Rather than using a hardcoded table of list-to-type extraction function, add a 'ListTo' attribute to the function data. No error is raised if more than one function exists to convert to the same type.
This change is of questionable usefulness, but it should soothe those allergic to magic names/numbers. I cringed a bit myself.
While on it, change the syntax error that was raised when the corresponding conversion function did not exist, to a tailor-made error.
After more thought, we believe that transforming llDumpList2String into a sum of strings is a gain even if there is a list constructor containing function calls as first parameter. The rationale is explained in the comment.
In particular, variables and fields. When we implement an analysis of functions contained in subexpressions, we can optimize more expressions, so add that as a TODO.
--prenodef was causing the preprocessor-specific options (like -std=c99 for gcpp or -V199901L for mcpp) to be omitted. That makes no sense; '-p ext' should be used when custom options are desired (also modify the text that mentions it to make that clearer). Only the macros should be omitted.
The comment that warned about side effects with the order of --prenodef with respect to -p no longer applies, so remove it.
Float addition is commutative. Swap the constant to the left side if it's not there. This is a "cheap" version of a bigger change that is planned, to minimize stack usage as much as possible on savepoints.
Float addition is not associative, therefore we don't optimize e.g. 1 + (2 + float).
Integer addition is commutative and associative. If there's a constant, we swap it to the left side. If there's a chained summation of the form const + (const + expression), we apply associativity to turn it into (const + const) + expression and reoptimize.
This doesn't cover all possible cases. Expressions of the form (const + expr) + (const + expr) are not optimized. We need to flatten sums if we want to do the right thing here, but that's not yet implemented.
Get rid of some older code and TODOs that are no longer needed.
The missing bit was to mark labels are SEF when they are not referenced. Label references are now counted at parse time, enabling us to do this.
Also, make FoldStmt clearer when the node is an expression.
(float)"1.1754944e-38" is != 0
(float)"1.1754943e-38" is == 0
Yet, 1.1754944e-38 == 1.1754943e-38.
The fix is to perform the operations as doubles, and convert to F32 *after* comparing the denormal range.
LSO allows this. The compiler does too, but it chokes in RAIL.
This affected a test, which has been adjusted too.
Untyped lazy list elements can no longer be used in isolation in expression lists (including FOR initializator and iterator).
Also rename the terribly named 'self.forbidlabels' to 'self.optenabled' which is more descriptive.
This extremely uncommon coding pattern was becoming a hell to support. It has caused many bugs in past that need them being treated as special cases.
Getting rid of the possibility entirely seems like the best approach.
It's still supported if the code is not to be optimized (e.g. with --pretty).
While not strictly a bug because it would be caught later in the function (it passes the tests either way), it made me nervous to leave a dangling NextToken().
This may cause more trouble than it's worth, but it's how LSL behaves and one of our objectives is to document the darker corners of LSL. Mono chokes at the RAIL postprocessing stage, not in compilation proper. LSO chokes at runtime for string, key and list, and works fine for the other types.
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.
-a == -b -> a == b
If both a and b either are constants or have a minus sign, negate both.
!(a - b) can be optimized to a == b.
!(a + b) can be optimized to -a == b, relying on the first optimization to remove redundant minus signs.
int != int was not properly optimized, because the != was transformed into the equivalent !(int == int) at an earlier stage. Fixed.
!(a ^ b) can be optimized to a == b, so do it.
