Merge pull request #75 from CodaFi/cold-calling

Model Call and Invoke as higher-level structures

Author: CodaFi

Sources/LLVM/Call.swift

@@ -0,0 +1,66 @@
+#if !NO_SWIFTPM
+import cllvm
+#endif
+
+/// Represents a simple function call.
+public struct Call: IRValue {
+  let llvm: LLVMValueRef
+
+  /// Retrieves the underlying LLVM value object.
+  public func asLLVM() -> LLVMValueRef {
+    return self.llvm
+  }
+
+  /// Retrieves the number of argument operands passed by this call.
+  public var argumentCount: Int {
+    return Int(LLVMGetNumArgOperands(self.llvm))
+  }
+
+  /// Accesses the calling convention for this function call.
+  public var callingConvention: CallingConvention {
+    get { return CallingConvention(rawValue: LLVMGetInstructionCallConv(self.llvm))! }
+    set { LLVMSetInstructionCallConv(self.llvm, newValue.rawValue) }
+  }
+
+  /// Returns whether this function call is a tail call.  That is, if the callee
+  /// may reuse the stack memory of the caller.
+  ///
+  /// This attribute requires support from the target architecture.
+  public var isTailCall: Bool {
+    get { return LLVMIsTailCall(self.llvm) != 0 }
+    set { LLVMSetTailCall(self.llvm, newValue.llvm) }
+  }
+
+  /// Retrieves the alignment of the parameter at the given index.
+  ///
+  /// This property is currently set-only due to limitations of the LLVM C API.
+  ///
+  /// - parameter i: The index of the parameter to retrieve.
+  /// - parameter alignment: The alignment to apply to the parameter.
+  public func setParameterAlignment(at i : Int, to alignment: Int) {
+    LLVMSetInstrParamAlignment(self.llvm, UInt32(i), UInt32(alignment))
+  }
+}
+
+/// Represents a function call that may transfer control to an exception handler.
+public struct Invoke: IRValue {
+  let llvm: LLVMValueRef
+
+  /// Retrieves the underlying LLVM value object.
+  public func asLLVM() -> LLVMValueRef {
+    return self.llvm
+  }
+
+  /// Accesses the destination block the flow of control will transfer to if an
+  /// exception does not occur.
+  public var normalDestination: BasicBlock {
+    get { return BasicBlock(llvm: LLVMGetNormalDest(self.llvm)) }
+    set { LLVMSetNormalDest(self.llvm, newValue.asLLVM()) }
+  }
+
+  /// Accesses the destination block that exception unwinding will jump to.
+  public var unwindDestination: BasicBlock {
+    get { return BasicBlock(llvm: LLVMGetUnwindDest(self.llvm)) }
+    set { LLVMSetUnwindDest(self.llvm, newValue.asLLVM()) }
+  }
+}

Sources/LLVM/IRBuilder.swift

@@ -965,10 +965,10 @@ public class IRBuilder {
   /// - parameter name: The name for the newly inserted instruction.
   ///
   /// - returns: A value representing the result of returning from the callee.
-  public func buildCall(_ fn: IRValue, args: [IRValue], name: String = "") -> IRValue {
+  public func buildCall(_ fn: IRValue, args: [IRValue], name: String = "") -> Call {
     var args = args.map { $0.asLLVM() as Optional }
     return args.withUnsafeMutableBufferPointer { buf in
-      return LLVMBuildCall(llvm, fn.asLLVM(), buf.baseAddress!, UInt32(buf.count), name)
+      return Call(llvm: LLVMBuildCall(llvm, fn.asLLVM(), buf.baseAddress!, UInt32(buf.count), name))
     }
   }
 
@@ -994,12 +994,12 @@ public class IRBuilder {
   /// - returns: A value representing the result of returning from the callee
   ///   under normal circumstances.  Under exceptional circumstances, the value
   ///   represents the value of any `resume` instruction in the `catch` block.
-  public func buildInvoke(_ fn: IRValue, args: [IRValue], next: BasicBlock, catch: BasicBlock, name: String = "") -> IRValue {
+  public func buildInvoke(_ fn: IRValue, args: [IRValue], next: BasicBlock, catch: BasicBlock, name: String = "") -> Invoke {
     precondition(`catch`.firstInstruction!.opCode == .landingPad, "First instruction of catch block must be a landing pad")
 
     var args = args.map { $0.asLLVM() as Optional }
     return args.withUnsafeMutableBufferPointer { buf in
-      return LLVMBuildInvoke(llvm, fn.asLLVM(), buf.baseAddress!, UInt32(buf.count), next.llvm, `catch`.llvm, name)
+      return Invoke(llvm: LLVMBuildInvoke(llvm, fn.asLLVM(), buf.baseAddress!, UInt32(buf.count), next.llvm, `catch`.llvm, name))
     }
   }