<div dir="ltr"><div dir="ltr">On Sat, Jan 5, 2019 at 10:16 AM Aaron Ballman <<a href="mailto:aaron@aaronballman.com">aaron@aaronballman.com</a>> wrote:<br></div><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">On Fri, Jan 4, 2019 at 8:41 PM Richard Smith <<a href="mailto:richard@metafoo.co.uk" target="_blank">richard@metafoo.co.uk</a>> wrote:<br>
><br>
> On Fri, 4 Jan 2019 at 17:33, Nico Weber via cfe-commits <<a href="mailto:cfe-commits@lists.llvm.org" target="_blank">cfe-commits@lists.llvm.org</a>> wrote:<br>
>><br>
>> Nice, this is finding bugs: <a href="https://bugs.chromium.org/p/chromium/issues/detail?id=919262" rel="noreferrer" target="_blank">https://bugs.chromium.org/p/chromium/issues/detail?id=919262</a><br>
>><br>
>> However, I noticed that for that case, the same warning is printed twice:<br>
>><br>
>> ../../third_party/crashpad/crashpad/util/win/process_info.cc(227,36):  error: expression result unused [-Werror,-Wunused-value]<br>
>>       NTSTATUS_LOG(ERROR, status), "NtQueryInformationProcess";<br>
>>                                    ^~~~~~~~~~~~~~~~~~~~~~~~~~~<br>
>> ../../third_party/crashpad/crashpad/util/win/process_info.cc(227,36):  error: expression result unused [-Werror,-Wunused-value]<br>
>>       NTSTATUS_LOG(ERROR, status), "NtQueryInformationProcess";<br>
>><br>
>><br>
>> Is that expected?<br>
<br>
Yes and no. It's not unexpected, but it's not super helpful either. As<br>
Richard points out below, this happens because of template<br>
instantiation.<br>
<br>
> The first diagnostic appears when parsing the template, the second one appears when instantiating it. In the complete diagnostic output:<br>
><br>
> ../../third_party/crashpad/crashpad/util/win/process_info.cc(227,36):  error: expression result unused [-Werror,-Wunused-value]<br>
>       NTSTATUS_LOG(ERROR, status), "NtQueryInformationProcess";<br>
>                                    ^~~~~~~~~~~~~~~~~~~~~~~~~~~<br>
><br>
> ../../third_party/crashpad/crashpad/util/win/process_info.cc(227,36):  error: expression result unused [-Werror,-Wunused-value]<br>
>       NTSTATUS_LOG(ERROR, status), "NtQueryInformationProcess";<br>
>                                    ^~~~~~~~~~~~~~~~~~~~~~~~~~~<br>
> ../../third_party/crashpad/crashpad/util/win/process_info.cc(531,17):  note: in instantiation of function template specialization 'crashpad::GetProcessBasicInformation<crashpad::process_types::internal::Traits32>' requested here<br>
>   bool result = GetProcessBasicInformation<process_types::internal::Traits32>(<br>
>                 ^<br>
><br>
> It'd be nice to suppress the diagnostic during instantiation if it appeared during the initial parse (generally, not with something specific to this warning).<br>
<br>
Agreed, though I don't have the time to work on that currently.<br>
Hopefully the behavior here isn't too onerous for Chromium (or other<br>
projects)?<br></blockquote><div><br></div><div>It wasn't a problem for us, no. The warning found a bug, we fixed the bug, everyone's happy. Just thought I'd mention the diag looks strange; thanks for the explanation (and the warning improvement) :-)</div><div> </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<br>
~Aaron<br>
<br>
><br>
>> Code is here:<br>
>> <a href="https://cs.chromium.org/chromium/src/third_party/crashpad/crashpad/util/win/process_info.cc?q=crashpad/util/win/process_info.cc&sq=package:chromium&g=0&l=227" rel="noreferrer" target="_blank">https://cs.chromium.org/chromium/src/third_party/crashpad/crashpad/util/win/process_info.cc?q=crashpad/util/win/process_info.cc&sq=package:chromium&g=0&l=227</a><br>
>> <a href="https://cs.chromium.org/chromium/src/third_party/crashpad/crashpad/util/win/ntstatus_logging.h?type=cs&q=NTSTATUS_LOG&sq=package:chromium&g=0&l=63" rel="noreferrer" target="_blank">https://cs.chromium.org/chromium/src/third_party/crashpad/crashpad/util/win/ntstatus_logging.h?type=cs&q=NTSTATUS_LOG&sq=package:chromium&g=0&l=63</a><br>
>><br>
>><br>
>> On Fri, Jan 4, 2019 at 12:01 PM Aaron Ballman via cfe-commits <<a href="mailto:cfe-commits@lists.llvm.org" target="_blank">cfe-commits@lists.llvm.org</a>> wrote:<br>
>>><br>
>>> Author: aaronballman<br>
>>> Date: Fri Jan  4 08:58:14 2019<br>
>>> New Revision: 350404<br>
>>><br>
>>> URL: <a href="http://llvm.org/viewvc/llvm-project?rev=350404&view=rev" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project?rev=350404&view=rev</a><br>
>>> Log:<br>
>>> Refactor the way we handle diagnosing unused expression results.<br>
>>><br>
>>> Rather than sprinkle calls to DiagnoseUnusedExprResult() around in places where we want diagnostics, we now diagnose unused expression statements and full expressions in a more generic way when acting on the final expression statement. This results in more appropriate diagnostics for [[nodiscard]] where we were previously lacking them, such as when the body of a for loop is not a compound statement.<br>
>>><br>
>>> This patch fixes PR39837.<br>
>>><br>
>>> Modified:<br>
>>>     cfe/trunk/include/clang/Parse/Parser.h<br>
>>>     cfe/trunk/include/clang/Sema/Sema.h<br>
>>>     cfe/trunk/lib/Parse/ParseObjc.cpp<br>
>>>     cfe/trunk/lib/Parse/ParseOpenMP.cpp<br>
>>>     cfe/trunk/lib/Parse/ParseStmt.cpp<br>
>>>     cfe/trunk/lib/Sema/SemaCoroutine.cpp<br>
>>>     cfe/trunk/lib/Sema/SemaDecl.cpp<br>
>>>     cfe/trunk/lib/Sema/SemaDeclCXX.cpp<br>
>>>     cfe/trunk/lib/Sema/SemaExpr.cpp<br>
>>>     cfe/trunk/lib/Sema/SemaExprCXX.cpp<br>
>>>     cfe/trunk/lib/Sema/SemaLambda.cpp<br>
>>>     cfe/trunk/lib/Sema/SemaOpenMP.cpp<br>
>>>     cfe/trunk/lib/Sema/SemaStmt.cpp<br>
>>>     cfe/trunk/lib/Sema/TreeTransform.h<br>
>>>     cfe/trunk/test/CXX/stmt.stmt/stmt.select/p3.cpp<br>
>>>     cfe/trunk/test/CodeCompletion/pragma-macro-token-caching.c<br>
>>>     cfe/trunk/test/Parser/cxx1z-init-statement.cpp<br>
>>>     cfe/trunk/test/Parser/switch-recovery.cpp<br>
>>>     cfe/trunk/test/SemaCXX/cxx1z-init-statement.cpp<br>
>>>     cfe/trunk/test/SemaCXX/for-range-examples.cpp<br>
>>>     cfe/trunk/test/SemaCXX/warn-unused-result.cpp<br>
>>><br>
>>> Modified: cfe/trunk/include/clang/Parse/Parser.h<br>
>>> URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Parse/Parser.h?rev=350404&r1=350403&r2=350404&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Parse/Parser.h?rev=350404&r1=350403&r2=350404&view=diff</a><br>
>>> ==============================================================================<br>
>>> --- cfe/trunk/include/clang/Parse/Parser.h (original)<br>
>>> +++ cfe/trunk/include/clang/Parse/Parser.h Fri Jan  4 08:58:14 2019<br>
>>> @@ -360,6 +360,11 @@ class Parser : public CodeCompletionHand<br>
>>>    /// just a regular sub-expression.<br>
>>>    SourceLocation ExprStatementTokLoc;<br>
>>><br>
>>> +  /// Tests whether an expression value is discarded based on token lookahead.<br>
>>> +  /// It will return true if the lexer is currently processing the })<br>
>>> +  /// terminating a GNU statement expression and false otherwise.<br>
>>> +  bool isExprValueDiscarded();<br>
>>> +<br>
>>>  public:<br>
>>>    Parser(Preprocessor &PP, Sema &Actions, bool SkipFunctionBodies);<br>
>>>    ~Parser() override;<br>
>>><br>
>>> Modified: cfe/trunk/include/clang/Sema/Sema.h<br>
>>> URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Sema/Sema.h?rev=350404&r1=350403&r2=350404&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Sema/Sema.h?rev=350404&r1=350403&r2=350404&view=diff</a><br>
>>> ==============================================================================<br>
>>> --- cfe/trunk/include/clang/Sema/Sema.h (original)<br>
>>> +++ cfe/trunk/include/clang/Sema/Sema.h Fri Jan  4 08:58:14 2019<br>
>>> @@ -1365,6 +1365,7 @@ public:<br>
>>>    void PopCompoundScope();<br>
>>><br>
>>>    sema::CompoundScopeInfo &getCurCompoundScope() const;<br>
>>> +  bool isCurCompoundStmtAStmtExpr() const;<br>
>>><br>
>>>    bool hasAnyUnrecoverableErrorsInThisFunction() const;<br>
