From 636463e4c43be15e2f0fd0b8a08667f3066d8af7 Mon Sep 17 00:00:00 2001
From: Anders Carlsson <andersca@mac.com>
Date: Thu, 30 Jul 2009 22:17:18 +0000
Subject: [PATCH] Factor code out into a DiagnoseUnusedExprResult function.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@77628 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Sema/Sema.h       |  4 ++++
 lib/Sema/SemaStmt.cpp | 32 ++++++++++++++++++++------------
 2 files changed, 24 insertions(+), 12 deletions(-)

diff --git a/lib/Sema/Sema.h b/lib/Sema/Sema.h
index f0fdce5aa3..fc70090906 100644
--- a/lib/Sema/Sema.h
+++ b/lib/Sema/Sema.h
@@ -1398,6 +1398,10 @@ public:
                                             MultiStmtArg Handlers);
   void DiagnoseReturnInConstructorExceptionHandler(CXXTryStmt *TryBlock);
 
+  /// DiagnoseUnusedExprResult - If the statement passed in is an expression
+  /// whose result is unused, warn.
+  void DiagnoseUnusedExprResult(const Stmt *S);
+  
   //===--------------------------------------------------------------------===//
   // Expression Parsing Callbacks: SemaExpr.cpp.
 
diff --git a/lib/Sema/SemaStmt.cpp b/lib/Sema/SemaStmt.cpp
index 11497037c5..badeba79ce 100644
--- a/lib/Sema/SemaStmt.cpp
+++ b/lib/Sema/SemaStmt.cpp
@@ -51,6 +51,23 @@ Sema::OwningStmtResult Sema::ActOnDeclStmt(DeclGroupPtrTy dg,
   return Owned(new (Context) DeclStmt(DG, StartLoc, EndLoc));
 }
 
+void Sema::DiagnoseUnusedExprResult(const Stmt *S) {
+  const Expr *E = dyn_cast<Expr>(S);
+  if (!E)
+    return;
+
+  // Ignore expressions that have void type.
+  if (E->getType()->isVoidType())
+    return;
+  
+  SourceLocation Loc;
+  SourceRange R1, R2;
+  if (!E->isUnusedResultAWarning(Loc, R1, R2))
+    return;
+  
+  Diag(Loc, diag::warn_unused_expr) << R1 << R2;
+}
+
 Action::OwningStmtResult
 Sema::ActOnCompoundStmt(SourceLocation L, SourceLocation R,
                         MultiStmtArg elts, bool isStmtExpr) {
@@ -76,20 +93,11 @@ Sema::ActOnCompoundStmt(SourceLocation L, SourceLocation R,
   }
   // Warn about unused expressions in statements.
   for (unsigned i = 0; i != NumElts; ++i) {
-    Expr *E = dyn_cast<Expr>(Elts[i]);
-    if (!E) continue;
-    
-    // Warn about expressions with unused results if they are non-void and if
-    // this not the last stmt in a stmt expr.
-    if (E->getType()->isVoidType() || (isStmtExpr && i == NumElts-1))
+    // Ignore statements that are last in a statement expression.
+    if (isStmtExpr && i == NumElts - 1)
       continue;
     
-    SourceLocation Loc;
-    SourceRange R1, R2;
-    if (!E->isUnusedResultAWarning(Loc, R1, R2))
-      continue;
-
-    Diag(Loc, diag::warn_unused_expr) << R1 << R2;
+    DiagnoseUnusedExprResult(Elts[i]);
   }
 
   return Owned(new (Context) CompoundStmt(Context, Elts, NumElts, L, R));
-- 
2.40.0