Fix horrific CFG bug where '@autoreleasepool' would be put in a dangling block in the CFG.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@152163 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 27 insertions, 0 deletions

diff --git a/lib/Analysis/CFG.cpp b/lib/Analysis/CFG.cpp
index 8ba6d448da..b06cf44344 100644
--- a/lib/Analysis/CFG.cpp
+++ b/lib/Analysis/CFG.cpp
@@ -339,6 +339,7 @@ private:
   CFGBlock *VisitLabelStmt(LabelStmt *L);
   CFGBlock *VisitMemberExpr(MemberExpr *M, AddStmtChoice asc);
   CFGBlock *VisitObjCAtCatchStmt(ObjCAtCatchStmt *S);
+  CFGBlock *VisitObjCAutoreleasePoolStmt(ObjCAutoreleasePoolStmt *S);
   CFGBlock *VisitObjCAtSynchronizedStmt(ObjCAtSynchronizedStmt *S);
   CFGBlock *VisitObjCAtThrowStmt(ObjCAtThrowStmt *S);
   CFGBlock *VisitObjCAtTryStmt(ObjCAtTryStmt *S);
@@ -1014,6 +1015,9 @@ CFGBlock *CFGBuilder::Visit(Stmt * S, AddStmtChoice asc) {
     case Stmt::ObjCAtCatchStmtClass:
       return VisitObjCAtCatchStmt(cast<ObjCAtCatchStmt>(S));
 
+    case Stmt::ObjCAutoreleasePoolStmtClass:
+    return VisitObjCAutoreleasePoolStmt(cast<ObjCAutoreleasePoolStmt>(S));
+
     case Stmt::ObjCAtSynchronizedStmtClass:
       return VisitObjCAtSynchronizedStmt(cast<ObjCAtSynchronizedStmt>(S));
 
@@ -1929,6 +1933,12 @@ CFGBlock *CFGBuilder::VisitObjCForCollectionStmt(ObjCForCollectionStmt *S) {
   return addStmt(S->getCollection());
 }
 
+CFGBlock *CFGBuilder::VisitObjCAutoreleasePoolStmt(ObjCAutoreleasePoolStmt *S) {
+  // Inline the body.
+  return addStmt(S->getSubStmt());
+  // TODO: consider adding cleanups for the end of @autoreleasepool scope.
+}
+
 CFGBlock *CFGBuilder::VisitObjCAtSynchronizedStmt(ObjCAtSynchronizedStmt *S) {
   // FIXME: Add locking 'primitives' to CFG for @synchronized.
 
diff --git a/test/SemaObjC/warn-unreachable.m b/test/SemaObjC/warn-unreachable.m
new file mode 100644
index 0000000000..832cbd23d2
--- /dev/null
+++ b/test/SemaObjC/warn-unreachable.m
@@ -0,0 +1,17 @@
+// RUN: %clang %s -fsyntax-only -Xclang -verify -fblocks -Wunreachable-code -Wno-unused-value -Wno-covered-switch-default
+
+// This previously triggered a warning from -Wunreachable-code because of
+// a busted CFG.
+typedef signed char BOOL;
+BOOL radar10989084() {
+  @autoreleasepool {  // no-warning
+    return __objc_yes;
+  }
+}
+
+// Test the warning works.
+void test_unreachable() {
+  return;
+  return; // expected-warning {{will never be executed}}
+}
+