[analyzer] Use call graph to determine order in which functions are

analyzed.

The CallGraph is used when inlining is on, which is the current default.

This alone does not bring any performance improvement. It's a
stepping stone for the upcoming optimization in which we do not
re-analyze a function that has already been analyzed while inlined in
other functions. Using the call graph makes it easier to play with
the order of functions to minimize redundant analyzes.

llvm-svn: 152352

clang/lib/StaticAnalyzer/Frontend/AnalysisConsumer.cpp

@@ -11,6 +11,8 @@
 //
 //===----------------------------------------------------------------------===//
 
+#define DEBUG_TYPE "AnalysisConsumer"
+
 #include "AnalysisConsumer.h"
 #include "clang/AST/ASTConsumer.h"
 #include "clang/AST/Decl.h"
@@ -18,6 +20,7 @@
 #include "clang/AST/DeclObjC.h"
 #include "clang/AST/ParentMap.h"
 #include "clang/Analysis/CFG.h"
+#include "clang/Analysis/CallGraph.h"
 #include "clang/StaticAnalyzer/Frontend/CheckerRegistration.h"
 #include "clang/StaticAnalyzer/Core/CheckerManager.h"
 #include "clang/StaticAnalyzer/Checkers/LocalCheckers.h"
@@ -35,14 +38,18 @@
 #include "llvm/Support/Path.h"
 #include "llvm/Support/Program.h"
 #include "llvm/Support/Timer.h"
+#include "llvm/ADT/DepthFirstIterator.h"
 #include "llvm/ADT/OwningPtr.h"
 #include "llvm/ADT/Statistic.h"
 
 using namespace clang;
 using namespace ento;
+using llvm::SmallPtrSet;
 
 static ExplodedNode::Auditor* CreateUbiViz();
 
+STATISTIC(NumFunctionsAnalyzed, "The # of functions analysed (as top level).");
+
 //===----------------------------------------------------------------------===//
 // Special PathDiagnosticConsumers.
 //===----------------------------------------------------------------------===//
@@ -180,6 +187,7 @@ public:
   virtual void HandleTranslationUnit(ASTContext &C);
   void HandleDeclContext(ASTContext &C, DeclContext *dc);
   void HandleDeclContextDecl(ASTContext &C, Decl *D);
+  void HandleDeclContextDeclFunction(ASTContext &C, Decl *D);
 
   void HandleCode(Decl *D);
 };
@@ -195,6 +203,50 @@ void AnalysisConsumer::HandleDeclContext(ASTContext &C, DeclContext *dc) {
        I != E; ++I) {
     HandleDeclContextDecl(C, *I);
   }
+
+  // If inlining is not turned on, use the simplest function order.
+  if (!Mgr->shouldInlineCall()) {
+    for (DeclContext::decl_iterator I = dc->decls_begin(), E = dc->decls_end();
+         I != E; ++I)
+      HandleDeclContextDeclFunction(C, *I);
+    return;
+  }
+
+  // Otherwise, use the Callgraph to derive the order.
+  // Build the Call Graph.
+  CallGraph CG;
+  CG.addToCallGraph(dc);
+
+  // Find the top level nodes - children of root + the unreachable (parentless)
+  // nodes.
+  llvm::SmallVector<CallGraphNode*, 24>  TopLevelFunctions;
+  CallGraphNode *Entry = CG.getRoot();
+  for (CallGraphNode::iterator I = Entry->begin(),
+                               E = Entry->end(); I != E; ++I)
+    TopLevelFunctions.push_back(*I);
+
+  for (CallGraph::nodes_iterator TI = CG.parentless_begin(),
+                                 TE = CG.parentless_end(); TI != TE; ++TI)
+    TopLevelFunctions.push_back(*TI);
+
+  // TODO: Sort TopLevelFunctions.
+
+  // DFS over all of the top level nodes. Use external Visited set, which is
+  // also modified when we inline a function.
+  SmallPtrSet<CallGraphNode*,24> Visited;
+  for (llvm::SmallVector<CallGraphNode*, 24>::iterator
+         TI = TopLevelFunctions.begin(), TE = TopLevelFunctions.end();
+         TI != TE; ++TI) {
+    for (llvm::df_ext_iterator<CallGraphNode*, SmallPtrSet<CallGraphNode*,24> >
+        DFI = llvm::df_ext_begin(*TI, Visited),
+        E = llvm::df_ext_end(*TI, Visited);
+        DFI != E; ++DFI) {
+      Decl *D = (*DFI)->getDecl();
+      assert(D);
+      HandleCode(D);
+    }
+  }
+
 }
 
