Debugger: Initial implementation of conditional breakpoints

Expression class to store compiled expressions and associated variable list.

Co-authored-by:  TryTwo <taolas@gmail.com>

Source/Core/Core/CMakeLists.txt

@@ -438,6 +438,8 @@ add_library(core
   PowerPC/CachedInterpreter/InterpreterBlockCache.h
   PowerPC/ConditionRegister.cpp
   PowerPC/ConditionRegister.h
+  PowerPC/Expression.cpp
+  PowerPC/Expression.h
   PowerPC/Interpreter/ExceptionUtils.h
   PowerPC/Interpreter/Interpreter_Branch.cpp
   PowerPC/Interpreter/Interpreter_FloatingPoint.cpp
@@ -582,6 +584,7 @@ PUBLIC
   cubeb
   discio
   enet
+  expr
   inputcommon
   ${MBEDTLS_LIBRARIES}
   pugixml

Source/Core/Core/PowerPC/BreakPoints.cpp

@@ -13,6 +13,7 @@
 #include "Common/DebugInterface.h"
 #include "Common/Logging/Log.h"
 #include "Core/Core.h"
+#include "Core/PowerPC/Expression.h"
 #include "Core/PowerPC/JitInterface.h"
 #include "Core/PowerPC/MMU.h"
 
@@ -35,17 +36,16 @@ bool BreakPoints::IsTempBreakPoint(u32 address) const
   });
 }
 
-bool BreakPoints::IsBreakPointBreakOnHit(u32 address) const
+const TBreakPoint* BreakPoints::GetBreakpoint(u32 address) const
 {
-  return std::any_of(m_breakpoints.begin(), m_breakpoints.end(), [address](const auto& bp) {
-    return bp.address == address && bp.break_on_hit;
+  auto bp = std::find_if(m_breakpoints.begin(), m_breakpoints.end(), [address](const auto& bp) {
+    return bp.is_enabled && bp.address == address;
   });
-}
 
-bool BreakPoints::IsBreakPointLogOnHit(u32 address) const
-{
-  return std::any_of(m_breakpoints.begin(), m_breakpoints.end(),
-                     [address](const auto& bp) { return bp.address == address && bp.log_on_hit; });
+  if (bp == m_breakpoints.end() || !EvaluateCondition(bp->condition))
+    return nullptr;
+
+  return &*bp;
 }
 
 BreakPoints::TBreakPointsStr BreakPoints::GetStrings() const
@@ -57,10 +57,16 @@ BreakPoints::TBreakPointsStr BreakPoints::GetStrings() const
     {
       std::ostringstream ss;
       ss.imbue(std::locale::classic());
-
-      ss << std::hex << bp.address << " " << (bp.is_enabled ? "n" : "")
-         << (bp.log_on_hit ? "l" : "") << (bp.break_on_hit ? "b" : "");
-      bp_strings.push_back(ss.str());
+      ss << fmt::format("${:08x} ", bp.address);
+      if (bp.is_enabled)
+        ss << "n";
+      if (bp.log_on_hit)
+        ss << "l";
+      if (bp.break_on_hit)
+        ss << "b";
+      if (bp.condition)
+        ss << "c " << bp.condition->GetText();
+      bp_strings.emplace_back(ss.str());
     }
   }
 
@@ -76,32 +82,43 @@ void BreakPoints::AddFromStrings(const TBreakPointsStr& bp_strings)
     std::istringstream iss(bp_string);
     iss.imbue(std::locale::classic());
 
+    if (iss.peek() == '$')
+      iss.ignore();
+
     iss >> std::hex >> bp.address;
     iss >> flags;
     bp.is_enabled = flags.find('n') != flags.npos;
     bp.log_on_hit = flags.find('l') != flags.npos;
     bp.break_on_hit = flags.find('b') != flags.npos;
+    if (flags.find('c') != std::string::npos)
+    {
+      iss >> std::ws;
+      std::string condition;
+      std::getline(iss, condition);
+      bp.condition = Expression::TryParse(condition);
+    }
     bp.is_temporary = false;
-    Add(bp);
+    Add(std::move(bp));
   }
 }
 
-void BreakPoints::Add(const TBreakPoint& bp)
+void BreakPoints::Add(TBreakPoint bp)
 {
   if (IsAddressBreakPoint(bp.address))
     return;
 
-  m_breakpoints.push_back(bp);
-
   JitInterface::InvalidateICache(bp.address, 4, true);
+
+  m_breakpoints.emplace_back(std::move(bp));
 }
 
 void BreakPoints::Add(u32 address, bool temp)
 {
-  BreakPoints::Add(address, temp, true, false);
+  BreakPoints::Add(address, temp, true, false, std::nullopt);
 }
 
