r350404 - Refactor the way we handle diagnosing unused expression results.
Aaron Ballman via cfe-commits
cfe-commits at lists.llvm.org
Sun Jan 6 08:44:38 PST 2019
On Sun, Jan 6, 2019 at 10:58 AM Nico Weber <thakis at chromium.org> wrote:
>
> On Sat, Jan 5, 2019 at 10:16 AM Aaron Ballman <aaron at aaronballman.com> wrote:
>>
>> On Fri, Jan 4, 2019 at 8:41 PM Richard Smith <richard at metafoo.co.uk> wrote:
>> >
>> > On Fri, 4 Jan 2019 at 17:33, Nico Weber via cfe-commits <cfe-commits at lists.llvm.org> wrote:
>> >>
>> >> Nice, this is finding bugs: https://bugs.chromium.org/p/chromium/issues/detail?id=919262
>> >>
>> >> However, I noticed that for that case, the same warning is printed twice:
>> >>
>> >> ../../third_party/crashpad/crashpad/util/win/process_info.cc(227,36): error: expression result unused [-Werror,-Wunused-value]
>> >> NTSTATUS_LOG(ERROR, status), "NtQueryInformationProcess";
>> >> ^~~~~~~~~~~~~~~~~~~~~~~~~~~
>> >> ../../third_party/crashpad/crashpad/util/win/process_info.cc(227,36): error: expression result unused [-Werror,-Wunused-value]
>> >> NTSTATUS_LOG(ERROR, status), "NtQueryInformationProcess";
>> >>
>> >>
>> >> Is that expected?
>>
>> Yes and no. It's not unexpected, but it's not super helpful either. As
>> Richard points out below, this happens because of template
>> instantiation.
>>
>> > The first diagnostic appears when parsing the template, the second one appears when instantiating it. In the complete diagnostic output:
>> >
>> > ../../third_party/crashpad/crashpad/util/win/process_info.cc(227,36): error: expression result unused [-Werror,-Wunused-value]
>> > NTSTATUS_LOG(ERROR, status), "NtQueryInformationProcess";
>> > ^~~~~~~~~~~~~~~~~~~~~~~~~~~
>> >
>> > ../../third_party/crashpad/crashpad/util/win/process_info.cc(227,36): error: expression result unused [-Werror,-Wunused-value]
>> > NTSTATUS_LOG(ERROR, status), "NtQueryInformationProcess";
>> > ^~~~~~~~~~~~~~~~~~~~~~~~~~~
>> > ../../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
>> > bool result = GetProcessBasicInformation<process_types::internal::Traits32>(
>> > ^
>> >
>> > 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).
>>
>> Agreed, though I don't have the time to work on that currently.
>> Hopefully the behavior here isn't too onerous for Chromium (or other
>> projects)?
>
>
> 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) :-)
I'm glad to hear the refactoring is catching more issues, that's
great! I'm also glad the template instantiation stuff isn't causing
too much of a problem for you.
~Aaron
>
>>
>>
>> ~Aaron
>>
>> >
>> >> Code is here:
>> >> 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
>> >> 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
>> >>
>> >>
>> >> On Fri, Jan 4, 2019 at 12:01 PM Aaron Ballman via cfe-commits <cfe-commits at lists.llvm.org> wrote:
>> >>>
>> >>> Author: aaronballman
>> >>> Date: Fri Jan 4 08:58:14 2019
>> >>> New Revision: 350404
>> >>>
>> >>> URL: http://llvm.org/viewvc/llvm-project?rev=350404&view=rev
>> >>> Log:
>> >>> Refactor the way we handle diagnosing unused expression results.
>> >>>
>> >>> 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.
>> >>>
>> >>> This patch fixes PR39837.
>> >>>
>> >>> Modified:
>> >>> cfe/trunk/include/clang/Parse/Parser.h
>> >>> cfe/trunk/include/clang/Sema/Sema.h
>> >>> cfe/trunk/lib/Parse/ParseObjc.cpp
>> >>> cfe/trunk/lib/Parse/ParseOpenMP.cpp
>> >>> cfe/trunk/lib/Parse/ParseStmt.cpp
>> >>> cfe/trunk/lib/Sema/SemaCoroutine.cpp
>> >>> cfe/trunk/lib/Sema/SemaDecl.cpp
>> >>> cfe/trunk/lib/Sema/SemaDeclCXX.cpp
>> >>> cfe/trunk/lib/Sema/SemaExpr.cpp
>> >>> cfe/trunk/lib/Sema/SemaExprCXX.cpp
>> >>> cfe/trunk/lib/Sema/SemaLambda.cpp
>> >>> cfe/trunk/lib/Sema/SemaOpenMP.cpp
>> >>> cfe/trunk/lib/Sema/SemaStmt.cpp
>> >>> cfe/trunk/lib/Sema/TreeTransform.h
>> >>> cfe/trunk/test/CXX/stmt.stmt/stmt.select/p3.cpp
>> >>> cfe/trunk/test/CodeCompletion/pragma-macro-token-caching.c
>> >>> cfe/trunk/test/Parser/cxx1z-init-statement.cpp
>> >>> cfe/trunk/test/Parser/switch-recovery.cpp
>> >>> cfe/trunk/test/SemaCXX/cxx1z-init-statement.cpp
>> >>> cfe/trunk/test/SemaCXX/for-range-examples.cpp
>> >>> cfe/trunk/test/SemaCXX/warn-unused-result.cpp
>> >>>
>> >>> Modified: cfe/trunk/include/clang/Parse/Parser.h
>> >>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Parse/Parser.h?rev=350404&r1=350403&r2=350404&view=diff
>> >>> ==============================================================================
>> >>> --- cfe/trunk/include/clang/Parse/Parser.h (original)
>> >>> +++ cfe/trunk/include/clang/Parse/Parser.h Fri Jan 4 08:58:14 2019
>> >>> @@ -360,6 +360,11 @@ class Parser : public CodeCompletionHand
>> >>> /// just a regular sub-expression.
>> >>> SourceLocation ExprStatementTokLoc;
>> >>>
>> >>> + /// Tests whether an expression value is discarded based on token lookahead.
>> >>> + /// It will return true if the lexer is currently processing the })
>> >>> + /// terminating a GNU statement expression and false otherwise.
>> >>> + bool isExprValueDiscarded();
>> >>> +
>> >>> public:
>> >>> Parser(Preprocessor &PP, Sema &Actions, bool SkipFunctionBodies);
>> >>> ~Parser() override;
>> >>>
>> >>> Modified: cfe/trunk/include/clang/Sema/Sema.h
>> >>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Sema/Sema.h?rev=350404&r1=350403&r2=350404&view=diff
>> >>> ==============================================================================
>> >>> --- cfe/trunk/include/clang/Sema/Sema.h (original)
>> >>> +++ cfe/trunk/include/clang/Sema/Sema.h Fri Jan 4 08:58:14 2019
>> >>> @@ -1365,6 +1365,7 @@ public:
>> >>> void PopCompoundScope();
>> >>>
>> >>> sema::CompoundScopeInfo &getCurCompoundScope() const;
>> >>> + bool isCurCompoundStmtAStmtExpr() const;
>> >>>
>> >>> bool hasAnyUnrecoverableErrorsInThisFunction() const;
>> >>>
>> >>> @@ -3685,16 +3686,17 @@ public:
>> >>> return MakeFullExpr(Arg, Arg ? Arg->getExprLoc() : SourceLocation());
>> >>> }
>> >>> FullExprArg MakeFullExpr(Expr *Arg, SourceLocation CC) {
>> >>> - return FullExprArg(ActOnFinishFullExpr(Arg, CC).get());
>> >>> + return FullExprArg(
>> >>> + ActOnFinishFullExpr(Arg, CC, /*DiscardedValue*/ false).get());
>> >>> }
>> >>> FullExprArg MakeFullDiscardedValueExpr(Expr *Arg) {
>> >>> ExprResult FE =
>> >>> - ActOnFinishFullExpr(Arg, Arg ? Arg->getExprLoc() : SourceLocation(),
>> >>> - /*DiscardedValue*/ true);
>> >>> + ActOnFinishFullExpr(Arg, Arg ? Arg->getExprLoc() : SourceLocation(),
>> >>> + /*DiscardedValue*/ true);
>> >>> return FullExprArg(FE.get());
>> >>> }
>> >>>
>> >>> - StmtResult ActOnExprStmt(ExprResult Arg);
>> >>> + StmtResult ActOnExprStmt(ExprResult Arg, bool DiscardedValue = true);
>> >>> StmtResult ActOnExprStmtError();
>> >>>
>> >>> StmtResult ActOnNullStmt(SourceLocation SemiLoc,
>> >>> @@ -5340,13 +5342,12 @@ public:
>> >>> CreateMaterializeTemporaryExpr(QualType T, Expr *Temporary,
>> >>> bool BoundToLvalueReference);
>> >>>
>> >>> - ExprResult ActOnFinishFullExpr(Expr *Expr) {
>> >>> - return ActOnFinishFullExpr(Expr, Expr ? Expr->getExprLoc()
>> >>> - : SourceLocation());
>> >>> + ExprResult ActOnFinishFullExpr(Expr *Expr, bool DiscardedValue) {
>> >>> + return ActOnFinishFullExpr(
>> >>> + Expr, Expr ? Expr->getExprLoc() : SourceLocation(), DiscardedValue);
>> >>> }
>> >>> ExprResult ActOnFinishFullExpr(Expr *Expr, SourceLocation CC,
>> >>> - bool DiscardedValue = false,
>> >>> - bool IsConstexpr = false);
>> >>> + bool DiscardedValue, bool IsConstexpr = false);
>> >>> StmtResult ActOnFinishFullStmt(Stmt *Stmt);
>> >>>
>> >>> // Marks SS invalid if it represents an incomplete type.