>>><br>
>>> @@ -3685,16 +3686,17 @@ public:<br>
>>>      return MakeFullExpr(Arg, Arg ? Arg->getExprLoc() : SourceLocation());<br>
>>>    }<br>
>>>    FullExprArg MakeFullExpr(Expr *Arg, SourceLocation CC) {<br>
>>> -    return FullExprArg(ActOnFinishFullExpr(Arg, CC).get());<br>
>>> +    return FullExprArg(<br>
>>> +        ActOnFinishFullExpr(Arg, CC, /*DiscardedValue*/ false).get());<br>
>>>    }<br>
>>>    FullExprArg MakeFullDiscardedValueExpr(Expr *Arg) {<br>
>>>      ExprResult FE =<br>
>>> -      ActOnFinishFullExpr(Arg, Arg ? Arg->getExprLoc() : SourceLocation(),<br>
>>> -                          /*DiscardedValue*/ true);<br>
>>> +        ActOnFinishFullExpr(Arg, Arg ? Arg->getExprLoc() : SourceLocation(),<br>
>>> +                            /*DiscardedValue*/ true);<br>
>>>      return FullExprArg(FE.get());<br>
>>>    }<br>
>>><br>
>>> -  StmtResult ActOnExprStmt(ExprResult Arg);<br>
>>> +  StmtResult ActOnExprStmt(ExprResult Arg, bool DiscardedValue = true);<br>
>>>    StmtResult ActOnExprStmtError();<br>
>>><br>
>>>    StmtResult ActOnNullStmt(SourceLocation SemiLoc,<br>
>>> @@ -5340,13 +5342,12 @@ public:<br>
>>>    CreateMaterializeTemporaryExpr(QualType T, Expr *Temporary,<br>
>>>                                   bool BoundToLvalueReference);<br>
>>><br>
>>> -  ExprResult ActOnFinishFullExpr(Expr *Expr) {<br>
>>> -    return ActOnFinishFullExpr(Expr, Expr ? Expr->getExprLoc()<br>
>>> -                                          : SourceLocation());<br>
>>> +  ExprResult ActOnFinishFullExpr(Expr *Expr, bool DiscardedValue) {<br>
>>> +    return ActOnFinishFullExpr(<br>
>>> +        Expr, Expr ? Expr->getExprLoc() : SourceLocation(), DiscardedValue);<br>
>>>    }<br>
>>>    ExprResult ActOnFinishFullExpr(Expr *Expr, SourceLocation CC,<br>
>>> -                                 bool DiscardedValue = false,<br>
>>> -                                 bool IsConstexpr = false);<br>
>>> +                                 bool DiscardedValue, bool IsConstexpr = false);<br>
>>>    StmtResult ActOnFinishFullStmt(Stmt *Stmt);<br>
>>><br>
>>>    // Marks SS invalid if it represents an incomplete type.<br>
>>><br>
>>> Modified: cfe/trunk/lib/Parse/ParseObjc.cpp<br>
>>> URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Parse/ParseObjc.cpp?rev=350404&r1=350403&r2=350404&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Parse/ParseObjc.cpp?rev=350404&r1=350403&r2=350404&view=diff</a><br>
>>> ==============================================================================<br>
>>> --- cfe/trunk/lib/Parse/ParseObjc.cpp (original)<br>
>>> +++ cfe/trunk/lib/Parse/ParseObjc.cpp Fri Jan  4 08:58:14 2019<br>
>>> @@ -2741,7 +2741,7 @@ StmtResult Parser::ParseObjCAtStatement(<br>
>>><br>
>>>    // Otherwise, eat the semicolon.<br>
>>>    ExpectAndConsumeSemi(diag::err_expected_semi_after_expr);<br>
>>> -  return Actions.ActOnExprStmt(Res);<br>
>>> +  return Actions.ActOnExprStmt(Res, isExprValueDiscarded());<br>
>>>  }<br>
>>><br>
>>>  ExprResult Parser::ParseObjCAtExpression(SourceLocation AtLoc) {<br>
>>><br>
>>> Modified: cfe/trunk/lib/Parse/ParseOpenMP.cpp<br>
>>> URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Parse/ParseOpenMP.cpp?rev=350404&r1=350403&r2=350404&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Parse/ParseOpenMP.cpp?rev=350404&r1=350403&r2=350404&view=diff</a><br>
>>> ==============================================================================<br>
>>> --- cfe/trunk/lib/Parse/ParseOpenMP.cpp (original)<br>
>>> +++ cfe/trunk/lib/Parse/ParseOpenMP.cpp Fri Jan  4 08:58:14 2019<br>
>>> @@ -314,7 +314,7 @@ Parser::ParseOpenMPDeclareReductionDirec<br>
>>>      Actions.ActOnOpenMPDeclareReductionCombinerStart(getCurScope(), D);<br>
>>>      ExprResult CombinerResult =<br>
>>>          Actions.ActOnFinishFullExpr(ParseAssignmentExpression().get(),<br>
>>> -                                    D->getLocation(), /*DiscardedValue=*/true);<br>
>>> +                                    D->getLocation(), /*DiscardedValue*/ false);<br>
>>>      Actions.ActOnOpenMPDeclareReductionCombinerEnd(D, CombinerResult.get());<br>
>>><br>
>>>      if (CombinerResult.isInvalid() && Tok.isNot(tok::r_paren) &&<br>
>>> @@ -356,7 +356,7 @@ Parser::ParseOpenMPDeclareReductionDirec<br>
>>>            if (Actions.getLangOpts().CPlusPlus) {<br>
>>>              InitializerResult = Actions.ActOnFinishFullExpr(<br>
>>>                  ParseAssignmentExpression().get(), D->getLocation(),<br>
>>> -                /*DiscardedValue=*/true);<br>
>>> +                /*DiscardedValue*/ false);<br>
>>>            } else {<br>
>>>              ConsumeToken();<br>
>>>              ParseOpenMPReductionInitializerForDecl(OmpPrivParm);<br>
>>> @@ -364,7 +364,7 @@ Parser::ParseOpenMPDeclareReductionDirec<br>
>>>          } else {<br>
>>>            InitializerResult = Actions.ActOnFinishFullExpr(<br>
>>>                ParseAssignmentExpression().get(), D->getLocation(),<br>
>>> -              /*DiscardedValue=*/true);<br>
>>> +              /*DiscardedValue*/ false);<br>
>>>          }<br>
>>>          Actions.ActOnOpenMPDeclareReductionInitializerEnd(<br>
>>>              D, InitializerResult.get(), OmpPrivParm);<br>
>>> @@ -1455,7 +1455,7 @@ ExprResult Parser::ParseOpenMPParensExpr<br>
>>>    ExprResult LHS(ParseCastExpression(<br>
>>>        /*isUnaryExpression=*/false, /*isAddressOfOperand=*/false, NotTypeCast));<br>
>>>    ExprResult Val(ParseRHSOfBinaryExpression(LHS, prec::Conditional));<br>
>>> -  Val = Actions.ActOnFinishFullExpr(Val.get(), ELoc);<br>
>>> +  Val = Actions.ActOnFinishFullExpr(Val.get(), ELoc, /*DiscardedValue*/ false);<br>
>>><br>
>>>    // Parse ')'.<br>
>>>    RLoc = Tok.getLocation();<br>
>>> @@ -1711,7 +1711,8 @@ OMPClause *Parser::ParseOpenMPSingleExpr<br>
>>>      SourceLocation ELoc = Tok.getLocation();<br>
>>>      ExprResult LHS(ParseCastExpression(false, false, NotTypeCast));<br>
>>>      Val = ParseRHSOfBinaryExpression(LHS, prec::Conditional);<br>
>>> -    Val = Actions.ActOnFinishFullExpr(Val.get(), ELoc);<br>
>>> +    Val =<br>
>>> +        Actions.ActOnFinishFullExpr(Val.get(), ELoc, /*DiscardedValue*/ false);<br>
>>>    }<br>
>>><br>
>>>    // Parse ')'.<br>
>>> @@ -1996,7 +1997,8 @@ bool Parser::ParseOpenMPVarList(OpenMPDi<br>
>>>      Data.ColonLoc = Tok.getLocation();<br>
>>>      SourceLocation ELoc = ConsumeToken();<br>
>>>      ExprResult Tail = ParseAssignmentExpression();<br>
>>> -    Tail = Actions.ActOnFinishFullExpr(Tail.get(), ELoc);<br>
>>> +    Tail =<br>
>>> +        Actions.ActOnFinishFullExpr(Tail.get(), ELoc, /*DiscardedValue*/ false);<br>
>>>      if (Tail.isUsable())<br>
>>>        Data.TailExpr = Tail.get();<br>
>>>      else<br>
>>><br>
>>> Modified: cfe/trunk/lib/Parse/ParseStmt.cpp<br>
>>> URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Parse/ParseStmt.cpp?rev=350404&r1=350403&r2=350404&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Parse/ParseStmt.cpp?rev=350404&r1=350403&r2=350404&view=diff</a><br>
>>> ==============================================================================<br>
>>> --- cfe/trunk/lib/Parse/ParseStmt.cpp (original)<br>
>>> +++ cfe/trunk/lib/Parse/ParseStmt.cpp Fri Jan  4 08:58:14 2019<br>
>>> @@ -439,7 +439,7 @@ StmtResult Parser::ParseExprStatement()<br>
>>><br>
>>>    // Otherwise, eat the semicolon.<br>
>>>    ExpectAndConsumeSemi(diag::err_expected_semi_after_expr);<br>
>>> -  return Actions.ActOnExprStmt(Expr);<br>
>>> +  return Actions.ActOnExprStmt(Expr, isExprValueDiscarded());<br>
>>>  }<br>
>>><br>
>>>  /// ParseSEHTryBlockCommon<br>
>>> @@ -958,6 +958,16 @@ bool Parser::ConsumeNullStmt(StmtVector<br>
>>>    return true;<br>
>>>  }<br>
>>><br>
>>> +bool Parser::isExprValueDiscarded() {<br>
>>> +  if (Actions.isCurCompoundStmtAStmtExpr()) {<br>
>>> +    // Look to see if the next two tokens close the statement expression;<br>
