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
Various reflect operations permit assignability conversions,
i.e. their internals behave unlike y=x.(T) which unpacks only
those interface values in x that are identical to T.
We split typeAssertConstraint y=x.(T) into two constraints:
1) typeFilter, for when T is an interface type and no
representation change occurs.
2) unpack, for when T is a concrete type and the payload of the
tagged object is extracted. This constraint has an 'exact'
parameter indicating whether to use the predicate
IsIdentical (for type assertions) or
IsAssignable (for reflect operators).
+ Tests.
R=crawshaw
CC=golang-dev
https://golang.org/cl/14547043
(reflect.Value).Bytes
(reflect.Value).Elem
(reflect.Value).Index
(reflect.Value).SetBytes
(reflect.Value).Slice
reflect.PtrTo
reflect.SliceOf
+ Tests.
Also: comment out an 'info-'level print statement in the test; it was distracting.
R=crawshaw
CC=golang-dev
https://golang.org/cl/14454055
Revision 8f2c714c6d97 made the 'imports' map per-typechecker,
not per package, breaking an assumption of doImport0. This
API needs a rethink for a number of reasons, some of which are
noted in this CL.
R=gri
CC=golang-dev
https://golang.org/cl/14606044
Break the basic block at the function literal. The code to do this analysis
was already there; this CL just factors it out more nicely and uses it in
one new place. Also adds a test.
Fixesgolang/go#6555.
R=golang-dev, adg
CC=golang-dev
https://golang.org/cl/14601043
Given a built-in call f(args), Info.Types now maps f to the call-site
specific type of f (by looking at the argument types) if the built-in
call is not producing a constant (at typecheck time) result. If the
result is constant, the recorded type is invalid (a back-end won't
need it).
R=adonovan
CC=golang-dev
https://golang.org/cl/14598045
Catch ... errors earlier and in case of error, type-check all
arguments anyway for better type reporting and fewer "declared
but not used" errors.
R=adonovan
CC=golang-dev
https://golang.org/cl/14600043
This requires us to make a copy of (not clobber) the supplied
config, and retain their Import hook separately so that it can
be wrapped by Importer.doImport.
Fixes bug 6562.
R=gri
CC=golang-dev
https://golang.org/cl/14523054
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
The new method is functionally identical to typeCheck, and
obviates the LoadMainPackage method.
Updated all clients.
Fixes bug 6561.
R=gri
CC=golang-dev
https://golang.org/cl/14494051
Assignments to "comma, ok" expressions on the lhs of an
assignment are not permitted unless we have map index
"comma, ok" expression. Created new operand mode 'mapindex'
to distinguish this case. Renamed mode 'valueok' to the more
commonly used 'commaok' term, which also makes it easier to
distinguish from simply 'value'.
Added corresponding tests.
Fixes a TODO.
R=adonovan
CC=golang-dev
https://golang.org/cl/14526049
- removed support for nil constants from go/exact
- instead define a singleton Nil Object (the nil _value_)
- in assignments, follow more closely spec wording
(pending spec CL 14415043)
- removed use of goto in checker.unary
- cleanup around handling of isRepresentable for
constants, with better error messages
- fix missing checks in checker.convertUntyped
- added isTyped (== !isUntyped) and isInterface predicates
- fixed hasNil predicate: unsafe.Pointer also has nil
- adjusted ssa per adonovan
- implememted types.Implements (wrapper arounfd types.MissingMethod)
- use types.Implements in vet (and fix a bug)
R=adonovan, r
CC=golang-dev
https://golang.org/cl/14438052
This information can be used to specialize such calls, e.g.
- report location of unsound calls (done for reflect.NewAt)
- exploit argument information (done for constant 'dir' parameter to reflect.ChanOf)
+ tests.
R=crawshaw
CC=golang-dev
https://golang.org/cl/14517046
The $GOROOT/tests may print "BUG" on failure but do not
necessarily exit zero, so we must capture their output too.
Details:
- make plan9 use unix's valueToBytes function (now in externals.go)
- direct the target's syscall.Write and print/println built-ins to a new utility, write(). This may capture the output into a global variable.
R=gri, r
CC=golang-dev
https://golang.org/cl/14550044
Fixesgolang/go#6539
The problem happens on my win7,
for example, the path is "/content\\foo.article".
It leads to the wrong link in generated html page.
So I think we should replace all"\\" with "/" in path string at first.
R=golang-dev, dsymonds, mirtchovski, dave, adg, alex.brainman
CC=golang-dev
https://golang.org/cl/14023043
- factor out argument extraction logic
- cleaned up error handling in builtin.go (no need for goto's anymore)
- lots of additional test cases
- various cleanups, better documentation
Fixesgolang/go#5795.
R=adonovan
CC=golang-dev
https://golang.org/cl/14312044
It would be nice to be able to use this package
as a dependency (or other go utilities in the
ecosystem that depend on this package) in
environments which have not (or cannot) for
whatever reason upgraded to newer versions of
golang.
R=golang-dev, adg
CC=golang-dev
https://golang.org/cl/14283043
Not the right approach.
««« original CL description
go.tools/godoc: reverse reversed redirects
Make godoc work again for go spec and memory model doc.
TBR=rsc
CC=golang-dev
https://golang.org/cl/14368043
»»»
R=gri
CC=golang-dev
https://golang.org/cl/14370043
Present the files in lexical order so the output is reproducible
and easier to navigate. Do a little type rearrangement to simplify
things while we're there.
R=adg
CC=golang-dev
https://golang.org/cl/14357043
It was not enough to make /ref/spec work (which it now does),
because some of the docs on golang.org (in particular golang.org/doc)
are pulled from tip, and tip links to /doc/spec now.
Make those "too new" links work by redirecting /doc/spec
back to /ref/spec for now.
TBR=adg
CC=golang-dev
https://golang.org/cl/14348043
The redirect.PrefixHandler redirects "/foo/" to "/foo", which is what
we want in most cases ("/cl/", "/change/", etc) but not here.
So wrap it with a handler that handles "/blog/" explictly.
R=dsymonds
CC=golang-dev
https://golang.org/cl/14326043
Revision f280b8a485fd of the std library changed the
gc export format: anonymous fields may be qualified
with a package.
R=rsc
TBR=rsc
CC=golang-dev
https://golang.org/cl/14312043
`svn update` would fail if the updated files were in the gcc/libgo or gcc/go/gofrontend because unrevisioned versions of those files had been inserted in the last build of gcc.
R=adg, adg
CC=golang-dev
https://golang.org/cl/14299043
