[RegionInfo] Add debug-time region viewer functions

Summary:
Analogously to Function::viewCFG(), RegionInfo::view() and RegionInfo::viewOnly() are meant to be called in debugging sessions. They open a viewer to show how RegionInfo currently understands the region hierarchy.

The functions viewRegion(Function*) and viewRegionOnly(Function*) invoke a fresh region analysis of the function in contrast to viewRegion(RegionInfo*) and viewRegionOnly(RegionInfo*) which show the current analysis result.

Reviewers: grosser

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D11875

llvm-svn: 244444

2 files changed, 50 insertions, 0 deletions

diff --git a/llvm/lib/Analysis/RegionInfo.cpp b/llvm/lib/Analysis/RegionInfo.cpp
index 8cd85348fdc..f59d2673032 100644
--- a/llvm/lib/Analysis/RegionInfo.cpp
+++ b/llvm/lib/Analysis/RegionInfo.cpp
@@ -21,6 +21,9 @@
 #include <algorithm>
 #include <iterator>
 #include <set>
+#ifndef NDEBUG
+#include "llvm/Analysis/RegionPrinter.h"
+#endif
 
 using namespace llvm;
 
@@ -103,6 +106,12 @@ void RegionInfo::recalculate(Function &F, DominatorTree *DT_,
   calculate(F);
 }
 
+#ifndef NDEBUG
+void RegionInfo::view() { viewRegion(this); }
+
+void RegionInfo::viewOnly() { viewRegionOnly(this); }
+#endif
+
 //===----------------------------------------------------------------------===//
 // RegionInfoPass implementation
 //
diff --git a/llvm/lib/Analysis/RegionPrinter.cpp b/llvm/lib/Analysis/RegionPrinter.cpp
index f41725244a5..acb218d5fea 100644
--- a/llvm/lib/Analysis/RegionPrinter.cpp
+++ b/llvm/lib/Analysis/RegionPrinter.cpp
@@ -20,6 +20,9 @@
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/raw_ostream.h"
+#ifndef NDEBUG
+#include "llvm/IR/LegacyPassManager.h"
+#endif
 
 using namespace llvm;
 
@@ -224,3 +227,41 @@ FunctionPass* llvm::createRegionOnlyViewerPass() {
   return new RegionOnlyViewer();
 }
 
+#ifndef NDEBUG
+static void viewRegionInfo(RegionInfo *RI, bool ShortNames) {
+  assert(RI && "Argument must be non-null");
+
+  llvm::Function *F = RI->getTopLevelRegion()->getEntry()->getParent();
+  std::string GraphName = DOTGraphTraits<RegionInfo *>::getGraphName(RI);
+
+  llvm::ViewGraph(RI, "reg", ShortNames,
+                  Twine(GraphName) + " for '" + F->getName() + "' function");
+}
+
+static void invokeFunctionPass(const Function *F, FunctionPass *ViewerPass) {
+  assert(F && "Argument must be non-null");
+  assert(!F->isDeclaration() && "Function must have an implementation");
+
+  // The viewer and analysis passes do not modify anything, so we can safely
+  // remove the const qualifier
+  auto NonConstF = const_cast<Function *>(F);
+
+  llvm::legacy::FunctionPassManager FPM(NonConstF->getParent());
+  FPM.add(ViewerPass);
+  FPM.doInitialization();
+  FPM.run(*NonConstF);
+  FPM.doFinalization();
+}
+
+void llvm::viewRegion(RegionInfo *RI) { viewRegionInfo(RI, false); }
+
+void llvm::viewRegion(const Function *F) {
+  invokeFunctionPass(F, createRegionViewerPass());
+}
+
+void llvm::viewRegionOnly(RegionInfo *RI) { viewRegionInfo(RI, true); }
+
+void llvm::viewRegionOnly(const Function *F) {
+  invokeFunctionPass(F, createRegionOnlyViewerPass());
+}
+#endif