>>> +    // if so, this expression statement is the last statement in a<br>
>>> +    // statment expression.<br>
>>> +    return Tok.isNot(tok::r_brace) || NextToken().isNot(tok::r_paren);<br>
>>> +  }<br>
>>> +  return true;<br>
>>> +}<br>
>>> +<br>
>>>  /// ParseCompoundStatementBody - Parse a sequence of statements and invoke the<br>
>>>  /// ActOnCompoundStmt action.  This expects the '{' to be the current token, and<br>
>>>  /// consume the '}' at the end of the block.  It does not manipulate the scope<br>
>>> @@ -1062,7 +1072,7 @@ StmtResult Parser::ParseCompoundStatemen<br>
>>>          // Eat the semicolon at the end of stmt and convert the expr into a<br>
>>>          // statement.<br>
>>>          ExpectAndConsumeSemi(diag::err_expected_semi_after_expr);<br>
>>> -        R = Actions.ActOnExprStmt(Res);<br>
>>> +        R = Actions.ActOnExprStmt(Res, isExprValueDiscarded());<br>
>>>        }<br>
>>>      }<br>
>>><br>
>>> @@ -1698,8 +1708,16 @@ StmtResult Parser::ParseForStatement(Sou<br>
>>>      if (!Value.isInvalid()) {<br>
>>>        if (ForEach)<br>
>>>          FirstPart = Actions.ActOnForEachLValueExpr(Value.get());<br>
>>> -      else<br>
>>> -        FirstPart = Actions.ActOnExprStmt(Value);<br>
>>> +      else {<br>
>>> +        // We already know this is not an init-statement within a for loop, so<br>
>>> +        // if we are parsing a C++11 range-based for loop, we should treat this<br>
>>> +        // expression statement as being a discarded value expression because<br>
>>> +        // we will err below. This way we do not warn on an unused expression<br>
>>> +        // that was an error in the first place, like with: for (expr : expr);<br>
>>> +        bool IsRangeBasedFor =<br>
>>> +            getLangOpts().CPlusPlus11 && !ForEach && Tok.is(tok::colon);<br>
>>> +        FirstPart = Actions.ActOnExprStmt(Value, !IsRangeBasedFor);<br>
>>> +      }<br>
>>>      }<br>
>>><br>
>>>      if (Tok.is(tok::semi)) {<br>
>>><br>
>>> Modified: cfe/trunk/lib/Sema/SemaCoroutine.cpp<br>
>>> URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaCoroutine.cpp?rev=350404&r1=350403&r2=350404&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaCoroutine.cpp?rev=350404&r1=350403&r2=350404&view=diff</a><br>
>>> ==============================================================================<br>
>>> --- cfe/trunk/lib/Sema/SemaCoroutine.cpp (original)<br>
>>> +++ cfe/trunk/lib/Sema/SemaCoroutine.cpp Fri Jan  4 08:58:14 2019<br>
>>> @@ -647,7 +647,7 @@ bool Sema::ActOnCoroutineBodyStart(Scope<br>
>>>        return StmtError();<br>
>>>      Suspend = BuildResolvedCoawaitExpr(Loc, Suspend.get(),<br>
>>>                                         /*IsImplicit*/ true);<br>
>>> -    Suspend = ActOnFinishFullExpr(Suspend.get());<br>
>>> +    Suspend = ActOnFinishFullExpr(Suspend.get(), /*DiscardedValue*/ false);<br>
>>>      if (Suspend.isInvalid()) {<br>
>>>        Diag(Loc, diag::note_coroutine_promise_suspend_implicitly_required)<br>
>>>            << ((Name == "initial_suspend") ? 0 : 1);<br>
>>> @@ -868,7 +868,7 @@ StmtResult Sema::BuildCoreturnStmt(Sourc<br>
>>>    if (PC.isInvalid())<br>
>>>      return StmtError();<br>
>>><br>
>>> -  Expr *PCE = ActOnFinishFullExpr(PC.get()).get();<br>
>>> +  Expr *PCE = ActOnFinishFullExpr(PC.get(), /*DiscardedValue*/ false).get();<br>
>>><br>
>>>    Stmt *Res = new (Context) CoreturnStmt(Loc, E, PCE, IsImplicit);<br>
>>>    return Res;<br>
>>> @@ -1237,7 +1237,7 @@ bool CoroutineStmtBuilder::makeNewAndDel<br>
>>><br>
>>>    ExprResult NewExpr =<br>
>>>        S.ActOnCallExpr(S.getCurScope(), NewRef.get(), Loc, NewArgs, Loc);<br>
>>> -  NewExpr = S.ActOnFinishFullExpr(NewExpr.get());<br>
>>> +  NewExpr = S.ActOnFinishFullExpr(NewExpr.get(), /*DiscardedValue*/ false);<br>
>>>    if (NewExpr.isInvalid())<br>
>>>      return false;<br>
>>><br>
>>> @@ -1263,7 +1263,8 @@ bool CoroutineStmtBuilder::makeNewAndDel<br>
>>><br>
>>>    ExprResult DeleteExpr =<br>
>>>        S.ActOnCallExpr(S.getCurScope(), DeleteRef.get(), Loc, DeleteArgs, Loc);<br>
>>> -  DeleteExpr = S.ActOnFinishFullExpr(DeleteExpr.get());<br>
>>> +  DeleteExpr =<br>
>>> +      S.ActOnFinishFullExpr(DeleteExpr.get(), /*DiscardedValue*/ false);<br>
>>>    if (DeleteExpr.isInvalid())<br>
>>>      return false;<br>
>>><br>
>>> @@ -1348,7 +1349,8 @@ bool CoroutineStmtBuilder::makeOnExcepti<br>
>>><br>
>>>    ExprResult UnhandledException = buildPromiseCall(S, Fn.CoroutinePromise, Loc,<br>
>>>                                                     "unhandled_exception", None);<br>
>>> -  UnhandledException = S.ActOnFinishFullExpr(UnhandledException.get(), Loc);<br>
>>> +  UnhandledException = S.ActOnFinishFullExpr(UnhandledException.get(), Loc,<br>
>>> +                                             /*DiscardedValue*/ false);<br>
>>>    if (UnhandledException.isInvalid())<br>
>>>      return false;<br>
>>><br>
>>> @@ -1401,7 +1403,8 @@ bool CoroutineStmtBuilder::makeGroDeclAn<br>
>>>           "get_return_object type must no longer be dependent");<br>
>>><br>
>>>    if (FnRetType->isVoidType()) {<br>
>>> -    ExprResult Res = S.ActOnFinishFullExpr(this->ReturnValue, Loc);<br>
>>> +    ExprResult Res =<br>
>>> +        S.ActOnFinishFullExpr(this->ReturnValue, Loc, /*DiscardedValue*/ false);<br>
>>>      if (Res.isInvalid())<br>
>>>        return false;<br>
>>><br>
>>> @@ -1433,7 +1436,7 @@ bool CoroutineStmtBuilder::makeGroDeclAn<br>
>>>    if (Res.isInvalid())<br>
>>>      return false;<br>
>>><br>
>>> -  Res = S.ActOnFinishFullExpr(Res.get());<br>
>>> +  Res = S.ActOnFinishFullExpr(Res.get(), /*DiscardedValue*/ false);<br>
>>>    if (Res.isInvalid())<br>
>>>      return false;<br>
>>><br>
>>><br>
>>> Modified: cfe/trunk/lib/Sema/SemaDecl.cpp<br>
>>> URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaDecl.cpp?rev=350404&r1=350403&r2=350404&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaDecl.cpp?rev=350404&r1=350403&r2=350404&view=diff</a><br>
>>> ==============================================================================<br>
>>> --- cfe/trunk/lib/Sema/SemaDecl.cpp (original)<br>
>>> +++ cfe/trunk/lib/Sema/SemaDecl.cpp Fri Jan  4 08:58:14 2019<br>
>>> @@ -11204,9 +11204,9 @@ void Sema::AddInitializerToDecl(Decl *Re<br>
>>>    //   struct T { S a, b; } t = { Temp(), Temp() }<br>
>>>    //<br>
>>>    // we should destroy the first Temp before constructing the second.<br>
>>> -  ExprResult Result = ActOnFinishFullExpr(Init, VDecl->getLocation(),<br>
>>> -                                          false,<br>
>>> -                                          VDecl->isConstexpr());<br>
>>> +  ExprResult Result =<br>
>>> +      ActOnFinishFullExpr(Init, VDecl->getLocation(),<br>
>>> +                          /*DiscardedValue*/ false, VDecl->isConstexpr());<br>
>>>    if (Result.isInvalid()) {<br>
>>>      VDecl->setInvalidDecl();<br>
>>>      return;<br>
>>><br>
>>> Modified: cfe/trunk/lib/Sema/SemaDeclCXX.cpp<br>
>>> URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaDeclCXX.cpp?rev=350404&r1=350403&r2=350404&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaDeclCXX.cpp?rev=350404&r1=350403&r2=350404&view=diff</a><br>
>>> ==============================================================================<br>
>>> --- cfe/trunk/lib/Sema/SemaDeclCXX.cpp (original)<br>
>>> +++ cfe/trunk/lib/Sema/SemaDeclCXX.cpp Fri Jan  4 08:58:14 2019<br>
>>> @@ -1205,7 +1205,7 @@ static bool checkTupleLikeDecomposition(<br>
>>>      E = Seq.Perform(S, Entity, Kind, Init);<br>
>>>      if (E.isInvalid())<br>
>>>        return true;<br>
>>> -    E = S.ActOnFinishFullExpr(E.get(), Loc);<br>
>>> +    E = S.ActOnFinishFullExpr(E.get(), Loc, /*DiscardedValue*/ false);<br>
>>>      if (E.isInvalid())<br>
>>>        return true;<br>
>>>      RefVD->setInit(E.get());<br>
>>> @@ -3682,7 +3682,7 @@ void Sema::ActOnFinishCXXInClassMemberIn<br>
>>>    // C++11 [class.base.init]p7:<br>
>>>    //   The initialization of each base and member constitutes a<br>
