cmd/compile/internal/typecheck: remove DeclContext

The last use of this was removed in go.dev/cl/518757.

Change-Id: I41ddc9601bfa7e553b83c4c5a055104b2044d5d0
Reviewed-on: https://go-review.googlesource.com/c/go/+/520610
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Auto-Submit: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>

src/cmd/compile/internal/gc/compile.go

@@ -16,7 +16,6 @@ import (
 	"cmd/compile/internal/objw"
 	"cmd/compile/internal/ssagen"
 	"cmd/compile/internal/staticinit"
-	"cmd/compile/internal/typecheck"
 	"cmd/compile/internal/types"
 	"cmd/compile/internal/walk"
 	"cmd/internal/obj"
@@ -105,11 +104,9 @@ func prepareFunc(fn *ir.Func) {
 	// Calculate parameter offsets.
 	types.CalcSize(fn.Type())
 
-	typecheck.DeclContext = ir.PAUTO
 	ir.CurFunc = fn
 	walk.Walk(fn)
 	ir.CurFunc = nil // enforce no further uses of CurFunc
-	typecheck.DeclContext = ir.PEXTERN
 }
 
 // compileFunctions compiles all functions in compilequeue.

src/cmd/compile/internal/pkginit/init.go

@@ -114,7 +114,6 @@ func MakeTask() {
 		if ni != 0 {
 			// Make an init._ function.
 			base.Pos = base.AutogeneratedPos
-			typecheck.DeclContext = ir.PEXTERN
 			name := noder.Renameinit()
 			fnInit := typecheck.DeclFunc(name, nil, nil, nil)
 

src/cmd/compile/internal/reflectdata/alg.go

@@ -141,7 +141,6 @@ func hashFunc(t *types.Type) *ir.Func {
 	}
 
 	base.Pos = base.AutogeneratedPos // less confusing than end of input
-	typecheck.DeclContext = ir.PEXTERN
 
 	// func sym(p *T, h uintptr) uintptr
 	args := []*ir.Field{
@@ -367,7 +366,6 @@ func eqFunc(t *types.Type) *ir.Func {
 		return sym.Def.(*ir.Name).Func
 	}
 	base.Pos = base.AutogeneratedPos // less confusing than end of input
-	typecheck.DeclContext = ir.PEXTERN
 
 	// func sym(p, q *T) bool
 	fn := typecheck.DeclFunc(sym, nil,

src/cmd/compile/internal/ssagen/abi.go

@@ -237,11 +237,9 @@ func makeABIWrapper(f *ir.Func, wrapperABI obj.ABI) {
 
 	// Q: is this needed?
 	savepos := base.Pos
-	savedclcontext := typecheck.DeclContext
 	savedcurfn := ir.CurFunc
 
 	base.Pos = base.AutogeneratedPos
-	typecheck.DeclContext = ir.PEXTERN
 
 	// At the moment we don't support wrapping a method, we'd need machinery
 	// below to handle the receiver. Panic if we see this scenario.
@@ -329,7 +327,6 @@ func makeABIWrapper(f *ir.Func, wrapperABI obj.ABI) {
 
 	// Restore previous context.
 	base.Pos = savepos
-	typecheck.DeclContext = savedclcontext
 	ir.CurFunc = savedcurfn
 }
 

src/cmd/compile/internal/typecheck/dcl.go

@@ -15,11 +15,13 @@ import (
 	"cmd/internal/src"
 )
 
-var DeclContext ir.Class = ir.PEXTERN // PEXTERN/PAUTO
+var funcStack []*ir.Func // stack of previous values of ir.CurFunc
 
 func DeclFunc(sym *types.Sym, recv *ir.Field, params, results []*ir.Field) *ir.Func {
 	fn := ir.NewFunc(base.Pos, base.Pos, sym, nil)
-	StartFuncBody(fn)
+
+	funcStack = append(funcStack, ir.CurFunc)
+	ir.CurFunc = fn
 
 	var recv1 *types.Field
 	if recv != nil {
@@ -38,25 +40,11 @@ func DeclFunc(sym *types.Sym, recv *ir.Field, params, results []*ir.Field) *ir.F
 	return fn
 }
 
-// declare the function proper
-// and declare the arguments.
-// called in extern-declaration context
-// returns in auto-declaration context.
-func StartFuncBody(fn *ir.Func) {
-	// change the declaration context from extern to auto
-	funcStack = append(funcStack, funcStackEnt{ir.CurFunc, DeclContext})
-	ir.CurFunc = fn
-	DeclContext = ir.PAUTO
-}
-
 // finish the body.
 // called in auto-declaration context.
 // returns in extern-declaration context.
 func FinishFuncBody() {
-	// change the declaration context from auto to previous context
-	var e funcStackEnt
-	funcStack, e = funcStack[:len(funcStack)-1], funcStack[len(funcStack)-1]
-	ir.CurFunc, DeclContext = e.curfn, e.dclcontext
+	funcStack, ir.CurFunc = funcStack[:len(funcStack)-1], funcStack[len(funcStack)-1]
 }
 
 func CheckFuncStack() {
@@ -83,13 +71,6 @@ func checkdupfields(what string, fss ...[]*types.Field) {
 	}
 }
 
-var funcStack []funcStackEnt // stack of previous values of ir.CurFunc/DeclContext
-
-type funcStackEnt struct {
-	curfn      *ir.Func
-	dclcontext ir.Class
-}
-
 func declareParams(fn *ir.Func, ctxt ir.Class, l []*ir.Field) []*types.Field {
 	fields := make([]*types.Field, len(l))
 	for i, n := range l {