[analyzer] Do not add invalid source location to the coverage information

[george.karpenkov]

Summary

Invalid source locations may arise from generated code.

[NoQ]

Test? (:

[NoQ]

Yay.

clang/lib/StaticAnalyzer/Core/BugReporter.cpp

 
   PathPieces path = PD.path.flatten(/*ShouldFlattenMacros=*/true);
   FilesToLineNumsMap &ExecutedLines = PD.getExecutedLines();
 
   for (const auto &P : path) {
     FullSourceLoc Loc = P->getLocation().asLocation().getExpansionLoc();
     FileID FID = Loc.getFileID();
     unsigned LineNo = Loc.getLineNumber();
+    assert(FID.isValid());
     ExecutedLines[FID].insert(LineNo);
   }
 }
 
 /// This function is responsible for generating diagnostic pieces that are
 /// *not* provided by bug report visitors.
 /// These diagnostics may differ depending on the consumer's settings,
 /// and are therefore constructed separately for each consumer.

   } else if (const auto OD = dyn_cast<ObjCMethodDecl>(Signature)) {
     SignatureSourceRange = OD->getSourceRange();
   } else {
     return;
   }
   SourceLocation Start = SignatureSourceRange.getBegin();
   SourceLocation End = Body ? Body->getSourceRange().getBegin()
     : SignatureSourceRange.getEnd();
+  if (!Start.isValid() || !End.isValid())
+    return;
   unsigned StartLine = SM.getExpansionLineNumber(Start);
   unsigned EndLine = SM.getExpansionLineNumber(End);
 
   FileID FID = SM.getFileID(SM.getExpansionLoc(Start));
   for (unsigned Line = StartLine; Line <= EndLine; Line++)
     ExecutedLines[FID].insert(Line);
 }
 
 static void populateExecutedLinesWithStmt(
     const Stmt *S, SourceManager &SM,
     FilesToLineNumsMap &ExecutedLines) {
   SourceLocation Loc = S->getSourceRange().getBegin();
+  if (!Loc.isValid())
+    return;
   SourceLocation ExpansionLoc = SM.getExpansionLoc(Loc);
   FileID FID = SM.getFileID(ExpansionLoc);
   unsigned LineNo = SM.getExpansionLineNumber(ExpansionLoc);
   ExecutedLines[FID].insert(LineNo);
 }
 
 /// \return all executed lines including function signatures on the path
 /// starting from \p N.