Method DerefInclude

source/script.cpp:12161–12232

ResultType Script::DerefInclude(LPTSTR &aOutput, LPTSTR aBuf)
// For #Include, #IncludeAgain and #DllLoad.
// Based on Line::Deref above, but with a few differences for backward-compatibility:
//  1) Percent signs that aren't part of a valid deref are not omitted.
//  2) Escape sequences aren't recognized (`; is handled elsewhere).
//  3) It is restricted to built-in vars to reduce the risk of breaking any scripts
//     that use percent sign literally in a filename.  Most other vars are empty anyway.
{
	aOutput = nullptr; // Set default.

	VarSizeType expanded_length;
	size_t var_name_length;
	LPTSTR cp, cp1, dest;

	// Do two passes:
	// #1: Calculate the space needed.
	// #2: Expand the contents of aBuf into aOutput.

	for (int which_pass = 0; which_pass < 2; ++which_pass)
	{
		if (which_pass) // Starting second pass.
		{
			// Allocate a buffer to contain the result:
			if (  !(aOutput = tmalloc(expanded_length+1))  )
				return FAIL;
			dest = aOutput;
		}
		else // First pass.
			expanded_length = 0; // Init prior to accumulation.

		for (cp = aBuf; *cp; ++cp)  // Increment to skip over the deref/escape just found by the inner for().
		{
			if (*cp == g_DerefChar)
			{
				// It's a dereference symbol, so calculate the size of that variable's contents and add
				// that to expanded_length (or copy the contents into aOutputVar if this is the second pass).
				for (cp1 = cp + 1; *cp1 && *cp1 != g_DerefChar; ++cp1); // Find the reference's ending symbol.
				var_name_length = cp1 - cp - 1;
				if (*cp1 && var_name_length && var_name_length <= MAX_VAR_NAME_LENGTH)
				{
					Var *var = FindGlobalVar(cp + 1, var_name_length);
					if (var && var->Type() == VAR_VIRTUAL)
					{
						if (which_pass) // 2nd pass
						{
							size_t var_length = var->CharLength();
							tmemcpy(dest, var->Contents(), var_length);
							var->Free();
							dest += var_length;
						}
						else
						{
							if (!var->PopulateVirtualVar())
								return FAIL;
							expanded_length += var->CharLength();
						}
						cp = cp1; // For the next loop iteration, continue at the char after this reference's final deref symbol.
						continue;