1 files changed, 38 insertions, 15 deletions

diff --git a/clang/lib/Sema/SemaStmt.cpp b/clang/lib/Sema/SemaStmt.cpp
index 0adfb948009..b47e3d29d17 100644
--- a/clang/lib/Sema/SemaStmt.cpp
+++ b/clang/lib/Sema/SemaStmt.cpp
@@ -225,6 +225,18 @@ void Sema::DiagnoseUnusedExprResult(const Stmt *S) {
   DiagRuntimeBehavior(Loc, 0, PDiag(DiagID) << R1 << R2);
 }
 
+void Sema::ActOnStartOfCompoundStmt() {
+  PushCompoundScope();
+}
+
+void Sema::ActOnFinishOfCompoundStmt() {
+  PopCompoundScope();
+}
+
+sema::CompoundScopeInfo &Sema::getCurCompoundScope() const {
+  return getCurFunction()->CompoundScopes.back();
+}
+
 StmtResult
 Sema::ActOnCompoundStmt(SourceLocation L, SourceLocation R,
                         MultiStmtArg elts, bool isStmtExpr) {
@@ -257,6 +269,15 @@ Sema::ActOnCompoundStmt(SourceLocation L, SourceLocation R,
     DiagnoseUnusedExprResult(Elts[i]);
   }
 
+  // Check for suspicious empty body (null statement) in `for' and `while'
+  // statements.  Don't do anything for template instantiations, this just adds
+  // noise.
+  if (NumElts != 0 && !CurrentInstantiationScope &&
+      getCurCompoundScope().HasEmptyLoopBodies) {
+    for (unsigned i = 0; i != NumElts - 1; ++i)
+      DiagnoseEmptyLoopBody(Elts[i], Elts[i + 1]);
+  }
+
   return Owned(new (Context) CompoundStmt(Context, Elts, NumElts, L, R));
 }
 
@@ -355,21 +376,9 @@ Sema::ActOnIfStmt(SourceLocation IfLoc, FullExprArg CondVal, Decl *CondVar,
 
   DiagnoseUnusedExprResult(thenStmt);
 
-  // Warn if the if block has a null body without an else value.
-  // this helps prevent bugs due to typos, such as
-  // if (condition);
-  //   do_stuff();
-  //
   if (!elseStmt) {
-    if (NullStmt* stmt = dyn_cast<NullStmt>(thenStmt))
-      // But do not warn if the body is a macro that expands to nothing, e.g:
-      //
-      // #define CALL(x)
-      // if (condition)
-      //   CALL(0);
-      //
-      if (!stmt->hasLeadingEmptyMacro())
-        Diag(stmt->getSemiLoc(), diag::warn_empty_if_body);
+    DiagnoseEmptyStmtBody(ConditionExpr->getLocEnd(), thenStmt,
+                          diag::warn_empty_if_body);
   }
 
   DiagnoseUnusedExprResult(elseStmt);
@@ -957,6 +966,9 @@ Sema::ActOnFinishSwitchStmt(SourceLocation SwitchLoc, Stmt *Switch,
     }
   }
 
+  DiagnoseEmptyStmtBody(CondExpr->getLocEnd(), BodyStmt,
+                        diag::warn_empty_switch_body);
+
   // FIXME: If the case list was broken is some way, we don't have a good system
   // to patch it up.  Instead, just return the whole substmt as broken.
   if (CaseListIsErroneous)
@@ -983,6 +995,9 @@ Sema::ActOnWhileStmt(SourceLocation WhileLoc, FullExprArg Cond,
 
   DiagnoseUnusedExprResult(Body);
 
+  if (isa<NullStmt>(Body))
+    getCurCompoundScope().setHasEmptyLoopBodies();
+
   return Owned(new (Context) WhileStmt(Context, ConditionVar, ConditionExpr,
                                        Body, WhileLoc));
 }
@@ -1046,6 +1061,9 @@ Sema::ActOnForStmt(SourceLocation ForLoc, SourceLocation LParenLoc,
   DiagnoseUnusedExprResult(Third);
   DiagnoseUnusedExprResult(Body);
 
+  if (isa<NullStmt>(Body))
+    getCurCompoundScope().setHasEmptyLoopBodies();
+
   return Owned(new (Context) ForStmt(Context, First,
                                      SecondResult.take(), ConditionVar,
                                      Third, Body, ForLoc, LParenLoc,
@@ -1587,7 +1605,12 @@ StmtResult Sema::FinishCXXForRangeStmt(Stmt *S, Stmt *B) {
   if (!S || !B)
     return StmtError();
 
-  cast<CXXForRangeStmt>(S)->setBody(B);
+  CXXForRangeStmt *ForStmt = cast<CXXForRangeStmt>(S);
+  ForStmt->setBody(B);
+
+  DiagnoseEmptyStmtBody(ForStmt->getRParenLoc(), B,
+                        diag::warn_empty_range_based_for_body);
+
   return S;
 }