llgo/ssa: CType, CFuncDecl

ssa/type.go

@@ -48,27 +48,8 @@ const (
 	vkPhisExpr  = -2
 )
 
-// CFuncPtr represents a C function pointer.
-type CFuncPtr types.Signature
-
 // -----------------------------------------------------------------------------
 
-const (
-	NameValist = "__llgo_va_list"
-)
-
-func VArg() *types.Var {
-	return types.NewParam(0, nil, NameValist, types.Typ[types.Invalid])
-}
-
-func IsVArg(arg *types.Var) bool {
-	return arg.Name() == NameValist
-}
-
-func HasVArg(t *types.Tuple, n int) bool {
-	return n > 0 && IsVArg(t.At(n-1))
-}
-
 func indexType(t types.Type) types.Type {
 	switch t := t.(type) {
 	case *types.Slice:
@@ -102,18 +83,6 @@ func methodToFunc(sig *types.Signature) *types.Signature {
 
 // -----------------------------------------------------------------------------
 
-// CType convert a C type into Go.
-func CType(typ types.Type) types.Type {
-	panic("todo")
-}
-
-// CFuncDecl convert a C function decl into Go signature.
-func CFuncDecl(sig *types.Signature) *types.Signature {
-	panic("todo")
-}
-
-// -----------------------------------------------------------------------------
-
 type aType struct {
 	ll   llvm.Type
 	t    types.Type
@@ -278,6 +247,8 @@ func (p Program) toLLVMType(typ types.Type) Type {
 		return p.toLLVMNamed(t)
 	case *types.Signature:
 		return p.toLLVMFunc(t, false, false)
+	case *CFuncPtr:
+		return p.toLLVMFunc((*types.Signature)(t), true, false)
 	case *types.Array:
 		elem := p.Type(t.Elem())
 		return &aType{llvm.ArrayType(elem.ll, int(t.Len())), typ, vkInvalid}
@@ -327,14 +298,11 @@ func (p Program) toLLVMFunc(sig *types.Signature, inC, isDecl bool) Type {
 	var kind valueKind
 	var ft llvm.Type
 	if isDecl || inC {
-		var tParams = sig.Params()
-		var n = tParams.Len()
-		var hasVArg bool
-		if inC {
-			hasVArg = HasVArg(tParams, n)
-			if hasVArg {
-				n--
-			}
+		tParams := sig.Params()
+		n := tParams.Len()
+		hasVArg := HasVArg(tParams, n)
+		if hasVArg {
+			n--
 		}
 		params := p.toLLVMTypes(tParams, n)
 		out := sig.Results()
@@ -378,9 +346,6 @@ func (p Program) toLLVMNamed(typ *types.Named) Type {
 	case *types.Struct:
 		name := NameOf(typ)
 		return &aType{p.toLLVMNamedStruct(name, t), typ, vkInvalid}
-	case *types.Signature:
-		inC := true // TODO(xsw): how to check in C
-		return p.toLLVMFunc(t, inC, false)
 	default:
 		return p.Type(t)
 	}

ssa/type_c.go

@@ -0,0 +1,128 @@
+/*
+ * Copyright (c) 2024 The GoPlus Authors (goplus.org). All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ssa
+
+import "go/types"
+
+// -----------------------------------------------------------------------------
+
+const (
+	NameValist = "__llgo_va_list"
+)
+
+func VArg() *types.Var {
+	return types.NewParam(0, nil, NameValist, types.Typ[types.Invalid])
+}
+
+func IsVArg(arg *types.Var) bool {
+	return arg.Name() == NameValist
+}
+
+func HasVArg(t *types.Tuple, n int) bool {
+	return n > 0 && IsVArg(t.At(n-1))
+}
+
+// -----------------------------------------------------------------------------
+
+// CFuncPtr represents a C function pointer.
+type CFuncPtr types.Signature
+
+func (t *CFuncPtr) String() string         { return (*types.Signature)(t).String() }
+func (t *CFuncPtr) Underlying() types.Type { return (*types.Signature)(t) }
+
+// -----------------------------------------------------------------------------
+
+// CType convert a C type into Go.
+func CType(typ types.Type) types.Type {
+	t, _ := cvtCType(typ)
+	return t
+}
+
+// CFuncDecl convert a C function decl into Go signature.
+func CFuncDecl(sig *types.Signature) *types.Signature {
+	hasVArg := sig.Variadic()
+	params, cvt1 := cvtTuple(sig.Params(), hasVArg)
+	results, cvt2 := cvtTuple(sig.Results(), false)
+	if cvt1 || cvt2 {
+		return types.NewSignatureType(nil, nil, nil, params, results, hasVArg)
+	}
+	return sig
+}
+
+func cvtCType(typ types.Type) (types.Type, bool) {
+	switch t := typ.(type) {
+	case *types.Basic:
+	case *types.Pointer:
+		if elem, cvt := cvtCType(t.Elem()); cvt {
+			return types.NewPointer(elem), true
+		}
+	case *types.Struct:
+		return cvtCStruct(t)
+	case *types.Signature:
+		t = CFuncDecl(t)
+		return (*CFuncPtr)(t), true
+	case *types.Array:
+		if elem, cvt := cvtCType(t.Elem()); cvt {
+			return types.NewArray(elem, t.Len()), true
+		}
+	default:
+		panic("unreachable")
+	}
+	return typ, false
+}
+
+func cvtTuple(t *types.Tuple, hasVArg bool) (*types.Tuple, bool) {
+	n := t.Len()
+	vars := make([]*types.Var, n)
+	needcvt := false
+	if hasVArg {
+		n--
+		vars[n] = t.At(n)
+	}
+	for i := 0; i < n; i++ {
+		v := t.At(i)
+		if t, cvt := cvtCType(v.Type()); cvt {
+			v = types.NewParam(v.Pos(), v.Pkg(), v.Name(), t)
+			needcvt = true
+		}
+		vars[i] = v
+	}
+	if needcvt {
+		return types.NewTuple(vars...), true
+	}
+	return t, false
+}
+
+func cvtCStruct(typ *types.Struct) (*types.Struct, bool) {
+	n := typ.NumFields()
+	flds := make([]*types.Var, n)
+	needcvt := false
+	for i := 0; i < n; i++ {
+		f := typ.Field(i)
+		if t, cvt := cvtCType(f.Type()); cvt {
+			f = types.NewField(f.Pos(), f.Pkg(), f.Name(), t, f.Anonymous())
+			needcvt = true
+		}
+		flds[i] = f
+	}
+	if needcvt {
+		return types.NewStruct(flds, nil), true
+	}
+	return typ, false
+}
+
+// -----------------------------------------------------------------------------