[clang] 76c0092 - Ensure that checkInitIsICE is called exactly once for every variable
Nico Weber via cfe-commits
cfe-commits at lists.llvm.org
Mon Oct 26 13:46:35 PDT 2020
The original snippet:
const int64_t& kGraceMs =
AffiliationFetchThrottler::kGracePeriodAfterReconnectMs;
ASSERT_NO_FATAL_FAILURE(AssertReleaseInBetween(
true, kGraceMs * (1 - kPolicy.jitter_factor), kGraceMs));
kGracePeriod is declared here
https://source.chromium.org/chromium/chromium/src/+/master:components/password_manager/core/browser/android_affiliation/affiliation_fetch_throttler.h;l=109?q=kGracePeriodAfterReconnectMs&ss=chromium
as a class-level
static const int64_t kGracePeriodAfterReconnectMs;
which is then defined in some .cc file where the snippet above can't see
the value.
On Mon, Oct 26, 2020 at 4:40 PM Nico Weber <thakis at chromium.org> wrote:
> Hi Richard,
>
> this makes clang assert when building chromium/win.
> https://bugs.chromium.org/p/chromium/issues/detail?id=1142009#c4 has a
> reduced repro. Could you take a look?
>
> Thanks,
> Nico
>
> On Mon, Oct 19, 2020 at 10:04 PM Richard Smith via cfe-commits <
> cfe-commits at lists.llvm.org> wrote:
>
>>
>> Author: Richard Smith
>> Date: 2020-10-19T19:04:04-07:00
>> New Revision: 76c0092665867a6defcd328ba0d0d976eb65d991
>>
>> URL:
>> https://github.com/llvm/llvm-project/commit/76c0092665867a6defcd328ba0d0d976eb65d991
>> DIFF:
>> https://github.com/llvm/llvm-project/commit/76c0092665867a6defcd328ba0d0d976eb65d991.diff
>>
>> LOG: Ensure that checkInitIsICE is called exactly once for every variable
>> for which it matters.
>>
>> This is a step towards separating checking for a constant initializer
>> (in which std::is_constant_evaluated returns true) and any other
>> evaluation of a variable initializer (in which it returns false).
>>
>> Added:
>>
>>
>> Modified:
>> clang/include/clang/AST/Decl.h
>> clang/include/clang/Serialization/ASTRecordWriter.h
>> clang/lib/AST/ComparisonCategories.cpp
>> clang/lib/AST/Decl.cpp
>> clang/lib/AST/ExprConstant.cpp
>> clang/lib/CodeGen/ItaniumCXXABI.cpp
>> clang/lib/Sema/SemaDecl.cpp
>> clang/lib/Sema/SemaDeclCXX.cpp
>> clang/lib/Serialization/ASTReaderDecl.cpp
>> clang/lib/Serialization/ASTWriter.cpp
>> clang/lib/Serialization/ASTWriterDecl.cpp
>> clang/test/CodeGen/enable_if.c
>> clang/test/OpenMP/threadprivate_codegen.cpp
>> clang/test/Sema/enable_if.c
>> clang/test/SemaCXX/constant-expression.cpp
>> clang/test/SemaCXX/i-c-e-cxx.cpp
>>
>> Removed:
>>
>>
>>
>>
>> ################################################################################
>> diff --git a/clang/include/clang/AST/Decl.h
>> b/clang/include/clang/AST/Decl.h
>> index eae09832160d..e309819400f1 100644
>> --- a/clang/include/clang/AST/Decl.h
>> +++ b/clang/include/clang/AST/Decl.h
>> @@ -807,10 +807,6 @@ struct EvaluatedStmt {
>> /// integral constant expression.
>> bool CheckedICE : 1;
>>
>> - /// Whether we are checking whether this statement is an
>> - /// integral constant expression.
>> - bool CheckingICE : 1;
>> -
>> /// Whether this statement is an integral constant expression,
>> /// or in C++11, whether the statement is a constant expression. Only
>> /// valid if CheckedICE is true.
