cmd/compile: add traceback argument info to ABI0 assembly functions

For ABI0 assembly functions that have Go declarations, generate
traceback argument info and attach it to the assembly functions.
So we can print argument in tracebacks if e.g. assembly function
panics.

Only do this for ABI0 functions, as for ABIInternal assembly
functions it is likely that they never spill arguments to memory.

Change-Id: I7e601ccd9aded5e6af2f02be975bf81ff9948f4d
Reviewed-on: https://go-review.googlesource.com/c/go/+/315870
Trust: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>

diff --git a/src/cmd/compile/internal/gc/compile.go b/src/cmd/compile/internal/gc/compile.go
index a71684a859d59a25c1b376e6585f5e159fb91aac..a7380510d12aed074f73489ea228be84ff17b056 100644 (file)
--- a/src/cmd/compile/internal/gc/compile.go
+++ b/src/cmd/compile/internal/gc/compile.go
@@ -13,10 +13,12 @@ import (
        "cmd/compile/internal/base"
        "cmd/compile/internal/ir"
        "cmd/compile/internal/liveness"
+       "cmd/compile/internal/objw"
        "cmd/compile/internal/ssagen"
        "cmd/compile/internal/typecheck"
        "cmd/compile/internal/types"
        "cmd/compile/internal/walk"
+       "cmd/internal/obj"
 )
 
 // "Portable" code generation.
@@ -47,6 +49,10 @@ func enqueueFunc(fn *ir.Func) {
                a := ssagen.AbiForBodylessFuncStackMap(fn)
                abiInfo := a.ABIAnalyzeFuncType(fn.Type().FuncType()) // abiInfo has spill/home locations for wrapper
                liveness.WriteFuncMap(fn, abiInfo)
+               if fn.ABI == obj.ABI0 {
+                       x := ssagen.EmitArgInfo(fn, abiInfo)
+                       objw.Global(x, int32(len(x.P)), obj.RODATA|obj.LOCAL)
+               }
                return
        }
 

diff --git a/src/cmd/compile/internal/ssagen/ssa.go b/src/cmd/compile/internal/ssagen/ssa.go
index 0d4e3264bad6ccf8532de6184830daec4d53874c..b8f84f5712fffab8412d5d78456088e10f6d7752 100644 (file)
--- a/src/cmd/compile/internal/ssagen/ssa.go
+++ b/src/cmd/compile/internal/ssagen/ssa.go
@@ -6563,15 +6563,27 @@ func (s *State) DebugFriendlySetPosFrom(v *ssa.Value) {
 }
 
 // emit argument info (locations on stack) for traceback.
-func emitArgInfo(e *ssafn, pp *objw.Progs) {
+func emitArgInfo(e *ssafn, f *ssa.Func, pp *objw.Progs) {
        ft := e.curfn.Type()
        if ft.NumRecvs() == 0 && ft.NumParams() == 0 {
                return
        }
 
-       x := base.Ctxt.Lookup(fmt.Sprintf("%s.arginfo%d", e.curfn.LSym.Name, e.curfn.LSym.ABI()))
+       x := EmitArgInfo(e.curfn, f.OwnAux.ABIInfo())
        e.curfn.LSym.Func().ArgInfo = x
 
+       // Emit a funcdata pointing at the arg info data.
+       p := pp.Prog(obj.AFUNCDATA)
+       p.From.SetConst(objabi.FUNCDATA_ArgInfo)
+       p.To.Type = obj.TYPE_MEM
+       p.To.Name = obj.NAME_EXTERN
+       p.To.Sym = x
+}
+
+// emit argument info (locations on stack) of f for traceback.
+func EmitArgInfo(f *ir.Func, abiInfo *abi.ABIParamResultInfo) *obj.LSym {
+       x := base.Ctxt.Lookup(fmt.Sprintf("%s.arginfo%d", f.LSym.Name, f.ABI))
+
        PtrSize := int64(types.PtrSize)
 
        isAggregate := func(t *types.Type) bool {
@@ -6696,27 +6708,19 @@ func emitArgInfo(e *ssafn, pp *objw.Progs) {
        }
 
        c := true
-outer:
-       for _, fs := range &types.RecvsParams {
-               for _, a := range fs(ft).Fields().Slice() {
-                       if !c {
-                               writebyte(_dotdotdot)
-                               break outer
-                       }
-                       c = visitType(a.Offset, a.Type, 0)
+       for _, a := range abiInfo.InParams() {
+               if !c {
+                       writebyte(_dotdotdot)
+                       break
                }
+               c = visitType(a.FrameOffset(abiInfo), a.Type, 0)
        }
        writebyte(_endSeq)
        if wOff > maxLen {
                base.Fatalf("ArgInfo too large")
        }
 
