tree f4b82ea7bd48206e365b8a42bff13a7eb6b4067a
parent b9d76a314c1e4c79217df9cd9d168d007e90a51c
author Akira Hatanaka <ahatanaka@apple.com> 1506115926 +0000
committer Akira Hatanaka <ahatanaka@apple.com> 1506620178 -0700

[CodeGen][ObjC] Build the global block structure before emitting the
body of global block invoke functions.

This commit fixes an infinite loop in IRGen that occurs when compiling
the following code:

void FUNC2() {
  static void (^const block1)(int) = ^(int a){
    if (a--)
      block1(a);
  };
}

This is how IRGen gets stuck in the infinite loop:

1. GenerateBlockFunction is called to emit the body of "block1".

2. GetAddrOfGlobalBlock is called to get the address of "block1". The
   function calls getAddrOfGlobalBlockIfEmitted to check whether the
   global block has been emitted. If it hasn't been emitted, it then
   tries to emit the body of the block function by calling
   GenerateBlockFunction, which goes back to step 1.

This commit prevents the inifinite loop by building the global block in
GenerateBlockFunction before emitting the body of the block function.

rdar://problem/34541684

Differential Revision: https://reviews.llvm.org/D38118

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@314029 91177308-0d34-0410-b5e6-96231b3b80d8
(cherry picked from commit a3394c6dfe197d84e74eae9cc8b77dc4356cff54)