/*

 * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 *

 */

#include "precompiled.hpp"

#include "compiler/methodMatcher.hpp"

#include "memory/oopFactory.hpp"

#include "oops/oop.inline.hpp"

// The JVM specification defines the allowed characters.

// Tokens that are disallowed by the JVM specification can have

// a meaning to the parser so we need to include them here.

// The parser does not enforce all rules of the JVMS - a successful parse

// does not mean that it is an allowed name. Illegal names will

// be ignored since they never can match a class or method.

//

// '\0' and 0xf0-0xff are disallowed in constant string values

// 0x20 ' ', 0x09 '\t' and, 0x2c ',' are used in the matching

// 0x5b '[' and 0x5d ']' can not be used because of the matcher

// 0x28 '(' and 0x29 ')' are used for the signature

// 0x2e '.' is always replaced before the matching

// 0x2f '/' is only used in the class name as package separator

#define RANGEBASE "\x1\x2\x3\x4\x5\x6\x7\x8\xa\xb\xc\xd\xe\xf" \

    "\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f" \

    "\x21\x22\x23\x24\x25\x26\x27\x2a\x2b\x2c\x2d" \

    "\x30\x31\x32\x33\x34\x35\x36\x37\x38\x39\x3a\x3b\x3c\x3d\x3e\x3f" \

    "\x40\x41\x42\x43\x44\x45\x46\x47\x48\x49\x4a\x4b\x4c\x4d\x4e\x4f" \

    "\x50\x51\x52\x53\x54\x55\x56\x57\x58\x59\x5a\x5c\x5e\x5f" \

    "\x60\x61\x62\x63\x64\x65\x66\x67\x68\x69\x6a\x6b\x6c\x6d\x6e\x6f" \

    "\x70\x71\x72\x73\x74\x75\x76\x77\x78\x79\x7a\x7b\x7c\x7d\x7e\x7f" \

    "\x80\x81\x82\x83\x84\x85\x86\x87\x88\x89\x8a\x8b\x8c\x8d\x8e\x8f" \

    "\x90\x91\x92\x93\x94\x95\x96\x97\x98\x99\x9a\x9b\x9c\x9d\x9e\x9f" \

    "\xa0\xa1\xa2\xa3\xa4\xa5\xa6\xa7\xa8\xa9\xaa\xab\xac\xad\xae\xaf" \

    "\xb0\xb1\xb2\xb3\xb4\xb5\xb6\xb7\xb8\xb9\xba\xbb\xbc\xbd\xbe\xbf" \

    "\xc0\xc1\xc2\xc3\xc4\xc5\xc6\xc7\xc8\xc9\xca\xcb\xcc\xcd\xce\xcf" \

    "\xd0\xd1\xd2\xd3\xd4\xd5\xd6\xd7\xd8\xd9\xda\xdb\xdc\xdd\xde\xdf" \

    "\xe0\xe1\xe2\xe3\xe4\xe5\xe6\xe7\xe8\xe9\xea\xeb\xec\xed\xee\xef"

#define RANGE0 "[*" RANGEBASE "]"

#define RANGESLASH "[*" RANGEBASE "/]"

MethodMatcher::MethodMatcher():

    _class_mode(Exact)

  , _method_mode(Exact)

  , _class_name(NULL)

  , _method_name(NULL)

  , _signature(NULL) {

}

MethodMatcher::~MethodMatcher() {

  if (_class_name != NULL) {

    _class_name->decrement_refcount();

  }

  if (_method_name != NULL) {

    _method_name->decrement_refcount();

  }

  if (_signature != NULL) {

    _signature->decrement_refcount();

  }

}

void MethodMatcher::init(Symbol* class_name, Mode class_mode,

                             Symbol* method_name, Mode method_mode,

                             Symbol* signature) {

 _class_mode = class_mode;

 _method_mode = method_mode;

 _class_name = class_name;

 _method_name = method_name;

 _signature = signature;

