refactor: redesigned runtime errors with added functionality

src/main/wacc/backend/RuntimeError.scala

@@ -0,0 +1,104 @@
+package wacc
+
+import cats.data.Chain
+import wacc.assemblyIR._
+
+sealed trait RuntimeError {
+  def strLabel: String
+  def errStr: String
+  def errLabel: String
+
+  def stringDef: Chain[AsmLine] = Chain(
+    Directive.Int(errStr.length),
+    LabelDef(strLabel),
+    Directive.Asciz(errStr)
+  )
+
+  def generateHandler: Chain[AsmLine]
+
+}
+
+object RuntimeError {
+
+  // TODO: Refactor to mitigate imports and redeclared vals perhaps
+
+  import wacc.asmGenerator.stackAlign
+  import assemblyIR.Size._
+  import assemblyIR.RegName._
+
+  // private val RAX = Register(Q64, AX)
+  // private val EAX = Register(D32, AX)
+  private val RDI = Register(Q64, DI)
+  private val RIP = Register(Q64, IP)
+  // private val RBP = Register(Q64, BP)
+  private val RSI = Register(Q64, SI)
+  // private val RDX = Register(Q64, DX)
+  // private val RCX = Register(Q64, CX)
+
+  case object ZeroDivError extends RuntimeError {
+    val strLabel = ".L._errDivZero_str0"
+    val errStr = "fatal error: division or modulo by zero"
+    val errLabel = ".L._errDivZero"
+
+    def generateHandler: Chain[AsmLine] = Chain(
+      LabelDef(ZeroDivError.errLabel),
+      stackAlign,
+      Load(RDI, IndexAddress(RIP, LabelArg(ZeroDivError.strLabel))),
+      assemblyIR.Call(CLibFunc.PrintF),
+      Move(RDI, ImmediateVal(-1)),
+      assemblyIR.Call(CLibFunc.Exit)
+    )
+
+  }
+
+  case object BadChrError extends RuntimeError {
+    val strLabel = ".L._errBadChr_str0"
+    val errStr = "fatal error: int %d is not an ASCII character 0-127"
+    val errLabel = ".L._errBadChr"
+
+    def generateHandler: Chain[AsmLine] = Chain(
+      LabelDef(BadChrError.errLabel),
+      Pop(RSI),
+      stackAlign,
+      Load(RDI, IndexAddress(RIP, LabelArg(BadChrError.strLabel))),
+      assemblyIR.Call(CLibFunc.PrintF),
+      Move(RDI, ImmediateVal(255)),
+      assemblyIR.Call(CLibFunc.Exit)
+    )
+
+  }
+
+  case object NullPtrError extends RuntimeError {
+    val strLabel = ".L._errNullPtr_str0"
+    val errStr = "fatal error: null pair dereferenced or freed"
+    val errLabel = ".L._errNullPtr"
+
+    def generateHandler: Chain[AsmLine] = Chain(
+      LabelDef(NullPtrError.errLabel),
+      stackAlign,
+      Load(RDI, IndexAddress(RIP, LabelArg(NullPtrError.strLabel))),
+      assemblyIR.Call(CLibFunc.PrintF),
+      Move(RDI, ImmediateVal(255)),
+      assemblyIR.Call(CLibFunc.Exit)
+    )
+
+  }
+
+  case object OverflowError extends RuntimeError {
+    val strLabel = ".L._errOverflow_str0"
+    val errStr = "fatal error: integer overflow or underflow occurred"
+    val errLabel = ".L._errOverflow"
+
+    def generateHandler: Chain[AsmLine] = Chain(
+      LabelDef(OverflowError.errLabel),
+      stackAlign,
+      Load(RDI, IndexAddress(RIP, LabelArg(OverflowError.strLabel))),
+      assemblyIR.Call(CLibFunc.PrintF),
+      Move(RDI, ImmediateVal(255)),
+      assemblyIR.Call(CLibFunc.Exit)
+    )
+
+  }
+
+  val all: Chain[RuntimeError] = Chain(ZeroDivError, BadChrError, NullPtrError, OverflowError)
+}