Added test for []*map composite literals containing nested
literal subelements. This required implementing
(reflect.Value).Map{Keys,Index} in ssa/interp.
Plus two minor fixes in ssa/interp.
R=gri
CC=golang-dev
https://golang.org/cl/20470043
A function such as this:
func one() (x int) {
defer func() { recover() }()
x = 1
panic("return")
}
that combines named return parameters (NRPs) with deferred calls
that call recover, may return non-zero values despite the
fact it doesn't even contain a return statement. (!)
This requires a change to the SSA API: all functions'
control-flow graphs now have a second entry point, called
Recover, which is the block at which control flow resumes
after a recovered panic. The Recover block simply loads the
NRPs and returns them.
As an optimization, most functions don't need a Recover block,
so it is omitted. In fact it is only needed for functions that
have NRPs and defer a call to another function that _may_ call
recover.
Dataflow analysis of SSA now requires extra work, since every
may-panic instruction has an implicit control-flow edge to
the Recover block. The only dataflow analysis so far implemented
is SSA renaming, for which we make the following simplifying
assumption: the Recover block only loads the NRPs and returns.
This means we don't really need to analyze it, we can just
skip the "lifting" of such NRPs. We also special-case the Recover
block in the dominance computation.
Rejected alternative approaches:
- Specifying a Recover block for every defer instruction (like a
traditional exception handler).
This seemed like excessive generality, since Go programs
only need the same degenerate form of Recover block.
- Adding an instruction to set the Recover block immediately
after the named return values are set up, so that dominance
can be computed without special-casing.
This didn't seem worth the effort.
Interpreter:
- This CL completely reimplements the panic/recover/
defer logic in the interpreter. It's clearer and simpler
and closer to the model in the spec.
- Some runtime panic messages have been changed to be closer
to gc's, since tests depend on it.
- The interpreter now requires that the runtime.runtimeError
type be part of the SSA program. This requires that clients
import this package prior to invoking the interpreter.
This in turn requires (Importer).ImportPackage(path string),
which this CL adds.
- All $GOROOT/test/recover{,1,2,3}.go tests are now passing.
NB, the bug described in coverage.go (defer/recover in a concatenated
init function) remains. Will be fixed in a follow-up.
Fixesgolang/go#6381
R=gri
CC=crawshaw, golang-dev
https://golang.org/cl/13844043
Before, we would concatenate all the init() blocks together,
resulting in incorrect treatment of a recovered panic in one
init block: the implicit return would cause the subsequent ones
to be skipped.
The result is simpler, and closer to what gc does.
The additional functions are visible in the call graph,
so some tests required updating.
R=gri
CC=crawshaw, golang-dev
https://golang.org/cl/14671044
Before: func(any, ...interface{}).
After: func(any, ...any)
They are no longer variadic, so you can't write print(x, y...).
(Recall that print(1) and print(interface{}(1)) behave
differently and that this is useful.)
Fixes bug 6560
R=gri
CC=golang-dev
https://golang.org/cl/14455054
- This change implements the correct type-based equivalence
relation for aggregate types. e.g. comparison of struct
types no longer compares the anonymous fields. We do
analogous things for hash().
- equals() and eqnil() have been separated: the former panics
for uncomparable types, the latter permits comparisons of
slice/map/func types against a literal nil and is intended
for use only by "static" ssa.BinOp(EQL), not "dynamic" slice
comparisons encountered during (e.g.) interface comparisons,
which should panic regardless of operand nilness.
- we use a (global) typemap.Hasher to compute type hashes;
hashing the Type.String() value was not sound.
+ tests.
NB, this change unearthed a bug in defer/recover within
init(); it will be fixed in a followup change.
R=gri, crawshaw
CC=golang-dev
https://golang.org/cl/13719043
Map literals should use the same recursion logic as
struct/array/slice literals to apply an implicit &-operator to
the nested literals when a pointer is wanted.
+ test.
Also:
- ensure we set the source location for all Lookup and
MapUpdate instructions.
- remove obsolete address.object field.
R=gri, crawshaw
CC=golang-dev
https://golang.org/cl/12787048
They will be deleted from their current homes once this has landed.
Changes made to import paths to make the code compile, and to find
errchk in the right place in cmd/vet's Makefile.
TODO in a later CL: tidy up vet.
R=golang-dev, gri
CC=golang-dev
https://golang.org/cl/9495043