>> @@ -828,7 +824,7 @@ struct EvaluatedStmt {
>>
>> EvaluatedStmt()
>> : WasEvaluated(false), IsEvaluating(false), CheckedICE(false),
>> - CheckingICE(false), IsICE(false), HasConstantDestruction(false)
>> {}
>> + IsICE(false), HasConstantDestruction(false) {}
>> };
>>
>> /// Represents a variable declaration or definition.
>> @@ -1263,14 +1259,15 @@ class VarDecl : public DeclaratorDecl, public
>> Redeclarable<VarDecl> {
>> /// constant expression, according to the relevant language standard.
>> /// This only checks properties of the declaration, and does not check
>> /// whether the initializer is in fact a constant expression.
>> - bool mightBeUsableInConstantExpressions(ASTContext &C) const;
>> + bool mightBeUsableInConstantExpressions(const ASTContext &C) const;
>>
>> /// Determine whether this variable's value can be used in a
>> /// constant expression, according to the relevant language standard,
>> /// including checking whether it was initialized by a constant
>> expression.
>> - bool isUsableInConstantExpressions(ASTContext &C) const;
>> + bool isUsableInConstantExpressions(const ASTContext &C) const;
>>
>> EvaluatedStmt *ensureEvaluatedStmt() const;
>> + EvaluatedStmt *getEvaluatedStmt() const;
>>
>> /// Attempt to evaluate the value of the initializer attached to this
>> /// declaration, and produce notes explaining why it cannot be
>> evaluated or is
>> @@ -1305,7 +1302,7 @@ class VarDecl : public DeclaratorDecl, public
>> Redeclarable<VarDecl> {
>>
>> /// Determine whether the value of the initializer attached to this
>> /// declaration is an integral constant expression.
>> - bool checkInitIsICE() const;
>> + bool checkInitIsICE(SmallVectorImpl<PartialDiagnosticAt> &Notes) const;
>>
>> void setInitStyle(InitializationStyle Style) {
>> VarDeclBits.InitStyle = Style;
>>
>> diff --git a/clang/include/clang/Serialization/ASTRecordWriter.h
>> b/clang/include/clang/Serialization/ASTRecordWriter.h
>> index edfcd9c52e2e..e362463b2309 100644
>> --- a/clang/include/clang/Serialization/ASTRecordWriter.h
>> +++ b/clang/include/clang/Serialization/ASTRecordWriter.h
>> @@ -266,6 +266,9 @@ class ASTRecordWriter
>>
>> void AddCXXDefinitionData(const CXXRecordDecl *D);
>>
>> + /// Emit information about the initializer of a VarDecl.
>> + void AddVarDeclInit(const VarDecl *VD);
>> +
>> /// Write an OMPTraitInfo object.
>> void writeOMPTraitInfo(const OMPTraitInfo *TI);
>>
>>
>> diff --git a/clang/lib/AST/ComparisonCategories.cpp
>> b/clang/lib/AST/ComparisonCategories.cpp
>> index 6b6826c02a12..896050482644 100644
>> --- a/clang/lib/AST/ComparisonCategories.cpp
>> +++ b/clang/lib/AST/ComparisonCategories.cpp
>> @@ -42,7 +42,7 @@ clang::getComparisonCategoryForBuiltinCmp(QualType T) {
>>
>> bool ComparisonCategoryInfo::ValueInfo::hasValidIntValue() const {
>> assert(VD && "must have var decl");
>> - if (!VD->checkInitIsICE())
>> + if (!VD->isUsableInConstantExpressions(VD->getASTContext()))
>> return false;
>>
>> // Before we attempt to get the value of the first field, ensure that
>> we
>>
>> diff --git a/clang/lib/AST/Decl.cpp b/clang/lib/AST/Decl.cpp
>> index a6c7f30528eb..ee7f51c5218e 100644
>> --- a/clang/lib/AST/Decl.cpp
>> +++ b/clang/lib/AST/Decl.cpp
>> @@ -2277,7 +2277,7 @@ void VarDecl::setInit(Expr *I) {
>> Init = I;
>> }
>>
>> -bool VarDecl::mightBeUsableInConstantExpressions(ASTContext &C) const {
>> +bool VarDecl::mightBeUsableInConstantExpressions(const ASTContext &C)
>> const {
>> const LangOptions &Lang = C.getLangOpts();
>>
>> if (!Lang.CPlusPlus)
>> @@ -2312,7 +2312,7 @@ bool
>> VarDecl::mightBeUsableInConstantExpressions(ASTContext &C) const {
>> return Lang.CPlusPlus11 && isConstexpr();
>> }
>>
>> -bool VarDecl::isUsableInConstantExpressions(ASTContext &Context) const {
>> +bool VarDecl::isUsableInConstantExpressions(const ASTContext &Context)
>> const {
>> // C++2a [expr.const]p3:
>> // A variable is usable in constant expressions after its
>> initializing
>> // declaration is encountered...
