That was long overdue. Obviously, this is a large commit.
The new nr (node record) class has built-in dump capabilities, rather than using print_node().
SEF always exists now, and is a boolean, rather than using the existence of SEF as the flag. This was changed for sanity. However, other flags like 'X' are still possibly absent, and in some cases the absence itself has meaning (in the case of 'X', its absence means that the node has not yet been analyzed).
Similarly, an event is distinguished from a UDF by checking for the existence of the 'scope' attribute. This trick works because events are not in the symbol table therefore they have no scope. But this should probably be changed in future to something more rational and faster.
A few minor bugfixes were applied while going through the code.
- Some tabs used as Unicode were written as byte strings. Add the u'\t' prefix.
- After simplifying a%1 -> a&0, fold again the node and return. It's not clear why it didn't return, and whether it depended on subsequent passes (e.g. after DCR) for possibly optimizing out the result. Now we're sure.
- A few places lacked a SEF declaration.
- Formatting changes to split lines that spilled the margin.
- Some comment changes.
- Expanded lazy_list_set definition while adapting it to object format. The plan was to re-compress it after done, but decided to leave it in expanded form.
- Added a few TODOs & FIXMEs, resisting the temptation to fix them in the same commit:
- TODO: ~-~-~-expr -> expr + -3.
- FIXME: Now that we have CompareTrees, we can easily check if expr + -expr cancels out and remove a TODO. Low-hanging fruit.
- TODO: Check what we can do when comparing non-SEF and non-CONST values in '>' (current code relies on converting '>' to '<' for applying more optimizations, but that may miss some opportunities).
- FIXME: Could remove one comparison in nt == '&&' or nt == '||'. Low-hanging fruit.
Implements another TODO.
There was a TODO about a new counter per scope, but that makes no sense. The renamer only acts on global variables, global function and parameter names, state names, and event parameters. We're already restarting the counters at every function, which is the closest to what that TODO was about.
No other functional changes. This required quite some reorganization affecting many files. As a side effect, PythonType2LSL and LSLType2Python aren't duplicate anymore.
Commit 5804a9a introduced a bug where having the foldtabs option disabled (normal) prevented optimizations of functions. Fix it for good (hopefully). While on it, rename the nofoldtabs option to warntabs, making it default, and use it to disable a warning when there are tabs in a string.
When a function folds to a string that contains a tab, e.g. llUnescapeURL("%09"), or to a list that contains a string that contains a tab, a warning is emitted unless the foldtabs option (which forces the optimization) is used. This option allows to quiet the warning without forcing the optimization.
The output module adds parentheses where necessary, depending on the evaluation order in the tree. Or that's the idea. Prone to bugs, let's see how it bodes.
As an additional bonus, the condition folding function is now the one that converts a condition to -1, relieving that burden from the rest of the code and simplifying tests.
More precisely, the initializator list was not wrapped into EXPR nodes. Now it is.
While on it, fix a minor bug (the substitutive of a FOR statement should produce no output type), and change order of execution to the actual one (iterators come last).
Without empty statement removal, {;} would trick the optimizer into believing the statement was not empty. E.g. if(x) ; else {;} would not remove the else.
Fixed by backtracking in the parser, and keeping a copy of the original expression if it's a simple_expr, which is used for output in place of the folded one.
There's still the potential issue that if a global is optimized away, then it will "come back" during output and cause an error because the definition is missing.
