[analyzer] Don't emit extra context arrow after returning from an inlined call.

In this code

  int getZero() {
    return 0;
  }

  void test() {
    int problem = 1 / getZero(); // expected-warning {{Division by zero}}
  }

we generate these arrows:

    +-----------------+
    |                 v
    int problem = 1 / getZero();
                  ^   |
                  +---+

where the top one represents the control flow up to the first call, and the
bottom one represents the flow to the division.* It turns out, however, that
we were generating the top arrow twice, as if attempting to "set up context"
after we had already returned from the call. This resulted in poor
highlighting in Xcode.

* Arguably the best location for the division is the '/', but that's a
  different problem.

<rdar://problem/13326040>

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@179350 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 12 insertions, 9 deletions

diff --git a/lib/StaticAnalyzer/Core/BugReporter.cpp b/lib/StaticAnalyzer/Core/BugReporter.cpp
index 76cfb89d49..09b35da361 100644
--- a/lib/StaticAnalyzer/Core/BugReporter.cpp
+++ b/lib/StaticAnalyzer/Core/BugReporter.cpp
@@ -1026,7 +1026,8 @@ public:
     PrevLoc = PathDiagnosticLocation();
   }
   
-  void addEdge(PathDiagnosticLocation NewLoc, bool alwaysAdd = false);
+  void addEdge(PathDiagnosticLocation NewLoc, bool alwaysAdd = false,
+               bool IsPostJump = false);
 
   void rawAddEdge(PathDiagnosticLocation NewLoc);
 
@@ -1122,7 +1123,8 @@ void EdgeBuilder::rawAddEdge(PathDiagnosticLocation NewLoc) {
   PrevLoc = NewLoc;
 }
 
-void EdgeBuilder::addEdge(PathDiagnosticLocation NewLoc, bool alwaysAdd) {
+void EdgeBuilder::addEdge(PathDiagnosticLocation NewLoc, bool alwaysAdd,
+                          bool IsPostJump) {
 
   if (!alwaysAdd && NewLoc.asLocation().isMacroID())
     return;
@@ -1135,13 +1137,14 @@ void EdgeBuilder::addEdge(PathDiagnosticLocation NewLoc, bool alwaysAdd) {
     // Is the top location context the same as the one for the new location?
     if (TopContextLoc == CLoc) {
       if (alwaysAdd) {
-        if (IsConsumedExpr(TopContextLoc) &&
-            !IsControlFlowExpr(TopContextLoc.asStmt()))
-            TopContextLoc.markDead();
+        if (IsConsumedExpr(TopContextLoc))
+          TopContextLoc.markDead();
 
         rawAddEdge(NewLoc);
       }
 
+      if (IsPostJump)
+        TopContextLoc.markDead();
       return;
     }
 
@@ -1149,13 +1152,13 @@ void EdgeBuilder::addEdge(PathDiagnosticLocation NewLoc, bool alwaysAdd) {
       if (alwaysAdd) {
         rawAddEdge(NewLoc);
 
-        if (IsConsumedExpr(CLoc) && !IsControlFlowExpr(CLoc.asStmt())) {
-          CLocs.push_back(ContextLocation(CLoc, true));
+        if (IsConsumedExpr(CLoc)) {
+          CLocs.push_back(ContextLocation(CLoc, /*IsDead=*/true));
           return;
         }
       }
 
-      CLocs.push_back(CLoc);
+      CLocs.push_back(ContextLocation(CLoc, /*IsDead=*/IsPostJump));
       return;
     }
 
@@ -1409,7 +1412,7 @@ static bool GenerateExtensivePathDiagnostic(PathDiagnostic& PD,
         GRBugReporter& BR = PDB.getBugReporter();
         BR.addCallPieceLocationContextPair(C, CE->getCalleeContext());
 
-        EB.addEdge(C->callReturn, true);
+        EB.addEdge(C->callReturn, /*AlwaysAdd=*/true, /*IsPostJump=*/true);
         EB.flushLocations();
 
         PD.getActivePath().push_front(C);