void execSwitchStatement (void) {
getCodeToken();
char* branchTableLocation = getCodeAddressMarker();
getCodeToken();
TypePtr switchExpressionTypePtr = execExpression();
long switchExpressionValue;
if ((switchExpressionTypePtr == IntegerTypePtr) || (switchExpressionTypePtr->form == FRM_ENUM))
switchExpressionValue = tos->integer;
else
switchExpressionValue = tos->byte;
pop();
//---------------------------------------------------------
// Now, search the branch table for the expression value...
codeSegmentPtr = branchTableLocation;
getCodeToken();
long caseLabelCount = getCodeInteger();
bool done = false;
char* caseBranchLocation = NULL;
while (!done && caseLabelCount--) {
long caseLabelValue = getCodeInteger();
caseBranchLocation = getCodeAddress();
done = (caseLabelValue == switchExpressionValue);
}
//-----------------------------------------------
// If found, go to the aprropriate branch code...
if (caseLabelCount >= 0) {
codeSegmentPtr = caseBranchLocation;
getCodeToken();
if (codeToken != TKN_END_CASE)
do {
execStatement();
if (ExitWithReturn)
return;
} while (codeToken != TKN_END_CASE);
//----------------------------------
// Grab the end case and semi-colon...
getCodeToken();
getCodeToken();
codeSegmentPtr = getCodeAddressMarker();
getCodeToken();
}
else {
//-----------------------------------------------------------------
// Since the branch table is located at the end of the case blocks,
// the code directly after the switch statement follows our
// current code location, already. Just grab the endswitch
// and semi-colon...
getCodeToken();
getCodeToken();
}
}
void execIfStatement(void)
{
getCodeToken();
PSTR falseLocation = getCodeAddressMarker();
//-------------------------------
// Eval the boolean expression. Note that, unlike C/C++, the expression
// must be true(1) or false(0). In C/C++, an expression is true if it's
// non-zero. Not the case in ABL using this current implementation. Do we
// want to change this?
getCodeToken();
execExpression();
bool test = (tos->integer == 1);
pop();
if(test)
{
//---------------------------
// execute the TRUE branch...
getCodeToken();
if((codeToken != TKN_END_IF) && (codeToken != TKN_ELSE))
do
{
execStatement();
if(ExitWithReturn)
return;
}
while((codeToken != TKN_END_IF) && (codeToken != TKN_ELSE));
if(codeToken == TKN_ELSE)
{
getCodeToken();
codeSegmentPtr = getCodeAddressMarker();
getCodeToken();
}
}
else
{
//----------------------------
// Execute the FALSE branch...
codeSegmentPtr = falseLocation;
getCodeToken();
if(codeToken == TKN_ELSE)
{
getCodeToken();
getCodeAddressMarker();
getCodeToken();
if(codeToken != TKN_END_IF)
do
{
execStatement();
if(ExitWithReturn)
return;
}
while(codeToken != TKN_END_IF);
}
}
getCodeToken();
}
void execWhileStatement (void) {
getCodeToken();
char* loopEndLocation = getCodeAddressMarker();
char* testLocation = codeSegmentPtr;
bool loopDone = false;
long iterations = 0;
do {
//-------------------------------
// Eval the boolean expression...
getCodeToken();
execExpression();
if (tos->integer == 0) {
codeSegmentPtr = loopEndLocation;
loopDone = true;
}
//-------------------------
// Get the boolean value...
pop();
//----------------------------------
// If TRUE, execute the statement...
if (!loopDone) {
getCodeToken();
if (codeToken != TKN_END_WHILE)
do {
execStatement();
if (ExitWithReturn)
return;
} while (codeToken != TKN_END_WHILE);
codeSegmentPtr = testLocation;
//---------------------------
// Check for infinite loop...
iterations++;
if (iterations == MaxLoopIterations)
runtimeError(ABL_ERR_RUNTIME_INFINITE_LOOP);
}
} while (!loopDone);
getCodeToken();
}
void execForStatement(void)
{
getCodeToken();
//---------------------------------------
// Grab address of the end of the loop...
PSTR loopEndLocation = getCodeAddressMarker();
//--------------------------------------------------------
// Get the address of the control variable's stack item...
getCodeToken();
SymTableNodePtr controlIdPtr = getCodeSymTableNodePtr();
TypePtr controlTypePtr = execVariable(controlIdPtr, USE_TARGET);
StackItemPtr targetPtr = (StackItemPtr)tos->address;
//------------------------------------
// Control variable address...
pop();
//-------------------------------
// Eval the initial expression...
getCodeToken();
execExpression();
int32_t initialValue;
if(controlTypePtr == IntegerTypePtr)
initialValue = tos->integer;
else
initialValue = tos->byte;
//---------------------
// The initial value...
pop();
int32_t deltaValue;
if(codeToken == TKN_TO)
deltaValue = 1;
else
deltaValue = -1;
//----------------------------------
// Now, eval the final expression...
getCodeToken();
execExpression();
int32_t finalValue;
if(controlTypePtr == IntegerTypePtr)
finalValue = tos->integer;
else
finalValue = tos->byte;
//-------------------
// The final value...
pop();
//----------------------------
// Address of start of loop...
PSTR loopStartLocation = codeSegmentPtr;
int32_t controlValue = initialValue;
//-----------------------------
// Now, execute the FOR loop...
int32_t iterations = 0;
if(deltaValue == 1)
while(controlValue <= finalValue)
{
if(controlTypePtr == IntegerTypePtr)
targetPtr->integer = controlValue;
else
targetPtr->byte = (uint8_t)controlValue;
getCodeToken();
if(codeToken != TKN_END_FOR)
do
{
execStatement();
if(ExitWithReturn)
return;
}
while(codeToken != TKN_END_FOR);
//---------------------------
// Check for infinite loop...
if(++iterations == MaxLoopIterations)
runtimeError(ABL_ERR_RUNTIME_INFINITE_LOOP);
controlValue++;
codeSegmentPtr = loopStartLocation;
}
else
while(controlValue >= finalValue)
{
if(controlTypePtr == IntegerTypePtr)
targetPtr->integer = controlValue;
else
targetPtr->byte = (uint8_t)controlValue;
getCodeToken();
if(codeToken != TKN_END_FOR)
do
{
execStatement();
if(ExitWithReturn)
return;
}
while(codeToken != TKN_END_FOR);
//---------------------------
// Check for infinite loop...
if(++iterations == MaxLoopIterations)
runtimeError(ABL_ERR_RUNTIME_INFINITE_LOOP);
controlValue--;
codeSegmentPtr = loopStartLocation;
}
codeSegmentPtr = loopEndLocation;
getCodeToken();
}
