/* udbg.cpp

This file contains debug helpers that are common for all unix systems. See
udbg_bfd.cpp for the linux-specific stuff (Using BFD and backtrace() for symbol
lookups and backtraces)
*/

#include "precompiled.h"

#include "lib/timer.h"
#include "lib/sysdep/sysdep.h"
#include "lib/debug.h"

#if !OS_LINUX
// udbg stubs implementation. This is what's used on non-linux, so far.
void* debug_get_nth_caller(uint UNUSED(n), void *UNUSED(context))
{
	return NULL;
}

LibError debug_dump_stack(wchar_t* UNUSED(buf), size_t UNUSED(max_chars), uint UNUSED(skip), void* UNUSED(context))
{
	return ERR::NOT_IMPLEMENTED;
}

LibError debug_resolve_symbol(void* UNUSED(ptr_of_interest), char* UNUSED(sym_name), char* UNUSED(file), int* UNUSED(line))
{
	return ERR::NOT_IMPLEMENTED;
}
#endif

void unix_debug_break()
{
	kill(getpid(), SIGTRAP);
}

#define DEBUGGER_WAIT 3
#define DEBUGGER_CMD "gdb"
#define DEBUGGER_ARG_FORMAT "--pid=%d"
#define DEBUGGER_BREAK_AFTER_WAIT 0

/*
Start the debugger and tell it to attach to the current process/thread
(called by display_error)
*/
void udbg_launch_debugger()
{
	pid_t orgpid=getpid();
	pid_t ret=fork();
	if (ret == 0)
	{
		// Child Process: exec() gdb (Debugger), set to attach to old fork
		char buf[16];
		snprintf(buf, 16, DEBUGGER_ARG_FORMAT, orgpid);
		
		int ret=execlp(DEBUGGER_CMD, DEBUGGER_CMD, buf, NULL);
		// In case of success, we should never get here anyway, though...
		if (ret != 0)
		{
			perror("Debugger launch failed");
		}
	}
	else if (ret > 0)
	{
		// Parent (original) fork:
		debug_printf("Sleeping until debugger attaches.\nPlease wait.\n");
		sleep(DEBUGGER_WAIT);
	}
	else // fork error, ret == -1
	{
		perror("Debugger launch: fork failed");
	}
}

void debug_puts(const char* text)
{
	fputs(text, stdout);
	fflush(stdout);
}

// TODO: Do these properly. (I don't know what I'm doing; I just
// know that these functions are required in order to compile...)

int debug_write_crashlog(const char* UNUSED(file), wchar_t* UNUSED(header),
	void* UNUSED(context))
{
	abort();
}

int debug_is_pointer_bogus(const void* UNUSED(p))
{
	return false;
}

void debug_heap_check()
{
}

// if <full_monty> is true or PARANOIA #defined, all possible checks are
// performed as often as possible. this is really slow (we are talking x100),
// but reports errors closer to where they occurred.
void debug_heap_enable(DebugHeapChecks UNUSED(what))
{
	// No-op until we find out if glibc has heap debugging
}

// disable all automatic checks until the next debug_heap_enable.
void debug_heap_disable()
{
	// No-op until we find out if glibc has heap debugging
}