//===========================================================================//
// Copyright (C) Microsoft Corporation. All rights reserved.                 //
//===========================================================================//
//***************************************************************************
//
//								ABLEXEC.CPP
//
//***************************************************************************

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

#ifndef ABLGEN_H
#include "ablgen.h"
#endif

#ifndef ABLERR_H
#include "ablerr.h"
#endif

#ifndef ABLSCAN_H
#include "ablscan.h"
#endif

#ifndef ABLEXEC_H
#include "ablexec.h"
#endif

#ifndef ABLDBUG_H
#include "abldbug.h"
#endif

//***************************************************************************

//--------
// GLOBALS
char*					codeBuffer = NULL;
char*					codeBufferPtr = NULL;
char*					codeSegmentPtr = NULL;
char*					codeSegmentLimit = NULL;
char*					statementStartPtr = NULL;

TokenCodeType			codeToken;
long					execLineNumber;
long					execStatementCount = 0;

StackItem*				stack = NULL;
StackItemPtr			tos = NULL;
StackItemPtr			stackFrameBasePtr = NULL;
StackItemPtr			StaticDataPtr = NULL;
long*					StaticVariablesSizes = NULL;
long*					EternalVariablesSizes = NULL;
long					eternalOffset = 0;
long					MaxStaticVariables = 0;
long					MaxEternalVariables = 0;
long					NumStaticVariables = 0;
long					NumOrderCalls = 1;
long					NumStateHandles = 0;
StateHandleInfo			StateHandleList[MAX_STATE_HANDLES_PER_MODULE];
long					CurModuleHandle = 0;
long					MaxCodeBufferSize = 0;
bool					CallModuleInit = false;
bool					AutoReturnFromOrders = false;
long					MaxLoopIterations = 100001;
bool					AssertEnabled = false;
bool					PrintEnabled = true;
bool					StringFunctionsEnabled = true;
bool					DebugCodeEnabled = false;
bool					IncludeDebugInfo = true;
bool					ProfileABL = false;
bool					Crunch = true;

char					SetStateDebugStr[256];

//----------
// EXTERNALS

extern SymTableNodePtr	CurRoutineIdPtr;

extern ModuleEntryPtr	ModuleRegistry;
extern ABLModulePtr*	ModuleInstanceRegistry;
extern ABLModulePtr		CurModule;
extern ABLModulePtr		CurLibrary;
extern long				NumStateTransitions;

extern TokenCodeType	curToken;
extern long				lineNumber;
extern long				FileNumber;
extern long				level;
extern TypePtr			IntegerTypePtr;
extern TypePtr			CharTypePtr;
extern TypePtr			RealTypePtr;
extern TypePtr			BooleanTypePtr;

extern StackItem		returnValue;

extern bool				ExitWithReturn;
extern bool				ExitFromTacOrder;

extern DebuggerPtr		debugger;
extern bool				NewStateSet;

extern void (*ABLEndlessStateCallback) (UserFile* log);

//***************************************************************************
// CRUNCH/DECRUNCH routines
//***************************************************************************

void crunchToken (void) {

	if (!Crunch)
		return;

	if (codeBufferPtr >= (codeBuffer + MaxCodeBufferSize - 100))
		syntaxError(ABL_ERR_SYNTAX_CODE_SEGMENT_OVERFLOW);
	else {
		*codeBufferPtr = curToken;
		codeBufferPtr++;
	}
}

//***************************************************************************

void crunchSymTableNodePtr (SymTableNodePtr nodePtr) {

	if (!Crunch)
		return;

	if (codeBufferPtr >= (codeBuffer + MaxCodeBufferSize - 100))
		syntaxError(ABL_ERR_SYNTAX_CODE_SEGMENT_OVERFLOW);
	else {
		SymTableNodePtr* nodePtrPtr = (SymTableNodePtr*)codeBufferPtr;
		*nodePtrPtr = nodePtr;
		codeBufferPtr += sizeof(SymTableNodePtr);
	}
}

//***************************************************************************

void crunchStatementMarker (void) {

	if (!Crunch)
		return;

	if (codeBufferPtr >= (codeBuffer + MaxCodeBufferSize - 100))
		syntaxError(ABL_ERR_SYNTAX_CODE_SEGMENT_OVERFLOW);
	else {
		char saveCode = *(--codeBufferPtr);
		*codeBufferPtr = (char)TKN_STATEMENT_MARKER;
		codeBufferPtr++;
		if (IncludeDebugInfo) {
			*((unsigned char*)codeBufferPtr) = (unsigned char)FileNumber;
			codeBufferPtr += sizeof(unsigned char);
			*((long*)codeBufferPtr) = lineNumber;
			codeBufferPtr += sizeof(long);
		}
		*codeBufferPtr = saveCode;
		codeBufferPtr++;
	}
}

