MakeClosure, FreeVar; FuncAddCtx; aggregateAlloc

ssa/decl.go

@@ -130,15 +130,20 @@ type aFunction struct {
 	blks []BasicBlock
 
 	params  []Type
+	base    int // base = 1 if hasFreeVars; base = 0 otherwise
 	hasVArg bool
 }
 
 // Function represents a function or method.
 type Function = *aFunction
 
-func newFunction(fn llvm.Value, t Type, pkg Package, prog Program) Function {
+func newFunction(fn llvm.Value, t Type, pkg Package, prog Program, hasFreeVars bool) Function {
 	params, hasVArg := newParams(t, prog)
-	return &aFunction{Expr{fn, t}, pkg, prog, nil, params, hasVArg}
+	base := 0
+	if hasFreeVars {
+		base = 1
+	}
+	return &aFunction{Expr{fn, t}, pkg, prog, nil, params, base, hasVArg}
 }
 
 func newParams(fn Type, prog Program) (params []Type, hasVArg bool) {
@@ -158,9 +163,16 @@ func newParams(fn Type, prog Program) (params []Type, hasVArg bool) {
 
 // Params returns the function's ith parameter.
 func (p Function) Param(i int) Expr {
+	i += p.base // skip if hasFreeVars
 	return Expr{p.impl.Param(i), p.params[i]}
 }
 
+// FreeVar returns the function's ith free variable.
+func (p Function) FreeVar(b Builder, i int) Expr {
+	ctx := Expr{p.impl.Param(0), p.params[0]}
+	return b.Field(ctx, i)
+}
+
 // NewBuilder creates a new Builder for the function.
 func (p Function) NewBuilder() Builder {
 	prog := p.Prog