>> >>>
>> >>> Modified: cfe/trunk/lib/Parse/ParseObjc.cpp
>> >>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Parse/ParseObjc.cpp?rev=350404&r1=350403&r2=350404&view=diff
>> >>> ==============================================================================
>> >>> --- cfe/trunk/lib/Parse/ParseObjc.cpp (original)
>> >>> +++ cfe/trunk/lib/Parse/ParseObjc.cpp Fri Jan 4 08:58:14 2019
>> >>> @@ -2741,7 +2741,7 @@ StmtResult Parser::ParseObjCAtStatement(
>> >>>
>> >>> // Otherwise, eat the semicolon.
>> >>> ExpectAndConsumeSemi(diag::err_expected_semi_after_expr);
>> >>> - return Actions.ActOnExprStmt(Res);
>> >>> + return Actions.ActOnExprStmt(Res, isExprValueDiscarded());
>> >>> }
>> >>>
>> >>> ExprResult Parser::ParseObjCAtExpression(SourceLocation AtLoc) {
>> >>>
>> >>> Modified: cfe/trunk/lib/Parse/ParseOpenMP.cpp
>> >>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Parse/ParseOpenMP.cpp?rev=350404&r1=350403&r2=350404&view=diff
>> >>> ==============================================================================
>> >>> --- cfe/trunk/lib/Parse/ParseOpenMP.cpp (original)
>> >>> +++ cfe/trunk/lib/Parse/ParseOpenMP.cpp Fri Jan 4 08:58:14 2019
>> >>> @@ -314,7 +314,7 @@ Parser::ParseOpenMPDeclareReductionDirec
>> >>> Actions.ActOnOpenMPDeclareReductionCombinerStart(getCurScope(), D);
>> >>> ExprResult CombinerResult =
>> >>> Actions.ActOnFinishFullExpr(ParseAssignmentExpression().get(),
>> >>> - D->getLocation(), /*DiscardedValue=*/true);
>> >>> + D->getLocation(), /*DiscardedValue*/ false);
>> >>> Actions.ActOnOpenMPDeclareReductionCombinerEnd(D, CombinerResult.get());
>> >>>
>> >>> if (CombinerResult.isInvalid() && Tok.isNot(tok::r_paren) &&
>> >>> @@ -356,7 +356,7 @@ Parser::ParseOpenMPDeclareReductionDirec
>> >>> if (Actions.getLangOpts().CPlusPlus) {
>> >>> InitializerResult = Actions.ActOnFinishFullExpr(
>> >>> ParseAssignmentExpression().get(), D->getLocation(),
>> >>> - /*DiscardedValue=*/true);
>> >>> + /*DiscardedValue*/ false);
>> >>> } else {
>> >>> ConsumeToken();
>> >>> ParseOpenMPReductionInitializerForDecl(OmpPrivParm);
>> >>> @@ -364,7 +364,7 @@ Parser::ParseOpenMPDeclareReductionDirec
>> >>> } else {
>> >>> InitializerResult = Actions.ActOnFinishFullExpr(
>> >>> ParseAssignmentExpression().get(), D->getLocation(),
>> >>> - /*DiscardedValue=*/true);
>> >>> + /*DiscardedValue*/ false);
>> >>> }
>> >>> Actions.ActOnOpenMPDeclareReductionInitializerEnd(
>> >>> D, InitializerResult.get(), OmpPrivParm);
>> >>> @@ -1455,7 +1455,7 @@ ExprResult Parser::ParseOpenMPParensExpr
>> >>> ExprResult LHS(ParseCastExpression(
>> >>> /*isUnaryExpression=*/false, /*isAddressOfOperand=*/false, NotTypeCast));
>> >>> ExprResult Val(ParseRHSOfBinaryExpression(LHS, prec::Conditional));
>> >>> - Val = Actions.ActOnFinishFullExpr(Val.get(), ELoc);
>> >>> + Val = Actions.ActOnFinishFullExpr(Val.get(), ELoc, /*DiscardedValue*/ false);
>> >>>
>> >>> // Parse ')'.
>> >>> RLoc = Tok.getLocation();
>> >>> @@ -1711,7 +1711,8 @@ OMPClause *Parser::ParseOpenMPSingleExpr
>> >>> SourceLocation ELoc = Tok.getLocation();
>> >>> ExprResult LHS(ParseCastExpression(false, false, NotTypeCast));
>> >>> Val = ParseRHSOfBinaryExpression(LHS, prec::Conditional);
>> >>> - Val = Actions.ActOnFinishFullExpr(Val.get(), ELoc);
>> >>> + Val =
>> >>> + Actions.ActOnFinishFullExpr(Val.get(), ELoc, /*DiscardedValue*/ false);
>> >>> }
>> >>>
>> >>> // Parse ')'.
>> >>> @@ -1996,7 +1997,8 @@ bool Parser::ParseOpenMPVarList(OpenMPDi
>> >>> Data.ColonLoc = Tok.getLocation();
>> >>> SourceLocation ELoc = ConsumeToken();
>> >>> ExprResult Tail = ParseAssignmentExpression();
>> >>> - Tail = Actions.ActOnFinishFullExpr(Tail.get(), ELoc);
>> >>> + Tail =
>> >>> + Actions.ActOnFinishFullExpr(Tail.get(), ELoc, /*DiscardedValue*/ false);
>> >>> if (Tail.isUsable())
>> >>> Data.TailExpr = Tail.get();
>> >>> else
>> >>>
>> >>> Modified: cfe/trunk/lib/Parse/ParseStmt.cpp
>> >>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Parse/ParseStmt.cpp?rev=350404&r1=350403&r2=350404&view=diff
>> >>> ==============================================================================
>> >>> --- cfe/trunk/lib/Parse/ParseStmt.cpp (original)
>> >>> +++ cfe/trunk/lib/Parse/ParseStmt.cpp Fri Jan 4 08:58:14 2019
>> >>> @@ -439,7 +439,7 @@ StmtResult Parser::ParseExprStatement()
>> >>>
>> >>> // Otherwise, eat the semicolon.
>> >>> ExpectAndConsumeSemi(diag::err_expected_semi_after_expr);
>> >>> - return Actions.ActOnExprStmt(Expr);
>> >>> + return Actions.ActOnExprStmt(Expr, isExprValueDiscarded());
>> >>> }
>> >>>
>> >>> /// ParseSEHTryBlockCommon
>> >>> @@ -958,6 +958,16 @@ bool Parser::ConsumeNullStmt(StmtVector
>> >>> return true;
>> >>> }
>> >>>
>> >>> +bool Parser::isExprValueDiscarded() {
>> >>> + if (Actions.isCurCompoundStmtAStmtExpr()) {
>> >>> + // Look to see if the next two tokens close the statement expression;
>> >>> + // if so, this expression statement is the last statement in a
>> >>> + // statment expression.
>> >>> + return Tok.isNot(tok::r_brace) || NextToken().isNot(tok::r_paren);
>> >>> + }
>> >>> + return true;
>> >>> +}
>> >>> +
>> >>> /// ParseCompoundStatementBody - Parse a sequence of statements and invoke the
>> >>> /// ActOnCompoundStmt action. This expects the '{' to be the current token, and
>> >>> /// consume the '}' at the end of the block. It does not manipulate the scope
>> >>> @@ -1062,7 +1072,7 @@ StmtResult Parser::ParseCompoundStatemen
>> >>> // Eat the semicolon at the end of stmt and convert the expr into a
>> >>> // statement.
