If you get a stack of PCs from Callers, it would be expected
that every PC is immediately after a call instruction, so to find
the line of the call, you look up the line for PC-1.
CL 163550043 now explicitly documents that.
The most common exception to this is the top-most return PC
on the stack, which is the entry address of the runtime.goexit
function. Subtracting 1 from that PC will end up in a different
function entirely.
To remove this special case, make the top-most return PC
goexit+PCQuantum and then implement goexit in assembly
so that the first instruction can be skipped.
Fixes#7690.
LGTM=r
R=r
CC=golang-codereviews
https://golang.org/cl/170720043
This removes a bunch of ugly duplicate code.
The end goal is to factor the disassembly code
into cmd/internal/objfile too, so that pprof can use it,
but one step at a time.
LGTM=r, iant
R=r, alex.brainman, iant
CC=golang-codereviews
https://golang.org/cl/149400043
Originally traceback was only used for printing the stack
when an unexpected signal came in. In that case, the
initial PC is taken from the signal and should be used
unaltered. For the callers, the PC is the return address,
which might be on the line after the call; we subtract 1
to get to the CALL instruction.
Traceback is now used for a variety of things, and for
almost all of those the initial PC is a return address,
whether from getcallerpc, or gp->sched.pc, or gp->syscallpc.
In those cases, we need to subtract 1 from this initial PC,
but the traceback code had a hard rule "never subtract 1
from the initial PC", left over from the signal handling days.
Change gentraceback to take a flag that specifies whether
we are tracing a trap.
Change traceback to default to "starting with a return PC",
which is the overwhelmingly common case.
Add tracebacktrap, like traceback but starting with a trap PC.
Use tracebacktrap in signal handlers.
Fixes#7690.
LGTM=iant, r
R=r, iant
CC=golang-codereviews
https://golang.org/cl/167810044
Attempt to clear up confusion about how to turn
the PCs reported by Callers into the file and line
number people actually want.
Fixes#7690.
LGTM=r, chris.cs.guy
R=r, chris.cs.guy
CC=golang-codereviews
https://golang.org/cl/163550043
The goal here is to get the big-endian fixes so that
in some upcoming code movement for write barriers
I don't make them unmergeable.
LGTM=rlh
R=rlh
CC=golang-codereviews
https://golang.org/cl/166890043
goprintf is a printf-like print for Go.
It is used in the code generated by 'defer print(...)' and 'go print(...)'.
Normally print(1, 2, 3) turns into
printint(1)
printint(2)
printint(3)
but defer and go need a single function call to give the runtime;
they give the runtime something like goprintf("%d%d%d", 1, 2, 3).
Variadic functions like goprintf cannot be described in the new
type information world, so we have to replace it.
Replace with a custom function, so that defer print(1, 2, 3) turns
into
defer func(a1, a2, a3 int) {
print(a1, a2, a3)
}(1, 2, 3)
(and then the print becomes three different printints as usual).
Fixes#8614.
LGTM=austin
R=austin
CC=golang-codereviews, r
https://golang.org/cl/159700043
I removed support for jumping between functions years ago,
as part of doing the instruction layout for each function separately.
Given that, it makes sense to treat labels as function-scoped.
This lets each function have its own 'loop' label, for example.
Makes the assembly much cleaner and removes the last
reason anyone would reach for the 123(PC) form instead.
Note that this is on the dev.power64 branch, but it changes all
the assemblers. The change will ship in Go 1.5 (perhaps after
being ported into the new assembler).
Came up as part of CL 167730043.
LGTM=r
R=r
CC=austin, dave, golang-codereviews, minux
https://golang.org/cl/159670043
In CL 160670043 the write function was changed
so a zero-length write is now allowed. This leads
the ExampleWriter_Init test to fail.
The reason is that Plan 9 preserves message
boundaries, while the os library expects systems
that don't preserve them. We have to ignore
zero-length writes so they will never turn into EOF.
This issue was previously discussed in CL 7406046.
