cgo: implement void* pointer type

void* is translated to unsafe.Pointer on the Go side.

loader/libclang.go

@@ -307,9 +307,23 @@ func (info *fileInfo) makeASTType(typ C.CXType) ast.Expr {
 			typeName = "complex128"
 		}
 	case C.CXType_Pointer:
+		pointeeType := C.clang_getPointeeType(typ)
+		if pointeeType.kind == C.CXType_Void {
+			// void* type is translated to Go as unsafe.Pointer
+			return &ast.SelectorExpr{
+				X: &ast.Ident{
+					NamePos: info.importCPos,
+					Name:    "unsafe",
+				},
+				Sel: &ast.Ident{
+					NamePos: info.importCPos,
+					Name:    "Pointer",
+				},
+			}
+		}
 		return &ast.StarExpr{
 			Star: info.importCPos,
-			X:    info.makeASTType(C.clang_getPointeeType(typ)),
+			X:    info.makeASTType(pointeeType),
 		}
 	case C.CXType_ConstantArray:
 		return &ast.ArrayType{

testdata/cgo/main.c

@@ -9,6 +9,8 @@ _Complex float globalComplexFloat = 4.1+3.3i;
 _Complex double globalComplexDouble = 4.2+3.4i;
 _Complex double globalComplexLongDouble = 4.3+3.5i;
 char globalChar = 100;
+void *globalVoidPtrSet = &global;
+void *globalVoidPtrNull;
 collection_t globalStruct = {256, -123456, 3.14, 88};
 int globalStructSize = sizeof(globalStruct);
 short globalArray[3] = {5, 6, 7};

testdata/cgo/main.go

@@ -41,6 +41,8 @@ func main() {
 	println("complex double:", C.globalComplexDouble)
 	println("complex long double:", C.globalComplexLongDouble)
 	println("char match:", C.globalChar == 100)
+	var voidPtr unsafe.Pointer = C.globalVoidPtrNull
+	println("void* match:", voidPtr == nil, C.globalVoidPtrNull == nil, (*C.int)(C.globalVoidPtrSet) == &C.global)
 
 	// complex types
 	println("struct:", C.int(unsafe.Sizeof(C.globalStruct)) == C.globalStructSize, C.globalStruct.s, C.globalStruct.l, C.globalStruct.f)

testdata/cgo/main.h

@@ -37,6 +37,8 @@ extern _Complex float globalComplexFloat;
 extern _Complex double globalComplexDouble;
 extern _Complex double globalComplexLongDouble;
 extern char globalChar;
+extern void *globalVoidPtrSet;
+extern void *globalVoidPtrNull;
 extern collection_t globalStruct;
 extern int globalStructSize;
 extern short globalArray[3];

testdata/cgo/out.txt

@@ -15,6 +15,7 @@ complex float: (+4.100000e+000+3.300000e+000i)
 complex double: (+4.200000e+000+3.400000e+000i)
 complex long double: (+4.300000e+000+3.500000e+000i)
 char match: true
+void* match: true true true
 struct: true 256 -123456 +3.140000e+000
 array: 5 6 7
 union: true