A32: Introduce PreCodeTranslationHook

src/dynarmic/backend/x64/a32_interface.cpp

@@ -161,7 +161,7 @@ private:
             PerformCacheInvalidation();
         }
 
-        IR::Block ir_block = A32::Translate(A32::LocationDescriptor{descriptor}, [this](u32 vaddr) { return conf.callbacks->MemoryReadCode(vaddr); }, {conf.arch_version, conf.define_unpredictable_behaviour, conf.hook_hint_instructions});
+        IR::Block ir_block = A32::Translate(A32::LocationDescriptor{descriptor}, conf.callbacks, {conf.arch_version, conf.define_unpredictable_behaviour, conf.hook_hint_instructions});
         if (conf.HasOptimization(OptimizationFlag::GetSetElimination)) {
             Optimization::A32GetSetElimination(ir_block);
             Optimization::DeadCodeElimination(ir_block);

src/dynarmic/frontend/A32/translate/translate.cpp

@@ -3,17 +3,18 @@
  * SPDX-License-Identifier: 0BSD
  */
 
-#include "dynarmic/frontend/A32/location_descriptor.h"
 #include "dynarmic/frontend/A32/translate/translate.h"
+
+#include "dynarmic/frontend/A32/location_descriptor.h"
 #include "dynarmic/ir/basic_block.h"
 
 namespace Dynarmic::A32 {
 
-IR::Block TranslateArm(LocationDescriptor descriptor, MemoryReadCodeFuncType memory_read_code, const TranslationOptions& options);
+IR::Block TranslateArm(LocationDescriptor descriptor, TranslateCallbacks* tcb, const TranslationOptions& options);
-IR::Block TranslateThumb(LocationDescriptor descriptor, MemoryReadCodeFuncType memory_read_code, const TranslationOptions& options);
+IR::Block TranslateThumb(LocationDescriptor descriptor, TranslateCallbacks* tcb, const TranslationOptions& options);
 
-IR::Block Translate(LocationDescriptor descriptor, MemoryReadCodeFuncType memory_read_code, const TranslationOptions& options) {
+IR::Block Translate(LocationDescriptor descriptor, TranslateCallbacks* tcb, const TranslationOptions& options) {
-    return (descriptor.TFlag() ? TranslateThumb : TranslateArm)(descriptor, memory_read_code, options);
+    return (descriptor.TFlag() ? TranslateThumb : TranslateArm)(descriptor, tcb, options);
 }
 
 bool TranslateSingleArmInstruction(IR::Block& block, LocationDescriptor descriptor, u32 instruction);

src/dynarmic/frontend/A32/translate/translate.h

@@ -14,6 +14,7 @@ class Block;
 namespace Dynarmic::A32 {
 
 class LocationDescriptor;
+struct TranslateCallbacks;
 
 using MemoryReadCodeFuncType = std::function<u32(u32 vaddr)>;
 
@@ -34,11 +35,11 @@ struct TranslationOptions {
 /**
  * This function translates instructions in memory into our intermediate representation.
  * @param descriptor The starting location of the basic block. Includes information like PC, Thumb state, &c.
- * @param memory_read_code The function we should use to read emulated memory.
+ * @param tcb The callbacks we should use to read emulated memory.
  * @param options Configures how certain instructions are translated.
  * @return A translated basic block in the intermediate representation.
  */
-IR::Block Translate(LocationDescriptor descriptor, MemoryReadCodeFuncType memory_read_code, const TranslationOptions& options);
+IR::Block Translate(LocationDescriptor descriptor, TranslateCallbacks* tcb, const TranslationOptions& options);
 
 /**
  * This function translates a single provided instruction into our intermediate representation.

src/dynarmic/frontend/A32/translate/translate_arm.cpp

@@ -11,13 +11,14 @@
 #include "dynarmic/frontend/A32/translate/conditional_state.h"
 #include "dynarmic/frontend/A32/translate/impl/translate.h"
 #include "dynarmic/frontend/A32/translate/translate.h"
+#include "dynarmic/frontend/A32/translate/translate_callbacks.h"
 #include "dynarmic/frontend/A32/types.h"
 #include "dynarmic/interface/A32/config.h"
 #include "dynarmic/ir/basic_block.h"
 
 namespace Dynarmic::A32 {
 
-IR::Block TranslateArm(LocationDescriptor descriptor, MemoryReadCodeFuncType memory_read_code, const TranslationOptions& options) {
+IR::Block TranslateArm(LocationDescriptor descriptor, TranslateCallbacks* tcb, const TranslationOptions& options) {
     const bool single_step = descriptor.SingleStepping();
 