>> >>> ExpectAndConsumeSemi(diag::err_expected_semi_after_expr);
>> >>> - R = Actions.ActOnExprStmt(Res);
>> >>> + R = Actions.ActOnExprStmt(Res, isExprValueDiscarded());
>> >>> }
>> >>> }
>> >>>
>> >>> @@ -1698,8 +1708,16 @@ StmtResult Parser::ParseForStatement(Sou
>> >>> if (!Value.isInvalid()) {
>> >>> if (ForEach)
>> >>> FirstPart = Actions.ActOnForEachLValueExpr(Value.get());
>> >>> - else
>> >>> - FirstPart = Actions.ActOnExprStmt(Value);
>> >>> + else {
>> >>> + // We already know this is not an init-statement within a for loop, so
>> >>> + // if we are parsing a C++11 range-based for loop, we should treat this
>> >>> + // expression statement as being a discarded value expression because
>> >>> + // we will err below. This way we do not warn on an unused expression
>> >>> + // that was an error in the first place, like with: for (expr : expr);
>> >>> + bool IsRangeBasedFor =
>> >>> + getLangOpts().CPlusPlus11 && !ForEach && Tok.is(tok::colon);
>> >>> + FirstPart = Actions.ActOnExprStmt(Value, !IsRangeBasedFor);
>> >>> + }
>> >>> }
>> >>>
>> >>> if (Tok.is(tok::semi)) {
>> >>>
>> >>> Modified: cfe/trunk/lib/Sema/SemaCoroutine.cpp
>> >>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaCoroutine.cpp?rev=350404&r1=350403&r2=350404&view=diff
>> >>> ==============================================================================
>> >>> --- cfe/trunk/lib/Sema/SemaCoroutine.cpp (original)
>> >>> +++ cfe/trunk/lib/Sema/SemaCoroutine.cpp Fri Jan 4 08:58:14 2019
>> >>> @@ -647,7 +647,7 @@ bool Sema::ActOnCoroutineBodyStart(Scope
>> >>> return StmtError();
>> >>> Suspend = BuildResolvedCoawaitExpr(Loc, Suspend.get(),
>> >>> /*IsImplicit*/ true);
>> >>> - Suspend = ActOnFinishFullExpr(Suspend.get());
>> >>> + Suspend = ActOnFinishFullExpr(Suspend.get(), /*DiscardedValue*/ false);
>> >>> if (Suspend.isInvalid()) {
>> >>> Diag(Loc, diag::note_coroutine_promise_suspend_implicitly_required)
>> >>> << ((Name == "initial_suspend") ? 0 : 1);
>> >>> @@ -868,7 +868,7 @@ StmtResult Sema::BuildCoreturnStmt(Sourc
>> >>> if (PC.isInvalid())
>> >>> return StmtError();
>> >>>
>> >>> - Expr *PCE = ActOnFinishFullExpr(PC.get()).get();
>> >>> + Expr *PCE = ActOnFinishFullExpr(PC.get(), /*DiscardedValue*/ false).get();
>> >>>
>> >>> Stmt *Res = new (Context) CoreturnStmt(Loc, E, PCE, IsImplicit);
>> >>> return Res;
>> >>> @@ -1237,7 +1237,7 @@ bool CoroutineStmtBuilder::makeNewAndDel
>> >>>
>> >>> ExprResult NewExpr =
>> >>> S.ActOnCallExpr(S.getCurScope(), NewRef.get(), Loc, NewArgs, Loc);
>> >>> - NewExpr = S.ActOnFinishFullExpr(NewExpr.get());
>> >>> + NewExpr = S.ActOnFinishFullExpr(NewExpr.get(), /*DiscardedValue*/ false);
>> >>> if (NewExpr.isInvalid())
>> >>> return false;
>> >>>
>> >>> @@ -1263,7 +1263,8 @@ bool CoroutineStmtBuilder::makeNewAndDel
>> >>>
>> >>> ExprResult DeleteExpr =
>> >>> S.ActOnCallExpr(S.getCurScope(), DeleteRef.get(), Loc, DeleteArgs, Loc);
>> >>> - DeleteExpr = S.ActOnFinishFullExpr(DeleteExpr.get());
>> >>> + DeleteExpr =
>> >>> + S.ActOnFinishFullExpr(DeleteExpr.get(), /*DiscardedValue*/ false);
>> >>> if (DeleteExpr.isInvalid())
>> >>> return false;
>> >>>
>> >>> @@ -1348,7 +1349,8 @@ bool CoroutineStmtBuilder::makeOnExcepti
>> >>>
>> >>> ExprResult UnhandledException = buildPromiseCall(S, Fn.CoroutinePromise, Loc,
>> >>> "unhandled_exception", None);
>> >>> - UnhandledException = S.ActOnFinishFullExpr(UnhandledException.get(), Loc);
>> >>> + UnhandledException = S.ActOnFinishFullExpr(UnhandledException.get(), Loc,
>> >>> + /*DiscardedValue*/ false);
>> >>> if (UnhandledException.isInvalid())
>> >>> return false;
>> >>>
>> >>> @@ -1401,7 +1403,8 @@ bool CoroutineStmtBuilder::makeGroDeclAn
>> >>> "get_return_object type must no longer be dependent");
>> >>>
>> >>> if (FnRetType->isVoidType()) {
>> >>> - ExprResult Res = S.ActOnFinishFullExpr(this->ReturnValue, Loc);
>> >>> + ExprResult Res =
>> >>> + S.ActOnFinishFullExpr(this->ReturnValue, Loc, /*DiscardedValue*/ false);
>> >>> if (Res.isInvalid())
>> >>> return false;
>> >>>
>> >>> @@ -1433,7 +1436,7 @@ bool CoroutineStmtBuilder::makeGroDeclAn
>> >>> if (Res.isInvalid())
>> >>> return false;
>> >>>
>> >>> - Res = S.ActOnFinishFullExpr(Res.get());
>> >>> + Res = S.ActOnFinishFullExpr(Res.get(), /*DiscardedValue*/ false);
>> >>> if (Res.isInvalid())
>> >>> return false;
>> >>>
>> >>>
>> >>> Modified: cfe/trunk/lib/Sema/SemaDecl.cpp
>> >>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaDecl.cpp?rev=350404&r1=350403&r2=350404&view=diff
>> >>> ==============================================================================
>> >>> --- cfe/trunk/lib/Sema/SemaDecl.cpp (original)
>> >>> +++ cfe/trunk/lib/Sema/SemaDecl.cpp Fri Jan 4 08:58:14 2019
>> >>> @@ -11204,9 +11204,9 @@ void Sema::AddInitializerToDecl(Decl *Re
>> >>> // struct T { S a, b; } t = { Temp(), Temp() }
>> >>> //
>> >>> // we should destroy the first Temp before constructing the second.
>> >>> - ExprResult Result = ActOnFinishFullExpr(Init, VDecl->getLocation(),
>> >>> - false,
>> >>> - VDecl->isConstexpr());
>> >>> + ExprResult Result =
>> >>> + ActOnFinishFullExpr(Init, VDecl->getLocation(),
>> >>> + /*DiscardedValue*/ false, VDecl->isConstexpr());
>> >>> if (Result.isInvalid()) {
>> >>> VDecl->setInvalidDecl();
>> >>> return;
>> >>>
>> >>> Modified: cfe/trunk/lib/Sema/SemaDeclCXX.cpp
>> >>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaDeclCXX.cpp?rev=350404&r1=350403&r2=350404&view=diff
>> >>> ==============================================================================
>> >>> --- cfe/trunk/lib/Sema/SemaDeclCXX.cpp (original)
>> >>> +++ cfe/trunk/lib/Sema/SemaDeclCXX.cpp Fri Jan 4 08:58:14 2019
>> >>> @@ -1205,7 +1205,7 @@ static bool checkTupleLikeDecomposition(
>> >>> E = Seq.Perform(S, Entity, Kind, Init);
>> >>> if (E.isInvalid())
>> >>> return true;
>> >>> - E = S.ActOnFinishFullExpr(E.get(), Loc);
>> >>> + E = S.ActOnFinishFullExpr(E.get(), Loc, /*DiscardedValue*/ false);
>> >>> if (E.isInvalid())
>> >>> return true;
>> >>> RefVD->setInit(E.get());
>> >>> @@ -3682,7 +3682,7 @@ void Sema::ActOnFinishCXXInClassMemberIn
>> >>> // C++11 [class.base.init]p7:
>> >>> // The initialization of each base and member constitutes a
>> >>> // full-expression.
>> >>> - Init = ActOnFinishFullExpr(Init.get(), InitLoc);
>> >>> + Init = ActOnFinishFullExpr(Init.get(), InitLoc, /*DiscardedValue*/ false);
>> >>> if (Init.isInvalid()) {
>> >>> FD->setInvalidDecl();
>> >>> return;
>> >>> @@ -4040,7 +4040,8 @@ Sema::BuildMemberInitializer(ValueDecl *
>> >>> // C++11 [class.base.init]p7:
>> >>> // The initialization of each base and member constitutes a
>> >>> // full-expression.
>> >>> - MemberInit = ActOnFinishFullExpr(MemberInit.get(), InitRange.getBegin());
>> >>> + MemberInit = ActOnFinishFullExpr(MemberInit.get(), InitRange.getBegin(),
>> >>> + /*DiscardedValue*/ false);
>> >>> if (MemberInit.isInvalid())
>> >>> return true;
>> >>>
>> >>> @@ -4095,8 +4096,8 @@ Sema::BuildDelegatingInitializer(TypeSou
>> >>> // C++11 [class.base.init]p7:
>> >>> // The initialization of each base and member constitutes a
>> >>> // full-expression.
