Fix false positives for for-loop-analysis warning

Summary:
For PseudoObjectExpr, the DeclMatcher need to search only all the semantics
but also need to search pass OpaqueValueExpr for all potential uses for the
Decl.

Reviewers: thakis, rtrieu, rjmccall, doug.gregor

Subscribers: xazax.hun, rjmccall, doug.gregor, cfe-commits

Differential Revision: http://reviews.llvm.org/D17627

llvm-svn: 263087

1 files changed, 12 insertions, 0 deletions

diff --git a/clang/lib/Sema/SemaStmt.cpp b/clang/lib/Sema/SemaStmt.cpp
index b73b4f08841..1975fcb1102 100644
--- a/clang/lib/Sema/SemaStmt.cpp
+++ b/clang/lib/Sema/SemaStmt.cpp
@@ -1440,6 +1440,18 @@ namespace {
           FoundDecl = true;
     }
 
+    void VisitPseudoObjectExpr(PseudoObjectExpr *POE) {
+      // Only need to visit the semantics for POE.
+      // SyntaticForm doesn't really use the Decal.
+      for (auto *S : POE->semantics()) {
+        if (auto *OVE = dyn_cast<OpaqueValueExpr>(S))
+          // Look past the OVE into the expression it binds.
+          Visit(OVE->getSourceExpr());
+        else
+          Visit(S);
+      }
+    }
+
     bool FoundDeclInUse() { return FoundDecl; }
 
   };  // end class DeclMatcher