/* Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

parcel Lucy;

/** The Debug module provides multiple levels of debugging verbosity.  Code for
 * debug statements is only compiled "#ifdef LUCY_DEBUG" at compile-time.
 * Some statements will then always print; additional output can be enabled
 * using the environment variable LUCY_DEBUG.  Examples:
 *
 *   LUCY_DEBUG=file.C      -> all debug statements in path/file.C
 *   LUCY_DEBUG=func        -> all in functions named exactly 'func'
 *   LUCY_DEBUG=f*          -> all in functions (or files) starting with 'f'
 *   LUCY_DEBUG=file*       -> all in files (or functions) ending with file*'
 *   LUCY_DEBUG=func1,func2 -> either in func1 or in func2
 *   LUCY_DEBUG=*           -> just print all debug statements
 *
 * The wildcard character '*' can only go at the end of an identifier.
 */

inert class Lucy::Util::Debug {

    /** Private function, used only by the DEBUG macros.
     */
    inert void
    print_mess(const char *file, int line, const char *func,
               const char *pat, ...);

    /** Private function, used only by the DEBUG macros.
     */
    inert int
    debug_should_print(const char *path, const char *func);

    /** Force override in cached value of LUCY_DEBUG environment variable.
     */
    inert void
    set_env_cache(char *override);

    /* Under LUCY_DEBUG, track the number of objects allocated, the number
     * freed, and the number of global objects.  If, after all non-global
     * objects should have been cleaned up, these numbers don't balance out,
     * there's a memory leak somewhere.
     */
    inert int32_t num_allocated;
    inert int32_t num_freed;
    inert int32_t num_globals;
}

__C__
#ifdef LUCY_DEBUG

#undef LUCY_DEBUG   // undef prior to redefining the command line argument
#define LUCY_DEBUG_ENABLED 1

#include <stdio.h>
#include <stdlib.h>

/** Unconditionally print debug statement prepending file and line info.
 */
#define LUCY_DEBUG_PRINT(args...)                                         \
    lucy_Debug_print_mess(__FILE__, __LINE__, __func__, ##args)

/** Conditionally execute code if debugging enabled via LUCY_DEBUG environment
 * variable.
 */
#define LUCY_DEBUG_DO(actions)                                            \
    do {                                                                  \
        static int initialized = 0;                                       \
        static int do_it       = 0;                                       \
        if (!initialized) {                                               \
            initialized = 1;                                              \
            do_it = lucy_Debug_debug_should_print(__FILE__, __func__);    \
        }                                                                 \
        if (do_it) { actions; }                                           \
    } while (0)

/** Execute code so long as LUCY_DEBUG was defined during compilation.
 */
#define LUCY_IFDEF_DEBUG(actions) do { actions; } while (0)

/** Conditionally print debug statement depending on LUCY_DEBUG env variable.
 */
#define LUCY_DEBUG(args...)                                            \
        LUCY_DEBUG_DO(LUCY_DEBUG_PRINT(args));

/** Abort on error if test fails.
 *
 * Note: unlike the system assert(), this ASSERT() is #ifdef LUCY_DEBUG.
 */
#define LUCY_ASSERT(test , args...)                                    \
    do {                                                               \
        if (!(test)) {                                                 \
            LUCY_DEBUG_PRINT("ASSERT FAILED (" #test ")\n" args);      \
            abort();                                                   \
        }                                                              \
    } while (0)

#elif defined(CHY_HAS_GNUC_VARIADIC_MACROS) // not LUCY_DEBUG

#undef LUCY_DEBUG
#define LUCY_DEBUG_ENABLED 0
#define LUCY_DEBUG_DO(actions)
#define LUCY_IFDEF_DEBUG(actions)
#define LUCY_DEBUG_PRINT(args...)
#define LUCY_DEBUG(args...)
#define LUCY_ASSERT(test, args...)

#else  // also not LUCY_DEBUG

#undef LUCY_DEBUG
#define LUCY_DEBUG_ENABLED 0
#define LUCY_DEBUG_DO(actions)
#define LUCY_IFDEF_DEBUG(actions)
static void LUCY_DEBUG_PRINT(char *_ignore_me, ...) { }
static void LUCY_DEBUG(char *_ignore_me, ...) { }
static void LUCY_ASSERT(int _ignore_me, ...) { }

#endif // LUCY_DEBUG

#ifdef LUCY_USE_SHORT_NAMES
  #define DEBUG_ENABLED             LUCY_DEBUG_ENABLED
  #define DEBUG_PRINT               LUCY_DEBUG_PRINT
  #define DEBUG_DO                  LUCY_DEBUG_DO
  #define IFDEF_DEBUG               LUCY_IFDEF_DEBUG
  #define DEBUG                     LUCY_DEBUG
  #define ASSERT                    LUCY_ASSERT
#endif
__END_C__