>> >>> - DelegationInit = ActOnFinishFullExpr(DelegationInit.get(),
>> >>> - InitRange.getBegin());
>> >>> + DelegationInit = ActOnFinishFullExpr(
>> >>> + DelegationInit.get(), InitRange.getBegin(), /*DiscardedValue*/ false);
>> >>> if (DelegationInit.isInvalid())
>> >>> return true;
>> >>>
>> >>> @@ -4225,7 +4226,8 @@ Sema::BuildBaseInitializer(QualType Base
>> >>> // C++11 [class.base.init]p7:
>> >>> // The initialization of each base and member constitutes a
>> >>> // full-expression.
>> >>> - BaseInit = ActOnFinishFullExpr(BaseInit.get(), InitRange.getBegin());
>> >>> + BaseInit = ActOnFinishFullExpr(BaseInit.get(), InitRange.getBegin(),
>> >>> + /*DiscardedValue*/ false);
>> >>> if (BaseInit.isInvalid())
>> >>> return true;
>> >>>
>> >>>
>> >>> Modified: cfe/trunk/lib/Sema/SemaExpr.cpp
>> >>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaExpr.cpp?rev=350404&r1=350403&r2=350404&view=diff
>> >>> ==============================================================================
>> >>> --- cfe/trunk/lib/Sema/SemaExpr.cpp (original)
>> >>> +++ cfe/trunk/lib/Sema/SemaExpr.cpp Fri Jan 4 08:58:14 2019
>> >>> @@ -4736,8 +4736,9 @@ bool Sema::CheckCXXDefaultArgExpr(Source
>> >>> if (Result.isInvalid())
>> >>> return true;
>> >>>
>> >>> - Result = ActOnFinishFullExpr(Result.getAs<Expr>(),
>> >>> - Param->getOuterLocStart());
>> >>> + Result =
>> >>> + ActOnFinishFullExpr(Result.getAs<Expr>(), Param->getOuterLocStart(),
>> >>> + /*DiscardedValue*/ false);
>> >>> if (Result.isInvalid())
>> >>> return true;
>> >>>
>> >>>
>> >>> Modified: cfe/trunk/lib/Sema/SemaExprCXX.cpp
>> >>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaExprCXX.cpp?rev=350404&r1=350403&r2=350404&view=diff
>> >>> ==============================================================================
>> >>> --- cfe/trunk/lib/Sema/SemaExprCXX.cpp (original)
>> >>> +++ cfe/trunk/lib/Sema/SemaExprCXX.cpp Fri Jan 4 08:58:14 2019
>> >>> @@ -7803,6 +7803,8 @@ ExprResult Sema::ActOnFinishFullExpr(Exp
>> >>> FullExpr = IgnoredValueConversions(FullExpr.get());
>> >>> if (FullExpr.isInvalid())
>> >>> return ExprError();
>> >>> +
>> >>> + DiagnoseUnusedExprResult(FullExpr.get());
>> >>> }
>> >>>
>> >>> FullExpr = CorrectDelayedTyposInExpr(FullExpr.get());
>> >>>
>> >>> Modified: cfe/trunk/lib/Sema/SemaLambda.cpp
>> >>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaLambda.cpp?rev=350404&r1=350403&r2=350404&view=diff
>> >>> ==============================================================================
>> >>> --- cfe/trunk/lib/Sema/SemaLambda.cpp (original)
>> >>> +++ cfe/trunk/lib/Sema/SemaLambda.cpp Fri Jan 4 08:58:14 2019
>> >>> @@ -1724,7 +1724,7 @@ ExprResult Sema::BuildBlockForLambdaConv
>> >>> /*NRVO=*/false),
>> >>> CurrentLocation, Src);
>> >>> if (!Init.isInvalid())
>> >>> - Init = ActOnFinishFullExpr(Init.get());
>> >>> + Init = ActOnFinishFullExpr(Init.get(), /*DiscardedValue*/ false);
>> >>>
>> >>> if (Init.isInvalid())
>> >>> return ExprError();
>> >>>
>> >>> Modified: cfe/trunk/lib/Sema/SemaOpenMP.cpp
>> >>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaOpenMP.cpp?rev=350404&r1=350403&r2=350404&view=diff
>> >>> ==============================================================================
>> >>> --- cfe/trunk/lib/Sema/SemaOpenMP.cpp (original)
>> >>> +++ cfe/trunk/lib/Sema/SemaOpenMP.cpp Fri Jan 4 08:58:14 2019
>> >>> @@ -5320,7 +5320,7 @@ checkOpenMPLoop(OpenMPDirectiveKind DKin
>> >>> LastIteration.get(), UB.get());
>> >>> EUB = SemaRef.BuildBinOp(CurScope, InitLoc, BO_Assign, UB.get(),
>> >>> CondOp.get());
>> >>> - EUB = SemaRef.ActOnFinishFullExpr(EUB.get());
>> >>> + EUB = SemaRef.ActOnFinishFullExpr(EUB.get(), /*DiscardedValue*/ false);
>> >>>
>> >>> // If we have a combined directive that combines 'distribute', 'for' or
>> >>> // 'simd' we need to be able to access the bounds of the schedule of the
>> >>> @@ -5349,7 +5349,8 @@ checkOpenMPLoop(OpenMPDirectiveKind DKin
>> >>> LastIteration.get(), CombUB.get());
>> >>> CombEUB = SemaRef.BuildBinOp(CurScope, InitLoc, BO_Assign, CombUB.get(),
>> >>> CombCondOp.get());
>> >>> - CombEUB = SemaRef.ActOnFinishFullExpr(CombEUB.get());
>> >>> + CombEUB =
>> >>> + SemaRef.ActOnFinishFullExpr(CombEUB.get(), /*DiscardedValue*/ false);
>> >>>
>> >>> const CapturedDecl *CD = cast<CapturedStmt>(AStmt)->getCapturedDecl();
>> >>> // We expect to have at least 2 more parameters than the 'parallel'
>> >>> @@ -5383,7 +5384,7 @@ checkOpenMPLoop(OpenMPDirectiveKind DKin
>> >>> ? LB.get()
>> >>> : SemaRef.ActOnIntegerConstant(SourceLocation(), 0).get();
>> >>> Init = SemaRef.BuildBinOp(CurScope, InitLoc, BO_Assign, IV.get(), RHS);
>> >>> - Init = SemaRef.ActOnFinishFullExpr(Init.get());
>> >>> + Init = SemaRef.ActOnFinishFullExpr(Init.get(), /*DiscardedValue*/ false);
>> >>>
>> >>> if (isOpenMPLoopBoundSharingDirective(DKind)) {
>> >>> Expr *CombRHS =
>> >>> @@ -5394,7 +5395,8 @@ checkOpenMPLoop(OpenMPDirectiveKind DKin
>> >>> : SemaRef.ActOnIntegerConstant(SourceLocation(), 0).get();
>> >>> CombInit =
>> >>> SemaRef.BuildBinOp(CurScope, InitLoc, BO_Assign, IV.get(), CombRHS);
>> >>> - CombInit = SemaRef.ActOnFinishFullExpr(CombInit.get());
>> >>> + CombInit =
>> >>> + SemaRef.ActOnFinishFullExpr(CombInit.get(), /*DiscardedValue*/ false);
>> >>> }
>> >>> }
>> >>>
>> >>> @@ -5426,7 +5428,7 @@ checkOpenMPLoop(OpenMPDirectiveKind DKin
>> >>> if (!Inc.isUsable())
>> >>> return 0;
>> >>> Inc = SemaRef.BuildBinOp(CurScope, IncLoc, BO_Assign, IV.get(), Inc.get());
>> >>> - Inc = SemaRef.ActOnFinishFullExpr(Inc.get());
>> >>> + Inc = SemaRef.ActOnFinishFullExpr(Inc.get(), /*DiscardedValue*/ false);
>> >>> if (!Inc.isUsable())
>> >>> return 0;
>> >>>
>> >>> @@ -5444,7 +5446,8 @@ checkOpenMPLoop(OpenMPDirectiveKind DKin
>> >>> // LB = LB + ST
>> >>> NextLB =
>> >>> SemaRef.BuildBinOp(CurScope, IncLoc, BO_Assign, LB.get(), NextLB.get());
>> >>> - NextLB = SemaRef.ActOnFinishFullExpr(NextLB.get());
>> >>> + NextLB =
>> >>> + SemaRef.ActOnFinishFullExpr(NextLB.get(), /*DiscardedValue*/ false);
>> >>> if (!NextLB.isUsable())
>> >>> return 0;
>> >>> // UB + ST
>> >>> @@ -5454,7 +5457,8 @@ checkOpenMPLoop(OpenMPDirectiveKind DKin
>> >>> // UB = UB + ST
>> >>> NextUB =
>> >>> SemaRef.BuildBinOp(CurScope, IncLoc, BO_Assign, UB.get(), NextUB.get());
>> >>> - NextUB = SemaRef.ActOnFinishFullExpr(NextUB.get());
>> >>> + NextUB =
>> >>> + SemaRef.ActOnFinishFullExpr(NextUB.get(), /*DiscardedValue*/ false);
>> >>> if (!NextUB.isUsable())
>> >>> return 0;
>> >>> if (isOpenMPLoopBoundSharingDirective(DKind)) {
>> >>> @@ -5465,7 +5469,8 @@ checkOpenMPLoop(OpenMPDirectiveKind DKin
>> >>> // LB = LB + ST
>> >>> CombNextLB = SemaRef.BuildBinOp(CurScope, IncLoc, BO_Assign, CombLB.get(),
>> >>> CombNextLB.get());
>> >>> - CombNextLB = SemaRef.ActOnFinishFullExpr(CombNextLB.get());
