Method PreparseBlocks

Source/script.cpp:4852–4973

Line *Script::PreparseBlocks(Line *aStartingLine, bool aFindBlockEnd, Line *aParentLine)
// aFindBlockEnd should be true, only when this function is called
// by itself.  The end of this function relies upon this definition.
// Will return NULL to the top-level caller if there's an error, or if
// mLastLine is NULL (i.e. the script is empty).
{
	// Not thread-safe, so this can only parse one script at a time.
	// Not a problem for the foreseeable future:
	static nest_level; // Level zero is the outermost one: outside all blocks.
	static bool abort;
	if (aParentLine == NULL)
	{
		// We were called from outside, not recursively, so init these.  This is
		// very important if this function is ever to be called from outside
		// more than once, even though it isn't currently:
		nest_level = 0;
		abort = false;
	}

	// Don't check aStartingLine here at top: only do it at the bottom
	// for its differing return values.
	for (Line *line = aStartingLine; line != NULL;)
	{
		// All lines in our recursion layer are assigned to the block that the caller specified:
		if (line->mParentLine == NULL) // i.e. don't do it if it's already "owned" by an IF or ELSE.
			line->mParentLine = aParentLine; // Can be NULL.

		if (ACT_IS_IF(line->mActionType) || line->mActionType == ACT_ELSE
			|| line->mActionType == ACT_LOOP || line->mActionType == ACT_REPEAT)
		{
			// Make the line immediately following each ELSE, IF or LOOP be enclosed by that stmt.
			// This is done to make it illegal for a Goto or Gosub to jump into a deeper layer,
			// such as in this example:
			// #y::
			// ifwinexist, pad
			// {
			//    goto, label1
			//    ifwinexist, pad
			//    label1:
			//    ; With or without the enclosing block, the goto would still go to an illegal place
			//    ; in the below, resulting in an "unexpected else" error:
			//    {
			//	     msgbox, ifaction
			//    } ; not necessary to make this line enclosed by the if because labels can't point to it?
			// else
			//    msgbox, elseaction
			// }
			// return

			// In this case, the loader should have already ensured that line->mNextLine is not NULL:
			line->mNextLine->mParentLine = line;
			// Go onto the IF's or ELSE's action in case it too is an IF, rather than skipping over it:
			line = line->mNextLine;
			continue;
		}

		switch (line->mActionType)
		{