LGTM=bradfitz
R=rsc, bradfitz
CC=golang-codereviews
https://golang.org/cl/163510043
Power64 servers do not currently support sub-word size atomic
memory access, so atomicor8 uses word size atomic access.
However, previously atomicor8 made no attempt to align this
access, resulting in errors. Fix this by aligning the pointer
to a word boundary and shifting the value appropriately.
Since atomicor8 is used in GC, add a test to runtime·check to
make sure this doesn't break in the future.
This also fixes an incorrect branch label, an incorrectly
sized argument move, and adds argument names to help go vet.
LGTM=rsc
R=rsc, dave
CC=golang-codereviews
https://golang.org/cl/165820043
The "to" field was the penultimate argument to outgcode,
instead of the last argument, which swapped the third and
fourth operands. The argument order was correct in a.y, so
just swap the meaning of the arguments in outgcode. This
hadn't come up because we hadn't used these more obscure
operations in any hand-written assembly until now.
LGTM=rsc, dave
R=rsc, dave
CC=golang-codereviews
https://golang.org/cl/160690043
No easy way to test (would have to actually trigger some routing
events from kernel) but the code is clearly wrong as written.
If the header says there is a submessage, we need to at least
skip over its bytes, not just continue to the next iteration.
Fixes#8203.
LGTM=r
R=r
CC=golang-codereviews, mikioh.mikioh, p
https://golang.org/cl/164140044
get -u now checks that remote repo paths match the
ones predicted by the import paths: if you are get -u'ing
rsc.io/pdf, it has to be checked out from the right location.
This is important in case the rsc.io/pdf redirect changes.
In some cases, people have good reasons to use
non-standard remote repos. Add -f flag to allow that.
The f can stand for force or fork, as you see fit.
Fixes#8850.
LGTM=r
R=r
CC=golang-codereviews
https://golang.org/cl/164120043
The wrapper code was being emitted before the stack
reservation, rather than after.
LGTM=rsc
R=rsc, dave
CC=golang-codereviews
https://golang.org/cl/161540043
Just to confirm the fix, by typing the follwing:
go test -run=TestLookupIPDeadline -dnsflood or
go test -run=TestLookupIPDeadline -dnsflood -tags netgo
Update #8602
LGTM=iant
R=iant
CC=golang-codereviews
https://golang.org/cl/166740043
Add a short introductory section saying what most Go
programmers really need to know, which is that you
shouldn't have to read this document to understand
the behavior of your program.
LGTM=bradfitz, adg, tracey.brendan, iant, rsc, dsymonds
R=golang-codereviews, bradfitz, tracey.brendan, adg, iant, rsc, dsymonds
CC=golang-codereviews
https://golang.org/cl/158500043
Not a language change.
This is simply documenting the status quo which permits
builtin function names to be parenthesized in calls; e.g.,
both
len(s)
and
(((len)))(s)
are accepted by all compilers and go/types.
Changed the grammar by merging the details of BuiltinCall
with ordinary Calls. Also renamed the Call production to
Arguments which more clearly identifies that part of the
grammar and also matches better with its counterpart on
the declaration side (Parameters).
The fact that the first argument can be a type (for builtins)
or cannot be a type (for regular function calls) is expressed
in the prose, no need to make the grammar more complicated.
Fixes#9001.
LGTM=iant, r, rsc
R=r, rsc, iant, ken, dave
CC=golang-codereviews
https://golang.org/cl/160570043
The test just doubled a certain number of times
and then gave up. On a mostly fast but occasionally
slow machine this may never make the test run
long enough to see the linear growth.
Change test to keep doubling until the first round
takes at least a full second, to reduce the effect of
occasional scheduling or other jitter.
The failure we saw had a time for the first round
of around 100ms.
Note that this test still passes once it sees a linear
effect, even with a very small total time.
The timeout here only applies to how long the execution
must be to support a reported failure.
LGTM=khr
R=khr
CC=golang-codereviews, rlh
https://golang.org/cl/164070043