}

bool MethodMatcher::canonicalize(char * line, const char *& error_msg) {

  char* colon = strstr(line, "::");

  bool have_colon = (colon != NULL);

  if (have_colon) {

    // Don't allow multiple '::'

    if (colon + 2 != '\0') {

      if (strstr(colon+2, "::")) {

        error_msg = "Method pattern only allows one '::' allowed";

        return false;

      }

    }

    bool in_signature = false;

    char* pos = line;

    if (pos != NULL) {

      for (char* lp = pos + 1; *lp != '\0'; lp++) {

        if (*lp == '(') {

          break;

        }

        if (*lp == '/') {

          error_msg = "Method pattern uses '/' together with '::'";

          return false;

        }

      }

    }

  } else {

    // Don't allow mixed package separators

    char* pos = strchr(line, '.');

    bool in_signature = false;

    if (pos != NULL) {

      for (char* lp = pos + 1; *lp != '\0'; lp++) {

        if (*lp == '(') {

          in_signature = true;

        }

        // After any comma the method pattern has ended

        if (*lp == ',') {

          break;

        }

        if (!in_signature && (*lp == '/')) {

          error_msg = "Method pattern uses mixed '/' and '.' package separators";

          return false;

        }

        if (*lp == '.') {

          error_msg = "Method pattern uses multiple '.' in pattern";

          return false;

        }

      }

    }

  }

  for (char* lp = line; *lp != '\0'; lp++) {

    // Allow '.' to separate the class name from the method name.

    // This is the preferred spelling of methods:

    //      exclude java/lang/String.indexOf(I)I

    // Allow ',' for spaces (eases command line quoting).

    //      exclude,java/lang/String.indexOf

    // For backward compatibility, allow space as separator also.

    //      exclude java/lang/String indexOf

    //      exclude,java/lang/String,indexOf

    // For easy cut-and-paste of method names, allow VM output format

    // as produced by Method::print_short_name:

    //      exclude java.lang.String::indexOf

    // For simple implementation convenience here, convert them all to space.

    if (have_colon) {

      if (*lp == '.')  *lp = '/';   // dots build the package prefix

      if (*lp == ':')  *lp = ' ';

    }

    if (*lp == ',' || *lp == '.')  *lp = ' ';

  }

  return true;

}

bool MethodMatcher::match(Symbol* candidate, Symbol* match, Mode match_mode) const {

  if (match_mode == Any) {

    return true;

  }

  if (match_mode == Exact) {

    return candidate == match;

  }

  ResourceMark rm;

  const char * candidate_string = candidate->as_C_string();

  const char * match_string = match->as_C_string();

  switch (match_mode) {

  case Prefix:

    return strstr(candidate_string, match_string) == candidate_string;

  case Suffix: {

    size_t clen = strlen(candidate_string);

    size_t mlen = strlen(match_string);

    return clen >= mlen && strcmp(candidate_string + clen - mlen, match_string) == 0;

  }

  case Substring:

    return strstr(candidate_string, match_string) != NULL;

  default:

    return false;

  }

}

static MethodMatcher::Mode check_mode(char name[], const char*& error_msg) {

  int match = MethodMatcher::Exact;

  if (name[0] == '*') {

    if (strlen(name) == 1) {

      return MethodMatcher::Any;

    }

    match |= MethodMatcher::Suffix;

    memmove(name, name + 1, strlen(name + 1) + 1);

  }

  size_t len = strlen(name);

  if (len > 0 && name[len - 1] == '*') {

    match |= MethodMatcher::Prefix;

    name[--len] = '\0';

  }

  if (strlen(name) == 0) {

    error_msg = "** Not a valid pattern";

    return MethodMatcher::Any;

  }

  if (strstr(name, "*") != NULL) {

    error_msg = " Embedded * not allowed";

    return MethodMatcher::Unknown;

  }

  return (MethodMatcher::Mode)match;