>> @@ -2325,7 +2325,7 @@ bool
>> VarDecl::isUsableInConstantExpressions(ASTContext &Context) const {
>> if (!DefVD->mightBeUsableInConstantExpressions(Context))
>> return false;
>> // ... and its initializer is a constant initializer.
>> - return DefVD->checkInitIsICE();
>> + return DefVD->isInitKnownICE() && DefVD->isInitICE();
>> }
>>
>> /// Convert the initializer for this declaration to the elaborated
>> EvaluatedStmt
>> @@ -2345,6 +2345,10 @@ EvaluatedStmt *VarDecl::ensureEvaluatedStmt()
>> const {
>> return Eval;
>> }
>>
>> +EvaluatedStmt *VarDecl::getEvaluatedStmt() const {
>> + return Init.dyn_cast<EvaluatedStmt *>();
>> +}
>> +
>> APValue *VarDecl::evaluateValue() const {
>> SmallVector<PartialDiagnosticAt, 8> Notes;
>> return evaluateValue(Notes);
>> @@ -2354,19 +2358,17 @@ APValue *VarDecl::evaluateValue(
>> SmallVectorImpl<PartialDiagnosticAt> &Notes) const {
>> EvaluatedStmt *Eval = ensureEvaluatedStmt();
>>
>> + const auto *Init = cast<Expr>(Eval->Value);
>> + assert(!Init->isValueDependent());
>> +
>> // We only produce notes indicating why an initializer is non-constant
>> the
>> // first time it is evaluated. FIXME: The notes won't always be
>> emitted the
>> // first time we try evaluation, so might not be produced at all.
>> if (Eval->WasEvaluated)
>> return Eval->Evaluated.isAbsent() ? nullptr : &Eval->Evaluated;
>>
>> - const auto *Init = cast<Expr>(Eval->Value);
>> - assert(!Init->isValueDependent());
>> -
>> if (Eval->IsEvaluating) {
>> // FIXME: Produce a diagnostic for self-initialization.
>> - Eval->CheckedICE = true;
>> - Eval->IsICE = false;
>> return nullptr;
>> }
>>
>> @@ -2386,18 +2388,11 @@ APValue *VarDecl::evaluateValue(
>> Eval->IsEvaluating = false;
>> Eval->WasEvaluated = true;
>>
>> - // In C++11, we have determined whether the initializer was a constant
>> - // expression as a side-effect.
