[CFG] Fix CFG for statement-expressions in return values.

We're building the CFG from bottom to top, so when the return-value expression
has a non-trivial CFG on its own, we need to continue building from the entry
to the return-value expression CFG rather than from the block to which
we've just appended the return statement.

Fixes a false positive warning "control may reach end of non-void function".

llvm-svn: 370406

1 files changed, 2 insertions, 3 deletions

diff --git a/clang/lib/Analysis/CFG.cpp b/clang/lib/Analysis/CFG.cpp
index e4ed0f86b91..fb835d43680 100644
--- a/clang/lib/Analysis/CFG.cpp
+++ b/clang/lib/Analysis/CFG.cpp
@@ -2994,9 +2994,8 @@ CFGBlock *CFGBuilder::VisitReturnStmt(Stmt *S) {
 
   // Visit children
   if (ReturnStmt *RS = dyn_cast<ReturnStmt>(S)) {
-    Expr *O = RS->getRetValue();
-    if (O)
-      Visit(O, AddStmtChoice::AlwaysAdd, /*ExternallyDestructed=*/true);
+    if (Expr *O = RS->getRetValue())
+      return Visit(O, AddStmtChoice::AlwaysAdd, /*ExternallyDestructed=*/true);
     return Block;
   } else { // co_return
     return VisitChildren(S);