From e020b9480f2faba9fce76cb7acf584eee8aba845 Mon Sep 17 00:00:00 2001
From: =?utf8?q?=EB=B0=95=EC=A2=85=ED=98=84/=EB=8F=99=EC=9E=91=EC=A0=9C?=
 =?utf8?q?=EC=96=B4Lab=28SR=29/Staff=20Engineer/=EC=82=BC=EC=84=B1?=
 =?utf8?q?=EC=A0=84=EC=9E=90?= <jh1302.park@samsung.com>
Date: Mon, 16 Jul 2018 17:40:51 +0900
Subject: [PATCH] [nest] Add variable expression node (#664)

This commit adds 'nest::expr::VarNode' class which represents index
variable exression in nest IR.

Signed-off-by: Jonghyun Park <jh1302.park@samsung.com>
---
 contrib/nest/include/nest/Expr.h         |  2 ++
 contrib/nest/include/nest/expr/Node.def  |  1 +
 contrib/nest/include/nest/expr/VarNode.h | 36 ++++++++++++++++++++++++++++++++
 contrib/nest/src/expr/VarNode.test.cpp   | 31 +++++++++++++++++++++++++++
 4 files changed, 70 insertions(+)
 create mode 100644 contrib/nest/include/nest/expr/VarNode.h
 create mode 100644 contrib/nest/src/expr/VarNode.test.cpp

diff --git a/contrib/nest/include/nest/Expr.h b/contrib/nest/include/nest/Expr.h
index d7447d3..8c84c06 100644
--- a/contrib/nest/include/nest/Expr.h
+++ b/contrib/nest/include/nest/Expr.h
@@ -4,4 +4,6 @@
 #include "nest/expr/Node.h"
 #include "nest/expr/Visitor.h"
 
+#include "nest/expr/VarNode.h"
+
 #endif // __NEST_EXPR_H__
diff --git a/contrib/nest/include/nest/expr/Node.def b/contrib/nest/include/nest/expr/Node.def
index 64c522f..a2c0a0c 100644
--- a/contrib/nest/include/nest/expr/Node.def
+++ b/contrib/nest/include/nest/expr/Node.def
@@ -3,3 +3,4 @@
 #endif
 
 // EXPR(Tag)
+EXPR(Var)
diff --git a/contrib/nest/include/nest/expr/VarNode.h b/contrib/nest/include/nest/expr/VarNode.h
new file mode 100644
index 0000000..dcd13e6
--- /dev/null
+++ b/contrib/nest/include/nest/expr/VarNode.h
@@ -0,0 +1,36 @@
+#ifndef __NEXT_EXPR_VAR_NODE_H__
+#define __NEXT_EXPR_VAR_NODE_H__
+
+#include "nest/VarID.h"
+
+#include "nest/expr/Forward.h"
+#include "nest/expr/Visitor.h"
+#include "nest/expr/Node.h"
+
+namespace nest
+{
+namespace expr
+{
+
+class VarNode final : public Node
+{
+public:
+  VarNode(const VarID &id) : _id{id}
+  {
+    // DO NOTHING
+  }
+
+public:
+  const VarNode *asVar(void) const override { return this; }
+
+public:
+  const VarID &id(void) const { return _id; }
+
+private:
+  VarID const _id;
+};
+
+} // namespace expr
+} // namespace nest
+
+#endif // __NEXT_EXPR_VAR_NODE_H__
diff --git a/contrib/nest/src/expr/VarNode.test.cpp b/contrib/nest/src/expr/VarNode.test.cpp
new file mode 100644
index 0000000..810490c
--- /dev/null
+++ b/contrib/nest/src/expr/VarNode.test.cpp
@@ -0,0 +1,31 @@
+#include "nest/expr/VarNode.h"
+
+#include <memory>
+
+#include <gtest/gtest.h>
+
+TEST(VAR_NODE, ctor)
+{
+  auto make = [](uint32_t n) {
+    const nest::VarID id{n};
+
+    return std::make_shared<nest::expr::VarNode>(id);
+  };
+
+  auto node = make(4);
+
+  // NOTE 'id' should be copied
+  ASSERT_EQ(node->id().value(), 4);
+}
+
+TEST(VAR_NODE, cast)
+{
+  const nest::VarID id{0};
+
+  auto derived = std::make_shared<nest::expr::VarNode>(id);
+  std::shared_ptr<nest::expr::Node> base = derived;
+
+  // NOTE Cast method should be overrided
+  ASSERT_NE(derived.get(), nullptr);
+  ASSERT_EQ(base->asVar(), derived.get());
+}
-- 
2.7.4