feat:distinguish forwarddecl & empty decl

_xtool/internal/libclang/_wrap/cursor.cpp

@@ -37,6 +37,8 @@ void wrap_clang_getCursorSemanticParent(CXCursor *C, CXCursor *parent) { *parent
 
 void wrap_clang_getCursorDefinition(CXCursor *C, CXCursor *def) { *def = clang_getCursorDefinition(*C); }
 
+int wrap_clang_isCursorDefinition(CXCursor *cursor) { return clang_isCursorDefinition(*cursor); }
+
 void wrap_clang_getCursorLexicalParent(CXCursor *C, CXCursor *parent) { *parent = clang_getCursorLexicalParent(*C); }
 
 void wrap_clang_getOverriddenCursors(CXCursor *cursor, CXCursor **overridden, unsigned *num_overridden) {

_xtool/internal/libclang/clang.go

@@ -1643,6 +1643,17 @@ func (c Cursor) Definition() (def Cursor) {
 	return
 }
 
+/**
+ * Determine whether the declaration pointed to by this cursor
+ * is also a definition of that entity.
+ */
+// llgo:link (*Cursor).wrapIsCursorDefinition C.wrap_clang_isCursorDefinition
+func (c *Cursor) wrapIsCursorDefinition() c.Int { return 0 }
+
+func (c Cursor) IsCursorDefinition() c.Int {
+	return c.wrapIsCursorDefinition()
+}
+
 /**
  * Determine the lexical parent of the given cursor.
  *

_xtool/internal/parser/marshal.go

@@ -176,6 +176,9 @@ func XMarshalASTExpr(t ast.Expr) map[string]any {
 		root["Ret"] = XMarshalASTExpr(d.Ret)
 	case *ast.FieldList:
 		root["_Type"] = "FieldList"
+		if d == nil {
+			return nil
+		}
 		root["List"] = XMarshalFieldList(d.List)
 	case *ast.Field:
 		root["_Type"] = "Field"

_xtool/internal/parser/parser.go

@@ -768,7 +768,7 @@ func (ct *Converter) ProcessRecordDecl(cursor clang.Cursor) []ast.Decl {
 		typ := ct.ProcessRecordType(child)
 		// note(zzy):use len(typ.Fields.List) to ensure it has fields not a forward declaration
 		// but maybe make the forward decl in to AST is also good.
-		if child.IsAnonymous() == 0 && len(typ.Fields.List) > 0 {
+		if child.IsAnonymous() == 0 && typ.Fields != nil {
 			childName := clang.GoString(child.String())
 			ct.logln("ProcessRecordDecl: Found named nested struct:", childName)
 			decls = append(decls, &ast.TypeDecl{
@@ -826,23 +826,26 @@ func (ct *Converter) ProcessRecordType(cursor clang.Cursor) *ast.RecordType {
 	ct.incIndent()
 	defer ct.decIndent()
 
+	typ := &ast.RecordType{}
+
 	cursorName, cursorKind := getCursorDesc(cursor)
 	ct.logln("ProcessRecordType: CursorName:", cursorName, "CursorKind:", cursorKind)
 
-	tag := toTag(cursor.Kind)
-	ct.logln("ProcessRecordType: toTag", tag)
+	typ.Tag = toTag(cursor.Kind)
+	ct.logln("ProcessRecordType: toTag", typ.Tag)
+
+	if cursor.IsCursorDefinition() == 0 {
+		ct.logln("ProcessRecordType: forward declaration, no definition")
+		return typ
+	}
 
 	ct.logln("ProcessRecordType: ProcessFieldList")
-	fields := ct.ProcessFieldList(cursor)
+	typ.Fields = ct.ProcessFieldList(cursor)
 
 	ct.logln("ProcessRecordType: ProcessMethods")
-	methods := ct.ProcessMethods(cursor)
+	typ.Methods = ct.ProcessMethods(cursor)
 
-	return &ast.RecordType{
-		Tag:     tag,
-		Fields:  fields,
-		Methods: methods,
-	}
+	return typ
 }
 
