v8/src/utils.cc

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// Copyright 2006-2008 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 "v8.h"
#include "platform.h"
#include "sys/stat.h"
namespace v8 {
namespace internal {
// Implementation is from "Hacker's Delight" by Henry S. Warren, Jr.,
// figure 3-3, page 48, where the function is called clp2.
uint32_t RoundUpToPowerOf2(uint32_t x) {
ASSERT(x <= 0x80000000u);
x = x - 1;
x = x | (x >> 1);
x = x | (x >> 2);
x = x | (x >> 4);
x = x | (x >> 8);
x = x | (x >> 16);
return x + 1;
}
// Thomas Wang, Integer Hash Functions.
// http://www.concentric.net/~Ttwang/tech/inthash.htm
uint32_t ComputeIntegerHash(uint32_t key) {
uint32_t hash = key;
hash = ~hash + (hash << 15); // hash = (hash << 15) - hash - 1;
hash = hash ^ (hash >> 12);
hash = hash + (hash << 2);
hash = hash ^ (hash >> 4);
hash = hash * 2057; // hash = (hash + (hash << 3)) + (hash << 11);
hash = hash ^ (hash >> 16);
return hash;
}
void PrintF(const char* format, ...) {
va_list arguments;
va_start(arguments, format);
OS::VPrint(format, arguments);
va_end(arguments);
}
void Flush() {
fflush(stdout);
}
char* ReadLine(const char* prompt) {
char* result = NULL;
char line_buf[256];
int offset = 0;
bool keep_going = true;
fprintf(stdout, "%s", prompt);
fflush(stdout);
while (keep_going) {
if (fgets(line_buf, sizeof(line_buf), stdin) == NULL) {
// fgets got an error. Just give up.
if (result != NULL) {
DeleteArray(result);
}
return NULL;
}
int len = StrLength(line_buf);
if (len > 1 &&
line_buf[len - 2] == '\\' &&
line_buf[len - 1] == '\n') {
// When we read a line that ends with a "\" we remove the escape and
// append the remainder.
line_buf[len - 2] = '\n';
line_buf[len - 1] = 0;
len -= 1;
} else if ((len > 0) && (line_buf[len - 1] == '\n')) {
// Since we read a new line we are done reading the line. This
// will exit the loop after copying this buffer into the result.
keep_going = false;
}
if (result == NULL) {
// Allocate the initial result and make room for the terminating '\0'
result = NewArray<char>(len + 1);
} else {
// Allocate a new result with enough room for the new addition.
int new_len = offset + len + 1;
char* new_result = NewArray<char>(new_len);
// Copy the existing input into the new array and set the new
// array as the result.
memcpy(new_result, result, offset * kCharSize);
DeleteArray(result);
result = new_result;
}
// Copy the newly read line into the result.
memcpy(result + offset, line_buf, len * kCharSize);
offset += len;
}
ASSERT(result != NULL);
result[offset] = '\0';
return result;
}
char* ReadCharsFromFile(const char* filename,
int* size,
int extra_space,
bool verbose) {
FILE* file = OS::FOpen(filename, "rb");
if (file == NULL || fseek(file, 0, SEEK_END) != 0) {
if (verbose) {
OS::PrintError("Cannot read from file %s.\n", filename);
}
return NULL;
}
// Get the size of the file and rewind it.
*size = ftell(file);
rewind(file);
char* result = NewArray<char>(*size + extra_space);
for (int i = 0; i < *size;) {
int read = static_cast<int>(fread(&result[i], 1, *size - i, file));
if (read <= 0) {
fclose(file);
DeleteArray(result);
return NULL;
}
i += read;
}
fclose(file);
return result;
}
byte* ReadBytes(const char* filename, int* size, bool verbose) {
char* chars = ReadCharsFromFile(filename, size, 0, verbose);
return reinterpret_cast<byte*>(chars);
}
Vector<const char> ReadFile(const char* filename,
bool* exists,
bool verbose) {
int size;
char* result = ReadCharsFromFile(filename, &size, 1, verbose);
if (!result) {
*exists = false;
return Vector<const char>::empty();
}
result[size] = '\0';
*exists = true;
return Vector<const char>(result, size);
}
int WriteCharsToFile(const char* str, int size, FILE* f) {
int total = 0;
while (total < size) {
int write = static_cast<int>(fwrite(str, 1, size - total, f));
if (write == 0) {
return total;
}
total += write;
str += write;
}
return total;
}
int WriteChars(const char* filename,
const char* str,
int size,
bool verbose) {
FILE* f = OS::FOpen(filename, "wb");
if (f == NULL) {
if (verbose) {
OS::PrintError("Cannot open file %s for writing.\n", filename);
}
return 0;
}
int written = WriteCharsToFile(str, size, f);
fclose(f);
return written;
}
int WriteBytes(const char* filename,
const byte* bytes,
int size,
bool verbose) {
const char* str = reinterpret_cast<const char*>(bytes);
return WriteChars(filename, str, size, verbose);
}
StringBuilder::StringBuilder(int size) {
buffer_ = Vector<char>::New(size);
position_ = 0;
}
void StringBuilder::AddString(const char* s) {
AddSubstring(s, StrLength(s));
}
void StringBuilder::AddSubstring(const char* s, int n) {
ASSERT(!is_finalized() && position_ + n < buffer_.length());
ASSERT(static_cast<size_t>(n) <= strlen(s));
memcpy(&buffer_[position_], s, n * kCharSize);
position_ += n;
}
void StringBuilder::AddFormatted(const char* format, ...) {
ASSERT(!is_finalized() && position_ < buffer_.length());
va_list args;
va_start(args, format);
int n = OS::VSNPrintF(buffer_ + position_, format, args);
va_end(args);
if (n < 0 || n >= (buffer_.length() - position_)) {
position_ = buffer_.length();
} else {
position_ += n;
}
}
void StringBuilder::AddPadding(char c, int count) {
for (int i = 0; i < count; i++) {
AddCharacter(c);
}
}
char* StringBuilder::Finalize() {
ASSERT(!is_finalized() && position_ < buffer_.length());
buffer_[position_] = '\0';
// Make sure nobody managed to add a 0-character to the
// buffer while building the string.
ASSERT(strlen(buffer_.start()) == static_cast<size_t>(position_));
position_ = -1;
ASSERT(is_finalized());
return buffer_.start();
}
int TenToThe(int exponent) {
ASSERT(exponent <= 9);
ASSERT(exponent >= 1);
int answer = 10;
for (int i = 1; i < exponent; i++) answer *= 10;
return answer;
}
} } // namespace v8::internal