commit ed0a8a946efc8c0b4965102bd1990e01b9518a96
author Anders Carlsson <andersca@mac.com> Thu Jul 30 22:39:03 2009 +0000
committer Anders Carlsson <andersca@mac.com> Thu Jul 30 22:39:03 2009 +0000
tree 98c4f92b30bbb21b034ff9834540348c365a21ae
parent fdf504540efbdaf6e7da4850a39718c0354f90c4

Diagnose unused expression results for all statements, just not compound statements.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@77631 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Sema/SemaStmt.cpp

diff --git a/lib/Sema/SemaStmt.cpp b/lib/Sema/SemaStmt.cpp
index badeba7..f00d600 100644
--- a/lib/Sema/SemaStmt.cpp
+++ b/lib/Sema/SemaStmt.cpp
@@ -52,7 +52,7 @@
 }
 
 void Sema::DiagnoseUnusedExprResult(const Stmt *S) {
-  const Expr *E = dyn_cast<Expr>(S);
+  const Expr *E = dyn_cast_or_null<Expr>(S);
   if (!E)
     return;
 
@@ -215,6 +215,7 @@
   }
 
   Stmt *thenStmt = ThenVal.takeAs<Stmt>();
+  DiagnoseUnusedExprResult(thenStmt);
 
   // Warn if the if block has a null body without an else value.
   // this helps prevent bugs due to typos, such as
@@ -225,9 +226,12 @@
       Diag(stmt->getSemiLoc(), diag::warn_empty_if_body);
   }
 
+  Stmt *elseStmt = ElseVal.takeAs<Stmt>();
+  DiagnoseUnusedExprResult(elseStmt);
+  
   CondResult.release();
   return Owned(new (Context) IfStmt(IfLoc, condExpr, thenStmt,
-                                    ElseLoc, ElseVal.takeAs<Stmt>()));
+                                    ElseLoc, elseStmt));
 }
 
 Action::OwningStmtResult
@@ -571,9 +575,11 @@
                        << condType << condExpr->getSourceRange());
   }
 
+  Stmt *bodyStmt = Body.takeAs<Stmt>();
+  DiagnoseUnusedExprResult(bodyStmt);
+  
   CondArg.release();
-  return Owned(new (Context) WhileStmt(condExpr, Body.takeAs<Stmt>(), 
-                                       WhileLoc));
+  return Owned(new (Context) WhileStmt(condExpr, bodyStmt, WhileLoc));
 }
 
 Action::OwningStmtResult
@@ -597,8 +603,11 @@
                        << condType << condExpr->getSourceRange());
   }
 
+  Stmt *bodyStmt = Body.takeAs<Stmt>();
+  DiagnoseUnusedExprResult(bodyStmt);
+
   Cond.release();
-  return Owned(new (Context) DoStmt(Body.takeAs<Stmt>(), condExpr, DoLoc,
+  return Owned(new (Context) DoStmt(bodyStmt, condExpr, DoLoc,
                                     WhileLoc, CondRParen));
 }
 
@@ -639,6 +648,9 @@
                             diag::err_typecheck_statement_requires_scalar)
         << SecondType << Second->getSourceRange());
   }
+  
+  DiagnoseUnusedExprResult(Body);
+
   first.release();
   second.release();
   third.release();