>> - if (getASTContext().getLangOpts().CPlusPlus11 && !Eval->CheckedICE) {
>> - Eval->CheckedICE = true;
>> - Eval->IsICE = Result && Notes.empty();
>> - }
>> -
>> return Result ? &Eval->Evaluated : nullptr;
>> }
>>
>> APValue *VarDecl::getEvaluatedValue() const {
>> - if (EvaluatedStmt *Eval = Init.dyn_cast<EvaluatedStmt *>())
>> + if (EvaluatedStmt *Eval = getEvaluatedStmt())
>> if (Eval->WasEvaluated)
>> return &Eval->Evaluated;
>>
>> @@ -2405,7 +2400,7 @@ APValue *VarDecl::getEvaluatedValue() const {
>> }
>>
>> bool VarDecl::isInitKnownICE() const {
>> - if (EvaluatedStmt *Eval = Init.dyn_cast<EvaluatedStmt *>())
>> + if (EvaluatedStmt *Eval = getEvaluatedStmt())
>> return Eval->CheckedICE;
>>
>> return false;
>> @@ -2417,12 +2412,16 @@ bool VarDecl::isInitICE() const {
>> return Init.get<EvaluatedStmt *>()->IsICE;
>> }
>>
>> -bool VarDecl::checkInitIsICE() const {
>> +bool VarDecl::checkInitIsICE(
>> + SmallVectorImpl<PartialDiagnosticAt> &Notes) const {
>> EvaluatedStmt *Eval = ensureEvaluatedStmt();
>> - if (Eval->CheckedICE)
>> - // We have already checked whether this subexpression is an
>> - // integral constant expression.
>> - return Eval->IsICE;
>> + assert(!Eval->CheckedICE &&
>> + "should check whether var has constant init at most once");
>> + // If we ask for the value before we know whether we have a constant
>> + // initializer, we can compute the wrong value (for example, due to
>> + // std::is_constant_evaluated()).
>> + assert(!Eval->WasEvaluated &&
>> + "already evaluated var value before checking for constant
>> init");
>>
>> const auto *Init = cast<Expr>(Eval->Value);
>> assert(!Init->isValueDependent());
>> @@ -2430,8 +2429,8 @@ bool VarDecl::checkInitIsICE() const {
>> // In C++11, evaluate the initializer to check whether it's a constant
>> // expression.
>> if (getASTContext().getLangOpts().CPlusPlus11) {
>> - SmallVector<PartialDiagnosticAt, 8> Notes;
>> - evaluateValue(Notes);
>> + Eval->IsICE = evaluateValue(Notes) && Notes.empty();
>> + Eval->CheckedICE = true;
>> return Eval->IsICE;
>> }
>>
>> @@ -2439,12 +2438,8 @@ bool VarDecl::checkInitIsICE() const {
>> // out-of-line. See DR 721 and the discussion in Clang PR
>> // 6206 for details.
>>
>> - if (Eval->CheckingICE)
>> - return false;
>> - Eval->CheckingICE = true;
>> -
>> - Eval->IsICE = Init->isIntegerConstantExpr(getASTContext());
>> - Eval->CheckingICE = false;
>> + Eval->IsICE = getType()->isIntegralOrEnumerationType() &&
>> + Init->isIntegerConstantExpr(getASTContext());
>> Eval->CheckedICE = true;
>> return Eval->IsICE;
>> }
>> @@ -2599,7 +2594,7 @@ bool VarDecl::isNoDestroy(const ASTContext &Ctx)
>> const {
>>
>> QualType::DestructionKind
>> VarDecl::needsDestruction(const ASTContext &Ctx) const {
>> - if (EvaluatedStmt *Eval = Init.dyn_cast<EvaluatedStmt *>())
>> + if (EvaluatedStmt *Eval = getEvaluatedStmt())
>> if (Eval->HasConstantDestruction)
>> return QualType::DK_none;
>>
>>
>> diff --git a/clang/lib/AST/ExprConstant.cpp
>> b/clang/lib/AST/ExprConstant.cpp
>> index 7afc44dffffe..3014f948f9b1 100644
>> --- a/clang/lib/AST/ExprConstant.cpp
>> +++ b/clang/lib/AST/ExprConstant.cpp
>> @@ -3278,12 +3278,17 @@ static bool evaluateVarDeclInit(EvalInfo &Info,
>> const Expr *E,
>> return false;
>> }
>>
>> - // Check that the variable is actually usable in constant expressions.
