[analyzer] Explain why we need condition 8.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@163394 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/StaticAnalyzer/Core/ExplodedGraph.cpp b/lib/StaticAnalyzer/Core/ExplodedGraph.cpp
index ff29640..7e8a028 100644
--- a/lib/StaticAnalyzer/Core/ExplodedGraph.cpp
+++ b/lib/StaticAnalyzer/Core/ExplodedGraph.cpp
@@ -68,7 +68,7 @@
// (5) The 'store' is the same as the predecessor.
// (6) The 'GDM' is the same as the predecessor.
// (7) The LocationContext is the same as the predecessor.
- // (8) The PostStmt is for a non-consumed Stmt or Expr.
+ // (8) The PostStmt isn't for a non-consumed Stmt or Expr.
// (9) The successor is not a CallExpr StmtPoint (so that we would be able to
// find it when retrying a call with no inlining).
// FIXME: It may be safe to reclaim PreCall and PostCall nodes as well.
@@ -103,6 +103,9 @@
return false;
// Condition 8.
+ // Do not collect nodes for non-consumed Stmt or Expr to ensure precise
+ // diagnostic generation; specifically, so that we could anchor arrows
+ // pointing to the beginning of statements (as written in code).
if (!isa<Expr>(ps.getStmt()))
return false;