>>>    //   full-expression.<br>
>>> -  Init = ActOnFinishFullExpr(Init.get(), InitLoc);<br>
>>> +  Init = ActOnFinishFullExpr(Init.get(), InitLoc, /*DiscardedValue*/ false);<br>
>>>    if (Init.isInvalid()) {<br>
>>>      FD->setInvalidDecl();<br>
>>>      return;<br>
>>> @@ -4040,7 +4040,8 @@ Sema::BuildMemberInitializer(ValueDecl *<br>
>>>      // C++11 [class.base.init]p7:<br>
>>>      //   The initialization of each base and member constitutes a<br>
>>>      //   full-expression.<br>
>>> -    MemberInit = ActOnFinishFullExpr(MemberInit.get(), InitRange.getBegin());<br>
>>> +    MemberInit = ActOnFinishFullExpr(MemberInit.get(), InitRange.getBegin(),<br>
>>> +                                     /*DiscardedValue*/ false);<br>
>>>      if (MemberInit.isInvalid())<br>
>>>        return true;<br>
>>><br>
>>> @@ -4095,8 +4096,8 @@ Sema::BuildDelegatingInitializer(TypeSou<br>
>>>    // C++11 [class.base.init]p7:<br>
>>>    //   The initialization of each base and member constitutes a<br>
>>>    //   full-expression.<br>
>>> -  DelegationInit = ActOnFinishFullExpr(DelegationInit.get(),<br>
>>> -                                       InitRange.getBegin());<br>
>>> +  DelegationInit = ActOnFinishFullExpr(<br>
>>> +      DelegationInit.get(), InitRange.getBegin(), /*DiscardedValue*/ false);<br>
>>>    if (DelegationInit.isInvalid())<br>
>>>      return true;<br>
>>><br>
>>> @@ -4225,7 +4226,8 @@ Sema::BuildBaseInitializer(QualType Base<br>
>>>    // C++11 [class.base.init]p7:<br>
>>>    //   The initialization of each base and member constitutes a<br>
>>>    //   full-expression.<br>
>>> -  BaseInit = ActOnFinishFullExpr(BaseInit.get(), InitRange.getBegin());<br>
>>> +  BaseInit = ActOnFinishFullExpr(BaseInit.get(), InitRange.getBegin(),<br>
>>> +                                 /*DiscardedValue*/ false);<br>
>>>    if (BaseInit.isInvalid())<br>
>>>      return true;<br>
>>><br>
>>><br>
>>> Modified: cfe/trunk/lib/Sema/SemaExpr.cpp<br>
>>> URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaExpr.cpp?rev=350404&r1=350403&r2=350404&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaExpr.cpp?rev=350404&r1=350403&r2=350404&view=diff</a><br>
>>> ==============================================================================<br>
>>> --- cfe/trunk/lib/Sema/SemaExpr.cpp (original)<br>
>>> +++ cfe/trunk/lib/Sema/SemaExpr.cpp Fri Jan  4 08:58:14 2019<br>
>>> @@ -4736,8 +4736,9 @@ bool Sema::CheckCXXDefaultArgExpr(Source<br>
>>>      if (Result.isInvalid())<br>
>>>        return true;<br>
>>><br>
>>> -    Result = ActOnFinishFullExpr(Result.getAs<Expr>(),<br>
>>> -                                 Param->getOuterLocStart());<br>
>>> +    Result =<br>
>>> +        ActOnFinishFullExpr(Result.getAs<Expr>(), Param->getOuterLocStart(),<br>
>>> +                            /*DiscardedValue*/ false);<br>
>>>      if (Result.isInvalid())<br>
>>>        return true;<br>
>>><br>
>>><br>
>>> Modified: cfe/trunk/lib/Sema/SemaExprCXX.cpp<br>
>>> URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaExprCXX.cpp?rev=350404&r1=350403&r2=350404&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaExprCXX.cpp?rev=350404&r1=350403&r2=350404&view=diff</a><br>
>>> ==============================================================================<br>
>>> --- cfe/trunk/lib/Sema/SemaExprCXX.cpp (original)<br>
>>> +++ cfe/trunk/lib/Sema/SemaExprCXX.cpp Fri Jan  4 08:58:14 2019<br>
>>> @@ -7803,6 +7803,8 @@ ExprResult Sema::ActOnFinishFullExpr(Exp<br>
>>>      FullExpr = IgnoredValueConversions(FullExpr.get());<br>
>>>      if (FullExpr.isInvalid())<br>
>>>        return ExprError();<br>
>>> +<br>
>>> +    DiagnoseUnusedExprResult(FullExpr.get());<br>
>>>    }<br>
>>><br>
>>>    FullExpr = CorrectDelayedTyposInExpr(FullExpr.get());<br>
>>><br>
>>> Modified: cfe/trunk/lib/Sema/SemaLambda.cpp<br>
>>> URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaLambda.cpp?rev=350404&r1=350403&r2=350404&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaLambda.cpp?rev=350404&r1=350403&r2=350404&view=diff</a><br>
>>> ==============================================================================<br>
>>> --- cfe/trunk/lib/Sema/SemaLambda.cpp (original)<br>
>>> +++ cfe/trunk/lib/Sema/SemaLambda.cpp Fri Jan  4 08:58:14 2019<br>
>>> @@ -1724,7 +1724,7 @@ ExprResult Sema::BuildBlockForLambdaConv<br>
>>>                                                   /*NRVO=*/false),<br>
>>>        CurrentLocation, Src);<br>
>>>    if (!Init.isInvalid())<br>
>>> -    Init = ActOnFinishFullExpr(Init.get());<br>
>>> +    Init = ActOnFinishFullExpr(Init.get(), /*DiscardedValue*/ false);<br>
>>><br>
>>>    if (Init.isInvalid())<br>
>>>      return ExprError();<br>
>>><br>
>>> Modified: cfe/trunk/lib/Sema/SemaOpenMP.cpp<br>
>>> URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaOpenMP.cpp?rev=350404&r1=350403&r2=350404&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaOpenMP.cpp?rev=350404&r1=350403&r2=350404&view=diff</a><br>
>>> ==============================================================================<br>
>>> --- cfe/trunk/lib/Sema/SemaOpenMP.cpp (original)<br>
>>> +++ cfe/trunk/lib/Sema/SemaOpenMP.cpp Fri Jan  4 08:58:14 2019<br>
>>> @@ -5320,7 +5320,7 @@ checkOpenMPLoop(OpenMPDirectiveKind DKin<br>
>>>          LastIteration.get(), UB.get());<br>
>>>      EUB = SemaRef.BuildBinOp(CurScope, InitLoc, BO_Assign, UB.get(),<br>
>>>                               CondOp.get());<br>
>>> -    EUB = SemaRef.ActOnFinishFullExpr(EUB.get());<br>
>>> +    EUB = SemaRef.ActOnFinishFullExpr(EUB.get(), /*DiscardedValue*/ false);<br>
>>><br>
>>>      // If we have a combined directive that combines 'distribute', 'for' or<br>
>>>      // 'simd' we need to be able to access the bounds of the schedule of the<br>
>>> @@ -5349,7 +5349,8 @@ checkOpenMPLoop(OpenMPDirectiveKind DKin<br>
>>>                                       LastIteration.get(), CombUB.get());<br>
>>>        CombEUB = SemaRef.BuildBinOp(CurScope, InitLoc, BO_Assign, CombUB.get(),<br>
>>>                                     CombCondOp.get());<br>
>>> -      CombEUB = SemaRef.ActOnFinishFullExpr(CombEUB.get());<br>
>>> +      CombEUB =<br>
>>> +          SemaRef.ActOnFinishFullExpr(CombEUB.get(), /*DiscardedValue*/ false);<br>
>>><br>
>>>        const CapturedDecl *CD = cast<CapturedStmt>(AStmt)->getCapturedDecl();<br>
>>>        // We expect to have at least 2 more parameters than the 'parallel'<br>
>>> @@ -5383,7 +5384,7 @@ checkOpenMPLoop(OpenMPDirectiveKind DKin<br>
>>>              ? LB.get()<br>
>>>              : SemaRef.ActOnIntegerConstant(SourceLocation(), 0).get();<br>
>>>      Init = SemaRef.BuildBinOp(CurScope, InitLoc, BO_Assign, IV.get(), RHS);<br>
>>> -    Init = SemaRef.ActOnFinishFullExpr(Init.get());<br>
>>> +    Init = SemaRef.ActOnFinishFullExpr(Init.get(), /*DiscardedValue*/ false);<br>
>>><br>
>>>      if (isOpenMPLoopBoundSharingDirective(DKind)) {<br>
>>>        Expr *CombRHS =<br>
>>> @@ -5394,7 +5395,8 @@ checkOpenMPLoop(OpenMPDirectiveKind DKin<br>
>>>                : SemaRef.ActOnIntegerConstant(SourceLocation(), 0).get();<br>
>>>        CombInit =<br>
>>>            SemaRef.BuildBinOp(CurScope, InitLoc, BO_Assign, IV.get(), CombRHS);<br>
>>> -      CombInit = SemaRef.ActOnFinishFullExpr(CombInit.get());<br>
>>> +      CombInit =<br>
>>> +          SemaRef.ActOnFinishFullExpr(CombInit.get(), /*DiscardedValue*/ false);<br>
>>>      }<br>
>>>    }<br>
>>><br>
>>> @@ -5426,7 +5428,7 @@ checkOpenMPLoop(OpenMPDirectiveKind DKin<br>
>>>    if (!Inc.isUsable())<br>
>>>      return 0;<br>
>>>    Inc = SemaRef.BuildBinOp(CurScope, IncLoc, BO_Assign, IV.get(), Inc.get());<br>
>>> -  Inc = SemaRef.ActOnFinishFullExpr(Inc.get());<br>
>>> +  Inc = SemaRef.ActOnFinishFullExpr(Inc.get(), /*DiscardedValue*/ false);<br>
>>>    if (!Inc.isUsable())<br>
>>>      return 0;<br>
>>><br>
>>> @@ -5444,7 +5446,8 @@ checkOpenMPLoop(OpenMPDirectiveKind DKin<br>
