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runtime: consolidate stkframe and its methods into stkframe.go

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The stkframe struct and its methods are strewn across different source
files. Since they actually have a pretty coherent theme at this point,
migrate it all into a new file, stkframe.go. There are no code changes
in this CL.

For #54466, albeit rather indirectly.

Change-Id: Ibe53fc4b1106d131005e1c9d491be838a8f14211
Reviewed-on: https://go-review.googlesource.com/c/go/+/424516
Reviewed-by: Michael Pratt <mpratt@google.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Austin Clements <austin@google.com>
Auto-Submit: Austin Clements <austin@google.com>
This commit is contained in:
Austin Clements 2022-08-17 09:06:14 -04:00 • committed by Gopher Robot
parent b91e373729
commit 35026f3732
4 changed files with 288 additions and 276 deletions
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136
src/runtime/stack.go
View file

@ -1247,142 +1247,6 @@ func freeStackSpans() {
unlock(&stackLarge.lock)
}
// getStackMap returns the locals and arguments live pointer maps, and
// stack object list for frame.
func (frame *stkframe) getStackMap(cache *pcvalueCache, debug bool) (locals, args bitvector, objs []stackObjectRecord) {
targetpc := frame.continpc
if targetpc == 0 {
// Frame is dead. Return empty bitvectors.
return
}
f := frame.fn
pcdata := int32(-1)
if targetpc != f.entry() {
// Back up to the CALL. If we're at the function entry
// point, we want to use the entry map (-1), even if
// the first instruction of the function changes the
// stack map.
targetpc--
pcdata = pcdatavalue(f, _PCDATA_StackMapIndex, targetpc, cache)
}
if pcdata == -1 {
// We do not have a valid pcdata value but there might be a
// stackmap for this function. It is likely that we are looking
// at the function prologue, assume so and hope for the best.
pcdata = 0
}
// Local variables.
size := frame.varp - frame.sp
var minsize uintptr
switch goarch.ArchFamily {
case goarch.ARM64:
minsize = sys.StackAlign
default:
minsize = sys.MinFrameSize
}
if size > minsize {
stackid := pcdata
stkmap := (*stackmap)(funcdata(f, _FUNCDATA_LocalsPointerMaps))
if stkmap == nil || stkmap.n <= 0 {
print("runtime: frame ", funcname(f), " untyped locals ", hex(frame.varp-size), "+", hex(size), "\n")
throw("missing stackmap")
}
// If nbit == 0, there's no work to do.
if stkmap.nbit > 0 {
if stackid < 0 || stackid >= stkmap.n {
// don't know where we are
print("runtime: pcdata is ", stackid, " and ", stkmap.n, " locals stack map entries for ", funcname(f), " (targetpc=", hex(targetpc), ")\n")
throw("bad symbol table")
}
locals = stackmapdata(stkmap, stackid)
if stackDebug >= 3 && debug {
print(" locals ", stackid, "/", stkmap.n, " ", locals.n, " words ", locals.bytedata, "\n")
}
} else if stackDebug >= 3 && debug {
print(" no locals to adjust\n")
}
}
// Arguments. First fetch frame size and special-case argument maps.
var isReflect bool
args, isReflect = frame.argMapInternal()
if args.n > 0 && args.bytedata == nil {
// Non-empty argument frame, but not a special map.
// Fetch the argument map at pcdata.
stackmap := (*stackmap)(funcdata(f, _FUNCDATA_ArgsPointerMaps))
if stackmap == nil || stackmap.n <= 0 {
print("runtime: frame ", funcname(f), " untyped args ", hex(frame.argp), "+", hex(args.n*goarch.PtrSize), "\n")
throw("missing stackmap")
}
if pcdata < 0 || pcdata >= stackmap.n {
// don't know where we are
print("runtime: pcdata is ", pcdata, " and ", stackmap.n, " args stack map entries for ", funcname(f), " (targetpc=", hex(targetpc), ")\n")
throw("bad symbol table")
}
if stackmap.nbit == 0 {
args.n = 0
} else {
args = stackmapdata(stackmap, pcdata)
}
}
// stack objects.
if (GOARCH == "amd64" || GOARCH == "arm64" || GOARCH == "ppc64" || GOARCH == "ppc64le" || GOARCH == "riscv64") &&
unsafe.Sizeof(abi.RegArgs{}) > 0 && isReflect {
// For reflect.makeFuncStub and reflect.methodValueCall,
// we need to fake the stack object record.
// These frames contain an internal/abi.RegArgs at a hard-coded offset.
// This offset matches the assembly code on amd64 and arm64.
objs = methodValueCallFrameObjs[:]
} else {
p := funcdata(f, _FUNCDATA_StackObjects)
if p != nil {
n := *(*uintptr)(p)
p = add(p, goarch.PtrSize)
r0 := (*stackObjectRecord)(noescape(p))
objs = unsafe.Slice(r0, int(n))
// Note: the noescape above is needed to keep
// getStackMap from "leaking param content:
// frame". That leak propagates up to getgcmask, then
// GCMask, then verifyGCInfo, which converts the stack
// gcinfo tests into heap gcinfo tests :(
}
}
return
}
var methodValueCallFrameObjs [1]stackObjectRecord // initialized in stackobjectinit
func stkobjinit() {
var abiRegArgsEface any = abi.RegArgs{}
abiRegArgsType := efaceOf(&abiRegArgsEface)._type
if abiRegArgsType.kind&kindGCProg != 0 {
throw("abiRegArgsType needs GC Prog, update methodValueCallFrameObjs")
}
// Set methodValueCallFrameObjs[0].gcdataoff so that
// stackObjectRecord.gcdata() will work correctly with it.
ptr := uintptr(unsafe.Pointer(&methodValueCallFrameObjs[0]))
var mod *moduledata
for datap := &firstmoduledata; datap != nil; datap = datap.next {
if datap.gofunc <= ptr && ptr < datap.end {
mod = datap
break
}
}
if mod == nil {
throw("methodValueCallFrameObjs is not in a module")
}
methodValueCallFrameObjs[0] = stackObjectRecord{
off: -int32(alignUp(abiRegArgsType.size, 8)), // It's always the highest address local.
size: int32(abiRegArgsType.size),
_ptrdata: int32(abiRegArgsType.ptrdata),
gcdataoff: uint32(uintptr(unsafe.Pointer(abiRegArgsType.gcdata)) - mod.rodata),
}
}
// A stackObjectRecord is generated by the compiler for each stack object in a stack frame.
// This record must match the generator code in cmd/compile/internal/liveness/plive.go:emitStackObjects.
type stackObjectRecord struct {