[PM] Split the CallGraph out from the ModulePass which creates the

CallGraph.

This makes the CallGraph a totally generic analysis object that is the
container for the graph data structure and the primary interface for
querying and manipulating it. The pass logic is separated into its own
class. For compatibility reasons, the pass provides wrapper methods for
most of the methods on CallGraph -- they all just forward.

This will allow the new pass manager infrastructure to provide its own
analysis pass that constructs the same CallGraph object and makes it
available. The idea is that in the new pass manager, the analysis pass's
'run' method returns a concrete analysis 'result'. Here, that result is
a 'CallGraph'. The 'run' method will typically do only minimal work,
deferring much of the work into the implementation of the result object
in order to be lazy about computing things, but when (like DomTree)
there is *some* up-front computation, the analysis does it prior to
handing the result back to the querying pass.

I know some of this is fairly ugly. I'm happy to change it around if
folks can suggest a cleaner interim state, but there is going to be some
amount of unavoidable ugliness during the transition period. The good
thing is that this is very limited and will naturally go away when the
old pass infrastructure goes away. It won't hang around to bother us
later.

Next up is the initial new-PM-style call graph analysis. =]

llvm-svn: 195722

1 files changed, 4 insertions, 4 deletions

diff --git a/llvm/lib/Analysis/IPA/CallGraphSCCPass.cpp b/llvm/lib/Analysis/IPA/CallGraphSCCPass.cpp
index 182beca3643..a3f77b7eb47 100644
--- a/llvm/lib/Analysis/IPA/CallGraphSCCPass.cpp
+++ b/llvm/lib/Analysis/IPA/CallGraphSCCPass.cpp
@@ -60,7 +60,7 @@ public:
   /// Pass Manager itself does not invalidate any analysis info.
   void getAnalysisUsage(AnalysisUsage &Info) const {
     // CGPassManager walks SCC and it needs CallGraph.
-    Info.addRequired<CallGraph>();
+    Info.addRequired<CallGraphWrapperPass>();
     Info.setPreservesAll();
   }
 
@@ -424,7 +424,7 @@ bool CGPassManager::RunAllPassesOnSCC(CallGraphSCC &CurSCC, CallGraph &CG,
 /// run - Execute all of the passes scheduled for execution.  Keep track of
 /// whether any of the passes modifies the module, and if so, return true.
 bool CGPassManager::runOnModule(Module &M) {
-  CallGraph &CG = getAnalysis<CallGraph>();
+  CallGraph &CG = getAnalysis<CallGraphWrapperPass>().getCallGraph();
   bool Changed = doInitialization(CG);
   
   // Walk the callgraph in bottom-up SCC order.
@@ -570,8 +570,8 @@ void CallGraphSCCPass::assignPassManager(PMStack &PMS,
 /// the call graph.  If the derived class implements this method, it should
 /// always explicitly call the implementation here.
 void CallGraphSCCPass::getAnalysisUsage(AnalysisUsage &AU) const {
-  AU.addRequired<CallGraph>();
-  AU.addPreserved<CallGraph>();
+  AU.addRequired<CallGraphWrapperPass>();
+  AU.addPreserved<CallGraphWrapperPass>();
 }