diff options
Diffstat (limited to 'src/cmd/compile/internal/noder/stencil.go')
| -rw-r--r-- | src/cmd/compile/internal/noder/stencil.go | 15 |
1 files changed, 11 insertions, 4 deletions
diff --git a/src/cmd/compile/internal/noder/stencil.go b/src/cmd/compile/internal/noder/stencil.go index 4c6eaf3fb0..e5f59d0286 100644 --- a/src/cmd/compile/internal/noder/stencil.go +++ b/src/cmd/compile/internal/noder/stencil.go @@ -1228,7 +1228,11 @@ func (g *genInst) dictPass(info *instInfo) { // we do a type assert to the type bound. mse.X = assertToBound(info, info.dictParam, m.Pos(), mse.X, dst) } else { - mse.X = convertUsingDictionary(info, info.dictParam, m.Pos(), mse.X, m, dst) + mse.X = convertUsingDictionary(info, info.dictParam, m.Pos(), mse.X, m, dst, true) + // Note: we set nonEscaping==true, because we can assume the backing store for the + // interface conversion doesn't escape. The method call will immediately go to + // a wrapper function which copies all the data out of the interface value. + // (It only matters for non-pointer-shaped interface conversions. See issue 50182.) } transformDot(mse, false) } @@ -1254,7 +1258,7 @@ func (g *genInst) dictPass(info *instInfo) { // Note: x's argument is still typed as a type parameter. // m's argument now has an instantiated type. if mce.X.Type().HasShape() || (mce.X.Type().IsInterface() && m.Type().HasShape()) { - m = convertUsingDictionary(info, info.dictParam, m.Pos(), m.(*ir.ConvExpr).X, m, m.Type()) + m = convertUsingDictionary(info, info.dictParam, m.Pos(), m.(*ir.ConvExpr).X, m, m.Type(), false) } case ir.ODOTTYPE, ir.ODOTTYPE2: if !m.Type().HasShape() { @@ -1347,7 +1351,9 @@ func findDictType(info *instInfo, t *types.Type) int { // type dst, by returning a new set of nodes that make use of a dictionary entry. in is the // instantiated node of the CONVIFACE node or XDOT node (for a bound method call) that is causing the // conversion. -func convertUsingDictionary(info *instInfo, dictParam *ir.Name, pos src.XPos, v ir.Node, in ir.Node, dst *types.Type) ir.Node { +// If nonEscaping is true, the caller guarantees that the backing store needed for the interface data +// word will not escape. +func convertUsingDictionary(info *instInfo, dictParam *ir.Name, pos src.XPos, v ir.Node, in ir.Node, dst *types.Type, nonEscaping bool) ir.Node { assert(v.Type().HasShape() || v.Type().IsInterface() && in.Type().HasShape()) assert(dst.IsInterface()) @@ -1417,6 +1423,7 @@ func convertUsingDictionary(info *instInfo, dictParam *ir.Name, pos src.XPos, v // Figure out what the data field of the interface will be. data := ir.NewConvExpr(pos, ir.OCONVIDATA, nil, v) typed(types.Types[types.TUNSAFEPTR], data) + data.NonEscaping = nonEscaping // Build an interface from the type and data parts. var i ir.Node = ir.NewBinaryExpr(pos, ir.OEFACE, rt, data) @@ -2147,7 +2154,7 @@ func (g *genInst) buildClosure2(info *instInfo, m ir.Node) ir.Node { // the type bound. rcvr = assertToBound(info, dictVar, pos, rcvr, dst) } else { - rcvr = convertUsingDictionary(info, dictVar, pos, rcvr, m, dst) + rcvr = convertUsingDictionary(info, dictVar, pos, rcvr, m, dst, false) } dot := ir.NewSelectorExpr(pos, ir.ODOTINTER, rcvr, m.(*ir.SelectorExpr).Sel) dot.Selection = typecheck.Lookdot1(dot, dot.Sel, dot.X.Type(), dot.X.Type().AllMethods(), 1) |