initial checkin of SkSL compiler

src/sksl/ir/SkSLFieldAccess.h

+/*
+ * Copyright 2016 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+ 
+#ifndef SKSL_FIELDACCESS
+#define SKSL_FIELDACCESS
+
+#include "SkSLExpression.h"
+#include "SkSLUtil.h"
+
+namespace SkSL {
+
+/**
+ * An expression which extracts a field from a struct, as in 'foo.bar'.
+ */
+struct FieldAccess : public Expression {
+    FieldAccess(std::unique_ptr<Expression> base, int fieldIndex)
+    : INHERITED(base->fPosition, kFieldAccess_Kind, base->fType->fields()[fieldIndex].fType)
+    , fBase(std::move(base))
+    , fFieldIndex(fieldIndex) {}
+
+    virtual std::string description() const override {
+        return fBase->description() + "." + fBase->fType->fields()[fFieldIndex].fName;
+    }
+
+    const std::unique_ptr<Expression> fBase;
+    const int fFieldIndex;
+
+    typedef Expression INHERITED;
+};
+
+} // namespace
+
+#endif