 void AnalysisConsumer::HandleDeclContextDecl(ASTContext &C, Decl *D) {
@@ -208,6 +260,24 @@ void AnalysisConsumer::HandleDeclContextDecl(ASTContext &C, Decl *D) {
       HandleDeclContext(C, cast<NamespaceDecl>(D));
       break;
     }
+    case Decl::ObjCCategoryImpl:
+    case Decl::ObjCImplementation: {
+      ObjCImplDecl *ID = cast<ObjCImplDecl>(D);
+      for (ObjCContainerDecl::method_iterator MI = ID->meth_begin(),
+           ME = ID->meth_end(); MI != ME; ++MI) {
+        BugReporter BR(*Mgr);
+        checkerMgr->runCheckersOnASTDecl(*MI, *Mgr, BR);
+      }
+      break;
+    }
+
+    default:
+      break;
+  }
+}
+
+void AnalysisConsumer::HandleDeclContextDeclFunction(ASTContext &C, Decl *D) {
+  switch (D->getKind()) {
     case Decl::CXXConstructor:
     case Decl::CXXDestructor:
     case Decl::CXXConversion:
@@ -221,7 +291,6 @@ void AnalysisConsumer::HandleDeclContextDecl(ASTContext &C, Decl *D) {
         if (!Opts.AnalyzeSpecificFunction.empty() &&
             FD->getDeclName().getAsString() != Opts.AnalyzeSpecificFunction)
           break;
-        DisplayFunction(FD);
         HandleCode(FD);
       }
       break;
@@ -230,19 +299,13 @@ void AnalysisConsumer::HandleDeclContextDecl(ASTContext &C, Decl *D) {
     case Decl::ObjCCategoryImpl:
     case Decl::ObjCImplementation: {
       ObjCImplDecl *ID = cast<ObjCImplDecl>(D);
-      HandleCode(ID);
-      
       for (ObjCContainerDecl::method_iterator MI = ID->meth_begin(), 
            ME = ID->meth_end(); MI != ME; ++MI) {
-        BugReporter BR(*Mgr);
-        checkerMgr->runCheckersOnASTDecl(*MI, *Mgr, BR);
-
         if ((*MI)->isThisDeclarationADefinition()) {
           if (!Opts.AnalyzeSpecificFunction.empty() &&
               Opts.AnalyzeSpecificFunction != 
                 (*MI)->getSelector().getAsString())
             continue;
-          DisplayFunction(*MI);
           HandleCode(*MI);
         }
       }
@@ -290,7 +353,24 @@ static void FindBlocks(DeclContext *D, SmallVectorImpl<Decl*> &WL) {
 static void RunPathSensitiveChecks(AnalysisConsumer &C, AnalysisManager &mgr,
                                    Decl *D);
 
+static std::string getFunctionName(const Decl *D) {
+  if (const ObjCMethodDecl *ID = dyn_cast<ObjCMethodDecl>(D)) {
+    return ID->getSelector().getAsString();
+  }
+  if (const FunctionDecl *ND = dyn_cast<FunctionDecl>(D)) {
+    IdentifierInfo *II = ND->getIdentifier();
+    if (II)
+      return II->getName();
+  }
+  return "";
+}
+
 void AnalysisConsumer::HandleCode(Decl *D) {
+  if (!Opts.AnalyzeSpecificFunction.empty() &&
+      getFunctionName(D) != Opts.AnalyzeSpecificFunction)
+    return;
+
+  DisplayFunction(D);
 
   // Don't run the actions if an error has occurred with parsing the file.
   DiagnosticsEngine &Diags = PP.getDiagnostics();
@@ -322,6 +402,7 @@ void AnalysisConsumer::HandleCode(Decl *D) {
       if (checkerMgr->hasPathSensitiveCheckers())
         RunPathSensitiveChecks(*this, *Mgr, *WI);
     }
+  NumFunctionsAnalyzed++;
 }
 
 //===----------------------------------------------------------------------===//