During jump-scope checking, build an ExprWithCleanups immediately

into the enclosing scope;  this is a more accurate model but is
(I believe) unnecessary in my test case due to other flaws.
However, one of those flaws is now intentional:  blocks which
appear in return statements can be trivially observed to not
extend in lifetime past the return, and so we can allow a jump
past them.  Do the necessary magic in IR-generation to make
this work.

llvm-svn: 164589

1 files changed, 8 insertions, 3 deletions

diff --git a/clang/lib/Sema/JumpDiagnostics.cpp b/clang/lib/Sema/JumpDiagnostics.cpp
index ab786c65aab..a48779a1c36 100644
--- a/clang/lib/Sema/JumpDiagnostics.cpp
+++ b/clang/lib/Sema/JumpDiagnostics.cpp
@@ -453,14 +453,19 @@ void JumpScopeChecker::BuildScopeInformation(Stmt *S, unsigned &origParentScope)
       BuildScopeInformation(AS->getSubStmt(), (newParentScope = Scopes.size()-1));
       continue;
     }
-    
-    if (const BlockExpr *BE = dyn_cast<BlockExpr>(SubStmt)) {
-        const BlockDecl *BDecl = BE->getBlockDecl();
+
+    // Disallow jumps past full-expressions that use blocks with
+    // non-trivial cleanups of their captures.  This is theoretically
+    // implementable but a lot of work which we haven't felt up to doing.
+    if (ExprWithCleanups *EWC = dyn_cast<ExprWithCleanups>(SubStmt)) {
+      for (unsigned i = 0, e = EWC->getNumObjects(); i != e; ++i) {
+        const BlockDecl *BDecl = EWC->getObject(i);
         for (BlockDecl::capture_const_iterator ci = BDecl->capture_begin(),
              ce = BDecl->capture_end(); ci != ce; ++ci) {
           VarDecl *variable = ci->getVariable();
           BuildScopeInformation(variable, BDecl, ParentScope);
         }
+      }
     }
     
     // Recursively walk the AST.