>> >>> + CombNextLB = SemaRef.ActOnFinishFullExpr(CombNextLB.get(),
>> >>> + /*DiscardedValue*/ false);
>> >>> if (!CombNextLB.isUsable())
>> >>> return 0;
>> >>> // UB + ST
>> >>> @@ -5476,7 +5481,8 @@ checkOpenMPLoop(OpenMPDirectiveKind DKin
>> >>> // UB = UB + ST
>> >>> CombNextUB = SemaRef.BuildBinOp(CurScope, IncLoc, BO_Assign, CombUB.get(),
>> >>> CombNextUB.get());
>> >>> - CombNextUB = SemaRef.ActOnFinishFullExpr(CombNextUB.get());
>> >>> + CombNextUB = SemaRef.ActOnFinishFullExpr(CombNextUB.get(),
>> >>> + /*DiscardedValue*/ false);
>> >>> if (!CombNextUB.isUsable())
>> >>> return 0;
>> >>> }
>> >>> @@ -5497,7 +5503,8 @@ checkOpenMPLoop(OpenMPDirectiveKind DKin
>> >>> assert(DistInc.isUsable() && "distribute inc expr was not built");
>> >>> DistInc = SemaRef.BuildBinOp(CurScope, DistIncLoc, BO_Assign, IV.get(),
>> >>> DistInc.get());
>> >>> - DistInc = SemaRef.ActOnFinishFullExpr(DistInc.get());
>> >>> + DistInc =
>> >>> + SemaRef.ActOnFinishFullExpr(DistInc.get(), /*DiscardedValue*/ false);
>> >>> assert(DistInc.isUsable() && "distribute inc expr was not built");
>> >>>
>> >>> // Build expression: UB = min(UB, prevUB) for #for in composite or combined
>> >>> @@ -5509,7 +5516,8 @@ checkOpenMPLoop(OpenMPDirectiveKind DKin
>> >>> DistEUBLoc, DistEUBLoc, IsUBGreater.get(), PrevUB.get(), UB.get());
>> >>> PrevEUB = SemaRef.BuildBinOp(CurScope, DistIncLoc, BO_Assign, UB.get(),
>> >>> CondOp.get());
>> >>> - PrevEUB = SemaRef.ActOnFinishFullExpr(PrevEUB.get());
>> >>> + PrevEUB =
>> >>> + SemaRef.ActOnFinishFullExpr(PrevEUB.get(), /*DiscardedValue*/ false);
>> >>>
>> >>> // Build IV <= PrevUB to be used in parallel for is in combination with
>> >>> // a distribute directive with schedule(static, 1)
>> >>> @@ -5613,8 +5621,10 @@ checkOpenMPLoop(OpenMPDirectiveKind DKin
>> >>> Built.IterationVarRef = IV.get();
>> >>> Built.LastIteration = LastIteration.get();
>> >>> Built.NumIterations = NumIterations.get();
>> >>> - Built.CalcLastIteration =
>> >>> - SemaRef.ActOnFinishFullExpr(CalcLastIteration.get()).get();
>> >>> + Built.CalcLastIteration = SemaRef
>> >>> + .ActOnFinishFullExpr(CalcLastIteration.get(),
>> >>> + /*DiscardedValue*/ false)
>> >>> + .get();
>> >>> Built.PreCond = PreCond.get();
>> >>> Built.PreInits = buildPreInits(C, Captures);
>> >>> Built.Cond = Cond.get();
>> >>> @@ -10267,8 +10277,8 @@ OMPClause *Sema::ActOnOpenMPLastprivateC
>> >>> PseudoDstExpr, PseudoSrcExpr);
>> >>> if (AssignmentOp.isInvalid())
>> >>> continue;
>> >>> - AssignmentOp = ActOnFinishFullExpr(AssignmentOp.get(), ELoc,
>> >>> - /*DiscardedValue=*/true);
>> >>> + AssignmentOp =
>> >>> + ActOnFinishFullExpr(AssignmentOp.get(), ELoc, /*DiscardedValue*/ false);
>> >>> if (AssignmentOp.isInvalid())
>> >>> continue;
>> >>>
>> >>> @@ -11274,7 +11284,8 @@ static bool actOnOMPReductionKindClause(
>> >>> BO_Assign, LHSDRE, ConditionalOp);
>> >>> }
>> >>> if (ReductionOp.isUsable())
>> >>> - ReductionOp = S.ActOnFinishFullExpr(ReductionOp.get());
>> >>> + ReductionOp = S.ActOnFinishFullExpr(ReductionOp.get(),
>> >>> + /*DiscardedValue*/ false);
>> >>> }
>> >>> if (!ReductionOp.isUsable())
>> >>> continue;
>> >>> @@ -11612,7 +11623,7 @@ OMPClause *Sema::ActOnOpenMPLinearClause
>> >>> buildDeclRefExpr(*this, SaveVar, StepExpr->getType(), StepLoc);
>> >>> ExprResult CalcStep =
>> >>> BuildBinOp(CurScope, StepLoc, BO_Assign, SaveRef.get(), StepExpr);
>> >>> - CalcStep = ActOnFinishFullExpr(CalcStep.get());
>> >>> + CalcStep = ActOnFinishFullExpr(CalcStep.get(), /*DiscardedValue*/ false);
>> >>>
>> >>> // Warn about zero linear step (it would be probably better specified as
>> >>> // making corresponding variables 'const').
>> >>> @@ -11700,7 +11711,7 @@ static bool FinishOpenMPLinearClause(OMP
>> >>> else
>> >>> Update = *CurPrivate;
>> >>> Update = SemaRef.ActOnFinishFullExpr(Update.get(), DE->getBeginLoc(),
>> >>> - /*DiscardedValue=*/true);
>> >>> + /*DiscardedValue*/ false);
>> >>>
>> >>> // Build final: Var = InitExpr + NumIterations * Step
>> >>> ExprResult Final;
>> >>> @@ -11711,7 +11722,7 @@ static bool FinishOpenMPLinearClause(OMP
>> >>> else
>> >>> Final = *CurPrivate;
>> >>> Final = SemaRef.ActOnFinishFullExpr(Final.get(), DE->getBeginLoc(),
>> >>> - /*DiscardedValue=*/true);
>> >>> + /*DiscardedValue*/ false);
>> >>>
>> >>> if (!Update.isUsable() || !Final.isUsable()) {
>> >>> Updates.push_back(nullptr);
>> >>> @@ -11879,7 +11890,7 @@ OMPClause *Sema::ActOnOpenMPCopyinClause
>> >>> if (AssignmentOp.isInvalid())
>> >>> continue;
>> >>> AssignmentOp = ActOnFinishFullExpr(AssignmentOp.get(), DE->getExprLoc(),
>> >>> - /*DiscardedValue=*/true);
>> >>> + /*DiscardedValue*/ false);
>> >>> if (AssignmentOp.isInvalid())
>> >>> continue;
>> >>>
>> >>> @@ -11987,8 +11998,8 @@ OMPClause *Sema::ActOnOpenMPCopyprivateC
>> >>> DSAStack->getCurScope(), ELoc, BO_Assign, PseudoDstExpr, PseudoSrcExpr);
>> >>> if (AssignmentOp.isInvalid())
>> >>> continue;
>> >>> - AssignmentOp = ActOnFinishFullExpr(AssignmentOp.get(), ELoc,
>> >>> - /*DiscardedValue=*/true);
>> >>> + AssignmentOp =
>> >>> + ActOnFinishFullExpr(AssignmentOp.get(), ELoc, /*DiscardedValue*/ false);
>> >>> if (AssignmentOp.isInvalid())
>> >>> continue;
>> >>>
>> >>>
>> >>> Modified: cfe/trunk/lib/Sema/SemaStmt.cpp
>> >>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaStmt.cpp?rev=350404&r1=350403&r2=350404&view=diff
>> >>> ==============================================================================
>> >>> --- cfe/trunk/lib/Sema/SemaStmt.cpp (original)
>> >>> +++ cfe/trunk/lib/Sema/SemaStmt.cpp Fri Jan 4 08:58:14 2019
>> >>> @@ -42,12 +42,11 @@
>> >>> using namespace clang;
>> >>> using namespace sema;
>> >>>
>> >>> -StmtResult Sema::ActOnExprStmt(ExprResult FE) {
>> >>> +StmtResult Sema::ActOnExprStmt(ExprResult FE, bool DiscardedValue) {
>> >>> if (FE.isInvalid())
>> >>> return StmtError();
>> >>>
>> >>> - FE = ActOnFinishFullExpr(FE.get(), FE.get()->getExprLoc(),
>> >>> - /*DiscardedValue*/ true);
>> >>> + FE = ActOnFinishFullExpr(FE.get(), FE.get()->getExprLoc(), DiscardedValue);
>> >>> if (FE.isInvalid())
>> >>> return StmtError();
>> >>>
>> >>> @@ -348,6 +347,10 @@ sema::CompoundScopeInfo &Sema::getCurCom
>> >>> return getCurFunction()->CompoundScopes.back();
>> >>> }
>> >>>
>> >>> +bool Sema::isCurCompoundStmtAStmtExpr() const {
>> >>> + return getCurCompoundScope().IsStmtExpr;
>> >>> +}
>> >>> +
>> >>> StmtResult Sema::ActOnCompoundStmt(SourceLocation L, SourceLocation R,
>> >>> ArrayRef<Stmt *> Elts, bool isStmtExpr) {
>> >>> const unsigned NumElts = Elts.size();
>> >>> @@ -370,14 +373,6 @@ StmtResult Sema::ActOnCompoundStmt(Sourc
>> >>> Diag(D->getLocation(), diag::ext_mixed_decls_code);
>> >>> }
>> >>> }
>> >>> - // Warn about unused expressions in statements.