>>>      // LB = LB + ST<br>
>>>      NextLB =<br>
>>>          SemaRef.BuildBinOp(CurScope, IncLoc, BO_Assign, LB.get(), NextLB.get());<br>
>>> -    NextLB = SemaRef.ActOnFinishFullExpr(NextLB.get());<br>
>>> +    NextLB =<br>
>>> +        SemaRef.ActOnFinishFullExpr(NextLB.get(), /*DiscardedValue*/ false);<br>
>>>      if (!NextLB.isUsable())<br>
>>>        return 0;<br>
>>>      // UB + ST<br>
>>> @@ -5454,7 +5457,8 @@ checkOpenMPLoop(OpenMPDirectiveKind DKin<br>
>>>      // UB = UB + ST<br>
>>>      NextUB =<br>
>>>          SemaRef.BuildBinOp(CurScope, IncLoc, BO_Assign, UB.get(), NextUB.get());<br>
>>> -    NextUB = SemaRef.ActOnFinishFullExpr(NextUB.get());<br>
>>> +    NextUB =<br>
>>> +        SemaRef.ActOnFinishFullExpr(NextUB.get(), /*DiscardedValue*/ false);<br>
>>>      if (!NextUB.isUsable())<br>
>>>        return 0;<br>
>>>      if (isOpenMPLoopBoundSharingDirective(DKind)) {<br>
>>> @@ -5465,7 +5469,8 @@ checkOpenMPLoop(OpenMPDirectiveKind DKin<br>
>>>        // LB = LB + ST<br>
>>>        CombNextLB = SemaRef.BuildBinOp(CurScope, IncLoc, BO_Assign, CombLB.get(),<br>
>>>                                        CombNextLB.get());<br>
>>> -      CombNextLB = SemaRef.ActOnFinishFullExpr(CombNextLB.get());<br>
>>> +      CombNextLB = SemaRef.ActOnFinishFullExpr(CombNextLB.get(),<br>
>>> +                                               /*DiscardedValue*/ false);<br>
>>>        if (!CombNextLB.isUsable())<br>
>>>          return 0;<br>
>>>        // UB + ST<br>
>>> @@ -5476,7 +5481,8 @@ checkOpenMPLoop(OpenMPDirectiveKind DKin<br>
>>>        // UB = UB + ST<br>
>>>        CombNextUB = SemaRef.BuildBinOp(CurScope, IncLoc, BO_Assign, CombUB.get(),<br>
>>>                                        CombNextUB.get());<br>
>>> -      CombNextUB = SemaRef.ActOnFinishFullExpr(CombNextUB.get());<br>
>>> +      CombNextUB = SemaRef.ActOnFinishFullExpr(CombNextUB.get(),<br>
>>> +                                               /*DiscardedValue*/ false);<br>
>>>        if (!CombNextUB.isUsable())<br>
>>>          return 0;<br>
>>>      }<br>
>>> @@ -5497,7 +5503,8 @@ checkOpenMPLoop(OpenMPDirectiveKind DKin<br>
>>>      assert(DistInc.isUsable() && "distribute inc expr was not built");<br>
>>>      DistInc = SemaRef.BuildBinOp(CurScope, DistIncLoc, BO_Assign, IV.get(),<br>
>>>                                   DistInc.get());<br>
>>> -    DistInc = SemaRef.ActOnFinishFullExpr(DistInc.get());<br>
>>> +    DistInc =<br>
>>> +        SemaRef.ActOnFinishFullExpr(DistInc.get(), /*DiscardedValue*/ false);<br>
>>>      assert(DistInc.isUsable() && "distribute inc expr was not built");<br>
>>><br>
>>>      // Build expression: UB = min(UB, prevUB) for #for in composite or combined<br>
>>> @@ -5509,7 +5516,8 @@ checkOpenMPLoop(OpenMPDirectiveKind DKin<br>
>>>          DistEUBLoc, DistEUBLoc, IsUBGreater.get(), PrevUB.get(), UB.get());<br>
>>>      PrevEUB = SemaRef.BuildBinOp(CurScope, DistIncLoc, BO_Assign, UB.get(),<br>
>>>                                   CondOp.get());<br>
>>> -    PrevEUB = SemaRef.ActOnFinishFullExpr(PrevEUB.get());<br>
>>> +    PrevEUB =<br>
>>> +        SemaRef.ActOnFinishFullExpr(PrevEUB.get(), /*DiscardedValue*/ false);<br>
>>><br>
>>>      // Build IV <= PrevUB to be used in parallel for is in combination with<br>
>>>      // a distribute directive with schedule(static, 1)<br>
>>> @@ -5613,8 +5621,10 @@ checkOpenMPLoop(OpenMPDirectiveKind DKin<br>
>>>    Built.IterationVarRef = IV.get();<br>
>>>    Built.LastIteration = LastIteration.get();<br>
>>>    Built.NumIterations = NumIterations.get();<br>
>>> -  Built.CalcLastIteration =<br>
>>> -      SemaRef.ActOnFinishFullExpr(CalcLastIteration.get()).get();<br>
>>> +  Built.CalcLastIteration = SemaRef<br>
>>> +                                .ActOnFinishFullExpr(CalcLastIteration.get(),<br>
>>> +                                                     /*DiscardedValue*/ false)<br>
>>> +                                .get();<br>
>>>    Built.PreCond = PreCond.get();<br>
>>>    Built.PreInits = buildPreInits(C, Captures);<br>
>>>    Built.Cond = Cond.get();<br>
>>> @@ -10267,8 +10277,8 @@ OMPClause *Sema::ActOnOpenMPLastprivateC<br>
>>>                                           PseudoDstExpr, PseudoSrcExpr);<br>
>>>      if (AssignmentOp.isInvalid())<br>
>>>        continue;<br>
>>> -    AssignmentOp = ActOnFinishFullExpr(AssignmentOp.get(), ELoc,<br>
>>> -                                       /*DiscardedValue=*/true);<br>
>>> +    AssignmentOp =<br>
>>> +        ActOnFinishFullExpr(AssignmentOp.get(), ELoc, /*DiscardedValue*/ false);<br>
>>>      if (AssignmentOp.isInvalid())<br>
>>>        continue;<br>
>>><br>
>>> @@ -11274,7 +11284,8 @@ static bool actOnOMPReductionKindClause(<br>
>>>                             BO_Assign, LHSDRE, ConditionalOp);<br>
>>>          }<br>
>>>          if (ReductionOp.isUsable())<br>
>>> -          ReductionOp = S.ActOnFinishFullExpr(ReductionOp.get());<br>
>>> +          ReductionOp = S.ActOnFinishFullExpr(ReductionOp.get(),<br>
>>> +                                              /*DiscardedValue*/ false);<br>
>>>        }<br>
>>>        if (!ReductionOp.isUsable())<br>
>>>          continue;<br>
>>> @@ -11612,7 +11623,7 @@ OMPClause *Sema::ActOnOpenMPLinearClause<br>
>>>          buildDeclRefExpr(*this, SaveVar, StepExpr->getType(), StepLoc);<br>
>>>      ExprResult CalcStep =<br>
>>>          BuildBinOp(CurScope, StepLoc, BO_Assign, SaveRef.get(), StepExpr);<br>
>>> -    CalcStep = ActOnFinishFullExpr(CalcStep.get());<br>
>>> +    CalcStep = ActOnFinishFullExpr(CalcStep.get(), /*DiscardedValue*/ false);<br>
>>><br>
>>>      // Warn about zero linear step (it would be probably better specified as<br>
>>>      // making corresponding variables 'const').<br>
>>> @@ -11700,7 +11711,7 @@ static bool FinishOpenMPLinearClause(OMP<br>
>>>      else<br>
>>>        Update = *CurPrivate;<br>
>>>      Update = SemaRef.ActOnFinishFullExpr(Update.get(), DE->getBeginLoc(),<br>
>>> -                                         /*DiscardedValue=*/true);<br>
>>> +                                         /*DiscardedValue*/ false);<br>
>>><br>
>>>      // Build final: Var = InitExpr + NumIterations * Step<br>
>>>      ExprResult Final;<br>
>>> @@ -11711,7 +11722,7 @@ static bool FinishOpenMPLinearClause(OMP<br>
>>>      else<br>
>>>        Final = *CurPrivate;<br>
>>>      Final = SemaRef.ActOnFinishFullExpr(Final.get(), DE->getBeginLoc(),<br>
>>> -                                        /*DiscardedValue=*/true);<br>
>>> +                                        /*DiscardedValue*/ false);<br>
>>><br>
>>>      if (!Update.isUsable() || !Final.isUsable()) {<br>
>>>        Updates.push_back(nullptr);<br>
>>> @@ -11879,7 +11890,7 @@ OMPClause *Sema::ActOnOpenMPCopyinClause<br>
>>>      if (AssignmentOp.isInvalid())<br>
>>>        continue;<br>
>>>      AssignmentOp = ActOnFinishFullExpr(AssignmentOp.get(), DE->getExprLoc(),<br>
>>> -                                       /*DiscardedValue=*/true);<br>
>>> +                                       /*DiscardedValue*/ false);<br>
>>>      if (AssignmentOp.isInvalid())<br>
>>>        continue;<br>
>>><br>
>>> @@ -11987,8 +11998,8 @@ OMPClause *Sema::ActOnOpenMPCopyprivateC<br>
>>>          DSAStack->getCurScope(), ELoc, BO_Assign, PseudoDstExpr, PseudoSrcExpr);<br>
>>>      if (AssignmentOp.isInvalid())<br>
>>>        continue;<br>
>>> -    AssignmentOp = ActOnFinishFullExpr(AssignmentOp.get(), ELoc,<br>
>>> -                                       /*DiscardedValue=*/true);<br>
>>> +    AssignmentOp =<br>
>>> +        ActOnFinishFullExpr(AssignmentOp.get(), ELoc, /*DiscardedValue*/ false);<br>
>>>      if (AssignmentOp.isInvalid())<br>
>>>        continue;<br>
>>><br>
>>><br>
>>> Modified: cfe/trunk/lib/Sema/SemaStmt.cpp<br>
>>> URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaStmt.cpp?rev=350404&r1=350403&r2=350404&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaStmt.cpp?rev=350404&r1=350403&r2=350404&view=diff</a><br>