     IR::Block block{descriptor};
@@ -26,9 +27,11 @@ IR::Block TranslateArm(LocationDescriptor descriptor, MemoryReadCodeFuncType mem
     bool should_continue = true;
     do {
         const u32 arm_pc = visitor.ir.current_location.PC();
-        const u32 arm_instruction = memory_read_code(arm_pc);
+        const u32 arm_instruction = tcb->MemoryReadCode(arm_pc);
         visitor.current_instruction_size = 4;
 
+        tcb->PreCodeTranslationHook(false, arm_pc, visitor.ir);
+
         if (const auto vfp_decoder = DecodeVFP<TranslatorVisitor>(arm_instruction)) {
             should_continue = vfp_decoder->get().call(visitor, arm_instruction);
         } else if (const auto asimd_decoder = DecodeASIMD<TranslatorVisitor>(arm_instruction)) {

src/dynarmic/frontend/A32/translate/translate_callbacks.h

@@ -0,0 +1,25 @@
+/* This file is part of the dynarmic project.
+ * Copyright (c) 2021 MerryMage
+ * SPDX-License-Identifier: 0BSD
+ */
+#pragma once
+
+#include "dynarmic/common/common_types.h"
+
+namespace Dynarmic::A32 {
+
+using VAddr = u32;
+
+class IREmitter;
+
+struct TranslateCallbacks {
+    // All reads through this callback are 4-byte aligned.
+    // Memory must be interpreted as little endian.
+    virtual std::uint32_t MemoryReadCode(VAddr vaddr) = 0;
+
+    // Thus function is called before the instruction at pc is interpreted.
+    // IR code can be emitted by the callee prior to translation of the instruction.
+    virtual void PreCodeTranslationHook(bool is_thumb, VAddr pc, A32::IREmitter& ir) = 0;
+};
+
+} // namespace Dynarmic::A32

src/dynarmic/frontend/A32/translate/translate_thumb.cpp

@@ -16,6 +16,7 @@
 #include "dynarmic/frontend/A32/translate/conditional_state.h"
 #include "dynarmic/frontend/A32/translate/impl/translate.h"
 #include "dynarmic/frontend/A32/translate/translate.h"
+#include "dynarmic/frontend/A32/translate/translate_callbacks.h"
 #include "dynarmic/frontend/imm.h"
 #include "dynarmic/interface/A32/config.h"
 
@@ -40,8 +41,8 @@ bool IsUnconditionalInstruction(bool is_thumb_16, u32 instruction) {
     return false;
 }
 
-std::tuple<u32, ThumbInstSize> ReadThumbInstruction(u32 arm_pc, MemoryReadCodeFuncType memory_read_code) {
+std::tuple<u32, ThumbInstSize> ReadThumbInstruction(u32 arm_pc, TranslateCallbacks* tcb) {
-    u32 first_part = memory_read_code(arm_pc & 0xFFFFFFFC);
+    u32 first_part = tcb->MemoryReadCode(arm_pc & 0xFFFFFFFC);
     if ((arm_pc & 0x2) != 0) {
         first_part >>= 16;
     }
@@ -55,7 +56,7 @@ std::tuple<u32, ThumbInstSize> ReadThumbInstruction(u32 arm_pc, MemoryReadCodeFu
     // 32-bit thumb instruction
     // These always start with 0b11101, 0b11110 or 0b11111.
 
-    u32 second_part = memory_read_code((arm_pc + 2) & 0xFFFFFFFC);
+    u32 second_part = tcb->MemoryReadCode((arm_pc + 2) & 0xFFFFFFFC);
     if (((arm_pc + 2) & 0x2) != 0) {
         second_part >>= 16;
     }
@@ -84,7 +85,7 @@ bool MaybeVFPOrASIMDInstruction(u32 thumb_instruction) {
 
 } // local namespace
 
-IR::Block TranslateThumb(LocationDescriptor descriptor, MemoryReadCodeFuncType memory_read_code, const TranslationOptions& options) {
+IR::Block TranslateThumb(LocationDescriptor descriptor, TranslateCallbacks* tcb, const TranslationOptions& options) {
     const bool single_step = descriptor.SingleStepping();
 