-void BreakPoints::Add(u32 address, bool temp, bool break_on_hit, bool log_on_hit)
+void BreakPoints::Add(u32 address, bool temp, bool break_on_hit, bool log_on_hit,
+                      std::optional<Expression> condition)
 {
   // Only add new addresses
   if (IsAddressBreakPoint(address))
@@ -113,8 +130,9 @@ void BreakPoints::Add(u32 address, bool temp, bool break_on_hit, bool log_on_hit
   bp.break_on_hit = break_on_hit;
   bp.log_on_hit = log_on_hit;
   bp.address = address;
+  bp.condition = std::move(condition);
 
-  m_breakpoints.push_back(bp);
+  m_breakpoints.emplace_back(std::move(bp));
 
   JitInterface::InvalidateICache(address, 4, true);
 }

Source/Core/Core/PowerPC/BreakPoints.h

@@ -4,10 +4,12 @@
 #pragma once
 
 #include <cstddef>
+#include <optional>
 #include <string>
 #include <vector>
 
 #include "Common/CommonTypes.h"
+#include "Core/PowerPC/Expression.h"
 
 namespace Common
 {
@@ -21,6 +23,7 @@ struct TBreakPoint
   bool is_temporary = false;
   bool log_on_hit = false;
   bool break_on_hit = false;
+  std::optional<Expression> condition;
 };
 
 struct TMemCheck
@@ -59,13 +62,13 @@ public:
   bool IsAddressBreakPoint(u32 address) const;
   bool IsBreakPointEnable(u32 adresss) const;
   bool IsTempBreakPoint(u32 address) const;
-  bool IsBreakPointBreakOnHit(u32 address) const;
-  bool IsBreakPointLogOnHit(u32 address) const;
+  const TBreakPoint* GetBreakpoint(u32 address) const;
 
   // Add BreakPoint
-  void Add(u32 address, bool temp, bool break_on_hit, bool log_on_hit);
+  void Add(u32 address, bool temp, bool break_on_hit, bool log_on_hit,
+           std::optional<Expression> condition);
   void Add(u32 address, bool temp = false);
-  void Add(const TBreakPoint& bp);
+  void Add(TBreakPoint bp);
 
   // Modify Breakpoint
   bool ToggleBreakPoint(u32 address);

Source/Core/Core/PowerPC/Expression.cpp

@@ -0,0 +1,130 @@
+// Copyright 2020 Dolphin Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include "Core/PowerPC/Expression.h"
+
+#include <cstdlib>
+#include <optional>
+#include <string>
+#include <string_view>
+#include <utility>
+
+#include <expr.h>
+
+#include "Core/PowerPC/PowerPC.h"
+
+void ExprDeleter::operator()(expr* expression) const
+{
+  expr_destroy(expression, nullptr);
+}
+
+void ExprVarListDeleter::operator()(expr_var_list* vars) const
+{
+  // Free list elements
+  expr_destroy(nullptr, vars);
+  // Free list object
+  delete vars;
+}
+
+Expression::Expression(std::string_view text, ExprPointer ex, ExprVarListPointer vars)
+    : m_text(text), m_expr(std::move(ex)), m_vars(std::move(vars))
+{
+  for (auto* v = m_vars->head; v != nullptr; v = v->next)
+  {
+    const std::string_view name = v->name;
+    VarBinding bind;
+
+    if (name.length() >= 2 && name.length() <= 3)
+    {
+      if (name[0] == 'r' || name[0] == 'f')
+      {
+        char* end = nullptr;
+        const int index = std::strtol(name.data() + 1, &end, 10);
+        if (index >= 0 && index <= 31 && end == name.data() + name.length())
+        {
+          bind.type = name[0] == 'r' ? VarBindingType::GPR : VarBindingType::FPR;
+          bind.index = index;
+        }
+      }
+      else if (name == "lr")
+      {
+        bind.type = VarBindingType::SPR;
+        bind.index = SPR_LR;
+      }
+      else if (name == "ctr")
+      {
+        bind.type = VarBindingType::SPR;
+        bind.index = SPR_CTR;
+      }
+      else if (name == "pc")
+      {
+        bind.type = VarBindingType::PCtr;
+      }
+    }
+
+    m_binds.emplace_back(bind);
+  }
+}
+
+std::optional<Expression> Expression::TryParse(std::string_view text)
+{
+  ExprVarListPointer vars{new expr_var_list{}};
+  ExprPointer ex{expr_create(text.data(), text.length(), vars.get(), nullptr)};
+  if (!ex)
+    return std::nullopt;
+
+  return Expression{text, std::move(ex), std::move(vars)};
+}
+
+double Expression::Evaluate() const
+{
+  SynchronizeBindings(SynchronizeDirection::From);
+
+  double result = expr_eval(m_expr.get());
+
+  SynchronizeBindings(SynchronizeDirection::To);
+
+  return result;
+}
+
+void Expression::SynchronizeBindings(SynchronizeDirection dir) const
+{
+  auto bind = m_binds.begin();
+  for (auto* v = m_vars->head; v != nullptr; v = v->next, ++bind)
+  {
+    switch (bind->type)
+    {
+    case VarBindingType::Zero:
+      if (dir == SynchronizeDirection::From)
+        v->value = 0;
+      break;
+    case VarBindingType::GPR:
+      if (dir == SynchronizeDirection::From)
+        v->value = static_cast<double>(GPR(bind->index));
+      else
+        GPR(bind->index) = static_cast<u32>(static_cast<s64>(v->value));
+      break;
+    case VarBindingType::FPR:
+      if (dir == SynchronizeDirection::From)
+        v->value = rPS(bind->index).PS0AsDouble();
+      else
+        rPS(bind->index).SetPS0(v->value);
+      break;
+    case VarBindingType::SPR:
+      if (dir == SynchronizeDirection::From)
+        v->value = static_cast<double>(rSPR(bind->index));
+      else
+        rSPR(bind->index) = static_cast<u32>(static_cast<s64>(v->value));
+      break;
+    case VarBindingType::PCtr:
+      if (dir == SynchronizeDirection::From)
+        v->value = static_cast<double>(PC);
+      break;
+    }
+  }
+}
+
+std::string Expression::GetText() const
+{
+  return m_text;
+}