>> >>> - for (unsigned i = 0; i != NumElts; ++i) {
>> >>> - // Ignore statements that are last in a statement expression.
>> >>> - if (isStmtExpr && i == NumElts - 1)
>> >>> - continue;
>> >>> -
>> >>> - 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
>> >>> @@ -469,15 +464,12 @@ Sema::ActOnCaseStmt(SourceLocation CaseL
>> >>>
>> >>> /// ActOnCaseStmtBody - This installs a statement as the body of a case.
>> >>> void Sema::ActOnCaseStmtBody(Stmt *S, Stmt *SubStmt) {
>> >>> - DiagnoseUnusedExprResult(SubStmt);
>> >>> cast<CaseStmt>(S)->setSubStmt(SubStmt);
>> >>> }
>> >>>
>> >>> StmtResult
>> >>> Sema::ActOnDefaultStmt(SourceLocation DefaultLoc, SourceLocation ColonLoc,
>> >>> Stmt *SubStmt, Scope *CurScope) {
>> >>> - DiagnoseUnusedExprResult(SubStmt);
>> >>> -
>> >>> if (getCurFunction()->SwitchStack.empty()) {
>> >>> Diag(DefaultLoc, diag::err_default_not_in_switch);
>> >>> return SubStmt;
>> >>> @@ -571,9 +563,6 @@ StmtResult Sema::BuildIfStmt(SourceLocat
>> >>> if (IsConstexpr || isa<ObjCAvailabilityCheckExpr>(Cond.get().second))
>> >>> setFunctionHasBranchProtectedScope();
>> >>>
>> >>> - DiagnoseUnusedExprResult(thenStmt);
>> >>> - DiagnoseUnusedExprResult(elseStmt);
>> >>> -
>> >>> return IfStmt::Create(Context, IfLoc, IsConstexpr, InitStmt, Cond.get().first,
>> >>> Cond.get().second, thenStmt, ElseLoc, elseStmt);
>> >>> }
>> >>> @@ -1301,8 +1290,6 @@ StmtResult Sema::ActOnWhileStmt(SourceLo
>> >>> !Diags.isIgnored(diag::warn_comma_operator, CondVal.second->getExprLoc()))
>> >>> CommaVisitor(*this).Visit(CondVal.second);
>> >>>
>> >>> - DiagnoseUnusedExprResult(Body);
>> >>> -
>> >>> if (isa<NullStmt>(Body))
>> >>> getCurCompoundScope().setHasEmptyLoopBodies();
>> >>>
>> >>> @@ -1322,7 +1309,7 @@ Sema::ActOnDoStmt(SourceLocation DoLoc,
>> >>> return StmtError();
>> >>> Cond = CondResult.get();
>> >>>
>> >>> - CondResult = ActOnFinishFullExpr(Cond, DoLoc);
>> >>> + CondResult = ActOnFinishFullExpr(Cond, DoLoc, /*DiscardedValue*/ false);
>> >>> if (CondResult.isInvalid())
>> >>> return StmtError();
>> >>> Cond = CondResult.get();
>> >>> @@ -1332,8 +1319,6 @@ Sema::ActOnDoStmt(SourceLocation DoLoc,
>> >>> !Diags.isIgnored(diag::warn_comma_operator, Cond->getExprLoc()))
>> >>> CommaVisitor(*this).Visit(Cond);
>> >>>
>> >>> - DiagnoseUnusedExprResult(Body);
>> >>> -
>> >>> return new (Context) DoStmt(Body, Cond, DoLoc, WhileLoc, CondRParen);
>> >>> }
>> >>>
>> >>> @@ -1778,11 +1763,6 @@ StmtResult Sema::ActOnForStmt(SourceLoca
>> >>> CommaVisitor(*this).Visit(Second.get().second);
>> >>>
>> >>> Expr *Third = third.release().getAs<Expr>();
>> >>> -
>> >>> - DiagnoseUnusedExprResult(First);
>> >>> - DiagnoseUnusedExprResult(Third);
>> >>> - DiagnoseUnusedExprResult(Body);
>> >>> -
>> >>> if (isa<NullStmt>(Body))
>> >>> getCurCompoundScope().setHasEmptyLoopBodies();
>> >>>
>> >>> @@ -1802,7 +1782,7 @@ StmtResult Sema::ActOnForEachLValueExpr(
>> >>> if (result.isInvalid()) return StmtError();
>> >>> E = result.get();
>> >>>
>> >>> - ExprResult FullExpr = ActOnFinishFullExpr(E);
>> >>> + ExprResult FullExpr = ActOnFinishFullExpr(E, /*DiscardedValue*/ false);
>> >>> if (FullExpr.isInvalid())
>> >>> return StmtError();
>> >>> return StmtResult(static_cast<Stmt*>(FullExpr.get()));
>> >>> @@ -1956,7 +1936,8 @@ Sema::ActOnObjCForCollectionStmt(SourceL
>> >>> if (CollectionExprResult.isInvalid())
>> >>> return StmtError();
>> >>>
>> >>> - CollectionExprResult = ActOnFinishFullExpr(CollectionExprResult.get());
>> >>> + CollectionExprResult =
>> >>> + ActOnFinishFullExpr(CollectionExprResult.get(), /*DiscardedValue*/ false);
>> >>> if (CollectionExprResult.isInvalid())
>> >>> return StmtError();
>> >>>
>> >>> @@ -2593,7 +2574,8 @@ StmtResult Sema::BuildCXXForRangeStmt(So
>> >>> if (!NotEqExpr.isInvalid())
>> >>> NotEqExpr = CheckBooleanCondition(ColonLoc, NotEqExpr.get());
>> >>> if (!NotEqExpr.isInvalid())
>> >>> - NotEqExpr = ActOnFinishFullExpr(NotEqExpr.get());
>> >>> + NotEqExpr =
>> >>> + ActOnFinishFullExpr(NotEqExpr.get(), /*DiscardedValue*/ false);
>> >>> if (NotEqExpr.isInvalid()) {
>> >>> Diag(RangeLoc, diag::note_for_range_invalid_iterator)
>> >>> << RangeLoc << 0 << BeginRangeRef.get()->getType();
>> >>> @@ -2616,7 +2598,7 @@ StmtResult Sema::BuildCXXForRangeStmt(So
>> >>> // co_await during the initial parse.