     IR::Block block{descriptor};
@@ -93,10 +94,12 @@ IR::Block TranslateThumb(LocationDescriptor descriptor, MemoryReadCodeFuncType m
     bool should_continue = true;
     do {
         const u32 arm_pc = visitor.ir.current_location.PC();
-        const auto [thumb_instruction, inst_size] = ReadThumbInstruction(arm_pc, memory_read_code);
+        const auto [thumb_instruction, inst_size] = ReadThumbInstruction(arm_pc, tcb);
         const bool is_thumb_16 = inst_size == ThumbInstSize::Thumb16;
         visitor.current_instruction_size = is_thumb_16 ? 2 : 4;
 
+        tcb->PreCodeTranslationHook(false, arm_pc, visitor.ir);
+
         if (IsUnconditionalInstruction(is_thumb_16, thumb_instruction) || visitor.ThumbConditionPassed()) {
             if (is_thumb_16) {
                 if (const auto decoder = DecodeThumb16<TranslatorVisitor>(static_cast<u16>(thumb_instruction))) {

src/dynarmic/interface/A32/config.h

@@ -10,6 +10,7 @@
 #include <cstdint>
 #include <memory>
 
+#include "dynarmic/frontend/A32/translate/translate_callbacks.h"
 #include "dynarmic/interface/A32/arch_version.h"
 #include "dynarmic/interface/optimization_flags.h"
 
@@ -53,12 +54,16 @@ enum class Exception {
 };
 
 /// These function pointers may be inserted into compiled code.
-struct UserCallbacks {
+struct UserCallbacks : public TranslateCallbacks {
     virtual ~UserCallbacks() = default;
 
     // All reads through this callback are 4-byte aligned.
     // Memory must be interpreted as little endian.
-    virtual std::uint32_t MemoryReadCode(VAddr vaddr) { return MemoryRead32(vaddr); }
+    std::uint32_t MemoryReadCode(VAddr vaddr) override { return MemoryRead32(vaddr); }
+
+    // Thus function is called before the instruction at pc is interpreted.
+    // IR code can be emitted by the callee prior to translation of the instruction.
+    void PreCodeTranslationHook(bool /*is_thumb*/, VAddr /*pc*/, A32::IREmitter& /*ir*/) override {}
 
     // Reads through these callbacks may not be aligned.
     // Memory must be interpreted as if ENDIANSTATE == 0, endianness will be corrected by the JIT.
@@ -83,7 +88,7 @@ struct UserCallbacks {
     // return the same value at any point in time for this vaddr. The JIT may use this information
     // in optimizations.
     // A conservative implementation that always returns false is safe.
-    virtual bool IsReadOnlyMemory(VAddr /* vaddr */) { return false; }
+    virtual bool IsReadOnlyMemory(VAddr /*vaddr*/) { return false; }
 
     /// The interpreter must execute exactly num_instructions starting from PC.
     virtual void InterpreterFallback(VAddr pc, size_t num_instructions) = 0;

tests/A32/fuzz_thumb.cpp

@@ -19,10 +19,10 @@
 #include "./testenv.h"
 #include "dynarmic/common/bit_util.h"
 #include "dynarmic/common/common_types.h"
-#include "dynarmic/frontend/A32/disassembler/disassembler.h"
 #include "dynarmic/frontend/A32/FPSCR.h"
-#include "dynarmic/frontend/A32/location_descriptor.h"
 #include "dynarmic/frontend/A32/PSR.h"
+#include "dynarmic/frontend/A32/disassembler/disassembler.h"
+#include "dynarmic/frontend/A32/location_descriptor.h"
 #include "dynarmic/frontend/A32/translate/translate.h"
 #include "dynarmic/interface/A32/a32.h"
 #include "dynarmic/ir/basic_block.h"
@@ -177,7 +177,7 @@ static void RunInstance(size_t run_number, ThumbTestEnv& test_env, A32Unicorn<Th
         size_t num_insts = 0;
         while (num_insts < instructions_to_execute_count) {
             A32::LocationDescriptor descriptor = {u32(num_insts * 4), cpsr, A32::FPSCR{}};
-            IR::Block ir_block = A32::Translate(descriptor, [&test_env](u32 vaddr) { return test_env.MemoryReadCode(vaddr); }, {});
+            IR::Block ir_block = A32::Translate(descriptor, &test_env, {});
             Optimization::A32GetSetElimination(ir_block);
             Optimization::DeadCodeElimination(ir_block);
             Optimization::A32ConstantMemoryReads(ir_block, &test_env);