Stowage/go
2
0
Fork 0
mirror of https://github.com/golang/go.git synced 2025-12-08 06:10:04 +00:00
Code Issues Projects Releases Packages Wiki Activity

cmd/compile: replace calls to typecheck with transform functions

Browse source 
For additions, compares, and slices, create transform functions that do
just the transformations for those nodes by the typecheck package (given
that the code has been fully typechecked by types2). For nodes that have
no args with typeparams, we call these transform functions directly in
noder2. But for nodes that have args with typeparams, we have to delay
and call the tranform functions during stenciling, since we don't know
the specific types involved.

We indicate that a node still needs transformation by setting Typecheck
to a new value 3. This value means the current type of the node has been
set (via types2), but the node may still need transformation.

Had to export typcheck.IsCmp and typecheck.Assignop from the typecheck
package.

Added new tests list2.go (required delaying compare typecheck/transform
because of != compare in checkList) and adder.go (requires delaying add
typecheck/transform, since it can do addition for numbers or strings).

There are several more transformation functions needed for expressions
(indexing, calls, etc.) and several more complicated ones needed for
statements (mainly various kinds of assignments).

Change-Id: I7d89d13a4108308ea0304a4b815ab60b40c59b0a
Reviewed-on: https://go-review.googlesource.com/c/go/+/303091
Run-TryBot: Dan Scales <danscales@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Trust: Dan Scales <danscales@google.com>
Trust: Robert Griesemer <gri@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
This commit is contained in:
Dan Scales 2021-03-18 14:36:39 -07:00
parent b8371d495b
commit 0265b6475f
10 changed files with 785 additions and 24 deletions
Download patch file Download diff file Expand all files Collapse all files

