Refactor ControlInstructions and VMThread

fernandezseb · Jan 23, 2024 · 1c1ee10 · 1c1ee10
1 parent 5857dea
commit 1c1ee10
Show file tree

Hide file tree

Showing 3 changed files with 31 additions and 92 deletions.
diff --git a/src/VM/Instructions/ControlInstructions.cpp b/src/VM/Instructions/ControlInstructions.cpp
@@ -18,6 +18,13 @@
 #include "VM/VM.h"
 #include "Data/Variable.h"
 
+static void returnCat1Var(VMThread* thread)
+{
+    const Variable returnVal = thread->m_currentFrame->popOperand();
+    thread->popFrame();
+    thread->returnVar(returnVal);
+}
+
 void gotoInstruction(INSTRUCTION_ARGS)
 {
     u1 byte1 = args[0];
@@ -30,98 +37,27 @@ void gotoInstruction(INSTRUCTION_ARGS)
 
 void freturnInstruction(INSTRUCTION_ARGS)
 {
-    StackFrame* stackFrame = thread->m_currentFrame;
-    thread->m_pc = stackFrame->previousPc;
-    thread->m_currentClass = stackFrame->previousClass;
-    thread->m_currentMethod = stackFrame->previousMethod;
-
-    Variable returnVal = thread->m_currentFrame->popOperand();
-
-    thread->m_stack.frames.pop_back();
-    if (thread->m_stack.frames.size() > 0)
-    {
-        thread->m_currentFrame = &thread->m_stack.frames[thread->m_stack.frames.size()-1];
-        thread->m_currentFrame->operands.push_back(returnVal);
-    } else
-    {
-        thread->m_currentFrame = 0;
-    }
+    returnCat1Var(thread);
 }
 
 void ireturnInstruction(INSTRUCTION_ARGS)
 {
-    StackFrame* stackFrame = thread->m_currentFrame;
-    thread->m_pc = stackFrame->previousPc;
-    thread->m_currentClass = stackFrame->previousClass;
-    thread->m_currentMethod = stackFrame->previousMethod;
-
-    Variable returnVal = thread->m_currentFrame->popOperand();
-
-    thread->m_stack.frames.pop_back();
-    if (thread->m_stack.frames.size() > 0)
-    {
-        thread->m_currentFrame = &thread->m_stack.frames[thread->m_stack.frames.size()-1];
-        thread->m_currentFrame->operands.push_back(returnVal);
-    } else
-    {
-        thread->m_currentFrame = 0;
-    }
+    returnCat1Var(thread);
 }
 
 void dreturnInstruction(INSTRUCTION_ARGS) {
-    StackFrame* stackFrame = thread->m_currentFrame;
-    thread->m_pc = stackFrame->previousPc;
-    thread->m_currentClass = stackFrame->previousClass;
-    thread->m_currentMethod = stackFrame->previousMethod;
-
-    Variable lowByte = thread->m_currentFrame->popOperand();
-    Variable highByte = thread->m_currentFrame->popOperand();
-
-    thread->m_stack.frames.pop_back();
-    if (thread->m_stack.frames.size() > 0)
-    {
-        thread->m_currentFrame = &thread->m_stack.frames[thread->m_stack.frames.size()-1];
-        thread->m_currentFrame->operands.push_back(highByte);
-        thread->m_currentFrame->operands.push_back(lowByte);
-    } else
-    {
-        thread->m_currentFrame = 0;
-    }
+    const Variable lowByte = thread->m_currentFrame->popOperand();
+    const Variable highByte = thread->m_currentFrame->popOperand();
+    thread->popFrame();
+    thread->returnVar(highByte, lowByte);
 }
 
 void areturnInstruction(INSTRUCTION_ARGS)
 {
-    StackFrame* stackFrame = thread->m_currentFrame;
-    thread->m_pc = stackFrame->previousPc;
-    thread->m_currentClass = stackFrame->previousClass;
-    thread->m_currentMethod = stackFrame->previousMethod;
-
-    Variable returnVal = thread->m_currentFrame->popOperand();
-
-
-    thread->m_stack.frames.pop_back();
-
-    StackFrame* nonNativeFrame = thread->getTopFrameNonNative();
-    thread->m_currentFrame = &thread->m_stack.frames[thread->m_stack.frames.size()-1];
-    if (nonNativeFrame != nullptr)
-    {
-        nonNativeFrame->operands.push_back(returnVal);
-    }
-
+    returnCat1Var(thread);
 }
 