>> - if (!VD->checkInitIsICE()) {
>> - Info.CCEDiag(E, diag::note_constexpr_var_init_non_constant,
>> - Notes.size() + 1) << VD;
>> + // Check that the variable is actually usable in constant expressions.
>> For a
>> + // const integral variable or a reference, we might have a non-constant
>> + // initializer that we can nonetheless evaluate the initializer for.
>> Such
>> + // variables are not usable in constant expressions.
>> + //
>> + // FIXME: It would be cleaner to check
>> VD->isUsableInConstantExpressions
>> + // here, but that regresses diagnostics for things like reading from a
>> + // volatile constexpr variable.
>> + if (VD->isInitKnownICE() && !VD->isInitICE()) {
>> + Info.CCEDiag(E, diag::note_constexpr_var_init_non_constant, 1) << VD;
>> NoteLValueLocation(Info, Base);
>> - Info.addNotes(Notes);
>> }
>>
>> // Never use the initializer of a weak variable, not even for constant
>> @@ -3298,11 +3303,6 @@ static bool evaluateVarDeclInit(EvalInfo &Info,
>> const Expr *E,
>> return true;
>> }
>>
>> -static bool IsConstNonVolatile(QualType T) {
>> - Qualifiers Quals = T.getQualifiers();
>> - return Quals.hasConst() && !Quals.hasVolatile();
>> -}
>> -
>> /// Get the base index of the given base class within an APValue
>> representing
>> /// the given derived class.
>> static unsigned getBaseIndex(const CXXRecordDecl *Derived,
>> @@ -8114,6 +8114,12 @@ bool LValueExprEvaluator::VisitVarDecl(const Expr
>> *E, const VarDecl *VD) {
>> return Success(VD);
>> }
>>
>> + if (!Info.getLangOpts().CPlusPlus11) {
>> + Info.CCEDiag(E, diag::note_constexpr_ltor_non_integral, 1)
>> + << VD << VD->getType();
>> + Info.Note(VD->getLocation(), diag::note_declared_at);
>> + }
>> +
>> APValue *V;
>> if (!evaluateVarDeclInit(Info, E, VD, Frame, Version, V))
>> return false;
>> @@ -15030,30 +15036,12 @@ static ICEDiag CheckICE(const Expr* E, const
>> ASTContext &Ctx) {
>> case Expr::DeclRefExprClass: {
>> if (isa<EnumConstantDecl>(cast<DeclRefExpr>(E)->getDecl()))
>> return NoDiag();
>> - const ValueDecl *D = cast<DeclRefExpr>(E)->getDecl();
>> - if (Ctx.getLangOpts().CPlusPlus &&
>> - D && IsConstNonVolatile(D->getType())) {
>> - // Parameter variables are never constants. Without this check,
>> - // getAnyInitializer() can find a default argument, which leads
>> - // to chaos.
>> - if (isa<ParmVarDecl>(D))
>> - return ICEDiag(IK_NotICE, cast<DeclRefExpr>(E)->getLocation());
>> -
>> + const VarDecl *VD =
>> dyn_cast<VarDecl>(cast<DeclRefExpr>(E)->getDecl());
>> + if (VD && VD->isUsableInConstantExpressions(Ctx)) {
>> // C++ 7.1.5.1p2
>> // A variable of non-volatile const-qualified integral or
>> enumeration
>> // type initialized by an ICE can be used in ICEs.
>> - if (const VarDecl *Dcl = dyn_cast<VarDecl>(D)) {
>> - if (!Dcl->getType()->isIntegralOrEnumerationType())
>> - return ICEDiag(IK_NotICE, cast<DeclRefExpr>(E)->getLocation());
>> -
>> - const VarDecl *VD;
>> - // Look for a declaration of this variable that has an
>> initializer, and
>> - // check whether it is an ICE.
