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cmd/compile: use abiutils for all rcvr/in/out frame offsets.

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types thought it knew how to do this, but that's a lie, because types
doesn't know what the ABI is.

includes extra checking to help prevent things from accidentally working
if they need to be changed but aren't.

For #40724.

Change-Id: I166cd948f262344b7bebde6a2c25e7a7f878bbfb
Reviewed-on: https://go-review.googlesource.com/c/go/+/293393
Trust: David Chase <drchase@google.com>
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
This commit is contained in:
David Chase 2021-02-09 15:14:43 -05:00
parent aea1259a72
commit 77973863c3
9 changed files with 107 additions and 82 deletions
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33
src/cmd/compile/internal/abi/abiutils.go
View file

@ -151,6 +151,13 @@ func (a *ABIConfig) Copy() *ABIConfig {
return &b
}
// LocalsOffset returns the architecture-dependent offset from SP for args and results.
// In theory this is only used for debugging; it ought to already be incorporated into
// results from the ABI-related methods
func (a *ABIConfig) LocalsOffset() int64 {
return a.offsetForLocals
}
// NumParamRegs returns the number of parameter registers used for a given type,
// without regard for the number available.
func (a *ABIConfig) NumParamRegs(t *types.Type) int {
@ -237,23 +244,22 @@ func (config *ABIConfig) ABIAnalyzeTypes(rcvr *types.Type, ins, outs []*types.Ty
return result
}
// ABIAnalyze takes a function type 't' and an ABI rules description
// ABIAnalyzeFuncType takes a function type 'ft' and an ABI rules description
// 'config' and analyzes the function to determine how its parameters
// and results will be passed (in registers or on the stack), returning
// an ABIParamResultInfo object that holds the results of the analysis.
func (config *ABIConfig) ABIAnalyze(t *types.Type) *ABIParamResultInfo {
func (config *ABIConfig) ABIAnalyzeFuncType(ft *types.Func) *ABIParamResultInfo {
setup()
s := assignState{
stackOffset: config.offsetForLocals,
rTotal: config.regAmounts,
}
result := &ABIParamResultInfo{config: config}
ft := t.FuncType()
result.preAllocateParams(t.NumRecvs() != 0, ft.Params.NumFields(), ft.Results.NumFields())
result.preAllocateParams(ft.Receiver != nil, ft.Params.NumFields(), ft.Results.NumFields())
// Receiver
// TODO(register args) ? seems like "struct" and "fields" is not right anymore for describing function parameters
if t.NumRecvs() != 0 {
if ft.Receiver != nil && ft.Receiver.NumFields() != 0 {
r := ft.Receiver.FieldSlice()[0]
result.inparams = append(result.inparams,
s.assignParamOrReturn(r.Type, r.Nname, false))
@ -279,7 +285,14 @@ func (config *ABIConfig) ABIAnalyze(t *types.Type) *ABIParamResultInfo {
result.offsetToSpillArea = alignTo(s.stackOffset, types.RegSize)
result.spillAreaSize = alignTo(s.spillOffset, types.RegSize)
result.outRegistersUsed = s.rUsed.intRegs + s.rUsed.floatRegs
return result
}
// ABIAnalyze returns the same result as ABIAnalyzeFuncType, but also
// updates the offsets of all the receiver, input, and output fields.
func (config *ABIConfig) ABIAnalyze(t *types.Type) *ABIParamResultInfo {
ft := t.FuncType()
result := config.ABIAnalyzeFuncType(ft)
// Fill in the frame offsets for receiver, inputs, results
k := 0
if t.NumRecvs() != 0 {
@ -296,13 +309,11 @@ func (config *ABIConfig) ABIAnalyze(t *types.Type) *ABIParamResultInfo {
}
func (config *ABIConfig) updateOffset(result *ABIParamResultInfo, f *types.Field, a ABIParamAssignment, isReturn bool) {
// Everything except return values in registers has either a frame home (if not in a register) or a frame spill location.
if !isReturn || len(a.Registers) == 0 {
// TODO in next CL, assign
if f.Offset+config.offsetForLocals != a.FrameOffset(result) {
if config.regAmounts.intRegs == 0 && config.regAmounts.floatRegs == 0 {
panic(fmt.Errorf("Expected node offset %d != abi offset %d", f.Offset, a.FrameOffset(result)))
}
}
// The type frame offset DOES NOT show effects of minimum frame size.
// Getting this wrong breaks stackmaps, see liveness/plive.go:WriteFuncMap and typebits/typebits.go:Set
f.Offset = a.FrameOffset(result)-config.LocalsOffset()
}
}