-       // Emit a funcdata pointing at the arg info data.
-       p := pp.Prog(obj.AFUNCDATA)
-       p.From.SetConst(objabi.FUNCDATA_ArgInfo)
-       p.To.Type = obj.TYPE_MEM
-       p.To.Name = obj.NAME_EXTERN
-       p.To.Sym = x
+       return x
 }
 
 // genssa appends entries to pp for each instruction in f.
@@ -6727,7 +6731,7 @@ func genssa(f *ssa.Func, pp *objw.Progs) {
        e := f.Frontend().(*ssafn)
 
        s.livenessMap, s.partLiveArgs = liveness.Compute(e.curfn, f, e.stkptrsize, pp)
-       emitArgInfo(e, pp)
+       emitArgInfo(e, f, pp)
 
        openDeferInfo := e.curfn.LSym.Func().OpenCodedDeferInfo
        if openDeferInfo != nil {

diff --git a/src/cmd/internal/obj/plist.go b/src/cmd/internal/obj/plist.go
index 54b035bb96a94cd5de2cd16dad4c263d88d115d4..6beb4dd94cfdc61a9a3716fa6ab7b831fed2ea51 100644 (file)
--- a/src/cmd/internal/obj/plist.go
+++ b/src/cmd/internal/obj/plist.go
@@ -75,38 +75,51 @@ func Flushplist(ctxt *Link, plist *Plist, newprog ProgAlloc, myimportpath string
                newprog = ctxt.NewProg
        }
 
-       // Add reference to Go arguments for C or assembly functions without them.
-       for _, s := range text {
-               if !strings.HasPrefix(s.Name, "\"\".") {
-                       continue
-               }
-               if s.ABIWrapper() {
-                       // Don't create an args_stackmap symbol reference for an ABI
-                       // wrapper function
-                       continue
-               }
-               // The current args_stackmap generation in the compiler assumes
-               // that the function in question is ABI0, so avoid introducing
-               // an args_stackmap reference if the func is not ABI0 (better to
-               // have no stackmap than an incorrect/lying stackmap).
-               if s.ABI() != ABI0 {
-                       continue
-               }
-               found := false
-               for p := s.Func().Text; p != nil; p = p.Link {
-                       if p.As == AFUNCDATA && p.From.Type == TYPE_CONST && p.From.Offset == objabi.FUNCDATA_ArgsPointerMaps {
-                               found = true
-                               break
+       // Add reference to Go arguments for assembly functions without them.
+       if ctxt.IsAsm {
+               for _, s := range text {
+                       if !strings.HasPrefix(s.Name, "\"\".") {
+                               continue
+                       }
+                       // The current args_stackmap generation in the compiler assumes
+                       // that the function in question is ABI0, so avoid introducing
+                       // an args_stackmap reference if the func is not ABI0 (better to
+                       // have no stackmap than an incorrect/lying stackmap).
+                       if s.ABI() != ABI0 {
+                               continue
+                       }
+                       foundArgMap, foundArgInfo := false, false
+                       for p := s.Func().Text; p != nil; p = p.Link {
+                               if p.As == AFUNCDATA && p.From.Type == TYPE_CONST {
+                                       if p.From.Offset == objabi.FUNCDATA_ArgsPointerMaps {
+                                               foundArgMap = true
+                                       }
+                                       if p.From.Offset == objabi.FUNCDATA_ArgInfo {
+                                               foundArgInfo = true
+                                       }
+                                       if foundArgMap && foundArgInfo {
+                                               break
+                                       }
+                               }
+                       }
+                       if !foundArgMap {
+                               p := Appendp(s.Func().Text, newprog)
+                               p.As = AFUNCDATA
+                               p.From.Type = TYPE_CONST
+                               p.From.Offset = objabi.FUNCDATA_ArgsPointerMaps
+                               p.To.Type = TYPE_MEM
+                               p.To.Name = NAME_EXTERN
+                               p.To.Sym = ctxt.LookupDerived(s, s.Name+".args_stackmap")
+                       }
+                       if !foundArgInfo {
+                               p := Appendp(s.Func().Text, newprog)
+                               p.As = AFUNCDATA
+                               p.From.Type = TYPE_CONST
+                               p.From.Offset = objabi.FUNCDATA_ArgInfo
+                               p.To.Type = TYPE_MEM
+                               p.To.Name = NAME_EXTERN
+                               p.To.Sym = ctxt.LookupDerived(s, fmt.Sprintf("%s.arginfo%d", s.Name, s.ABI()))
                        }
-               }
-               if !found {
-                       p := Appendp(s.Func().Text, newprog)
-                       p.As = AFUNCDATA
-                       p.From.Type = TYPE_CONST
-                       p.From.Offset = objabi.FUNCDATA_ArgsPointerMaps
-                       p.To.Type = TYPE_MEM
-                       p.To.Name = NAME_EXTERN
-                       p.To.Sym = ctxt.LookupDerived(s, s.Name+".args_stackmap")
                }
        }