126
src/cmd/compile/internal/noder/helpers.go
View file

@ -67,16 +67,47 @@ func Assert(pos src.XPos, x ir.Node, typ *types.Type) ir.Node {
return typed(typ, ir.NewTypeAssertExpr(pos, x, nil))
}
func Binary(pos src.XPos, op ir.Op, x, y ir.Node) ir.Node {
// transformAdd transforms an addition operation (currently just addition of
// strings). Equivalent to the "binary operators" case in typecheck.typecheck1.
func transformAdd(n *ir.BinaryExpr) ir.Node {
l := n.X
if l.Type().IsString() {
var add *ir.AddStringExpr
if l.Op() == ir.OADDSTR {
add = l.(*ir.AddStringExpr)
add.SetPos(n.Pos())
} else {
add = ir.NewAddStringExpr(n.Pos(), []ir.Node{l})
}
r := n.Y
if r.Op() == ir.OADDSTR {
r := r.(*ir.AddStringExpr)
add.List.Append(r.List.Take()...)
} else {
add.List.Append(r)
}
add.SetType(l.Type())
return add
}
return n
}
func Binary(pos src.XPos, op ir.Op, typ *types.Type, x, y ir.Node) ir.Node {
switch op {
case ir.OANDAND, ir.OOROR:
return typed(x.Type(), ir.NewLogicalExpr(pos, op, x, y))
case ir.OADD:
if x.Type().IsString() {
// TODO(mdempsky): Construct OADDSTR directly.
return typecheck.Expr(ir.NewBinaryExpr(pos, op, x, y))
n := ir.NewBinaryExpr(pos, op, x, y)
if x.Type().HasTParam() || y.Type().HasTParam() {
// Delay transformAdd() if either arg has a type param,
// since it needs to know the exact types to decide whether
// to transform OADD to OADDSTR.
n.SetType(typ)
n.SetTypecheck(3)
return n
}
fallthrough
n1 := transformAdd(n)
return typed(typ, n1)
default:
return typed(x.Type(), ir.NewBinaryExpr(pos, op, x, y))
}
@ -178,12 +209,56 @@ func Call(pos src.XPos, typ *types.Type, fun ir.Node, args []ir.Node, dots bool)
return n
}
// transformCompare transforms a compare operation (currently just equals/not
// equals). Equivalent to the "comparison operators" case in
// typecheck.typecheck1, including tcArith.
func transformCompare(n *ir.BinaryExpr) {
if (n.Op() == ir.OEQ || n.Op() == ir.ONE) && !types.Identical(n.X.Type(), n.Y.Type()) {
// Comparison is okay as long as one side is assignable to the
// other. The only allowed case where the conversion is not CONVNOP is
// "concrete == interface". In that case, check comparability of
// the concrete type. The conversion allocates, so only do it if
// the concrete type is huge.
l, r := n.X, n.Y
lt, rt := l.Type(), r.Type()
converted := false
if rt.Kind() != types.TBLANK {
aop, _ := typecheck.Assignop(lt, rt)
if aop != ir.OXXX {
types.CalcSize(lt)
if rt.IsInterface() == lt.IsInterface() || lt.Width >= 1<<16 {
l = ir.NewConvExpr(base.Pos, aop, rt, l)
l.SetTypecheck(1)
}
converted = true
}
}
if !converted && lt.Kind() != types.TBLANK {
aop, _ := typecheck.Assignop(rt, lt)
if aop != ir.OXXX {
types.CalcSize(rt)
if rt.IsInterface() == lt.IsInterface() || rt.Width >= 1<<16 {
r = ir.NewConvExpr(base.Pos, aop, lt, r)
r.SetTypecheck(1)
}
}
}
n.X, n.Y = l, r
}
}
func Compare(pos src.XPos, typ *types.Type, op ir.Op, x, y ir.Node) ir.Node {
n := ir.NewBinaryExpr(pos, op, x, y)
if !types.Identical(x.Type(), y.Type()) {
// TODO(mdempsky): Handle subtleties of constructing mixed-typed comparisons.
n = typecheck.Expr(n).(*ir.BinaryExpr)
if x.Type().HasTParam() || y.Type().HasTParam() {
// Delay transformCompare() if either arg has a type param, since
// it needs to know the exact types to decide on any needed conversions.
n.SetType(typ)
n.SetTypecheck(3)
return n
}
transformCompare(n)
return typed(typ, n)
}
@ -267,13 +342,42 @@ func Index(pos src.XPos, typ *types.Type, x, index ir.Node) ir.Node {
return typecheck.Expr(n)
}
func Slice(pos src.XPos, x, low, high, max ir.Node) ir.Node {
// transformSlice transforms a slice operation. Equivalent to typecheck.tcSlice.
func transformSlice(n *ir.SliceExpr) {
l := n.X
if l.Type().IsArray() {
addr := typecheck.NodAddr(n.X)
addr.SetImplicit(true)
typed(types.NewPtr(n.X.Type()), addr)
n.X = addr
l = addr
}
t := l.Type()
if t.IsString() {
n.SetOp(ir.OSLICESTR)
} else if t.IsPtr() && t.Elem().IsArray() {
if n.Op().IsSlice3() {
n.SetOp(ir.OSLICE3ARR)
} else {
n.SetOp(ir.OSLICEARR)
}
}
}
func Slice(pos src.XPos, typ *types.Type, x, low, high, max ir.Node) ir.Node {
op := ir.OSLICE
if max != nil {
op = ir.OSLICE3
}
// TODO(mdempsky): Avoid typecheck.Expr.
return typecheck.Expr(ir.NewSliceExpr(pos, op, x, low, high, max))
n := ir.NewSliceExpr(pos, op, x, low, high, max)
if x.Type().HasTParam() {
// transformSlice needs to know if x.Type() is a string or an array or a slice.
n.SetType(typ)
n.SetTypecheck(3)
return n
}
transformSlice(n)
return typed(typ, n)
}
func Unary(pos src.XPos, op ir.Op, x ir.Node) ir.Node {