>> - if (Dcl->getAnyInitializer(VD) && !VD->isWeak() &&
>> VD->checkInitIsICE())
>> - return NoDiag();
>> - else
>> - return ICEDiag(IK_NotICE, cast<DeclRefExpr>(E)->getLocation());
>> - }
>> + return NoDiag();
>> }
>> return ICEDiag(IK_NotICE, E->getBeginLoc());
>> }
>>
>> diff --git a/clang/lib/CodeGen/ItaniumCXXABI.cpp
>> b/clang/lib/CodeGen/ItaniumCXXABI.cpp
>> index cfb736ce0ff1..40cd5c54185f 100644
>> --- a/clang/lib/CodeGen/ItaniumCXXABI.cpp
>> +++ b/clang/lib/CodeGen/ItaniumCXXABI.cpp
>> @@ -361,8 +361,9 @@ class ItaniumCXXABI : public CodeGen::CGCXXABI {
>> return !VD->needsDestruction(getContext()) &&
>> InitDecl->evaluateValue();
>>
>> // Otherwise, we need a thread wrapper unless we know that every
>> - // translation unit will emit the value as a constant. We rely on
>> - // ICE-ness not varying between translation units, which isn't
>> actually
>> + // translation unit will emit the value as a constant. We rely on the
>> + // variable being constant-initialized in every translation unit if
>> it's
>> + // constant-initialized in any translation unit, which isn't actually
>> // guaranteed by the standard but is necessary for sanity.
>> return InitDecl->isInitKnownICE() && InitDecl->isInitICE();
>> }
>>
>> diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
>> index 481b48e21942..1a27667fc106 100644
>> --- a/clang/lib/Sema/SemaDecl.cpp
>> +++ b/clang/lib/Sema/SemaDecl.cpp
>> @@ -12958,18 +12958,14 @@ void
>> Sema::CheckCompleteVariableDeclaration(VarDecl *var) {
>>
>> // All the following checks are C++ only.
>> if (!getLangOpts().CPlusPlus) {
>> - // If this variable must be emitted, add it as an initializer for
>> the
>> - // current module.
>> - if (Context.DeclMustBeEmitted(var) && !ModuleScopes.empty())
>> - Context.addModuleInitializer(ModuleScopes.back().Module, var);
>> - return;
>> + // If this variable must be emitted, add it as an initializer for the
>> + // current module.
>> + if (Context.DeclMustBeEmitted(var) && !ModuleScopes.empty())
>> + Context.addModuleInitializer(ModuleScopes.back().Module, var);
>> + return;
>> }
>>
>> - if (auto *DD = dyn_cast<DecompositionDecl>(var))
>> - CheckCompleteDecompositionDeclaration(DD);
>> -
>> QualType type = var->getType();
>> - if (type->isDependentType()) return;
>>
>> if (var->hasAttr<BlocksAttr>())
>> getCurFunction()->addByrefBlockVar(var);
>> @@ -12978,79 +12974,86 @@ void
>> Sema::CheckCompleteVariableDeclaration(VarDecl *var) {
>> bool IsGlobal = GlobalStorage && !var->isStaticLocal();
>> QualType baseType = Context.getBaseElementType(type);
>>
>> - if (Init && !Init->isValueDependent()) {
>> - if (var->isConstexpr()) {
>> - SmallVector<PartialDiagnosticAt, 8> Notes;
>> - if (!var->evaluateValue(Notes) || !var->isInitICE()) {
>> - SourceLocation DiagLoc = var->getLocation();
>> - // If the note doesn't add any useful information other than a
>> source
>> - // location, fold it into the primary diagnostic.
>> - if (Notes.size() == 1 && Notes[0].second.getDiagID() ==
>> - diag::note_invalid_subexpr_in_const_expr) {
>> - DiagLoc = Notes[0].first;
>> - Notes.clear();
>> - }
>> - Diag(DiagLoc, diag::err_constexpr_var_requires_const_init)
>> - << var << Init->getSourceRange();
>> - for (unsigned I = 0, N = Notes.size(); I != N; ++I)
>> - Diag(Notes[I].first, Notes[I].second);
>> - }
>> - } else if (var->mightBeUsableInConstantExpressions(Context)) {
>> - // Check whether the initializer of a const variable of integral or
>> - // enumeration type is an ICE now, since we can't tell whether it
>> was
>> - // initialized by a constant expression if we check later.