>>> ==============================================================================<br>
>>> --- cfe/trunk/lib/Sema/SemaStmt.cpp (original)<br>
>>> +++ cfe/trunk/lib/Sema/SemaStmt.cpp Fri Jan  4 08:58:14 2019<br>
>>> @@ -42,12 +42,11 @@<br>
>>>  using namespace clang;<br>
>>>  using namespace sema;<br>
>>><br>
>>> -StmtResult Sema::ActOnExprStmt(ExprResult FE) {<br>
>>> +StmtResult Sema::ActOnExprStmt(ExprResult FE, bool DiscardedValue) {<br>
>>>    if (FE.isInvalid())<br>
>>>      return StmtError();<br>
>>><br>
>>> -  FE = ActOnFinishFullExpr(FE.get(), FE.get()->getExprLoc(),<br>
>>> -                           /*DiscardedValue*/ true);<br>
>>> +  FE = ActOnFinishFullExpr(FE.get(), FE.get()->getExprLoc(), DiscardedValue);<br>
>>>    if (FE.isInvalid())<br>
>>>      return StmtError();<br>
>>><br>
>>> @@ -348,6 +347,10 @@ sema::CompoundScopeInfo &Sema::getCurCom<br>
>>>    return getCurFunction()->CompoundScopes.back();<br>
>>>  }<br>
>>><br>
>>> +bool Sema::isCurCompoundStmtAStmtExpr() const {<br>
>>> +  return getCurCompoundScope().IsStmtExpr;<br>
>>> +}<br>
>>> +<br>
>>>  StmtResult Sema::ActOnCompoundStmt(SourceLocation L, SourceLocation R,<br>
>>>                                     ArrayRef<Stmt *> Elts, bool isStmtExpr) {<br>
>>>    const unsigned NumElts = Elts.size();<br>
>>> @@ -370,14 +373,6 @@ StmtResult Sema::ActOnCompoundStmt(Sourc<br>
>>>        Diag(D->getLocation(), diag::ext_mixed_decls_code);<br>
>>>      }<br>
>>>    }<br>
>>> -  // Warn about unused expressions in statements.<br>
>>> -  for (unsigned i = 0; i != NumElts; ++i) {<br>
>>> -    // Ignore statements that are last in a statement expression.<br>
>>> -    if (isStmtExpr && i == NumElts - 1)<br>
>>> -      continue;<br>
>>> -<br>
>>> -    DiagnoseUnusedExprResult(Elts[i]);<br>
>>> -  }<br>
>>><br>
>>>    // Check for suspicious empty body (null statement) in `for' and `while'<br>
>>>    // statements.  Don't do anything for template instantiations, this just adds<br>
>>> @@ -469,15 +464,12 @@ Sema::ActOnCaseStmt(SourceLocation CaseL<br>
>>><br>
>>>  /// ActOnCaseStmtBody - This installs a statement as the body of a case.<br>
>>>  void Sema::ActOnCaseStmtBody(Stmt *S, Stmt *SubStmt) {<br>
>>> -  DiagnoseUnusedExprResult(SubStmt);<br>
>>>    cast<CaseStmt>(S)->setSubStmt(SubStmt);<br>
>>>  }<br>
>>><br>
>>>  StmtResult<br>
>>>  Sema::ActOnDefaultStmt(SourceLocation DefaultLoc, SourceLocation ColonLoc,<br>
>>>                         Stmt *SubStmt, Scope *CurScope) {<br>
>>> -  DiagnoseUnusedExprResult(SubStmt);<br>
>>> -<br>
>>>    if (getCurFunction()->SwitchStack.empty()) {<br>
>>>      Diag(DefaultLoc, diag::err_default_not_in_switch);<br>
>>>      return SubStmt;<br>
>>> @@ -571,9 +563,6 @@ StmtResult Sema::BuildIfStmt(SourceLocat<br>
>>>    if (IsConstexpr || isa<ObjCAvailabilityCheckExpr>(Cond.get().second))<br>
>>>      setFunctionHasBranchProtectedScope();<br>
>>><br>
>>> -  DiagnoseUnusedExprResult(thenStmt);<br>
>>> -  DiagnoseUnusedExprResult(elseStmt);<br>
>>> -<br>
>>>    return IfStmt::Create(Context, IfLoc, IsConstexpr, InitStmt, Cond.get().first,<br>
>>>                          Cond.get().second, thenStmt, ElseLoc, elseStmt);<br>
>>>  }<br>
>>> @@ -1301,8 +1290,6 @@ StmtResult Sema::ActOnWhileStmt(SourceLo<br>
>>>        !Diags.isIgnored(diag::warn_comma_operator, CondVal.second->getExprLoc()))<br>
>>>      CommaVisitor(*this).Visit(CondVal.second);<br>
>>><br>
>>> -  DiagnoseUnusedExprResult(Body);<br>
>>> -<br>
>>>    if (isa<NullStmt>(Body))<br>
>>>      getCurCompoundScope().setHasEmptyLoopBodies();<br>
>>><br>
>>> @@ -1322,7 +1309,7 @@ Sema::ActOnDoStmt(SourceLocation DoLoc,<br>
>>>      return StmtError();<br>
>>>    Cond = CondResult.get();<br>
>>><br>
>>> -  CondResult = ActOnFinishFullExpr(Cond, DoLoc);<br>
>>> +  CondResult = ActOnFinishFullExpr(Cond, DoLoc, /*DiscardedValue*/ false);<br>
>>>    if (CondResult.isInvalid())<br>
>>>      return StmtError();<br>
>>>    Cond = CondResult.get();<br>
>>> @@ -1332,8 +1319,6 @@ Sema::ActOnDoStmt(SourceLocation DoLoc,<br>
>>>        !Diags.isIgnored(diag::warn_comma_operator, Cond->getExprLoc()))<br>
>>>      CommaVisitor(*this).Visit(Cond);<br>
>>><br>
>>> -  DiagnoseUnusedExprResult(Body);<br>
>>> -<br>
>>>    return new (Context) DoStmt(Body, Cond, DoLoc, WhileLoc, CondRParen);<br>
>>>  }<br>
>>><br>
>>> @@ -1778,11 +1763,6 @@ StmtResult Sema::ActOnForStmt(SourceLoca<br>
>>>      CommaVisitor(*this).Visit(Second.get().second);<br>
>>><br>
>>>    Expr *Third  = third.release().getAs<Expr>();<br>
>>> -<br>
>>> -  DiagnoseUnusedExprResult(First);<br>
>>> -  DiagnoseUnusedExprResult(Third);<br>
>>> -  DiagnoseUnusedExprResult(Body);<br>
>>> -<br>
>>>    if (isa<NullStmt>(Body))<br>
>>>      getCurCompoundScope().setHasEmptyLoopBodies();<br>
>>><br>
>>> @@ -1802,7 +1782,7 @@ StmtResult Sema::ActOnForEachLValueExpr(<br>
>>>    if (result.isInvalid()) return StmtError();<br>
>>>    E = result.get();<br>
>>><br>
>>> -  ExprResult FullExpr = ActOnFinishFullExpr(E);<br>
>>> +  ExprResult FullExpr = ActOnFinishFullExpr(E, /*DiscardedValue*/ false);<br>
>>>    if (FullExpr.isInvalid())<br>
>>>      return StmtError();<br>
>>>    return StmtResult(static_cast<Stmt*>(FullExpr.get()));<br>
>>> @@ -1956,7 +1936,8 @@ Sema::ActOnObjCForCollectionStmt(SourceL<br>
>>>    if (CollectionExprResult.isInvalid())<br>
>>>      return StmtError();<br>
>>><br>
>>> -  CollectionExprResult = ActOnFinishFullExpr(CollectionExprResult.get());<br>
>>> +  CollectionExprResult =<br>
>>> +      ActOnFinishFullExpr(CollectionExprResult.get(), /*DiscardedValue*/ false);<br>
>>>    if (CollectionExprResult.isInvalid())<br>
>>>      return StmtError();<br>
>>><br>
>>> @@ -2593,7 +2574,8 @@ StmtResult Sema::BuildCXXForRangeStmt(So<br>
>>>      if (!NotEqExpr.isInvalid())<br>
>>>        NotEqExpr = CheckBooleanCondition(ColonLoc, NotEqExpr.get());<br>
>>>      if (!NotEqExpr.isInvalid())<br>
>>> -      NotEqExpr = ActOnFinishFullExpr(NotEqExpr.get());<br>
>>> +      NotEqExpr =<br>
>>> +          ActOnFinishFullExpr(NotEqExpr.get(), /*DiscardedValue*/ false);<br>
>>>      if (NotEqExpr.isInvalid()) {<br>
>>>        Diag(RangeLoc, diag::note_for_range_invalid_iterator)<br>
>>>          << RangeLoc << 0 << BeginRangeRef.get()->getType();<br>
>>> @@ -2616,7 +2598,7 @@ StmtResult Sema::BuildCXXForRangeStmt(So<br>
>>>        // co_await during the initial parse.<br>
>>>        IncrExpr = ActOnCoawaitExpr(S, CoawaitLoc, IncrExpr.get());<br>
>>>      if (!IncrExpr.isInvalid())<br>
>>> -      IncrExpr = ActOnFinishFullExpr(IncrExpr.get());<br>
>>> +      IncrExpr = ActOnFinishFullExpr(IncrExpr.get(), /*DiscardedValue*/ false);<br>
>>>      if (IncrExpr.isInvalid()) {<br>
>>>        Diag(RangeLoc, diag::note_for_range_invalid_iterator)<br>
>>>          << RangeLoc << 2 << BeginRangeRef.get()->getType() ;<br>
>>> @@ -2871,7 +2853,7 @@ Sema::ActOnIndirectGotoStmt(SourceLocati<br>
>>>        return StmtError();<br>
>>>    }<br>
>>><br>
>>> -  ExprResult ExprRes = ActOnFinishFullExpr(E);<br>
>>> +  ExprResult ExprRes = ActOnFinishFullExpr(E, /*DiscardedValue*/ false);<br>
>>>    if (ExprRes.isInvalid())<br>
>>>      return StmtError();<br>
>>>    E = ExprRes.get();<br>
>>> @@ -3221,7 +3203,8 @@ Sema::ActOnCapScopeReturnStmt(SourceLoca<br>
>>>            ExpressionEvaluationContext::DiscardedStatement &&<br>
>>>        (HasDeducedReturnType || CurCap->HasImplicitReturnType)) {<br>
>>>      if (RetValExp) {<br>
>>> -      ExprResult ER = ActOnFinishFullExpr(RetValExp, ReturnLoc);<br>
>>> +      ExprResult ER =<br>
>>> +          ActOnFinishFullExpr(RetValExp, ReturnLoc, /*DiscardedValue*/ false);<br>
>>>        if (ER.isInvalid())<br>
>>>          return StmtError();<br>
>>>        RetValExp = ER.get();<br>
>>> @@ -3348,7 +3331,8 @@ Sema::ActOnCapScopeReturnStmt(SourceLoca<br>
>>>    }<br>
>>><br>
