
+#ifdef DEBUG
+    int tmp = 0;
+    ASSERT_EQ(ch, unibrow::Utf8::ValueOf(buffer_ + offset_,
+                                         end_offset_ - offset_,
+                                         &tmp);
+#endif
+  }
+
+  virtual uc32 Advance() {
+    if (offset_ == end_offset_) return -1;
+    uint8_t first_char = buffer_[offset_];
+    if (first_char <= unibrow::Utf8::kMaxOneByteChar) {
+      pos_++;
+      offset_++;
+      return static_cast<uc32>(first_char);
+    }
+    unibrow::uchar codepoint =
+        unibrow::Utf8::CalculateValue(buffer_ + offset_,
+                                      end_offset_ - offset_,
+                                      &offset_);
+    pos_++;
+    return static_cast<uc32>(codepoint);
+  }
+
+  virtual void SeekForward(int pos) {
+    while (pos_ < pos) {
+      uint8_t first_byte = buffer_[offset_++];
+      while (first_byte & 0x80u && offset_ < end_offset_) {
+        offset_++;
+        first_byte <<= 1;
+      }
+      pos_++;
+    }
+  }
+
+ private:
+  const uint8_t* buffer_;
+  unsigned offset_;
+  unsigned end_offset_;
+};
+
+
+class StandAloneJavaScriptScanner : public JavaScriptScanner {
+ public:
+  void Initialize(UTF16Buffer* source) {
+    source_ = source;
+    literal_flags_ = kLiteralString | kLiteralIdentifier;
+    Init();
+    // Skip initial whitespace allowing HTML comment ends just like
+    // after a newline and scan first token.
+    has_line_terminator_before_next_ = true;
+    SkipWhiteSpace();
+    Scan();
+  }
+};
+
+
+// Write a number to dest in network byte order.
+void WriteUInt32(FILE* dest, uint32_t value, bool* ok) {
+  for (int i = 3; i >= 0; i--) {
+    uint8_t byte = static_cast<uint8_t>(value >> (i << 3));
+    int result = fputc(byte, dest);
+    if (result == EOF) {
+      *ok = false;
+      return;
+    }
+  }
+}
+
+// Read number from FILE* in network byte order.
+uint32_t ReadUInt32(FILE* source, bool* ok) {
+  uint32_t n = 0;
+  for (int i = 0; i < 4; i++) {
+    int c = fgetc(source);
+    if (c == EOF) {
+      *ok = false;
+      return 0;
+    }
+    n = (n << 8) + static_cast<uint32_t>(c);
+  }
+  return n;
+}
+
+
+bool ReadBuffer(FILE* source, void* buffer, size_t length) {
+  size_t actually_read = fread(buffer, 1, length, stdin);
+  return (actually_read == length);
+}
+
+
+bool WriteBuffer(FILE* dest, void* buffer, size_t length) {
+  size_t actually_written = fwrite(buffer, 1, length, dest);
+  return (actually_written == length);
+}
+
+// Preparse stdin and output result on stdout.
+int PreParseIO() {
+  fprintf(stderr, "LOG: Enter parsing loop\n");
+  bool ok = true;
+  uint32_t length = ReadUInt32(stdin, &ok);
+  if (!ok) return kErrorReading;
+  SmartPointer<byte> buffer(NewArray<byte>(length));
+  if (!ReadBuffer(stdin, *buffer, length)) {
+    return kErrorReading;
+  }
+  UTF8UTF16Buffer input_buffer(*buffer, static_cast<size_t>(length));
+  StandAloneJavaScriptScanner scanner;
+  scanner.Initialize(&input_buffer);
+  CompleteParserRecorder recorder;
+  preparser::PreParser preparser;
+
+  if (!preparser.PreParseProgram(&scanner, &recorder, true)) {
+    if (scanner.stack_overflow()) {
+      // Report stack overflow error/no-preparser-data.
+      WriteUInt32(stdout, 0, &ok);
+      if (!ok) return kErrorWriting;
+      return 0;
+    }
+  }
+  Vector<unsigned> pre_data = recorder.ExtractData();
+
+  uint32_t size = static_cast<uint32_t>(pre_data.length() * sizeof(uint32_t));
+  WriteUInt32(stdout, size, &ok);
+  if (!ok) return kErrorWriting;
+  if (!WriteBuffer(stdout,
+                   reinterpret_cast<byte*>(pre_data.start()),
+                   size)) {
+    return kErrorWriting;
+  }
+  return 0;
+}
+
+// Functions declared by allocation.h
+
+void FatalProcessOutOfMemory(const char* location) {
+  V8_Fatal("", 0, location);
+}
+
+bool EnableSlowAsserts() { return true; }
+
+} }  // namespace v8::internal
+
+
+int main(int argc, char* argv[]) {
+  int status = 0;
+  do {
+    status = v8::internal::PreParseIO();
+  } while (status == 0);
+  fprintf(stderr, "EXIT: Failure %d\n", status);
+  return EXIT_FAILURE;
+}
+
+
+// Fatal error handling declared by checks.h.
+
+extern "C" void V8_Fatal(const char* file, int line, const char* format, ...) {
+  fflush(stdout);
+  fflush(stderr);
+  va_list arguments;
+  va_start(arguments, format);
+  vfprintf(stderr, format, arguments);
+  va_end(arguments);
+  fputs("\n#\n\n", stderr);
+  exit(EXIT_FAILURE);
+}