 void returnInstruction(INSTRUCTION_ARGS)
 {
-    StackFrame* stackFrame = thread->m_currentFrame;
-    thread->m_pc = stackFrame->previousPc;
-    thread->m_currentClass = stackFrame->previousClass;
-    thread->m_currentMethod = stackFrame->previousMethod;
-    thread->m_stack.frames.pop_back();
-    if (thread->m_stack.frames.size() > 0)
-    {
-        thread->m_currentFrame = &thread->m_stack.frames[thread->m_stack.frames.size()-1];
-    } else
-    {
-        thread->m_currentFrame = 0;
-    }
+    thread->popFrame();
 }
diff --git a/src/VM/VMThread.cpp b/src/VM/VMThread.cpp
@@ -19,6 +19,8 @@
 
 #include <stack>
 
+static constexpr std::string_view NoNonNativeStackFrameFound{"Can't return to previous frame because there is no previous non-native frame"};
+
 void VMThread::pushStackFrameWithoutParams(ClassInfo* classInfo, const MethodInfo* methodInfo)
 {
     StackFrame stackFrame;
@@ -123,9 +125,9 @@ void VMThread::pushStackFrameSpecial(ClassInfo* classInfo, const MethodInfo* met
     }
 }
 
-void VMThread::internalError(const char* error)
+void VMThread::internalError(const std::string_view error) const
 {
-    fprintf(stdout, "Unhandled VM error in thread \"%s\": %s\n", m_name.data(), error);
+    fprintf(stdout, "Unhandled VM error in thread \"%s\": %s\n", m_name.data(), error.data());
     for (i8 currentFrame = m_stack.frames.size() - 1; currentFrame >= 0; --currentFrame)
     {
         const StackFrame frame = m_stack.frames[currentFrame];
@@ -155,26 +157,27 @@ StackFrame* VMThread::getTopFrameNonNative()
 
 void VMThread::returnVar(const Variable returnValue)
 {
-    if (m_stack.frames.size() > 1)
+    StackFrame* targetFrame = getTopFrameNonNative();
+    if (targetFrame != nullptr)
     {
-        StackFrame* previousStackFrame = &m_stack.frames[m_stack.frames.size()-2];
-        previousStackFrame->operands.push_back(returnValue);
-    } else
+        targetFrame->operands.push_back(returnValue);
+    }
+    else
     {
-        internalError("Can't return to previous frame because there is no previous frame");
+        internalError(NoNonNativeStackFrameFound);
     }
 }
 
 void VMThread::returnVar(Variable highByte, Variable lowByte)
 {
-    if (m_stack.frames.size() > 1)
+    StackFrame* targetFrame = getTopFrameNonNative();
+    if (targetFrame != nullptr)
     {
-        StackFrame* previousStackFrame = &m_stack.frames[m_stack.frames.size()-2];
-        previousStackFrame->operands.push_back(highByte);
-        previousStackFrame->operands.push_back(lowByte);
+        targetFrame->operands.push_back(highByte);
+        targetFrame->operands.push_back(lowByte);
     } else
     {
-        internalError("Can't return to previous frame because there is no previous frame");
+        internalError(NoNonNativeStackFrameFound);
     }
 }
 

diff --git a/src/VM/VMThread.h b/src/VM/VMThread.h
@@ -29,7 +29,7 @@ class VMThread
     void pushStackFrameSpecial(ClassInfo* classInfo, const MethodInfo* methodInfo, StackFrame* previousFrame, JavaHeap* heap);
     void returnVar(Variable returnValue);
     void returnVar(Variable highByte, Variable lowByte);
-    void internalError(const char* error);
+    void internalError(std::string_view error) const;
 
     StackFrame* getTopFrameNonNative();
 };