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Fix bug with multiple anonymous unions and named unions fields (#66)
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@xoofx
xoofx committed Nov 30, 2022
1 parent 0894624 commit d0e90c7
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Showing 2 changed files with 120 additions and 23 deletions.
62 changes: 60 additions & 2 deletions src/CppAst.Tests/TestStructs.cs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -111,7 +111,7 @@ public void TestAnonymous()


[Test]
public void TestUnion()
public void TestAnonymousUnion()
{
ParseAssert(@"
struct HelloWorld
Expand All @@ -122,6 +122,10 @@ struct HelloWorld
int d;
};
int b;
union {
int e;
int f;
};
};
",
compilation =>
Expand All @@ -132,7 +136,61 @@ struct HelloWorld

{
var cppStruct = compilation.Classes[0];
Assert.AreEqual(3, cppStruct.Fields.Count);
Assert.AreEqual(4, cppStruct.Fields.Count);

for (int i = 0; i < 4; i++)
{
Assert.AreEqual(i * 4, cppStruct.Fields[i].Offset);
Assert.AreEqual(4, cppStruct.Fields[i].Type.SizeOf);
}

// Check first union
Assert.AreEqual(string.Empty, cppStruct.Fields[1].Name);
Assert.IsInstanceOf<CppClass>(cppStruct.Fields[1].Type);
var cppUnion = ((CppClass)cppStruct.Fields[1].Type);
Assert.AreEqual(CppClassKind.Union, ((CppClass)cppStruct.Fields[1].Type).ClassKind);
Assert.AreEqual(2, cppUnion.Fields.Count);

// Check 2nd union
Assert.AreEqual(string.Empty, cppStruct.Fields[3].Name);
Assert.IsInstanceOf<CppClass>(cppStruct.Fields[3].Type);
cppUnion = ((CppClass)cppStruct.Fields[3].Type);
Assert.AreEqual(CppClassKind.Union, ((CppClass)cppStruct.Fields[3].Type).ClassKind);
Assert.AreEqual(2, cppUnion.Fields.Count);
}
}
);
}

[Test]
public void TestAnonymousUnionWithField()
{
ParseAssert(@"
struct HelloWorld
{
int a;
union {
int c;
int d;
} e;
};
",
compilation =>
{
Assert.False(compilation.HasErrors);

Assert.AreEqual(1, compilation.Classes.Count);

{
var cppStruct = compilation.Classes[0];

// Only one union
Assert.AreEqual(1, cppStruct.Classes.Count);

// Only 2 fields
Assert.AreEqual(2, cppStruct.Fields.Count);

// Check the union
Assert.AreEqual(string.Empty, cppStruct.Fields[1].Name);
Assert.IsInstanceOf<CppClass>(cppStruct.Fields[1].Type);
var cppUnion = ((CppClass)cppStruct.Fields[1].Type);
Expand Down
81 changes: 60 additions & 21 deletions src/CppAst/CppModelBuilder.cs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -51,8 +51,14 @@ public CXChildVisitResult VisitTranslationUnit(CXCursor cursor, CXCursor parent,

private CppContainerContext GetOrCreateDeclarationContainer(CXCursor cursor, void* data)
{
var fullName = clang.getCursorUSR(cursor).CString;
if (_containers.TryGetValue(fullName, out var containerContext))
var typeAsCString = clang.getCursorUSR(cursor).CString.ToString();
if (string.IsNullOrEmpty(typeAsCString))
{
typeAsCString = clang.getCursorDisplayName(cursor).ToString();
}
// Try to workaround anonymous types
var typeKey = $"{cursor.Kind}:{typeAsCString}{(cursor.IsAnonymous ? "/" + cursor.Hash : string.Empty)}";
if (_containers.TryGetValue(typeKey, out var containerContext))
{
return containerContext;
}
Expand Down Expand Up @@ -153,9 +159,9 @@ private CppContainerContext GetOrCreateDeclarationContainer(CXCursor cursor, voi
containerContext = new CppContainerContext(symbol) { CurrentVisibility = defaultContainerVisibility };

