From 6c1f3a139616613ddb0824df04e6f7e1f5a52275 Mon Sep 17 00:00:00 2001
From: Randy Heit <rheit@zdoom.fake>
Date: Thu, 8 Aug 2013 22:16:13 -0500
Subject: [PATCH] Added PStruct::AddField()

---
 src/dobjtype.cpp | 28 ++++++++++++++++++++++++++++
 src/dobjtype.h   |  4 ++++
 2 files changed, 32 insertions(+)

diff --git a/src/dobjtype.cpp b/src/dobjtype.cpp
index e9892ea2e..66ee86f5a 100644
--- a/src/dobjtype.cpp
+++ b/src/dobjtype.cpp
@@ -920,6 +920,34 @@ PStruct::PStruct(FName name, DObject *outer)
 {
 }
 
+//==========================================================================
+//
+// PStruct :: AddField
+//
+// Appends a new field to the end of a struct.
+//
+//==========================================================================
+
+PField *PStruct::AddField(FName name, PType *type)
+{
+	PField *field = new PField(name, type);
+
+	// The new field is added to the end of this struct, alignment permitting.
+	field->FieldOffset = (Size + (type->Align - 1)) & ~(type->Align - 1);
+
+	// Enlarge this struct to enclose the new field.
+	Size = field->FieldOffset + type->Size;
+
+	// This struct's alignment is the same as the largest alignment of any of
+	// its fields.
+	Align = MAX(Align, type->Align);
+
+	Fields.Push(field);
+	Symbols.AddSymbol(field);
+
+	return field;
+}
+
 //==========================================================================
 //
 // PStruct :: PropagateMark
diff --git a/src/dobjtype.h b/src/dobjtype.h
index 91b5ae269..4e867c102 100644
--- a/src/dobjtype.h
+++ b/src/dobjtype.h
@@ -325,6 +325,8 @@ class PField : public PSymbol
 	DECLARE_CLASS(PField, PSymbol);
 	HAS_OBJECT_POINTERS
 public:
+	PField(FName name, PType *type) : PSymbol(name), FieldOffset(0), FieldType(type) {}
+
 	unsigned int FieldOffset;
 	PType *FieldType;
 };
@@ -411,6 +413,8 @@ public:
 	TArray<PField *> Fields;
 	PSymbolTable	 Symbols;
 
+	PField *AddField(FName name, PType *type);
+
 	size_t PropagateMark();
 protected:
 	PStruct();