>> >>> IncrExpr = ActOnCoawaitExpr(S, CoawaitLoc, IncrExpr.get());
>> >>> if (!IncrExpr.isInvalid())
>> >>> - IncrExpr = ActOnFinishFullExpr(IncrExpr.get());
>> >>> + IncrExpr = ActOnFinishFullExpr(IncrExpr.get(), /*DiscardedValue*/ false);
>> >>> if (IncrExpr.isInvalid()) {
>> >>> Diag(RangeLoc, diag::note_for_range_invalid_iterator)
>> >>> << RangeLoc << 2 << BeginRangeRef.get()->getType() ;
>> >>> @@ -2871,7 +2853,7 @@ Sema::ActOnIndirectGotoStmt(SourceLocati
>> >>> return StmtError();
>> >>> }
>> >>>
>> >>> - ExprResult ExprRes = ActOnFinishFullExpr(E);
>> >>> + ExprResult ExprRes = ActOnFinishFullExpr(E, /*DiscardedValue*/ false);
>> >>> if (ExprRes.isInvalid())
>> >>> return StmtError();
>> >>> E = ExprRes.get();
>> >>> @@ -3221,7 +3203,8 @@ Sema::ActOnCapScopeReturnStmt(SourceLoca
>> >>> ExpressionEvaluationContext::DiscardedStatement &&
>> >>> (HasDeducedReturnType || CurCap->HasImplicitReturnType)) {
>> >>> if (RetValExp) {
>> >>> - ExprResult ER = ActOnFinishFullExpr(RetValExp, ReturnLoc);
>> >>> + ExprResult ER =
>> >>> + ActOnFinishFullExpr(RetValExp, ReturnLoc, /*DiscardedValue*/ false);
>> >>> if (ER.isInvalid())
>> >>> return StmtError();
>> >>> RetValExp = ER.get();
>> >>> @@ -3348,7 +3331,8 @@ Sema::ActOnCapScopeReturnStmt(SourceLoca
>> >>> }
>> >>>
>> >>> if (RetValExp) {
>> >>> - ExprResult ER = ActOnFinishFullExpr(RetValExp, ReturnLoc);
>> >>> + ExprResult ER =
>> >>> + ActOnFinishFullExpr(RetValExp, ReturnLoc, /*DiscardedValue*/ false);
>> >>> if (ER.isInvalid())
>> >>> return StmtError();
>> >>> RetValExp = ER.get();
>> >>> @@ -3578,7 +3562,8 @@ StmtResult Sema::BuildReturnStmt(SourceL
>> >>> ExpressionEvaluationContext::DiscardedStatement &&
>> >>> FnRetType->getContainedAutoType()) {
>> >>> if (RetValExp) {
>> >>> - ExprResult ER = ActOnFinishFullExpr(RetValExp, ReturnLoc);
>> >>> + ExprResult ER =
>> >>> + ActOnFinishFullExpr(RetValExp, ReturnLoc, /*DiscardedValue*/ false);
>> >>> if (ER.isInvalid())
>> >>> return StmtError();
>> >>> RetValExp = ER.get();
>> >>> @@ -3672,7 +3657,8 @@ StmtResult Sema::BuildReturnStmt(SourceL
>> >>> }
>> >>>
>> >>> if (RetValExp) {
>> >>> - ExprResult ER = ActOnFinishFullExpr(RetValExp, ReturnLoc);
>> >>> + ExprResult ER =
>> >>> + ActOnFinishFullExpr(RetValExp, ReturnLoc, /*DiscardedValue*/ false);
>> >>> if (ER.isInvalid())
>> >>> return StmtError();
>> >>> RetValExp = ER.get();
>> >>> @@ -3751,7 +3737,8 @@ StmtResult Sema::BuildReturnStmt(SourceL
>> >>> }
>> >>>
>> >>> if (RetValExp) {
>> >>> - ExprResult ER = ActOnFinishFullExpr(RetValExp, ReturnLoc);
>> >>> + ExprResult ER =
>> >>> + ActOnFinishFullExpr(RetValExp, ReturnLoc, /*DiscardedValue*/ false);
>> >>> if (ER.isInvalid())
>> >>> return StmtError();
>> >>> RetValExp = ER.get();
>> >>> @@ -3804,7 +3791,7 @@ StmtResult Sema::BuildObjCAtThrowStmt(So
>> >>> if (Result.isInvalid())
>> >>> return StmtError();
>> >>>
>> >>> - Result = ActOnFinishFullExpr(Result.get());
>> >>> + Result = ActOnFinishFullExpr(Result.get(), /*DiscardedValue*/ false);
>> >>> if (Result.isInvalid())
>> >>> return StmtError();
>> >>> Throw = Result.get();
>> >>> @@ -3876,7 +3863,7 @@ Sema::ActOnObjCAtSynchronizedOperand(Sou
>> >>> }
>> >>>
>> >>> // The operand to @synchronized is a full-expression.
>> >>> - return ActOnFinishFullExpr(operand);
>> >>> + return ActOnFinishFullExpr(operand, /*DiscardedValue*/ false);
>> >>> }
>> >>>
>> >>> StmtResult
>> >>>
>> >>> Modified: cfe/trunk/lib/Sema/TreeTransform.h
>> >>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/TreeTransform.h?rev=350404&r1=350403&r2=350404&view=diff
>> >>> ==============================================================================
>> >>> --- cfe/trunk/lib/Sema/TreeTransform.h (original)
>> >>> +++ cfe/trunk/lib/Sema/TreeTransform.h Fri Jan 4 08:58:14 2019
>> >>> @@ -328,7 +328,7 @@ public:
>> >>> /// other mechanism.
>> >>> ///
>> >>> /// \returns the transformed statement.
>> >>> - StmtResult TransformStmt(Stmt *S);
>> >>> + StmtResult TransformStmt(Stmt *S, bool DiscardedValue = false);
>> >>>
>> >>> /// Transform the given statement.
>> >>> ///
>> >>> @@ -3269,8 +3269,8 @@ private:
>> >>> bool DeducibleTSTContext);
>> >>> };
>> >>>
>> >>> -template<typename Derived>
>> >>> -StmtResult TreeTransform<Derived>::TransformStmt(Stmt *S) {
>> >>> +template <typename Derived>
>> >>> +StmtResult TreeTransform<Derived>::TransformStmt(Stmt *S, bool DiscardedValue) {
>> >>> if (!S)
>> >>> return S;
>> >>>
>> >>> @@ -3294,7 +3294,7 @@ StmtResult TreeTransform<Derived>::Trans
>> >>> if (E.isInvalid())
>> >>> return StmtError();
>> >>>
>> >>> - return getSema().ActOnExprStmt(E);
>> >>> + return getSema().ActOnExprStmt(E, DiscardedValue);
>> >>> }
>> >>> }
>> >>>
>> >>> @@ -4715,7 +4715,8 @@ TreeTransform<Derived>::TransformVariabl
>> >>> }
>> >>> if (SizeResult.isInvalid())
>> >>> return QualType();
>> >>> - SizeResult = SemaRef.ActOnFinishFullExpr(SizeResult.get());
>> >>> + SizeResult =
>> >>> + SemaRef.ActOnFinishFullExpr(SizeResult.get(), /*DiscardedValue*/ false);
>> >>> if (SizeResult.isInvalid())
>> >>> return QualType();
>> >>>
>> >>> @@ -6520,7 +6521,9 @@ TreeTransform<Derived>::TransformCompoun
>> >>> bool SubStmtChanged = false;
>> >>> SmallVector<Stmt*, 8> Statements;
>> >>> for (auto *B : S->body()) {
>> >>> - StmtResult Result = getDerived().TransformStmt(B);
>> >>> + StmtResult Result =
>> >>> + getDerived().TransformStmt(B, !IsStmtExpr || B != S->body_back());
>> >>> +
>> >>> if (Result.isInvalid()) {
>> >>> // Immediately fail if this was a DeclStmt, since it's very
>> >>> // likely that this will cause problems for future statements.
>> >>>
>> >>> Modified: cfe/trunk/test/CXX/stmt.stmt/stmt.select/p3.cpp
>> >>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CXX/stmt.stmt/stmt.select/p3.cpp?rev=350404&r1=350403&r2=350404&view=diff
>> >>> ==============================================================================
>> >>> --- cfe/trunk/test/CXX/stmt.stmt/stmt.select/p3.cpp (original)
>> >>> +++ cfe/trunk/test/CXX/stmt.stmt/stmt.select/p3.cpp Fri Jan 4 08:58:14 2019
>> >>> @@ -1,5 +1,5 @@
>> >>> -// RUN: %clang_cc1 -fsyntax-only -verify %s
>> >>> -// RUN: %clang_cc1 -fsyntax-only -std=c++1z -Wc++14-compat -verify %s -DCPP17
>> >>> +// RUN: %clang_cc1 -fsyntax-only -Wno-unused-value -verify %s
>> >>> +// RUN: %clang_cc1 -fsyntax-only -Wno-unused-value -std=c++1z -Wc++14-compat -verify %s -DCPP17
>> >>>
>> >>> int f();
>> >>>
>> >>> @@ -71,7 +71,6 @@ void whileInitStatement() {
>> >>> // last loop above. It would be nice to remove this.
