[PM/AA] Hoist the AliasResult enum out of the AliasAnalysis class.

This will allow classes to implement the AA interface without deriving
from the class or referencing an internal enum of some other class as
their return types.

Also, to a pretty fundamental extent, concepts such as 'NoAlias',
'MayAlias', and 'MustAlias' are first class concepts in LLVM and we
aren't saving anything by scoping them heavily.

My mild preference would have been to use a scoped enum, but that
feature is essentially completely broken AFAICT. I'm extremely
disappointed. For example, we cannot through any reasonable[1] means
construct an enum class (or analog) which has scoped names but converts
to a boolean in order to test for the possibility of aliasing.

[1]: Richard Smith came up with a "solution", but it requires class
templates, and lots of boilerplate setting up the enumeration multiple
times. Something like Boost.PP could potentially bundle this up, but
even that would be quite painful and it doesn't seem realistically worth
it. The enum class solution would probably work without the need for
a bool conversion.

Differential Revision: http://reviews.llvm.org/D10495

llvm-svn: 240255

1 files changed, 2 insertions, 2 deletions

diff --git a/llvm/lib/Analysis/IPA/GlobalsModRef.cpp b/llvm/lib/Analysis/IPA/GlobalsModRef.cpp
index a32631d0c3b..623ca1e8e59 100644
--- a/llvm/lib/Analysis/IPA/GlobalsModRef.cpp
+++ b/llvm/lib/Analysis/IPA/GlobalsModRef.cpp
@@ -479,8 +479,8 @@ void GlobalsModRef::AnalyzeCallGraph(CallGraph &CG, Module &M) {
 /// alias - If one of the pointers is to a global that we are tracking, and the
 /// other is some random pointer, we know there cannot be an alias, because the
 /// address of the global isn't taken.
-AliasAnalysis::AliasResult GlobalsModRef::alias(const MemoryLocation &LocA,
-                                                const MemoryLocation &LocB) {
+AliasResult GlobalsModRef::alias(const MemoryLocation &LocA,
+                                 const MemoryLocation &LocB) {
   // Get the base object these pointers point to.
   const Value *UV1 = GetUnderlyingObject(LocA.Ptr, *DL);
   const Value *UV2 = GetUnderlyingObject(LocB.Ptr, *DL);