Start implementing Thumb disassembler

src/frontend/disassembler_thumb.cpp

@@ -0,0 +1,141 @@
+/* This file is part of the dynarmic project.
+ * Copyright (c) 2016 MerryMage
+ * This software may be used and distributed according to the terms of the GNU
+ * General Public License version 2 or any later version.
+ */
+
+#include <cstdlib>
+#include <string>
+
+#include "common/bit_util.h"
+#include "common/string_util.h"
+#include "frontend/arm_types.h"
+#include "frontend/decoder/thumb1.h"
+
+namespace Dynarmic {
+namespace Arm {
+
+class DisassemblerVisitor {
+public:
+    const char* CondStr(Cond cond) {
+        switch (cond) {
+            case Cond::EQ:
+                return "eq";
+            case Cond::NE:
+                return "ne";
+            case Cond::CS:
+                return "cs";
+            case Cond::CC:
+                return "cc";
+            case Cond::MI:
+                return "mi";
+            case Cond::PL:
+                return "pl";
+            case Cond::VS:
+                return "vs";
+            case Cond::VC:
+                return "vc";
+            case Cond::HI:
+                return "hi";
+            case Cond::LS:
+                return "ls";
+            case Cond::GE:
+                return "ge";
+            case Cond::LT:
+                return "lt";
+            case Cond::GT:
+                return "gt";
+            case Cond::LE:
+                return "le";
+            case Cond::AL:
+                return "";
+            case Cond::NV:
+                break;
+        }
+        assert(false);
+        return "<internal error>";
+    }
+
+    template<typename T>
+    const char* SignStr(T value) {
+        return value >= 0 ? "+" : "-";
+    }
+
+    const char* RegStr(Reg reg) {
+        switch (reg) {
+            case Reg::R0:
+                return "r0";
+            case Reg::R1:
+                return "r1";
+            case Reg::R2:
+                return "r2";
+            case Reg::R3:
+                return "r3";
+            case Reg::R4:
+                return "r4";
+            case Reg::R5:
+                return "r5";
+            case Reg::R6:
+                return "r6";
+            case Reg::R7:
+                return "r7";
+            case Reg::R8:
+                return "r8";
+            case Reg::R9:
+                return "r9";
+            case Reg::R10:
+                return "r10";
+            case Reg::R11:
+                return "r11";
+            case Reg::R12:
+                return "r12";
+            case Reg::R13:
+                return "sp";
+            case Reg::R14:
+                return "lr";
+            case Reg::R15:
+                return "pc";
+            case Reg::INVALID_REG:
+                break;
+        }
+        assert(false);
+        return "<internal error>";
+    }
+
+    std::string thumb1_LSL_imm(Imm5 imm5, Reg m, Reg d) {
+        return Common::StringFromFormat("lsls %s, %s, #%u", RegStr(d), RegStr(m), imm5);
+    }
+
+    std::string thumb1_LSR_imm(Imm5 imm5, Reg m, Reg d) {
+        return Common::StringFromFormat("lsrs %s, %s, #%u", RegStr(d), RegStr(m), imm5);
+    }
+
+    std::string thumb1_ASR_imm(Imm5 imm5, Reg m, Reg d) {
+        return Common::StringFromFormat("asrs %s, %s, #%u", RegStr(d), RegStr(m), imm5);
+    }
+
+    std::string thumb1_LSL_reg(Reg d_n, Reg m) {
+        return Common::StringFromFormat("lsls %s, %s", RegStr(d_n), RegStr(m));
+    }
+
+    std::string thumb1_LSR_reg(Reg d_n, Reg m) {
+        return Common::StringFromFormat("lsrs %s, %s", RegStr(d_n), RegStr(m));
+    }
+
+    std::string thumb1_ASR_reg(Reg d_n, Reg m) {
+        return Common::StringFromFormat("asrs %s, %s", RegStr(d_n), RegStr(m));
+    }
+
+    std::string thumb1_UDF() {
+        return Common::StringFromFormat("udf");
+    }
+};
+
+std::string DisassembleThumb16(u16 instruction) {
+    DisassemblerVisitor visitor;
+    auto decoder = DecodeThumb16<DisassemblerVisitor>(instruction);
+    return !decoder ? Common::StringFromFormat("UNKNOWN: %x", instruction) : decoder->call(visitor, instruction);
+}
+
+} // namespace Arm
+} // namespace Dynarmic