1 files changed, 231 insertions, 0 deletions
diff --git a/gfx/skia/skia/include/sksl/DSLVar.h b/gfx/skia/skia/include/sksl/DSLVar.h
new file mode 100644
index 0000000000..f052a525e3
--- /dev/null
+++ b/gfx/skia/skia/include/sksl/DSLVar.h
@@ -0,0 +1,231 @@
+/*
+ * Copyright 2020 Google LLC
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef SKSL_DSL_VAR
+#define SKSL_DSL_VAR
+
+#include "include/private/SkSLStatement.h"
+#include "include/sksl/DSLExpression.h"
+#include "include/sksl/DSLModifiers.h"
+#include "include/sksl/DSLType.h"
+#include "include/sksl/SkSLPosition.h"
+
+#include <cstdint>
+#include <memory>
+#include <string_view>
+#include <utility>
+
+namespace SkSL {
+
+class Expression;
+class ExpressionArray;
+class Variable;
+enum class VariableStorage : int8_t;
+
+namespace dsl {
+
+class DSLVarBase {
+public:
+    /**
+     * Constructs a new variable with the specified type and name.
+     */
+    DSLVarBase(VariableStorage storage, DSLType type, std::string_view name,
+               DSLExpression initialValue, Position pos, Position namePos);
+
+    DSLVarBase(VariableStorage storage, const DSLModifiers& modifiers, DSLType type,
+               std::string_view name, DSLExpression initialValue, Position pos, Position namePos);
+
+    DSLVarBase(DSLVarBase&&) = default;
+
+    std::string_view name() const {
+        return fName;
+    }
+
+    const DSLModifiers& modifiers() const {
+        return fModifiers;
+    }
+
+    VariableStorage storage() const {
+        return fStorage;
+    }
+
+    DSLExpression x() {
+        return DSLExpression(*this).x();
+    }
+
+    DSLExpression y() {
+        return DSLExpression(*this).y();
+    }
+
+    DSLExpression z() {
+        return DSLExpression(*this).z();
+    }
+
+    DSLExpression w() {
+        return DSLExpression(*this).w();
+    }
+
+    DSLExpression r() {
+        return DSLExpression(*this).r();
+    }
+
+    DSLExpression g() {
+        return DSLExpression(*this).g();
+    }
+
+    DSLExpression b() {
+        return DSLExpression(*this).b();
+    }
+
+    DSLExpression a() {
+        return DSLExpression(*this).a();
+    }
+
+    DSLExpression field(std::string_view name) {
+        return DSLExpression(*this).field(name);
+    }
+
+    DSLExpression operator[](DSLExpression&& index);
+
+    DSLExpression operator++() {
+        return ++DSLExpression(*this);
+    }
+
+    DSLExpression operator++(int) {
+        return DSLExpression(*this)++;
+    }
+
+    DSLExpression operator--() {
+        return --DSLExpression(*this);
+    }
+
+    DSLExpression operator--(int) {
+        return DSLExpression(*this)--;
+    }
+
+    template <class T> DSLExpression assign(T&& param) {
+        return this->assignExpression(DSLExpression(std::forward<T>(param)));
+    }
+
+protected:
+    /**
+     * Creates an empty, unpopulated var. Can be replaced with a real var later via `swap`.
+     */
+    DSLVarBase(VariableStorage storage) : fType(kVoid_Type), fStorage(storage) {}
+
+    DSLExpression assignExpression(DSLExpression other);
+
+    void swap(DSLVarBase& other);
+
+    DSLModifiers fModifiers;
+    // We only need to keep track of the type here so that we can create the SkSL::Variable. For
+    // predefined variables this field is unnecessary, so we don't bother tracking it and just set
+    // it to kVoid; in other words, you shouldn't generally be relying on this field to be correct.
+    // If you need to determine the variable's type, look at DSLWriter::Var(...)->type() instead.
+    DSLType fType;
+    std::unique_ptr<SkSL::Statement> fDeclaration;
+    SkSL::Variable* fVar = nullptr;
+    Position fNamePosition;
+    std::string_view fName;
+    DSLExpression fInitialValue;
+    Position fPosition;
+    VariableStorage fStorage;
+    bool fInitialized = false;
+
+    friend class DSLCore;
+    friend class DSLFunction;
+    friend class DSLWriter;
+};
+
+/**
+ * A local variable.
+ */
+class DSLVar : public DSLVarBase {
+public:
+    DSLVar();
+
+    DSLVar(DSLType type, std::string_view name, DSLExpression initialValue = DSLExpression(),
+           Position pos = {}, Position namePos = {});
+
+    DSLVar(const DSLModifiers& modifiers, DSLType type, std::string_view name,
+           DSLExpression initialValue = DSLExpression(), Position pos = {}, Position namePos = {});
+
+    DSLVar(DSLVar&&) = default;
+
+    void swap(DSLVar& other);
+
+private:
+    using INHERITED = DSLVarBase;
+};
+
+/**
+ * A global variable.
+ */
+class DSLGlobalVar : public DSLVarBase {
+public:
+    DSLGlobalVar();
+
+    DSLGlobalVar(DSLType type, std::string_view name, DSLExpression initialValue = DSLExpression(),
+                 Position pos = {}, Position namePos = {});
+
+    DSLGlobalVar(const DSLModifiers& modifiers, DSLType type, std::string_view name,
+                 DSLExpression initialValue = DSLExpression(),
+                 Position pos = {}, Position namePos = {});
+
+    DSLGlobalVar(const char* name);
+
+    DSLGlobalVar(DSLGlobalVar&&) = default;
+
+    void swap(DSLGlobalVar& other);
+
+    /**
+     * Implements the following method calls:
+     *     half4 shader::eval(float2 coords);
+     *     half4 colorFilter::eval(half4 input);
+     */
+    DSLExpression eval(DSLExpression x, Position pos = {});
+
+    /**
+     * Implements the following method call:
+     *     half4 blender::eval(half4 src, half4 dst);
+     */
+    DSLExpression eval(DSLExpression x, DSLExpression y, Position pos = {});
+
+private:
+    DSLExpression eval(ExpressionArray args, Position pos);
+
+    std::unique_ptr<SkSL::Expression> methodCall(std::string_view methodName, Position pos);
+
+    using INHERITED = DSLVarBase;
+};
+
+/**
+ * A function parameter.
+ */
+class DSLParameter : public DSLVarBase {
+public:
+    DSLParameter();
+
+    DSLParameter(DSLType type, std::string_view name, Position pos = {}, Position namePos = {});
+
+    DSLParameter(const DSLModifiers& modifiers, DSLType type, std::string_view name,
+                 Position pos = {}, Position namePos = {});
+
+    DSLParameter(DSLParameter&&) = default;
+
+    void swap(DSLParameter& other);
+
+private:
+    using INHERITED = DSLVarBase;
+};
+
+} // namespace dsl
+
+} // namespace SkSL
+
+
+#endif