>> >>> void whileInitStatement2() {
>> >>> while (; false) {} // expected-error {{expected expression}}
>> >>> - // expected-warning at -1 {{expression result unused}}
>> >>> - // expected-error at -2 {{expected ';' after expression}}
>> >>> - // expected-error at -3 {{expected expression}}
>> >>> + // expected-error at -1 {{expected ';' after expression}}
>> >>> + // expected-error at -2 {{expected expression}}
>> >>> }
>> >>>
>> >>> Modified: cfe/trunk/test/CodeCompletion/pragma-macro-token-caching.c
>> >>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeCompletion/pragma-macro-token-caching.c?rev=350404&r1=350403&r2=350404&view=diff
>> >>> ==============================================================================
>> >>> --- cfe/trunk/test/CodeCompletion/pragma-macro-token-caching.c (original)
>> >>> +++ cfe/trunk/test/CodeCompletion/pragma-macro-token-caching.c Fri Jan 4 08:58:14 2019
>> >>> @@ -12,7 +12,7 @@ void completeParam(int param) {
>> >>>
>> >>> void completeParamPragmaError(int param) {
>> >>> Outer(__extension__({ _Pragma(2) })); // expected-error {{_Pragma takes a parenthesized string literal}}
>> >>> - param;
>> >>> + param; // expected-warning {{expression result unused}}
>> >>> }
>> >>>
>> >>> // RUN: %clang_cc1 -fsyntax-only -verify -code-completion-at=%s:16:1 %s | FileCheck %s
>> >>>
>> >>> Modified: cfe/trunk/test/Parser/cxx1z-init-statement.cpp
>> >>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Parser/cxx1z-init-statement.cpp?rev=350404&r1=350403&r2=350404&view=diff
>> >>> ==============================================================================
>> >>> --- cfe/trunk/test/Parser/cxx1z-init-statement.cpp (original)
>> >>> +++ cfe/trunk/test/Parser/cxx1z-init-statement.cpp Fri Jan 4 08:58:14 2019
>> >>> @@ -13,9 +13,9 @@ int f() {
>> >>> if (T(n) = 0; n) {}
>> >>>
>> >>> // init-statement expressions
>> >>> - if (T{f()}; f()) {}
>> >>> - if (T{f()}, g, h; f()) {} // expected-warning 2{{unused}}
>> >>> - if (T(f()), g, h + 1; f()) {} // expected-warning 2{{unused}}
>> >>> + if (T{f()}; f()) {} // expected-warning {{expression result unused}}
>> >>> + if (T{f()}, g, h; f()) {} // expected-warning 2{{unused}} expected-warning {{expression result unused}}
>> >>> + if (T(f()), g, h + 1; f()) {} // expected-warning 2{{unused}} expected-warning {{expression result unused}}
>> >>>
>> >>> // condition declarations
>> >>> if (T(n){g}) {}
>> >>> @@ -35,7 +35,7 @@ int f() {
>> >>>
>> >>> // Likewise for 'switch'
>> >>> switch (int n; n) {}
>> >>> - switch (g; int g = 5) {}
>> >>> + switch (g; int g = 5) {} // expected-warning {{expression result unused}}
>> >>>
>> >>> if (int a, b; int c = a) { // expected-note 6{{previous}}
>> >>> int a; // expected-error {{redefinition}}
>> >>>
>> >>> Modified: cfe/trunk/test/Parser/switch-recovery.cpp
>> >>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Parser/switch-recovery.cpp?rev=350404&r1=350403&r2=350404&view=diff
>> >>> ==============================================================================
>> >>> --- cfe/trunk/test/Parser/switch-recovery.cpp (original)
>> >>> +++ cfe/trunk/test/Parser/switch-recovery.cpp Fri Jan 4 08:58:14 2019
>> >>> @@ -105,7 +105,7 @@ void test9(int x) { // expected-note {{'
>> >>> expected-error {{expected expression}}
>> >>> 8:: x; // expected-error {{expected ';' after expression}} \
>> >>> expected-error {{no member named 'x' in the global namespace; did you mean simply 'x'?}} \
>> >>> - expected-warning 2 {{expression result unused}}
>> >>> + expected-warning {{expression result unused}}
>> >>> 9:: :y; // expected-error {{expected ';' after expression}} \
>> >>> expected-error {{expected unqualified-id}} \
>> >>> expected-warning {{expression result unused}}
>> >>>
>> >>> Modified: cfe/trunk/test/SemaCXX/cxx1z-init-statement.cpp
>> >>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/cxx1z-init-statement.cpp?rev=350404&r1=350403&r2=350404&view=diff
>> >>> ==============================================================================
>> >>> --- cfe/trunk/test/SemaCXX/cxx1z-init-statement.cpp (original)
>> >>> +++ cfe/trunk/test/SemaCXX/cxx1z-init-statement.cpp Fri Jan 4 08:58:14 2019
>> >>> @@ -1,5 +1,5 @@
>> >>> -// RUN: %clang_cc1 -std=c++1z -verify %s
>> >>> -// RUN: %clang_cc1 -std=c++17 -verify %s
>> >>> +// RUN: %clang_cc1 -std=c++1z -Wno-unused-value -verify %s
>> >>> +// RUN: %clang_cc1 -std=c++17 -Wno-unused-value -verify %s
>> >>>
>> >>> void testIf() {
>> >>> int x = 0;
>> >>> @@ -12,7 +12,7 @@ void testIf() {
>> >>> int x = 0; // expected-error {{redefinition of 'x'}}
>> >>>
>> >>> if (x; int a = 0) ++a;
>> >>> - if (x, +x; int a = 0) // expected-note 2 {{previous definition is here}} expected-warning {{unused}}
>> >>> + if (x, +x; int a = 0) // expected-note 2 {{previous definition is here}}
>> >>> int a = 0; // expected-error {{redefinition of 'a'}}
>> >>> else
>> >>> int a = 0; // expected-error {{redefinition of 'a'}}
>> >>> @@ -48,7 +48,7 @@ void testSwitch() {
>> >>> ++a;
>> >>> }
>> >>>
>> >>> - switch (x, +x; int a = 0) { // expected-note {{previous definition is here}} expected-warning {{unused}}
>> >>> + switch (x, +x; int a = 0) { // expected-note {{previous definition is here}}
>> >>> case 0:
>> >>> int a = 0; // expected-error {{redefinition of 'a'}} // expected-note {{previous definition is here}}
>> >>> case 1:
>> >>>
>> >>> Modified: cfe/trunk/test/SemaCXX/for-range-examples.cpp
>> >>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/for-range-examples.cpp?rev=350404&r1=350403&r2=350404&view=diff
>> >>> ==============================================================================
>> >>> --- cfe/trunk/test/SemaCXX/for-range-examples.cpp (original)
>> >>> +++ cfe/trunk/test/SemaCXX/for-range-examples.cpp Fri Jan 4 08:58:14 2019
>> >>> @@ -244,7 +244,7 @@ void foo ()
>> >>> {
>> >>> int b = 1, a[b];
>> >>> a[0] = 0;
>> >>> - [&] { for (int c : a) 0; } ();
>> >>> + [&] { for (int c : a) 0; } (); // expected-warning {{expression result unused}}
>> >>> }
>> >>>
>> >>>
>> >>>
>> >>> Modified: cfe/trunk/test/SemaCXX/warn-unused-result.cpp
>> >>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/warn-unused-result.cpp?rev=350404&r1=350403&r2=350404&view=diff
>> >>> ==============================================================================
>> >>> --- cfe/trunk/test/SemaCXX/warn-unused-result.cpp (original)
>> >>> +++ cfe/trunk/test/SemaCXX/warn-unused-result.cpp Fri Jan 4 08:58:14 2019
>> >>> @@ -33,6 +33,36 @@ void test() {
>> >>> const S &s4 = g1();
>> >>> }
>> >>>
>> >>> +void testSubstmts(int i) {
>> >>> + switch (i) {
>> >>> + case 0:
>> >>> + f(); // expected-warning {{ignoring return value}}
>> >>> + default:
>> >>> + f(); // expected-warning {{ignoring return value}}
>> >>> + }
>> >>> +
>> >>> + if (i)
>> >>> + f(); // expected-warning {{ignoring return value}}
>> >>> + else
>> >>> + f(); // expected-warning {{ignoring return value}}
>> >>> +
>> >>> + while (i)
>> >>> + f(); // expected-warning {{ignoring return value}}
>> >>> +
>> >>> + do
>> >>> + f(); // expected-warning {{ignoring return value}}
>> >>> + while (i);
>> >>> +
>> >>> + for (f(); // expected-warning {{ignoring return value}}
>> >>> + ;
>> >>> + f() // expected-warning {{ignoring return value}}
>> >>> + )
>> >>> + f(); // expected-warning {{ignoring return value}}
>> >>> +
>> >>> + f(), // expected-warning {{ignoring return value}}
>> >>> + (void)f();
>> >>> +}
>> >>> +
>> >>> struct X {
>> >>> int foo() __attribute__((warn_unused_result));
>> >>> };
>> >>> @@ -206,3 +236,13 @@ void f() {
>> >>> (void)++p;
>> >>> }
>> >>> } // namespace
>> >>> +
>> >>> +namespace PR39837 {
>> >>> +[[clang::warn_unused_result]] int f(int);
>> >>> +
>> >>> +void g() {
>> >>> + int a[2];
>> >>> + for (int b : a)
>> >>> + f(b); // expected-warning {{ignoring return value}}
>> >>> +}
>> >>> +} // namespace PR39837
>> >>>
>> >>>
>> >>> _______________________________________________
>> >>> cfe-commits mailing list
>> >>> cfe-commits at lists.llvm.org
>> >>> http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
>> >>
>> >> _______________________________________________
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>> >> cfe-commits at lists.llvm.org
>> >> http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
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