[analyzer] After CFG has been linearized, we can have a situation where an ExpoledNode has an invalid SourceLocation (which has no correspondence in the source code). This commit is the first step to solve this problem.

 - It adds LocationContext to the PathDiagnosticLocation object and uses it to lookup the enclosing statement with a valid location.
 - So far, the LocationContext is only available when the object is constructed from the ExplodedNode.
 - Already found some subtle bugs(in plist-output-alternate.m) where the intermediate diagnostic steps were not previously shown. 

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@139703 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 29 insertions, 5 deletions

diff --git a/lib/StaticAnalyzer/Core/PathDiagnostic.cpp b/lib/StaticAnalyzer/Core/PathDiagnostic.cpp
index 28a6d403f5..ac9b15e743 100644
--- a/lib/StaticAnalyzer/Core/PathDiagnostic.cpp
+++ b/lib/StaticAnalyzer/Core/PathDiagnostic.cpp
@@ -16,6 +16,7 @@
 #include "clang/AST/Expr.h"
 #include "clang/AST/Decl.h"
 #include "clang/AST/DeclObjC.h"
+#include "clang/AST/ParentMap.h"
 #include "clang/AST/StmtCXX.h"
 #include "llvm/ADT/SmallString.h"
 
@@ -137,14 +138,14 @@ PathDiagnosticLocation PathDiagnosticLocation::create(const ExplodedNode* N,
 
   while (NI) {
     ProgramPoint P = NI->getLocation();
-
+    const LocationContext *LC = P.getLocationContext();
     if (const StmtPoint *PS = dyn_cast<StmtPoint>(&P)) {
-      return PathDiagnosticLocation(PS->getStmt(), SM);
+      return PathDiagnosticLocation(PS->getStmt(), SM, LC);
     }
     else if (const BlockEdge *BE = dyn_cast<BlockEdge>(&P)) {
       const Stmt *Term = BE->getSrc()->getTerminator();
       assert(Term);
-      return PathDiagnosticLocation(Term, SM);
+      return PathDiagnosticLocation(Term, SM, LC);
     }
     NI = NI->succ_empty() ? 0 : *(NI->succ_begin());
   }
@@ -153,6 +154,28 @@ PathDiagnosticLocation PathDiagnosticLocation::create(const ExplodedNode* N,
   return PathDiagnosticLocation(D.getBodyRBrace(), SM);
 }
 
+static SourceLocation getValidSourceLocation(const Stmt* S,
+                                             const LocationContext *LC) {
+  SourceLocation L = S->getLocStart();
+
+  // S might be a temporary statement that does not have a location in the
+  // source code, so find an enclosing statement and use it's location.
+  if (!L.isValid() && LC) {
+    assert(LC);
+    ParentMap & PM = LC->getParentMap();
+
+    const Stmt *PS = S;
+    while (!L.isValid()) {
+      PS = PM.getParent(PS);
+      L = PS->getLocStart();
+    }
+  }
+
+  // TODO: either change the name or uncomment the assert.
+  //assert(L.isValid());
+  return L;
+}
+
 FullSourceLoc PathDiagnosticLocation::asLocation() const {
   assert(isValid());
   // Note that we want a 'switch' here so that the compiler can warn us in
@@ -162,7 +185,8 @@ FullSourceLoc PathDiagnosticLocation::asLocation() const {
     case RangeK:
       break;
     case StmtK:
-      return FullSourceLoc(S->getLocStart(), const_cast<SourceManager&>(*SM));
+      return FullSourceLoc(getValidSourceLocation(S, LC),
+                           const_cast<SourceManager&>(*SM));
     case DeclK:
       return FullSourceLoc(D->getLocation(), const_cast<SourceManager&>(*SM));
   }
@@ -205,7 +229,7 @@ PathDiagnosticRange PathDiagnosticLocation::asRange() const {
         case Stmt::BinaryConditionalOperatorClass:
         case Stmt::ConditionalOperatorClass:
         case Stmt::ObjCForCollectionStmtClass: {
-          SourceLocation L = S->getLocStart();
+          SourceLocation L = getValidSourceLocation(S, LC);
           return SourceRange(L, L);
         }
       }