}

// Skip any leading spaces

void skip_leading_spaces(char*& line, int* total_bytes_read ) {

  int bytes_read = 0;

  sscanf(line, "%*[ \t]%n", &bytes_read);

  if (bytes_read > 0) {

    line += bytes_read;

    *total_bytes_read += bytes_read;

  }

}

void MethodMatcher::parse_method_pattern(char*& line, const char*& error_msg, MethodMatcher* matcher) {

  MethodMatcher::Mode c_match;

  MethodMatcher::Mode m_match;

  char class_name[256] = {0};

  char method_name[256] = {0};

  char sig[1024] = {0};

  int bytes_read = 0;

  int total_bytes_read = 0;

  assert(error_msg == NULL, "Dont call here with error_msg already set");

  if (!MethodMatcher::canonicalize(line, error_msg)) {

    assert(error_msg != NULL, "Message must be set if parsing failed");

    return;

  }

  skip_leading_spaces(line, &total_bytes_read);

  if (2 == sscanf(line, "%255" RANGESLASH "%*[ ]" "%255"  RANGE0 "%n", class_name, method_name, &bytes_read)) {

    c_match = check_mode(class_name, error_msg);

    m_match = check_mode(method_name, error_msg);

    if ((strchr(class_name, '<') != NULL) || (strchr(class_name, '>') != NULL)) {

      error_msg = "Chars '<' and '>' not allowed in class name";

      return;

    }

    if ((strchr(method_name, '<') != NULL) || (strchr(method_name, '>') != NULL)) {

      if ((strncmp("<init>", method_name, 255) != 0) && (strncmp("<clinit>", method_name, 255) != 0)) {

        error_msg = "Chars '<' and '>' only allowed in <init> and <clinit>";

        return;

      }

    }

    if (c_match == MethodMatcher::Unknown || m_match == MethodMatcher::Unknown) {

      assert(error_msg != NULL, "Must have been set by check_mode()");

      return;

    }

    EXCEPTION_MARK;

    Symbol* signature = NULL;

    line += bytes_read;

    bytes_read = 0;

    skip_leading_spaces(line, &total_bytes_read);

    // there might be a signature following the method.

    // signatures always begin with ( so match that by hand

    if (line[0] == '(') {

      line++;

      sig[0] = '(';

      // scan the rest

      if (1 == sscanf(line, "%254[[);/" RANGEBASE "]%n", sig+1, &bytes_read)) {

        if (strchr(sig, '*') != NULL) {

          error_msg = " Wildcard * not allowed in signature";

          return;

        }

        line += bytes_read;

      }

      signature = SymbolTable::new_symbol(sig, CHECK);

    }

    Symbol* c_name = SymbolTable::new_symbol(class_name, CHECK);

    Symbol* m_name = SymbolTable::new_symbol(method_name, CHECK);

    matcher->init(c_name, c_match, m_name, m_match, signature);

    return;

  } else {

    error_msg = "Could not parse method pattern";

  }

}

bool MethodMatcher::matches(methodHandle method) const {

  Symbol* class_name  = method->method_holder()->name();

  Symbol* method_name = method->name();

  Symbol* signature = method->signature();

  if (match(class_name, this->class_name(), _class_mode) &&

      match(method_name, this->method_name(), _method_mode) &&

      ((this->signature() == NULL) || match(signature, this->signature(), Prefix))) {

    return true;

  }

  return false;

}

void MethodMatcher::print_symbol(outputStream* st, Symbol* h, Mode mode) {

  ResourceMark rm;

  if (mode == Suffix || mode == Substring || mode == Any) {

    st->print("*");

  }

  if (mode != Any) {

    h->print_symbol_on(st);

  }

  if (mode == Prefix || mode == Substring) {

    st->print("*");

  }

}

void MethodMatcher::print_base(outputStream* st) {

  print_symbol(st, class_name(), _class_mode);

  st->print(".");

  print_symbol(st, method_name(), _method_mode);

  if (signature() != NULL) {

    signature()->print_symbol_on(st);

  }

}