initial checkin of SkSL compiler
BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1984363002
CQ_EXTRA_TRYBOTS=client.skia.compile:Build-Ubuntu-GCC-x86_64-Release-CMake-Trybot,Build-Mac-Clang-x86_64-Release-CMake-Trybot
Review-Url: https://codereview.chromium.org/1984363002
diff --git a/src/sksl/ir/SkSLIndexExpression.h b/src/sksl/ir/SkSLIndexExpression.h
new file mode 100644
index 0000000..538c656
--- /dev/null
+++ b/src/sksl/ir/SkSLIndexExpression.h
@@ -0,0 +1,64 @@
+/*
+ * 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_INDEX
+#define SKSL_INDEX
+
+#include "SkSLExpression.h"
+#include "SkSLUtil.h"
+
+namespace SkSL {
+
+/**
+ * Given a type, returns the type that will result from extracting an array value from it.
+ */
+static std::shared_ptr<Type> index_type(const Type& type) {
+ if (type.kind() == Type::kMatrix_Kind) {
+ if (type.componentType() == kFloat_Type) {
+ switch (type.columns()) {
+ case 2: return kVec2_Type;
+ case 3: return kVec3_Type;
+ case 4: return kVec4_Type;
+ default: ASSERT(false);
+ }
+ } else {
+ ASSERT(type.componentType() == kDouble_Type);
+ switch (type.columns()) {
+ case 2: return kDVec2_Type;
+ case 3: return kDVec3_Type;
+ case 4: return kDVec4_Type;
+ default: ASSERT(false);
+ }
+ }
+ }
+ return type.componentType();
+}
+
+/**
+ * An expression which extracts a value from an array or matrix, as in 'm[2]'.
+ */
+struct IndexExpression : public Expression {
+ IndexExpression(std::unique_ptr<Expression> base, std::unique_ptr<Expression> index)
+ : INHERITED(base->fPosition, kIndex_Kind, index_type(*base->fType))
+ , fBase(std::move(base))
+ , fIndex(std::move(index)) {
+ ASSERT(fIndex->fType == kInt_Type);
+ }
+
+ std::string description() const override {
+ return fBase->description() + "[" + fIndex->description() + "]";
+ }
+
+ const std::unique_ptr<Expression> fBase;
+ const std::unique_ptr<Expression> fIndex;
+
+ typedef Expression INHERITED;
+};
+
+} // namespace
+
+#endif