>>>    if (RetValExp) {<br>
>>> -    ExprResult ER = ActOnFinishFullExpr(RetValExp, ReturnLoc);<br>
>>> +    ExprResult ER =<br>
>>> +        ActOnFinishFullExpr(RetValExp, ReturnLoc, /*DiscardedValue*/ false);<br>
>>>      if (ER.isInvalid())<br>
>>>        return StmtError();<br>
>>>      RetValExp = ER.get();<br>
>>> @@ -3578,7 +3562,8 @@ StmtResult Sema::BuildReturnStmt(SourceL<br>
>>>            ExpressionEvaluationContext::DiscardedStatement &&<br>
>>>        FnRetType->getContainedAutoType()) {<br>
>>>      if (RetValExp) {<br>
>>> -      ExprResult ER = ActOnFinishFullExpr(RetValExp, ReturnLoc);<br>
>>> +      ExprResult ER =<br>
>>> +          ActOnFinishFullExpr(RetValExp, ReturnLoc, /*DiscardedValue*/ false);<br>
>>>        if (ER.isInvalid())<br>
>>>          return StmtError();<br>
>>>        RetValExp = ER.get();<br>
>>> @@ -3672,7 +3657,8 @@ StmtResult Sema::BuildReturnStmt(SourceL<br>
>>>        }<br>
>>><br>
>>>        if (RetValExp) {<br>
>>> -        ExprResult ER = ActOnFinishFullExpr(RetValExp, ReturnLoc);<br>
>>> +        ExprResult ER =<br>
>>> +            ActOnFinishFullExpr(RetValExp, ReturnLoc, /*DiscardedValue*/ false);<br>
>>>          if (ER.isInvalid())<br>
>>>            return StmtError();<br>
>>>          RetValExp = ER.get();<br>
>>> @@ -3751,7 +3737,8 @@ StmtResult Sema::BuildReturnStmt(SourceL<br>
>>>      }<br>
>>><br>
>>>      if (RetValExp) {<br>
>>> -      ExprResult ER = ActOnFinishFullExpr(RetValExp, ReturnLoc);<br>
>>> +      ExprResult ER =<br>
>>> +          ActOnFinishFullExpr(RetValExp, ReturnLoc, /*DiscardedValue*/ false);<br>
>>>        if (ER.isInvalid())<br>
>>>          return StmtError();<br>
>>>        RetValExp = ER.get();<br>
>>> @@ -3804,7 +3791,7 @@ StmtResult Sema::BuildObjCAtThrowStmt(So<br>
>>>      if (Result.isInvalid())<br>
>>>        return StmtError();<br>
>>><br>
>>> -    Result = ActOnFinishFullExpr(Result.get());<br>
>>> +    Result = ActOnFinishFullExpr(Result.get(), /*DiscardedValue*/ false);<br>
>>>      if (Result.isInvalid())<br>
>>>        return StmtError();<br>
>>>      Throw = Result.get();<br>
>>> @@ -3876,7 +3863,7 @@ Sema::ActOnObjCAtSynchronizedOperand(Sou<br>
>>>    }<br>
>>><br>
>>>    // The operand to @synchronized is a full-expression.<br>
>>> -  return ActOnFinishFullExpr(operand);<br>
>>> +  return ActOnFinishFullExpr(operand, /*DiscardedValue*/ false);<br>
>>>  }<br>
>>><br>
>>>  StmtResult<br>
>>><br>
>>> Modified: cfe/trunk/lib/Sema/TreeTransform.h<br>
>>> URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/TreeTransform.h?rev=350404&r1=350403&r2=350404&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/TreeTransform.h?rev=350404&r1=350403&r2=350404&view=diff</a><br>
>>> ==============================================================================<br>
>>> --- cfe/trunk/lib/Sema/TreeTransform.h (original)<br>
>>> +++ cfe/trunk/lib/Sema/TreeTransform.h Fri Jan  4 08:58:14 2019<br>
>>> @@ -328,7 +328,7 @@ public:<br>
>>>    /// other mechanism.<br>
>>>    ///<br>
>>>    /// \returns the transformed statement.<br>
>>> -  StmtResult TransformStmt(Stmt *S);<br>
>>> +  StmtResult TransformStmt(Stmt *S, bool DiscardedValue = false);<br>
>>><br>
>>>    /// Transform the given statement.<br>
>>>    ///<br>
>>> @@ -3269,8 +3269,8 @@ private:<br>
>>>                                        bool DeducibleTSTContext);<br>
>>>  };<br>
>>><br>
>>> -template<typename Derived><br>
>>> -StmtResult TreeTransform<Derived>::TransformStmt(Stmt *S) {<br>
>>> +template <typename Derived><br>
>>> +StmtResult TreeTransform<Derived>::TransformStmt(Stmt *S, bool DiscardedValue) {<br>
>>>    if (!S)<br>
>>>      return S;<br>
>>><br>
>>> @@ -3294,7 +3294,7 @@ StmtResult TreeTransform<Derived>::Trans<br>
>>>        if (E.isInvalid())<br>
>>>          return StmtError();<br>
>>><br>
>>> -      return getSema().ActOnExprStmt(E);<br>
>>> +      return getSema().ActOnExprStmt(E, DiscardedValue);<br>
>>>      }<br>
>>>    }<br>
>>><br>
>>> @@ -4715,7 +4715,8 @@ TreeTransform<Derived>::TransformVariabl<br>
>>>    }<br>
>>>    if (SizeResult.isInvalid())<br>
>>>      return QualType();<br>
>>> -  SizeResult = SemaRef.ActOnFinishFullExpr(SizeResult.get());<br>
>>> +  SizeResult =<br>
>>> +      SemaRef.ActOnFinishFullExpr(SizeResult.get(), /*DiscardedValue*/ false);<br>
>>>    if (SizeResult.isInvalid())<br>
>>>      return QualType();<br>
>>><br>
>>> @@ -6520,7 +6521,9 @@ TreeTransform<Derived>::TransformCompoun<br>
>>>    bool SubStmtChanged = false;<br>
>>>    SmallVector<Stmt*, 8> Statements;<br>
>>>    for (auto *B : S->body()) {<br>
>>> -    StmtResult Result = getDerived().TransformStmt(B);<br>
>>> +    StmtResult Result =<br>
>>> +        getDerived().TransformStmt(B, !IsStmtExpr || B != S->body_back());<br>
>>> +<br>
>>>      if (Result.isInvalid()) {<br>
>>>        // Immediately fail if this was a DeclStmt, since it's very<br>
>>>        // likely that this will cause problems for future statements.<br>
>>><br>
>>> Modified: cfe/trunk/test/CXX/stmt.stmt/stmt.select/p3.cpp<br>
>>> URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CXX/stmt.stmt/stmt.select/p3.cpp?rev=350404&r1=350403&r2=350404&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CXX/stmt.stmt/stmt.select/p3.cpp?rev=350404&r1=350403&r2=350404&view=diff</a><br>
>>> ==============================================================================<br>
>>> --- cfe/trunk/test/CXX/stmt.stmt/stmt.select/p3.cpp (original)<br>
>>> +++ cfe/trunk/test/CXX/stmt.stmt/stmt.select/p3.cpp Fri Jan  4 08:58:14 2019<br>
>>> @@ -1,5 +1,5 @@<br>
>>> -// RUN: %clang_cc1 -fsyntax-only -verify %s<br>
>>> -// RUN: %clang_cc1 -fsyntax-only -std=c++1z -Wc++14-compat -verify %s -DCPP17<br>
>>> +// RUN: %clang_cc1 -fsyntax-only -Wno-unused-value -verify %s<br>
>>> +// RUN: %clang_cc1 -fsyntax-only -Wno-unused-value -std=c++1z -Wc++14-compat -verify %s -DCPP17<br>
>>><br>
>>>  int f();<br>
>>><br>
>>> @@ -71,7 +71,6 @@ void whileInitStatement() {<br>
>>>  // last loop above. It would be nice to remove this.<br>
>>>  void whileInitStatement2() {<br>
>>>    while (; false) {} // expected-error {{expected expression}}<br>
>>> -  // expected-warning@-1 {{expression result unused}}<br>
>>> -  // expected-error@-2 {{expected ';' after expression}}<br>
>>> -  // expected-error@-3 {{expected expression}}<br>
>>> +  // expected-error@-1 {{expected ';' after expression}}<br>
>>> +  // expected-error@-2 {{expected expression}}<br>
>>>  }<br>
>>><br>
>>> Modified: cfe/trunk/test/CodeCompletion/pragma-macro-token-caching.c<br>
>>> URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeCompletion/pragma-macro-token-caching.c?rev=350404&r1=350403&r2=350404&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeCompletion/pragma-macro-token-caching.c?rev=350404&r1=350403&r2=350404&view=diff</a><br>
>>> ==============================================================================<br>
>>> --- cfe/trunk/test/CodeCompletion/pragma-macro-token-caching.c (original)<br>
>>> +++ cfe/trunk/test/CodeCompletion/pragma-macro-token-caching.c Fri Jan  4 08:58:14 2019<br>
>>> @@ -12,7 +12,7 @@ void completeParam(int param) {<br>
>>><br>
>>>  void completeParamPragmaError(int param) {<br>
>>>      Outer(__extension__({ _Pragma(2) })); // expected-error {{_Pragma takes a parenthesized string literal}}<br>
>>> -    param;<br>
>>> +    param; // expected-warning {{expression result unused}}<br>
>>>  }<br>
>>><br>
>>>  // RUN: %clang_cc1 -fsyntax-only -verify -code-completion-at=%s:16:1 %s | FileCheck %s<br>
>>><br>
>>> Modified: cfe/trunk/test/Parser/cxx1z-init-statement.cpp<br>
>>> URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Parser/cxx1z-init-statement.cpp?rev=350404&r1=350403&r2=350404&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Parser/cxx1z-init-statement.cpp?rev=350404&r1=350403&r2=350404&view=diff</a><br>
>>> ==============================================================================<br>