// The type could have been added separately as part of the GetCppType above TemplateParameters
if (!_containers.ContainsKey(fullName))
if (!_containers.ContainsKey(typeKey))
{
_containers.Add(fullName, containerContext);
_containers.Add(typeKey, containerContext);
}
return containerContext;
}
Expand Down Expand Up @@ -196,7 +202,6 @@ private CppClass VisitClassDecl(CXCursor cursor, void* data)
private CXChildVisitResult VisitMember(CXCursor cursor, CXCursor parent, void* data)
{
CppElement element = null;

switch (cursor.Kind)
{
case CXCursorKind.CXCursor_FieldDecl:
Expand Down Expand Up @@ -230,12 +235,34 @@ private CXChildVisitResult VisitMember(CXCursor cursor, CXCursor parent, void* d
case CXCursorKind.CXCursor_StructDecl:
case CXCursorKind.CXCursor_UnionDecl:
{
bool isAnonymous = cursor.IsAnonymous;
var cppClass = VisitClassDecl(cursor, data);
// Empty struct/class/union declaration are considered as fields
if (string.IsNullOrEmpty(cppClass.Name))
if (isAnonymous)
{
Debug.Assert(string.IsNullOrEmpty(cppClass.Name));
var containerContext = GetOrCreateDeclarationContainer(parent, data);
var cppField = new CppField(cppClass, string.Empty);

// We try to recover the offset from the previous field
// Might not be always correct (with alignment rules),
// but not sure how to recover the offset without recalculating the entire offsets
var offset = 0;
var cppClassContainer = containerContext.Container as CppClass;
if (cppClassContainer is object && cppClassContainer.Fields.Count > 0)
{
var lastField = cppClassContainer.Fields[cppClassContainer.Fields.Count - 1];
offset = (int)lastField.Offset + lastField.Type.SizeOf;
}

// Create an anonymous field for the type
var cppField = new CppField(cppClass, string.Empty)
{
Visibility = containerContext.CurrentVisibility,
StorageQualifier = GetStorageQualifier(cursor),
IsAnonymous = true,
Offset = offset,
Attributes = ParseAttributes(cursor)
};
containerContext.DeclarationContainer.Fields.Add(cppField);
element = cppField;
}
Expand Down Expand Up @@ -735,22 +762,34 @@ private CppField VisitFieldOrVariable(CppContainerContext containerContext, CXCu
var fieldName = GetCursorSpelling(cursor);
var type = GetCppType(cursor.Type.Declaration, cursor.Type, cursor, data);

var cppField = new CppField(type, fieldName)
var previousField = containerContext.DeclarationContainer.Fields.Count > 0 ? containerContext.DeclarationContainer.Fields[containerContext.DeclarationContainer.Fields.Count - 1] : null;
CppField cppField;
// This happen in the type is anonymous, we create implicitly a field for it, but if type is the same
// we should reuse the anonymous field we created just before
if (previousField != null && previousField.IsAnonymous && ReferenceEquals(previousField.Type, type))
{
Visibility = containerContext.CurrentVisibility,
StorageQualifier = GetStorageQualifier(cursor),
IsBitField = cursor.IsBitField,
BitFieldWidth = cursor.FieldDeclBitWidth,
Offset = cursor.OffsetOfField / 8,
};
containerContext.DeclarationContainer.Fields.Add(cppField);
cppField.Attributes = ParseAttributes(cursor);

if (cursor.Kind == CXCursorKind.CXCursor_VarDecl)
cppField = previousField;
cppField.Offset = cursor.OffsetOfField / 8;
}
else
{
VisitInitValue(cursor, data, out var fieldExpr, out var fieldValue);
cppField.InitValue = fieldValue;
cppField.InitExpression = fieldExpr;
cppField = new CppField(type, fieldName)
{
Visibility = containerContext.CurrentVisibility,
StorageQualifier = GetStorageQualifier(cursor),
IsBitField = cursor.IsBitField,
BitFieldWidth = cursor.FieldDeclBitWidth,
Offset = cursor.OffsetOfField / 8,
};
containerContext.DeclarationContainer.Fields.Add(cppField);
cppField.Attributes = ParseAttributes(cursor);

if (cursor.Kind == CXCursorKind.CXCursor_VarDecl)
{
VisitInitValue(cursor, data, out var fieldExpr, out var fieldValue);
cppField.InitValue = fieldValue;
cppField.InitExpression = fieldExpr;
}
}

return cppField;
Expand Down

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