Fork channel

Create a new channel as a copy of main.

Rename channel

Rename main to:

Delete channel

Delete main? This cannot be undone.

2007-10-23-GC-WriteBarrier.m
// RUN: %clang_cc1 -emit-llvm %s -o /dev/null -fobjc-gc
// rdar://5541393

typedef unsigned int NSUInteger;
__attribute__((objc_gc(strong))) float *_scores;

void foo(int i, float f) {
  _scores[i] = f; 
}