//***************************************************************************

void uncrunchStatementMarker (void) {

	//-------------------------
	// Pull code off the buffer
	codeBufferPtr--;
	//-------------------------------
	// Pull debug info off the buffer
	if (IncludeDebugInfo)
		codeBufferPtr -= (sizeof(unsigned char) + sizeof(long));
	//-------------------------------------
	// Pull statement marker off the buffer
	codeBufferPtr--;
}

//***************************************************************************

char* crunchAddressMarker (Address address) {

	if (!Crunch)
		return(NULL);

	char* saveCodeBufferPtr = NULL;

	if (codeBufferPtr >= (codeBuffer + MaxCodeBufferSize - 100))
		syntaxError(ABL_ERR_SYNTAX_CODE_SEGMENT_OVERFLOW);
	else {
		char saveCode = *(--codeBufferPtr);
		*codeBufferPtr = (char)TKN_ADDRESS_MARKER;
		codeBufferPtr++;
		saveCodeBufferPtr = codeBufferPtr;
		*((Address*)codeBufferPtr) = address;
		codeBufferPtr += sizeof(Address);
		*codeBufferPtr = saveCode;
		codeBufferPtr++;
	}

	return(saveCodeBufferPtr);
}

//***************************************************************************

char* fixupAddressMarker (Address address) {

	if (!Crunch)
		return(NULL);

	char* oldAddress = *((Address*)address);

	*((long*)address) = codeBufferPtr - address;
	return(oldAddress);
}

//***************************************************************************

void crunchInteger (long value) {

	if (!Crunch)
		return;

	if (codeBufferPtr >= (codeBuffer + MaxCodeBufferSize - 100))
		syntaxError(ABL_ERR_SYNTAX_CODE_SEGMENT_OVERFLOW);
	else {
		*((long*)codeBufferPtr) = value;
		codeBufferPtr += sizeof(long);
	}
}

//***************************************************************************

void crunchByte (unsigned char value) {

	if (!Crunch)
		return;

	if (codeBufferPtr >= (codeBuffer + MaxCodeBufferSize - 100))
		syntaxError(ABL_ERR_SYNTAX_CODE_SEGMENT_OVERFLOW);
	else {
		*((unsigned char*)codeBufferPtr) = value;
		codeBufferPtr += sizeof(unsigned char);
	}
}

//***************************************************************************

void crunchOffset (Address address) {

	if (!Crunch)
		return;

	if (codeBufferPtr >= (codeBuffer + MaxCodeBufferSize - 100))
		syntaxError(ABL_ERR_SYNTAX_CODE_SEGMENT_OVERFLOW);
	else {
		*((long*)codeBufferPtr) = address - codeBufferPtr;
		codeBufferPtr += sizeof(long);
	}
}

//***************************************************************************

char* createCodeSegment (long& codeSegmentSize) {

	codeSegmentSize = codeBufferPtr - codeBuffer + 1;
	char* codeSegment = (char*)ABLCodeMallocCallback(codeSegmentSize);
	if (!codeSegment)
		ABL_Fatal(0, " ABL: Unable to AblCodeHeap->malloc code segment ");

	for (long i = 0; i < codeSegmentSize; i++)
		codeSegment[i] = codeBuffer[i];

	codeBufferPtr = codeBuffer;
	return(codeSegment);
}

//***************************************************************************

SymTableNodePtr getCodeSymTableNodePtr (void) {

	SymTableNodePtr* nodePtrPtr = (SymTableNodePtr*)codeSegmentPtr;

	SymTableNodePtr nodePtr = *nodePtrPtr;
	codeSegmentPtr += sizeof(SymTableNodePtr);
	return(nodePtr);
}

//***************************************************************************

long getCodeStatementMarker (void) {

	//------------------------------------------
	// NOTE: If there's a problem, we return -1.

	long lineNum = -1;
	if (codeToken == TKN_STATEMENT_MARKER) {
		if (IncludeDebugInfo) {
			FileNumber = *((unsigned char*)codeSegmentPtr);
			codeSegmentPtr += sizeof(unsigned char);
			lineNum = *((long*)codeSegmentPtr);
			codeSegmentPtr += sizeof(long);
		}
	}
	return(lineNum);
}