 // process ElaboratedType Reference

_xtool/internal/parser/parser_test.go

@@ -20,7 +20,7 @@ import (
 )
 
 func TestParserCppMode(t *testing.T) {
-	cases := []string{"class", "comment", "enum", "func", "scope", "struct", "typedef", "union", "macro", "forwarddecl1", "forwarddecl2", "include", "typeof"}
+	cases := []string{"class", "comment", "enum", "func", "scope", "struct", "typedef", "union", "macro", "forwarddecl1", "forwarddecl2", "include", "typeof", "forward_vs_empty"}
 	// https://github.com/goplus/llgo/issues/1114
 	// todo(zzy):use os.ReadDir
 	for _, folder := range cases {
@@ -31,7 +31,7 @@ func TestParserCppMode(t *testing.T) {
 }
 
 func TestParserCMode(t *testing.T) {
-	cases := []string{"enum", "struct", "union", "macro", "include", "typeof", "named_nested_struct"}
+	cases := []string{"enum", "struct", "union", "macro", "include", "typeof", "named_nested_struct", "forward_vs_empty"}
 	for _, folder := range cases {
 		t.Run(folder, func(t *testing.T) {
 			testFrom(t, filepath.Join("testdata", folder), "temp.h", false, false)
@@ -666,3 +666,31 @@ func TestPostOrderVisitChildren(t *testing.T) {
 		fmt.Println("Unexpected child order:", childStr)
 	}
 }
+
+func TestEmptyDeclVsForwardDecl(t *testing.T) {
+	config := &clangutils.Config{
+		File:  "./testdata/forward_vs_empty/temp.h",
+		Temp:  false,
+		IsCpp: false,
+	}
+
+	type isDefinition = bool
+	var decl map[string]isDefinition = map[string]isDefinition{
+		"ForwardOnly": false,
+		"EmptyStruct": true,
+	}
+
+	visit(config, func(cursor, parent clang.Cursor) clang.ChildVisitResult {
+		if cursor.Kind == clang.CursorStructDecl {
+			sdecl := clang.GoString(cursor.String())
+			if _, ok := decl[sdecl]; ok {
+				isDefine := cursor.IsCursorDefinition() != 0
+				if isDefine != decl[sdecl] {
+					t.Fatalf("StructDecl %s isDefinition expect %v, got %v", sdecl, decl[sdecl], isDefine)
+				}
+			}
+			fmt.Println("StructDecl Name:", clang.GoString(cursor.String()), "isDefinition:", cursor.IsCursorDefinition() != 0)
+		}
+		return clang.ChildVisit_Recurse
+	})
+}

_xtool/internal/parser/testdata/forward_vs_empty/expect.json

@@ -0,0 +1,48 @@
+{
+  "_Type": "File",
+  "decls": [
+    {
+      "Doc": null,
+      "Loc": {
+        "File": "testdata/forward_vs_empty/temp.h",
+        "_Type": "Location"
+      },
+      "Name": {
+        "Name": "ForwardOnly",
+        "_Type": "Ident"
+      },
+      "Parent": null,
+      "Type": {
+        "Fields": null,
+        "Methods": null,
+        "Tag": 0,
+        "_Type": "RecordType"
+      },
+      "_Type": "TypeDecl"
+    },
+    {
+      "Doc": null,
+      "Loc": {
+        "File": "testdata/forward_vs_empty/temp.h",
+        "_Type": "Location"
+      },
+      "Name": {
+        "Name": "EmptyStruct",
+        "_Type": "Ident"
+      },
+      "Parent": null,
+      "Type": {
+        "Fields": {
+          "List": null,
+          "_Type": "FieldList"
+        },
+        "Methods": null,
+        "Tag": 0,
+        "_Type": "RecordType"
+      },
+      "_Type": "TypeDecl"
+    }
+  ],
+  "includes": null,
+  "macros": null
+}

_xtool/internal/parser/testdata/forward_vs_empty/temp.h

@@ -0,0 +1,2 @@
+struct ForwardOnly;
+struct EmptyStruct {};