Source/Core/Core/PowerPC/Expression.h

@@ -0,0 +1,73 @@
+// Copyright 2020 Dolphin Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include <memory>
+#include <optional>
+#include <string>
+#include <string_view>
+#include <vector>
+
+struct expr;
+struct expr_var_list;
+
+struct ExprDeleter
+{
+  void operator()(expr* expression) const;
+};
+
+using ExprPointer = std::unique_ptr<expr, ExprDeleter>;
+
+struct ExprVarListDeleter
+{
+  void operator()(expr_var_list* vars) const;
+};
+
+using ExprVarListPointer = std::unique_ptr<expr_var_list, ExprVarListDeleter>;
+
+class Expression
+{
+public:
+  static std::optional<Expression> TryParse(std::string_view text);
+
+  double Evaluate() const;
+
+  std::string GetText() const;
+
+private:
+  enum class SynchronizeDirection
+  {
+    From,
+    To,
+  };
+
+  enum class VarBindingType
+  {
+    Zero,
+    GPR,
+    FPR,
+    SPR,
+    PCtr,
+  };
+
+  struct VarBinding
+  {
+    VarBindingType type = VarBindingType::Zero;
+    int index = -1;
+  };
+
+  Expression(std::string_view text, ExprPointer ex, ExprVarListPointer vars);
+
+  void SynchronizeBindings(SynchronizeDirection dir) const;
+
+  std::string m_text;
+  ExprPointer m_expr;
+  ExprVarListPointer m_vars;
+  std::vector<VarBinding> m_binds;
+};
+
+inline bool EvaluateCondition(const std::optional<Expression>& condition)
+{
+  return !condition || condition->Evaluate() != 0.0;
+}

Source/Core/Core/PowerPC/PowerPC.cpp

@@ -610,16 +610,18 @@ void CheckExternalExceptions()
 
 void CheckBreakPoints()
 {
-  if (!PowerPC::breakpoints.IsBreakPointEnable(PC))
+  const TBreakPoint* bp = PowerPC::breakpoints.GetBreakpoint(PC);
+
+  if (bp == nullptr)
     return;
 
-  if (PowerPC::breakpoints.IsBreakPointBreakOnHit(PC))
+  if (bp->break_on_hit)
   {
     CPU::Break();
     if (GDBStub::IsActive())
       GDBStub::TakeControl();
   }
-  if (PowerPC::breakpoints.IsBreakPointLogOnHit(PC))
+  if (bp->log_on_hit)
   {
     NOTICE_LOG_FMT(MEMMAP,
                    "BP {:08x} {}({:08x} {:08x} {:08x} {:08x} {:08x} {:08x} {:08x} {:08x} {:08x} "