//***************************************************************************

char* getCodeAddressMarker (void) {

	Address address = NULL;

	if (codeToken == TKN_ADDRESS_MARKER) {
		address = *((long*)codeSegmentPtr) + codeSegmentPtr - 1;
		codeSegmentPtr += sizeof(Address);
	}
	return(address);
}

//***************************************************************************

long getCodeInteger (void) {

	long value = *((long*)codeSegmentPtr);
	codeSegmentPtr += sizeof(long);
	return(value);
}

//***************************************************************************

unsigned char getCodeByte (void) {

	unsigned char value = *((unsigned char*)codeSegmentPtr);
	codeSegmentPtr += sizeof(unsigned char);
	return(value);
}

//***************************************************************************

char* getCodeAddress (void) {

	Address address = *((long*)codeSegmentPtr) + codeSegmentPtr - 1;
	codeSegmentPtr += sizeof(long);
	return(address);
}

//***************************************************************************
// STACK routines
//***************************************************************************

void pop (void) {

	--tos;
}

//***************************************************************************

void getCodeToken (void) {

	codeToken = (TokenCodeType)*codeSegmentPtr;
	codeSegmentPtr++;
}

//***************************************************************************

void pushInteger (long value) {

	StackItemPtr valuePtr = ++tos;

	if (valuePtr >= &stack[MAXSIZE_STACK])
		runtimeError(ABL_ERR_RUNTIME_STACK_OVERFLOW);
	valuePtr->integer = value;
}

//***************************************************************************

void pushReal (float value) {

	StackItemPtr valuePtr = ++tos;

	if (valuePtr >= &stack[MAXSIZE_STACK])
		runtimeError(ABL_ERR_RUNTIME_STACK_OVERFLOW);
	valuePtr->real = value;
}

//***************************************************************************

void pushByte (char value) {

	StackItemPtr valuePtr = ++tos;

	if (valuePtr >= &stack[MAXSIZE_STACK])
		runtimeError(ABL_ERR_RUNTIME_STACK_OVERFLOW);
	valuePtr->byte = value;
}

//***************************************************************************

void pushAddress (Address address) {

	StackItemPtr valuePtr = ++tos;

	if (valuePtr >= &stack[MAXSIZE_STACK])
		runtimeError(ABL_ERR_RUNTIME_STACK_OVERFLOW);
	valuePtr->address = address;
}

//***************************************************************************

void pushBoolean (bool value) {

	StackItemPtr valuePtr = ++tos;

	if (valuePtr >= &stack[MAXSIZE_STACK])
		runtimeError(ABL_ERR_RUNTIME_STACK_OVERFLOW);
	valuePtr->integer = (value ? 1 : 0);
}

//***************************************************************************
void pushStackFrameHeader (long oldLevel, long newLevel) {

	//-----------------------------------
	// Make space for the return value...
	pushInteger(0);

	StackFrameHeaderPtr headerPtr = (StackFrameHeaderPtr)stackFrameBasePtr;

	//----------------------------------------------------------------------
	// STATIC LINK
	// Currently, let's not allow functions defined within functions. Assume
	// the old scope level equals the new scope level, for now.
	if (newLevel == -1) {
		//--------------------------------------------------------------------
		// Calling a library function, so push a NULL static link since
		// it's scope is in a different module than the calling function.
		// Note that global variables in libraries should be STATIC, otherwise
		// they're never in scope! Weird "feature" which we may want
		// to fix later...
		pushAddress(NULL);
		}
	else if (newLevel == oldLevel + 1) {
		//----------------------------------------------------------------
		// Calling a routine nested within the caller, so push the pointer
		// to the caller's stack frame. In ABL, as currently defined
		// (2/22/96), this should only be when a module's code section is
		// calling a function...
		pushAddress((Address)headerPtr);
		}
	else if (newLevel == oldLevel) {
		//---------------------------------------------------------------
		// Calling a function at the same scope level. We like that! Push
		// pointer to stack frame of their common parent...
		pushAddress(headerPtr->staticLink.address);
		}
	else {
		//-------------------------------------------------------
		// Oops. We don't want nested functions, for now, in ABL.
		runtimeError(ABL_ERR_RUNTIME_NESTED_FUNCTION_CALL);
	}
	pushAddress((Address)stackFrameBasePtr);