_xtool/internal/parser/testdata/forwarddecl1/expect.json

@@ -101,10 +101,7 @@
       },
       "Parent": null,
       "Type": {
-        "Fields": {
-          "List": null,
-          "_Type": "FieldList"
-        },
+        "Fields": null,
         "Methods": null,
         "Tag": 0,
         "_Type": "RecordType"
@@ -167,10 +164,7 @@
       },
       "Parent": null,
       "Type": {
-        "Fields": {
-          "List": null,
-          "_Type": "FieldList"
-        },
+        "Fields": null,
         "Methods": null,
         "Tag": 0,
         "_Type": "RecordType"
@@ -189,10 +183,7 @@
       },
       "Parent": null,
       "Type": {
-        "Fields": {
-          "List": null,
-          "_Type": "FieldList"
-        },
+        "Fields": null,
         "Methods": null,
         "Tag": 0,
         "_Type": "RecordType"
@@ -367,10 +358,7 @@
       },
       "Parent": null,
       "Type": {
-        "Fields": {
-          "List": null,
-          "_Type": "FieldList"
-        },
+        "Fields": null,
         "Methods": null,
         "Tag": 0,
         "_Type": "RecordType"
@@ -536,10 +524,7 @@
       },
       "Parent": null,
       "Type": {
-        "Fields": {
-          "List": null,
-          "_Type": "FieldList"
-        },
+        "Fields": null,
         "Methods": null,
         "Tag": 0,
         "_Type": "RecordType"
@@ -558,10 +543,7 @@
       },
       "Parent": null,
       "Type": {
-        "Fields": {
-          "List": null,
-          "_Type": "FieldList"
-        },
+        "Fields": null,
         "Methods": null,
         "Tag": 0,
         "_Type": "RecordType"

_xtool/internal/parser/testdata/func/expect.json

@@ -472,10 +472,7 @@
       },
       "Parent": null,
       "Type": {
-        "Fields": {
-          "List": null,
-          "_Type": "FieldList"
-        },
+        "Fields": null,
         "Methods": null,
         "Tag": 0,
         "_Type": "RecordType"
@@ -494,10 +491,7 @@
       },
       "Parent": null,
       "Type": {
-        "Fields": {
-          "List": null,
-          "_Type": "FieldList"
-        },
+        "Fields": null,
         "Methods": null,
         "Tag": 0,
         "_Type": "RecordType"

cl/internal/convert/_testdata/forwarddecl/gogensig.expect

@@ -129,7 +129,17 @@ type X_xmlParserCtxt struct {
 type XmlParserCtxt X_xmlParserCtxt
 type HtmlParserCtxt XmlParserCtxt
 
+// https://github.com/goplus/llcppg/issues/526
+type ForwardOnly struct {
+	Unused [8]uint8
+}
+
+type EmptyStruct struct {
+}
+
 ===== llcppg.pub =====
+EmptyStruct
+ForwardOnly
 Fts5Context
 Fts5ExtensionApi
 Fts5PhraseIter

cl/internal/convert/_testdata/forwarddecl/hfile/temp.h

@@ -94,3 +94,7 @@ struct _xmlParserCtxt;
 typedef struct _xmlParserCtxt xmlParserCtxt;
 
 typedef xmlParserCtxt htmlParserCtxt;
+
+// https://github.com/goplus/llcppg/issues/526
+struct ForwardOnly;
+struct EmptyStruct {};

cl/internal/convert/package_test.go

@@ -719,7 +719,7 @@ func TestStructDecl(t *testing.T) {
 				},
 				Type: &ast.RecordType{
 					Tag:    ast.Struct,
-					Fields: nil,
+					Fields: &ast.FieldList{},
 				},
 			},
 			expected: `
@@ -1667,7 +1667,7 @@ func TestForwardDecl(t *testing.T) {
 		},
 		Type: &ast.RecordType{
 			Tag:    ast.Struct,
-			Fields: &ast.FieldList{},
+			Fields: nil,
 		},
 	}
 	// forward decl
@@ -1871,7 +1871,9 @@ func TestTypeClean(t *testing.T) {
 					Object: ast.Object{
 						Name: &ast.Ident{Name: "Foo1"},
 					},
-					Type: &ast.RecordType{Tag: ast.Struct},
+					Type: &ast.RecordType{
+						Tag:    ast.Struct,
+						Fields: &ast.FieldList{}},
 				}, nc)
 			},
 			headerFile: "/path/to/file1.h",

cl/internal/convert/type.go

@@ -334,7 +334,7 @@ func (p *TypeConv) ToDefaultEnumType() types.Type {
 // by only checking if Fields.List is empty
 // Should use recordType == nil to identify forward declarations, which requires llcppsigfetch support
 func (p *TypeConv) inComplete(recordType *ast.RecordType) bool {
-	return recordType.Fields != nil && len(recordType.Fields.List) == 0
+	return recordType.Fields == nil
 }
 
 // The field name should be public if it's a record field