[analyzer] Handle implicit statements used for end-of-path nodes' source locs.

Some implicit statements, such as the implicit 'self' inserted for "free"
Objective-C ivar access, have invalid source locations. If one of these
statements is the location where an issue is reported, we'll now look at
the enclosing statements for a valid source location.

<rdar://problem/12446776>

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@165354 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 13 insertions, 8 deletions

diff --git a/lib/StaticAnalyzer/Core/PathDiagnostic.cpp b/lib/StaticAnalyzer/Core/PathDiagnostic.cpp
index d37ac4ad96..258ad253bd 100644
--- a/lib/StaticAnalyzer/Core/PathDiagnostic.cpp
+++ b/lib/StaticAnalyzer/Core/PathDiagnostic.cpp
@@ -612,21 +612,26 @@ PathDiagnosticLocation
   assert(N && "Cannot create a location with a null node.");
 
   const ExplodedNode *NI = N;
+  const Stmt *S = 0;
 
   while (NI) {
     ProgramPoint P = NI->getLocation();
-    const LocationContext *LC = P.getLocationContext();
     if (const StmtPoint *PS = dyn_cast<StmtPoint>(&P))
-      return PathDiagnosticLocation(PS->getStmt(), SM, LC);
-    else if (const BlockEdge *BE = dyn_cast<BlockEdge>(&P)) {
-      const Stmt *Term = BE->getSrc()->getTerminator();
-      if (Term) {
-        return PathDiagnosticLocation(Term, SM, LC);
-      }
-    }
+      S = PS->getStmt();
+    else if (const BlockEdge *BE = dyn_cast<BlockEdge>(&P))
+      S = BE->getSrc()->getTerminator();
+    if (S)
+      break;
     NI = NI->succ_empty() ? 0 : *(NI->succ_begin());
   }
 
+  if (S) {
+    const LocationContext *LC = NI->getLocationContext();
+    if (S->getLocStart().isValid())
+      return PathDiagnosticLocation(S, SM, LC);
+    return PathDiagnosticLocation(getValidSourceLocation(S, LC), SM);
+  }
+
   return createDeclEnd(N->getLocationContext(), SM);
 }