>>> --- cfe/trunk/test/Parser/cxx1z-init-statement.cpp (original)<br>
>>> +++ cfe/trunk/test/Parser/cxx1z-init-statement.cpp Fri Jan  4 08:58:14 2019<br>
>>> @@ -13,9 +13,9 @@ int f() {<br>
>>>    if (T(n) = 0; n) {}<br>
>>><br>
>>>    // init-statement expressions<br>
>>> -  if (T{f()}; f()) {}<br>
>>> -  if (T{f()}, g, h; f()) {} // expected-warning 2{{unused}}<br>
>>> -  if (T(f()), g, h + 1; f()) {} // expected-warning 2{{unused}}<br>
>>> +  if (T{f()}; f()) {} // expected-warning {{expression result unused}}<br>
>>> +  if (T{f()}, g, h; f()) {} // expected-warning 2{{unused}} expected-warning {{expression result unused}}<br>
>>> +  if (T(f()), g, h + 1; f()) {} // expected-warning 2{{unused}} expected-warning {{expression result unused}}<br>
>>><br>
>>>    // condition declarations<br>
>>>    if (T(n){g}) {}<br>
>>> @@ -35,7 +35,7 @@ int f() {<br>
>>><br>
>>>    // Likewise for 'switch'<br>
>>>    switch (int n; n) {}<br>
>>> -  switch (g; int g = 5) {}<br>
>>> +  switch (g; int g = 5) {} // expected-warning {{expression result unused}}<br>
>>><br>
>>>    if (int a, b; int c = a) { // expected-note 6{{previous}}<br>
>>>      int a; // expected-error {{redefinition}}<br>
>>><br>
>>> Modified: cfe/trunk/test/Parser/switch-recovery.cpp<br>
>>> URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Parser/switch-recovery.cpp?rev=350404&r1=350403&r2=350404&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Parser/switch-recovery.cpp?rev=350404&r1=350403&r2=350404&view=diff</a><br>
>>> ==============================================================================<br>
>>> --- cfe/trunk/test/Parser/switch-recovery.cpp (original)<br>
>>> +++ cfe/trunk/test/Parser/switch-recovery.cpp Fri Jan  4 08:58:14 2019<br>
>>> @@ -105,7 +105,7 @@ void test9(int x) { // expected-note {{'<br>
>>>                expected-error {{expected expression}}<br>
>>>      8:: x; // expected-error {{expected ';' after expression}} \<br>
>>>                expected-error {{no member named 'x' in the global namespace; did you mean simply 'x'?}} \<br>
>>> -              expected-warning 2 {{expression result unused}}<br>
>>> +              expected-warning {{expression result unused}}<br>
>>>      9:: :y; // expected-error {{expected ';' after expression}} \<br>
>>>                 expected-error {{expected unqualified-id}} \<br>
>>>                 expected-warning {{expression result unused}}<br>
>>><br>
>>> Modified: cfe/trunk/test/SemaCXX/cxx1z-init-statement.cpp<br>
>>> URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/cxx1z-init-statement.cpp?rev=350404&r1=350403&r2=350404&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/cxx1z-init-statement.cpp?rev=350404&r1=350403&r2=350404&view=diff</a><br>
>>> ==============================================================================<br>
>>> --- cfe/trunk/test/SemaCXX/cxx1z-init-statement.cpp (original)<br>
>>> +++ cfe/trunk/test/SemaCXX/cxx1z-init-statement.cpp Fri Jan  4 08:58:14 2019<br>
>>> @@ -1,5 +1,5 @@<br>
>>> -// RUN: %clang_cc1 -std=c++1z -verify %s<br>
>>> -// RUN: %clang_cc1 -std=c++17 -verify %s<br>
>>> +// RUN: %clang_cc1 -std=c++1z -Wno-unused-value -verify %s<br>
>>> +// RUN: %clang_cc1 -std=c++17 -Wno-unused-value -verify %s<br>
>>><br>
>>>  void testIf() {<br>
>>>    int x = 0;<br>
>>> @@ -12,7 +12,7 @@ void testIf() {<br>
>>>      int x = 0; // expected-error {{redefinition of 'x'}}<br>
>>><br>
>>>    if (x; int a = 0) ++a;<br>
>>> -  if (x, +x; int a = 0) // expected-note 2 {{previous definition is here}} expected-warning {{unused}}<br>
>>> +  if (x, +x; int a = 0) // expected-note 2 {{previous definition is here}}<br>
>>>      int a = 0; // expected-error {{redefinition of 'a'}}<br>
>>>    else<br>
>>>      int a = 0; // expected-error {{redefinition of 'a'}}<br>
>>> @@ -48,7 +48,7 @@ void testSwitch() {<br>
>>>        ++a;<br>
>>>    }<br>
>>><br>
>>> -  switch (x, +x; int a = 0) { // expected-note {{previous definition is here}} expected-warning {{unused}}<br>
>>> +  switch (x, +x; int a = 0) { // expected-note {{previous definition is here}}<br>
>>>      case 0:<br>
>>>        int a = 0; // expected-error {{redefinition of 'a'}} // expected-note {{previous definition is here}}<br>
>>>      case 1:<br>
>>><br>
>>> Modified: cfe/trunk/test/SemaCXX/for-range-examples.cpp<br>
>>> URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/for-range-examples.cpp?rev=350404&r1=350403&r2=350404&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/for-range-examples.cpp?rev=350404&r1=350403&r2=350404&view=diff</a><br>
>>> ==============================================================================<br>
>>> --- cfe/trunk/test/SemaCXX/for-range-examples.cpp (original)<br>
>>> +++ cfe/trunk/test/SemaCXX/for-range-examples.cpp Fri Jan  4 08:58:14 2019<br>
>>> @@ -244,7 +244,7 @@ void foo ()<br>
>>>  {<br>
>>>    int b = 1, a[b];<br>
>>>    a[0] = 0;<br>
>>> -  [&] { for (int c : a) 0; } ();<br>
>>> +  [&] { for (int c : a) 0; } (); // expected-warning {{expression result unused}}<br>
>>>  }<br>
>>><br>
>>><br>
>>><br>
>>> Modified: cfe/trunk/test/SemaCXX/warn-unused-result.cpp<br>
>>> URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/warn-unused-result.cpp?rev=350404&r1=350403&r2=350404&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/warn-unused-result.cpp?rev=350404&r1=350403&r2=350404&view=diff</a><br>
>>> ==============================================================================<br>
>>> --- cfe/trunk/test/SemaCXX/warn-unused-result.cpp (original)<br>
>>> +++ cfe/trunk/test/SemaCXX/warn-unused-result.cpp Fri Jan  4 08:58:14 2019<br>
>>> @@ -33,6 +33,36 @@ void test() {<br>
>>>    const S &s4 = g1();<br>
>>>  }<br>
>>><br>
>>> +void testSubstmts(int i) {<br>
>>> +  switch (i) {<br>
>>> +  case 0:<br>
>>> +    f(); // expected-warning {{ignoring return value}}<br>
>>> +  default:<br>
>>> +    f(); // expected-warning {{ignoring return value}}<br>
>>> +  }<br>
>>> +<br>
>>> +  if (i)<br>
>>> +    f(); // expected-warning {{ignoring return value}}<br>
>>> +  else<br>
>>> +    f(); // expected-warning {{ignoring return value}}<br>
>>> +<br>
>>> +  while (i)<br>
>>> +    f(); // expected-warning {{ignoring return value}}<br>
>>> +<br>
>>> +  do<br>
>>> +    f(); // expected-warning {{ignoring return value}}<br>
>>> +  while (i);<br>
>>> +<br>
>>> +  for (f(); // expected-warning {{ignoring return value}}<br>
>>> +       ;<br>
>>> +       f() // expected-warning {{ignoring return value}}<br>
>>> +      )<br>
>>> +    f(); // expected-warning {{ignoring return value}}<br>
>>> +<br>
>>> +  f(),  // expected-warning {{ignoring return value}}<br>
>>> +  (void)f();<br>
>>> +}<br>
>>> +<br>
>>>  struct X {<br>
>>>   int foo() __attribute__((warn_unused_result));<br>
>>>  };<br>
>>> @@ -206,3 +236,13 @@ void f() {<br>
>>>    (void)++p;<br>
>>>  }<br>
>>>  } // namespace<br>
>>> +<br>
>>> +namespace PR39837 {<br>
>>> +[[clang::warn_unused_result]] int f(int);<br>
>>> +<br>
>>> +void g() {<br>
>>> +  int a[2];<br>
>>> +  for (int b : a)<br>
>>> +    f(b); // expected-warning {{ignoring return value}}<br>
>>> +}<br>
>>> +} // namespace PR39837<br>
>>><br>
>>><br>
>>> _______________________________________________<br>
>>> cfe-commits mailing list<br>
>>> <a href="mailto:cfe-commits@lists.llvm.org" target="_blank">cfe-commits@lists.llvm.org</a><br>
>>> <a href="http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits" rel="noreferrer" target="_blank">http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits</a><br>
>><br>
>> _______________________________________________<br>
>> cfe-commits mailing list<br>
>> <a href="mailto:cfe-commits@lists.llvm.org" target="_blank">cfe-commits@lists.llvm.org</a><br>
>> <a href="http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits" rel="noreferrer" target="_blank">http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits</a><br>
</blockquote></div></div>