[analyzer][Dominator] Add post dominators to CFG + a new debug checker

Transform clang::DominatorTree to be able to also calculate post dominators.

* Tidy up the documentation
* Make it clang::DominatorTree template class (similarly to how
  llvm::DominatorTreeBase works), rename it to clang::CFGDominatorTreeImpl
* Clang's dominator tree is now called clang::CFGDomTree
* Clang's brand new post dominator tree is called clang::CFGPostDomTree
* Add a lot of asserts to the dump() function
* Create a new checker to test the functionality

Differential Revision: https://reviews.llvm.org/D62551

llvm-svn: 365028

1 files changed, 5 insertions, 1 deletions

diff --git a/clang/lib/Analysis/Dominators.cpp b/clang/lib/Analysis/Dominators.cpp
index b872869f8cf..a350d4ca18b 100644
--- a/clang/lib/Analysis/Dominators.cpp
+++ b/clang/lib/Analysis/Dominators.cpp
@@ -10,4 +10,8 @@
 
 using namespace clang;
 
-void DominatorTree::anchor() {}
+template <>
+void CFGDominatorTreeImpl</*IsPostDom=*/true>::anchor() {}
+
+template <>
+void CFGDominatorTreeImpl</*IsPostDom=*/false>::anchor() {}