initial checkin of SkSL compiler

src/sksl/ast/SkSLASTInterfaceBlock.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_ASTINTERFACEBLOCK
+#define SKSL_ASTINTERFACEBLOCK
+
+#include "SkSLASTVarDeclaration.h"
+
+namespace SkSL {
+
+/**
+ * An interface block, as in:
+ *
+ * out gl_PerVertex {
+ *   layout(builtin=0) vec4 gl_Position;
+ *   layout(builtin=1) float gl_PointSize;
+ * };
+ */
+struct ASTInterfaceBlock : public ASTDeclaration {
+    // valueName is empty when it was not present in the source
+    ASTInterfaceBlock(Position position,
+                      ASTModifiers modifiers, 
+                      std::string interfaceName, 
+                      std::string valueName, 
+                      std::vector<std::unique_ptr<ASTVarDeclaration>> declarations)
+    : INHERITED(position, kInterfaceBlock_Kind)
+    , fModifiers(modifiers)
+    , fInterfaceName(std::move(interfaceName))
+    , fValueName(std::move(valueName))
+    , fDeclarations(std::move(declarations)) {}
+
+    std::string description() const override {
+        std::string result = fModifiers.description() + fInterfaceName + " {\n";
+        for (size_t i = 0; i < fDeclarations.size(); i++) {
+            result += fDeclarations[i]->description() + "\n";
+        }
+        result += "}";
+        if (fValueName.length()) {
+            result += " " + fValueName;
+        }
+        return result + ";";
+    }
+
+    const ASTModifiers fModifiers;
+    const std::string fInterfaceName;
+    const std::string fValueName;
+    const std::vector<std::unique_ptr<ASTVarDeclaration>> fDeclarations;
+
+    typedef ASTDeclaration INHERITED;
+};
+
+} // namespace
+
+#endif