	//---------------------------
	// Push the return address...
	pushAddress(0);
}

//***************************************************************************

void allocLocal (TypePtr typePtr) {

	if (typePtr == IntegerTypePtr)
		pushInteger(0);
	else if (typePtr == RealTypePtr)
		pushReal((float)0.0);
	else if (typePtr == BooleanTypePtr)
		pushByte(0);
	else if (typePtr == CharTypePtr)
		pushByte(0);
	else
		switch (typePtr->form) {
			case FRM_ENUM:
				pushInteger(0);
				break;
// NOTE: We currently are not supporting sub ranges, until
// we really want 'em...
//			case FRM_SUBRANGE:
//				allocLocal(typePtr->info.subrange.rangeTypePtr);
//				break;
			case FRM_ARRAY:
				char* ptr = (char*)ABLStackMallocCallback(typePtr->size);
				if (!ptr)
					ABL_Fatal(0, " ABL: Unable to AblStackHeap->malloc local array ");
				pushAddress((Address)ptr);
				break;
		}
}

//***************************************************************************

void freeLocal (SymTableNodePtr idPtr) {

	//---------------------------------------
	// Frees data allocated on local stack...

	TypePtr typePtr = (TypePtr)(idPtr->typePtr);

	StackItemPtr itemPtr = NULL;
	if (((typePtr->form == FRM_ARRAY) /* || (typePtr->form == FRM_RECORD)*/) &&
		(idPtr->defn.key != DFN_REFPARAM)) {
		switch (idPtr->defn.info.data.varType) {
			case VAR_TYPE_NORMAL:
				itemPtr = stackFrameBasePtr + idPtr->defn.info.data.offset;
				break;
//			case VAR_TYPE_ETERNAL:
//				itemPtr = stack + idPtr->defn.info.data.offset;
//				break;
//			case VAR_TYPE_STATIC:
//				itemPtr = StaticDataPtr + idPtr->defn.info.data.offset;
//				break;
		}
		if (!itemPtr)
			runtimeError(0);
		else
			ABLStackFreeCallback(itemPtr->address);
	}
}

//***************************************************************************
// FUNCTION ENTRY/EXIT routines
//***************************************************************************

void routineEntry (SymTableNodePtr routineIdPtr) {

	if (debugger)
		debugger->traceRoutineEntry(routineIdPtr);

	memset(&returnValue, 0, sizeof(StackItem));

	//------------------------------
	// Switch to new code segment...
	codeSegmentPtr = routineIdPtr->defn.info.routine.codeSegment;

	//----------------------------------------------
	// Allocate local variables onto system stack...
	for (SymTableNodePtr varIdPtr = (SymTableNodePtr)(routineIdPtr->defn.info.routine.locals);
		 varIdPtr != NULL;
		 varIdPtr = varIdPtr->next)
		if (varIdPtr->defn.info.data.varType == VAR_TYPE_NORMAL)
			allocLocal((TypePtr)(varIdPtr->typePtr));
}

//***************************************************************************

void routineExit (SymTableNodePtr routineIdPtr) {

	if (debugger)
		debugger->traceRoutineExit(routineIdPtr);

	//-----------------------------------------
	// De-alloc parameters & local variables...

	for (SymTableNodePtr idPtr = (SymTableNodePtr)(routineIdPtr->defn.info.routine.params);
		 idPtr != NULL;
		 idPtr = idPtr->next)
		freeLocal(idPtr);

	for (idPtr = (SymTableNodePtr)(routineIdPtr->defn.info.routine.locals);
		 idPtr != NULL;
		 idPtr = idPtr->next)
		if (idPtr->defn.info.data.varType == VAR_TYPE_NORMAL)
			freeLocal(idPtr);

	StackFrameHeaderPtr headerPtr = (StackFrameHeaderPtr)stackFrameBasePtr;
	codeSegmentPtr = headerPtr->returnAddress.address;

	if (routineIdPtr->typePtr == NULL)
		tos = stackFrameBasePtr - 1;
	else
		tos = stackFrameBasePtr;

	stackFrameBasePtr = (StackItemPtr)headerPtr->dynamicLink.address;
}

//***************************************************************************

void execute (SymTableNodePtr routineIdPtr) {

	SymTableNodePtr thisRoutineIdPtr = CurRoutineIdPtr;

	CurRoutineIdPtr = routineIdPtr;

	routineEntry(routineIdPtr);

