introduce ir nop to fix loop bugs

bir/src/main/kotlin/gay/pizza/pork/bir/IrNop.kt

@@ -0,0 +1,5 @@
+package gay.pizza.pork.bir
+
+object IrNop : IrCodeElement() {
+  override fun crawl(block: (IrElement) -> Unit) {}
+}

bir/src/main/kotlin/gay/pizza/pork/bir/IrVisitor.kt

@@ -30,6 +30,7 @@ interface IrVisitor<T> {
   fun visitIrIndex(ir: IrIndex): T
   fun visitIrListSize(ir: IrListSize): T
   fun visitIrDeclare(ir: IrDeclare): T
+  fun visitIrNop(ir: IrNop): T
 
   fun visit(ir: IrElement): T = when (ir) {
     is IrBreak -> visitIrBeak(ir)
@@ -61,5 +62,6 @@ interface IrVisitor<T> {
     is IrIndex -> visitIrIndex(ir)
     is IrListSize -> visitIrListSize(ir)
     is IrDeclare -> visitIrDeclare(ir)
+    IrNop -> visitIrNop(ir as IrNop)
   }
 }

compiler/src/main/kotlin/gay/pizza/pork/compiler/AstIrEmitter.kt

@@ -20,10 +20,26 @@ class AstIrEmitter(
   fun createFunctionArguments(functionDefinition: FunctionDefinition) {
     val functionSymbols = mutableListOf<IrFunctionArgument>()
     for (arg in functionDefinition.arguments) {
+      if (arg.typeSpec != null) {
+        validateTypeSpec(arg.typeSpec!!)
+      }
       val symbol = createLocalVariable(arg.symbol)
       functionSymbols.add(IrFunctionArgument(symbol))
     }
     functionArguments = functionSymbols
+    if (functionDefinition.returnType != null) {
+      validateTypeSpec(functionDefinition.returnType!!)
+    }
+  }
+
+  fun checkLetDefinition(letDefinition: LetDefinition) {
+    if (letDefinition.typeSpec != null) {
+      validateTypeSpec(letDefinition.typeSpec!!)
+    }
+  }
+
+  private fun validateTypeSpec(typeSpec: TypeSpec) {
+    lookup(typeSpec.symbol) ?: throw CompileError("Unresolved type: ${typeSpec.symbol.id}")
   }
 
   private fun startLoop(): IrSymbol {
@@ -204,7 +220,7 @@ class AstIrEmitter(
     IrConditional(
       conditional = node.condition.visit(this),
       ifTrue = node.thenBlock.visit(this),
-      ifFalse = node.elseBlock?.visit(this) ?: IrNoneConstant
+      ifFalse = node.elseBlock?.visit(this) ?: IrNop
     )
 
   override fun visitIndexedBy(node: IndexedBy): IrCodeElement = IrIndex(
@@ -240,6 +256,9 @@ class AstIrEmitter(
     IrIntegerConstant(node.value)
 
   override fun visitLetAssignment(node: LetAssignment): IrCodeElement {
+    if (node.typeSpec != null) {
+      validateTypeSpec(node.typeSpec!!)
+    }
     val symbol = createLocalVariable(node.symbol)
     return IrDeclare(symbol, node.value.visit(this))
   }
@@ -295,6 +314,9 @@ class AstIrEmitter(
   }
 
   override fun visitVarAssignment(node: VarAssignment): IrCodeElement {
+    if (node.typeSpec != null) {
+      validateTypeSpec(node.typeSpec!!)
+    }
     val local = createLocalVariable(node.symbol)
     return IrDeclare(local, node.value.visit(this))
   }

compiler/src/main/kotlin/gay/pizza/pork/compiler/CompilableSymbol.kt

@@ -52,6 +52,7 @@ class CompilableSymbol(val compilableSlab: CompilableSlab, val scopeSymbol: Scop
 
       else -> {
         val letDefinition = scopeSymbol.definition as LetDefinition
+        irCodeEmitter.checkLetDefinition(letDefinition)
         letDefinition.value
       }
     }

compiler/src/main/kotlin/gay/pizza/pork/compiler/IrStubOpEmitter.kt

@@ -194,6 +194,8 @@ class IrStubOpEmitter(val irDefinition: IrDefinition, val code: CodeBuilder) : I
     store(variable)
   }
 
+  override fun visitIrNop(ir: IrNop) {}
+
   override fun visitIrStore(ir: IrStore) {
     visit(ir.value)
     val variable = code.localState.createOrFindLocal(ir.target)

examples/ack.pork

@@ -0,0 +1,17 @@
+/* ackermann function */
+func ack(m: int32, n: int32): int32 {
+  if m == 0 {
+    return n + 1
+  }
+
+  if n == 0 {
+    return ack(m - 1, 1)
+  }
+
+  return ack(m - 1, ack(m, n - 1))
+}
+
+export func main() {
+  let result: int32 = ack(3, 1)
+  println(result)
+}

examples/ffi.pork

@@ -1,14 +1,7 @@
 import std ffi.struct
 
-export let timeval = ffiStructDefine(
+export type timeval = native ffi "long" "seconds" "unsigned int" "microseconds"
-  "long", "seconds",
+export type timezone = native ffi "int" "minutes_greenwich" "int" "dst_time"
-  "unsigned int", "microseconds"
-)
-
-export let timezone = ffiStructDefine(
-  "int", "minutes_greenwich",
-  "int", "dst_time"
-)
 
 func gettimeofday(value, tz)
   native ffi "c" "int gettimeofday(struct timeval*, struct timezone*)"

examples/fib.pork

@@ -8,6 +8,6 @@ func fib(n: int32): int32 {
 }
 
 export func main() {
-  let result: int32 = fib(28)
+  let result: int32 = fib(31)
   println(result)
 }

frontend/src/main/kotlin/gay/pizza/pork/frontend/scope/ExternalSymbolUsageAnalyzer.kt

@@ -11,6 +11,14 @@ class ExternalSymbolUsageAnalyzer : FunctionLevelVisitor<Unit>() {
     get() = symbols
 
   override fun visitFunctionDefinition(node: FunctionDefinition) {
+    for (argument in node.arguments) {
+      visit(argument.typeSpec!!)
+    }
+
+    if (node.returnType != null) {
+      visit(node.returnType!!)
+    }
+
     internalSymbols.add(node.arguments.map { it.symbol }.toMutableSet())
     node.block?.visit(this)
     internalSymbols.removeLast()

stdlib/src/main/pork/lang/prelude.pork

@@ -1,7 +1,10 @@
 export type int32 = native internal "int32"
 export type int64 = native internal "int64"
+export type float32 = native internal "float32"
+export type float64 = native internal "float64"
 export type string = native internal "string"
 export type list = native internal "list"
+export type bool = native internal "bool"
 export type any = native internal "any"
 
 export func print(values...: string)

tool/src/main/kotlin/gay/pizza/pork/tool/CompileCommand.kt

@@ -69,7 +69,7 @@ class CompileCommand : CliktCommand("compile") {
           annotation = " ; ${annotations.joinToString(", ") { it.text }}"
         }
         print("  ${symbol.offset + index.toUInt()} ${op}${annotation}")
-        if (op.code == Opcode.Constant || op.code == Opcode.NativeFunction) {
+        if (op.code == Opcode.Constant || op.code == Opcode.NativeFunction || op.code == Opcode.NativeType) {
           val constant = compiledWorld.constantPool.constants[op.args[0].toInt()]
           val constantString = when (constant.tag) {
             ConstantTag.String -> "string = \"" + constant.readAsString() + "\""