* In blocks, discard the result of any statement that has a return
type other than void. This was previously done by wrapping each
statement into an "implicit Unit conversion" that was actually
compiled down to a stack pop instead. If an expression happened to
already have type Unit, however, such a conversion was not inserted,
resulting in a stray reference on the stack. These conversions are
now redundant and should probably be removed.
* In assignments and non-exhaustive conditionals, materialize a Unit
on the stack to avoid depth mismatches that trip up the bytecode
validator. Because such expressions are generally used at block level
(and, indeed, the frontend will reject a non-exhaustive conditional
used as an expression), combined with the above change this results
in no additional GETSTATIC opcodes, as they are immediately removed
by the peephole optimizer.
Effectively, the following when structure:
when (s) {
s1, s2 -> e1,
s3 -> e2,
s4 -> e3,
...
else -> e
}
is implemented as:
when (s.hashCode()) {
h1 -> {
if (s == s1)
e1
else if (s == s2)
e1
else if (s == s3)
e2
else
e
}
h2 -> if (s == s3) e2 else e,
...
else -> e
}
where s1.hashCode() == s2.hashCode() == s3.hashCode() == h1,
s4.hashCode() == h2.
A tableswitch or lookupswitch is used for the hash code lookup.
Change-Id: I087bf623dbb4a41d3cc64399a1b42342a50757a6
Code such as
```
val b = getBoolean()
if (b) 4
else if (b) 5
```
didn't generate a value on the stack always and therefore would
have control-flow paths leading to a pop instruction with nothing
on the stack.
Change-Id: I09d059f361e56a41880006e3f4e51e9acdbd167d
* Move FinallyBlockLowering to common part
* Fix catching of dynamic exception
* Fix bridges for suspend functions
* Disable explicit cast to Unit
* Run lowering per module
* Update some test data
This patch mutes the following test categories:
* Tests with java dependencies (System class,
java stdlib, jvm-oriented annotations etc).
* Coroutines tests.
* Reflection tests.
* Tests with an inheritance from the standard
collections.
