From eac742b9f71823b3b17a3872d0cd77d0611ced19 Mon Sep 17 00:00:00 2001
From: David Nadlinger <code@klickverbot.at>
Date: Thu, 27 Dec 2012 23:22:46 +0100
Subject: [PATCH] Don't create IrType twice for aggregate arrays with forward
 references.

GitHub: Fixes #257.
---
 ir/irtype.cpp | 39 ++++++++++++++++-----------------------
 ir/irtype.h   |  4 +---
 2 files changed, 17 insertions(+), 26 deletions(-)

diff --git a/ir/irtype.cpp b/ir/irtype.cpp
index 1ac9073f..78ebf4b0 100644
--- a/ir/irtype.cpp
+++ b/ir/irtype.cpp
@@ -207,8 +207,8 @@ llvm::Type * IrTypeSArray::sarray2llvm(Type * t)
 //////////////////////////////////////////////////////////////////////////////
 //////////////////////////////////////////////////////////////////////////////
 
-IrTypeArray::IrTypeArray(Type * dt)
-: IrType(dt, array2llvm(dt))
+IrTypeArray::IrTypeArray(Type* dt, LLType* lt)
+: IrType(dt, lt)
 {
 }
 
@@ -216,30 +216,23 @@ IrTypeArray::IrTypeArray(Type * dt)
 
 IrTypeArray* IrTypeArray::get(Type* dt)
 {
-    IrTypeArray* t = new IrTypeArray(dt);
-    dt->irtype = t;
-    return t;
-}
+    assert(!dt->irtype);
+    assert(dt->ty == Tarray && "not dynamic array type");
 
-//////////////////////////////////////////////////////////////////////////////
+    LLType* elemType = DtoTypeNotVoid(dt->nextOf());
 
-llvm::Type * IrTypeArray::array2llvm(Type * t)
-{
-    assert(t->ty == Tarray && "not dynamic array type");
+    // Could have already built the type as part of a struct forward reference,
+    // just as for pointers.
+    if (!dt->irtype)
+    {
+        llvm::SmallVector<LLType*, 2> types;
+        types.push_back(DtoSize_t());
+        types.push_back(llvm::PointerType::get(elemType, 0));
+        LLType* at = llvm::StructType::get(llvm::getGlobalContext(), types/*, t->toChars()*/);
+        dt->irtype = new IrTypeArray(dt, at);
+    }
 
-    // get .ptr type
-    LLType* elemType = DtoType(t->nextOf());
-    if (elemType == llvm::Type::getVoidTy(llvm::getGlobalContext()))
-        elemType = llvm::Type::getInt8Ty(llvm::getGlobalContext());
-    elemType = llvm::PointerType::get(elemType, 0);
-
-    // create struct type
-    llvm::SmallVector<LLType*, 2> types;
-    types.push_back(DtoSize_t());
-    types.push_back(elemType);
-    LLType* at = llvm::StructType::get(llvm::getGlobalContext(), types/*, t->toChars()*/);
-
-    return at;
+    return dt->irtype->isArray();
 }
 
 //////////////////////////////////////////////////////////////////////////////
diff --git a/ir/irtype.h b/ir/irtype.h
index 21a43d23..a85a760b 100644
--- a/ir/irtype.h
+++ b/ir/irtype.h
@@ -161,9 +161,7 @@ public:
 
 protected:
     ///
-    IrTypeArray(Type* dt);
-    ///
-    static llvm::Type* array2llvm(Type* t);
+    IrTypeArray(Type* dt, LLType *lt);
 };
 
 //////////////////////////////////////////////////////////////////////////////