	//----------------------------------------------------
	// Now, search this module for the function we want...
	if (CallModuleInit) {
		CallModuleInit = false;
		SymTableNodePtr initFunctionIdPtr = searchSymTable("init", ModuleRegistry[CurModule->getHandle()].moduleIdPtr->defn.info.routine.localSymTable);
		if (initFunctionIdPtr) {
			execRoutineCall(initFunctionIdPtr, false);
			//-------------------------------------------------------------------------
			// Since we're calling the function directly, we need to compensate for the
			// codeSegmentPtr being incremented by 1 in the normal execRoutineCall...
			codeSegmentPtr--;
		}
	}

	if (routineIdPtr->defn.info.routine.flags & ROUTINE_FLAG_FSM) {
		NewStateSet = true;
		static char stateList[60][256];
		strcpy(SetStateDebugStr, "--");
		while (NewStateSet) {
			NumStateTransitions++;
			sprintf(stateList[NumStateTransitions], "%s (%s)", CurModule->getState()->name, SetStateDebugStr);
			if (NumStateTransitions == 50) {
				UserFile* userFile = UserFile::getNewFile();
				char errStr[512];
				if (userFile) {
					long err = userFile->open("endless.log");
					if (!err) {
						//char s[1024];
						//sprintf(s, "Current Date: %s\n", GetTime());
						//userFile->write(s);
						userFile->write(ModuleRegistry[CurModule->getHandle()].fileName);
						for (long i = 1; i < 51; i++)
							userFile->write(stateList[i]);
						userFile->write(" ");
						if (ABLEndlessStateCallback)
							(*ABLEndlessStateCallback)(userFile);
						userFile->close();
					}
				}
				sprintf(errStr, " ABL endless state loop in %s [%s:%s] ", ModuleRegistry[CurModule->getHandle()].fileName, CurModule->getState()->name, CurModule->getPrevState()->name);
				#if 0
				ABL_Fatal(NumStateTransitions, errStr);
				#else
				NewStateSet = false;
				#endif
				}
			else {
				NewStateSet = false;
				SymTableNodePtr curState = CurModule->getState();
				if (!curState)
					ABL_Fatal(0, " ABL.execute: NULL state in FSM ");
				execRoutineCall(curState, false);
				codeSegmentPtr--;
			}
			//---------------------------------------------
			// In case we exited with a return statement...
			ExitWithReturn = false;
			ExitFromTacOrder = false;
		}
		}
	else {
		getCodeToken();
		execStatement();
		//---------------------------------------------
		// In case we exited with a return statement...
		ExitWithReturn = false;
		ExitFromTacOrder = false;
	}

	routineExit(routineIdPtr);

	CurRoutineIdPtr = thisRoutineIdPtr;
}

//***************************************************************************

void executeChild (SymTableNodePtr routineIdPtr, SymTableNodePtr childRoutineIdPtr) {

	// THIS DOES NOT SUPPORT CALLING FUNCTIONS WITH PARAMETERS YET!

	SymTableNodePtr thisRoutineIdPtr = CurRoutineIdPtr;

	CurRoutineIdPtr = routineIdPtr;

	routineEntry(routineIdPtr);

	//----------------------------------------------------
	// Now, search this module for the function we want...
	SymTableNodePtr initFunctionIdPtr = NULL;
	if (CallModuleInit) {
		CallModuleInit = false;
		initFunctionIdPtr = searchSymTable("init", routineIdPtr->defn.info.routine.localSymTable);
		if (initFunctionIdPtr) {
			execRoutineCall(initFunctionIdPtr, false);
			//-------------------------------------------------------------------------
			// Since we're calling the function directly, we need to compensate for the
			// codeSegmentPtr being incremented by 1 in the normal execRoutineCall...
			codeSegmentPtr--;
		}
	}

	if (initFunctionIdPtr != childRoutineIdPtr) {
		//-----------------------------------------------------------------------
		// If we're calling the module's init function, and we just did above,
		// don't call it again! That's why we make the check on the above line...
		execRoutineCall(childRoutineIdPtr, false);
		//-------------------------------------------------------------------------
		// Since we're calling the function directly, we need to compensate for the
		// codeSegmentPtr being incremented by 1 in the normal execRoutineCall...
		codeSegmentPtr--;
	}

	//---------------------------------------------
	// In case we exited with a return statement...
	ExitWithReturn = false;
	ExitFromTacOrder = false;

	routineExit(routineIdPtr);

	CurRoutineIdPtr = thisRoutineIdPtr;
}

//***************************************************************************
// MISC routines
//***************************************************************************