[llvm] r290488 - [PM] Try to improve the comments here to make what's going on more

[Chandler Carruth via llvm-commits]

Author: chandlerc
Date: Fri Dec 23 23:11:17 2016
New Revision: 290488

URL: http://llvm.org/viewvc/llvm-project?rev=290488&view=rev
Log:
[PM] Try to improve the comments here to make what's going on more
clear.

Based on post-commit review suggestion from Sean. (Thanks!)

Modified:
    llvm/trunk/lib/Passes/PassBuilder.cpp

Modified: llvm/trunk/lib/Passes/PassBuilder.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Passes/PassBuilder.cpp?rev=290488&r1=290487&r2=290488&view=diff
==============================================================================
--- llvm/trunk/lib/Passes/PassBuilder.cpp (original)
+++ llvm/trunk/lib/Passes/PassBuilder.cpp Fri Dec 23 23:11:17 2016
@@ -561,10 +561,12 @@ AAManager PassBuilder::buildDefaultAAPip
   AA.registerFunctionAnalysis<TypeBasedAA>();
 
   // Add support for querying global aliasing information when available.
-  // Because this is a module analysis this will use any cached analysis state
-  // available but isn't enough to cause it to be available.
-  // FIXME: Enable once the invalidation logic supports this.
+  // Because the `AAManager` is a function analysis and `GlobalsAA` is a module
+  // analysis, all that the `AAManager` can do is query for any *cached*
+  // results from `GlobalsAA` through a readonly proxy..
 #if 0
+  // FIXME: Enable once the invalidation logic supports this. Currently, the
+  // `AAManager` will hold stale references to the module analyses.
   AA.registerModuleAnalysis<GlobalsAA>();
 #endif