From c17953978b16f82a3b2049f8b961275020c73dd0 Mon Sep 17 00:00:00 2001
From: Fernando Sahmkow <fsahmkow27@gmail.com>
Date: Thu, 27 Jun 2019 00:39:40 -0400
Subject: shader_ir: Initial Decompile Setup

---
 src/video_core/shader/ast.h | 184 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 184 insertions(+)
 create mode 100644 src/video_core/shader/ast.h

(limited to 'src/video_core/shader/ast.h')

diff --git a/src/video_core/shader/ast.h b/src/video_core/shader/ast.h
new file mode 100644
index 000000000..ca71543fb
--- /dev/null
+++ b/src/video_core/shader/ast.h
@@ -0,0 +1,184 @@
+// Copyright 2019 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <list>
+#include <memory>
+#include <optional>
+#include <string>
+#include <unordered_map>
+#include <vector>
+
+#include "video_core/shader/expr.h"
+#include "video_core/shader/node.h"
+
+namespace VideoCommon::Shader {
+
+class ASTBase;
+class ASTProgram;
+class ASTIf;
+class ASTBlockEncoded;
+class ASTVarSet;
+class ASTGoto;
+class ASTLabel;
+class ASTDoWhile;
+class ASTReturn;
+
+using ASTData = std::variant<ASTProgram, ASTIf, ASTBlockEncoded, ASTVarSet, ASTGoto, ASTLabel,
+                             ASTDoWhile, ASTReturn>;
+
+using ASTNode = std::shared_ptr<ASTBase>;
+
+class ASTProgram {
+public:
+    ASTProgram() = default;
+    std::list<ASTNode> nodes;
+};
+
+class ASTIf {
+public:
+    ASTIf(Expr condition, std::list<ASTNode> then_nodes, std::list<ASTNode> else_nodes)
+        : condition(condition), then_nodes{then_nodes}, else_nodes{then_nodes} {}
+    Expr condition;
+    std::list<ASTNode> then_nodes;
+    std::list<ASTNode> else_nodes;
+};
+
+class ASTBlockEncoded {
+public:
+    ASTBlockEncoded(u32 start, u32 end) : start{start}, end{end} {}
+    u32 start;
+    u32 end;
+};
+
+class ASTVarSet {
+public:
+    ASTVarSet(u32 index, Expr condition) : index{index}, condition{condition} {}
+    u32 index;
+    Expr condition;
+};
+
+class ASTLabel {
+public:
+    ASTLabel(u32 index) : index{index} {}
+    u32 index;
+};
+
+class ASTGoto {
+public:
+    ASTGoto(Expr condition, u32 label) : condition{condition}, label{label} {}
+    Expr condition;
+    u32 label;
+};
+
+class ASTDoWhile {
+public:
+    ASTDoWhile(Expr condition, std::list<ASTNode> loop_nodes)
+        : condition(condition), loop_nodes{loop_nodes} {}
+    Expr condition;
+    std::list<ASTNode> loop_nodes;
+};
+
+class ASTReturn {
+public:
+    ASTReturn(Expr condition, bool kills) : condition{condition}, kills{kills} {}
+    Expr condition;
+    bool kills;
+};
+
+class ASTBase {
+public:
+    explicit ASTBase(ASTNode parent, ASTData data) : parent{parent}, data{data} {}
+
+    template <class U, class... Args>
+    static ASTNode Make(ASTNode parent, Args&&... args) {
+        return std::make_shared<ASTBase>(parent, ASTData(U(std::forward<Args>(args)...)));
+    }
+
+    void SetParent(ASTNode new_parent) {
+        parent = new_parent;
+    }
+
+    ASTNode& GetParent() {
+        return parent;
+    }
+
+    const ASTNode& GetParent() const {
+        return parent;
+    }
+
+    u32 GetLevel() const {
+        u32 level = 0;
+        auto next = parent;
+        while (next) {
+            next = next->GetParent();
+            level++;
+        }
+        return level;
+    }
+
+    ASTData* GetInnerData() {
+        return &data;
+    }
+
+private:
+    ASTData data;
+    ASTNode parent;
+};
+
+class ASTManager final {
+public:
+    explicit ASTManager() {
+        main_node = ASTBase::Make<ASTProgram>(nullptr);
+        program = std::get_if<ASTProgram>(main_node->GetInnerData());
+    }
+
+    void DeclareLabel(u32 address) {
+        const auto pair = labels_map.emplace(address, labels_count);
+        if (pair.second) {
+            labels_count++;
+            labels.resize(labels_count);
+        }
+    }
+
+    void InsertLabel(u32 address) {
+        u32 index = labels_map[address];
+        ASTNode label = ASTBase::Make<ASTLabel>(main_node, index);
+        labels[index] = label;
+        program->nodes.push_back(label);
+    }
+
+    void InsertGoto(Expr condition, u32 address) {
+        u32 index = labels_map[address];
+        ASTNode goto_node = ASTBase::Make<ASTGoto>(main_node, condition, index);
+        gotos.push_back(goto_node);
+        program->nodes.push_back(goto_node);
+    }
+
+    void InsertBlock(u32 start_address, u32 end_address) {
+        ASTNode block = ASTBase::Make<ASTBlockEncoded>(main_node, start_address, end_address);
+        program->nodes.push_back(block);
+    }
+
+    void InsertReturn(Expr condition, bool kills) {
+        ASTNode node = ASTBase::Make<ASTReturn>(main_node, condition, kills);
+        program->nodes.push_back(node);
+    }
+
+    std::string Print();
+
+    void Decompile() {}
+
+private:
+    std::unordered_map<u32, u32> labels_map{};
+    u32 labels_count{};
+    std::vector<ASTNode> labels{};
+    std::list<ASTNode> gotos{};
+    u32 variables{};
+    ASTProgram* program;
+    ASTNode main_node;
+};
+
+} // namespace VideoCommon::Shader
-- 
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