Append CXXDefaultInitExpr's wrapped expression to the CFG when visiting a constructor initializer

Summary:
This patch is part of http://llvm-reviews.chandlerc.com/D2181.

In-class initializers are appended to the CFG when CFGBuilder::addInitializer is called.

Reviewers: jordan_rose, rsmith

Reviewed By: jordan_rose

Subscribers: cfe-commits, klimek

Differential Revision: http://reviews.llvm.org/D2370

llvm-svn: 238913

clang/include/clang/Analysis/CFG.h

@@ -738,6 +738,7 @@ public:
     bool AddTemporaryDtors;
     bool AddStaticInitBranches;
     bool AddCXXNewAllocator;
+    bool AddCXXDefaultInitExprInCtors;
 
     bool alwaysAdd(const Stmt *stmt) const {
       return alwaysAddMask[stmt->getStmtClass()];
@@ -758,7 +759,7 @@ public:
         PruneTriviallyFalseEdges(true), AddEHEdges(false),
         AddInitializers(false), AddImplicitDtors(false),
         AddTemporaryDtors(false), AddStaticInitBranches(false),
-        AddCXXNewAllocator(false) {}
+        AddCXXNewAllocator(false), AddCXXDefaultInitExprInCtors(false) {}
   };
 
   /// \brief Provides a custom implementation of the iterator class to have the

clang/lib/Analysis/CFG.cpp

@@ -1095,6 +1095,19 @@ CFGBlock *CFGBuilder::addInitializer(CXXCtorInitializer *I) {
       // generating destructors for the second time.
       return Visit(cast<ExprWithCleanups>(Init)->getSubExpr());
     }
+    if (BuildOpts.AddCXXDefaultInitExprInCtors) {
+      if (CXXDefaultInitExpr *Default = dyn_cast<CXXDefaultInitExpr>(Init)) {
+        // In general, appending the expression wrapped by a CXXDefaultInitExpr
+        // may cause the same Expr to appear more than once in the CFG. Doing it
+        // here is safe because there's only one initializer per field.
+        autoCreateBlock();
+        appendStmt(Block, Default);
+        if (Stmt *Child = Default->getExpr())
+          if (CFGBlock *R = Visit(Child))
+            Block = R;
+        return Block;
+      }
+    }
     return Visit(Init);
   }
 

clang/lib/Sema/AnalysisBasedWarnings.cpp

@@ -1886,6 +1886,7 @@ AnalysisBasedWarnings::IssueWarnings(sema::AnalysisBasedWarnings::Policy P,
   AC.getCFGBuildOptions().AddImplicitDtors = true;
   AC.getCFGBuildOptions().AddTemporaryDtors = true;
   AC.getCFGBuildOptions().AddCXXNewAllocator = false;
+  AC.getCFGBuildOptions().AddCXXDefaultInitExprInCtors = true;
 
   // Force that certain expressions appear as CFGElements in the CFG.  This
   // is used to speed up various analyses.