>> - var->checkInitIsICE();
>> - }
>> -
>> - // Don't emit further diagnostics about constexpr globals since they
>> - // were just diagnosed.
>> - if (!var->isConstexpr() && GlobalStorage &&
>> var->hasAttr<ConstInitAttr>()) {
>> - // FIXME: Need strict checking in C++03 here.
>> - bool DiagErr = getLangOpts().CPlusPlus11
>> - ? !var->checkInitIsICE() : !checkConstInit();
>> - if (DiagErr) {
>> - auto *Attr = var->getAttr<ConstInitAttr>();
>> - Diag(var->getLocation(), diag::err_require_constant_init_failed)
>> - << Init->getSourceRange();
>> - Diag(Attr->getLocation(),
>> - diag::note_declared_required_constant_init_here)
>> - << Attr->getRange() << Attr->isConstinit();
>> - if (getLangOpts().CPlusPlus11) {
>> - APValue Value;
>> - SmallVector<PartialDiagnosticAt, 8> Notes;
>> - Init->EvaluateAsInitializer(Value, getASTContext(), var,
>> Notes);
>> - for (auto &it : Notes)
>> - Diag(it.first, it.second);
>> - } else {
>> - Diag(CacheCulprit->getExprLoc(),
>> - diag::note_invalid_subexpr_in_const_expr)
>> - << CacheCulprit->getSourceRange();
>> - }
>> + // Check whether the initializer is sufficiently constant.
>> + if (!type->isDependentType() && Init && !Init->isValueDependent() &&
>> + (GlobalStorage || var->isConstexpr() ||
>> + var->mightBeUsableInConstantExpressions(Context))) {
>> + // If this variable might have a constant initializer or might be
>> usable in
>> + // constant expressions, check whether or not it actually is now.
>> We can't
>> + // do this lazily, because the result might depend on things that
>> change
>> + // later, such as which constexpr functions happen to be defined.
>> + SmallVector<PartialDiagnosticAt, 8> Notes;
>> + bool HasConstInit = var->checkInitIsICE(Notes);
>> +
>> + // Prior to C++11, in contexts where a constant initializer is
>> required,
>> + // additional kinds of constant expression are permitted beyond
>> ICEs, as
>> + // described in [expr.const]p2-6.
>> + // FIXME: Stricter checking for these rules would be useful for
>> constinit /
>> + // -Wglobal-constructors.
>> + if (!getLangOpts().CPlusPlus11 && !HasConstInit) {
>> + HasConstInit = checkConstInit();
>> + Notes.clear();
>> + if (CacheCulprit) {
>> + Notes.emplace_back(CacheCulprit->getExprLoc(),
>> +
>> PDiag(diag::note_invalid_subexpr_in_const_expr));
>> + Notes.back().second << CacheCulprit->getSourceRange();
>> }
>> }
>> - else if (!var->isConstexpr() && IsGlobal &&
>> - !getDiagnostics().isIgnored(diag::warn_global_constructor,
>> - var->getLocation())) {
>> +
>> + if (HasConstInit) {
>> + // FIXME: Consider replacing the initializer with a ConstantExpr.
>> + } else if (var->isConstexpr()) {
>> + SourceLocation DiagLoc = var->getLocation();
>> + // If the note doesn't add any useful information other than a
>> source
>> + // location, fold it into the primary diagnostic.
>> + if (Notes.size() == 1 && Notes[0].second.getDiagID() ==
>> +
>> diag::note_invalid_subexpr_in_const_expr) {
>> + DiagLoc = Notes[0].first;
>> + Notes.clear();
>> + }
>> + Diag(DiagLoc, diag::err_constexpr_var_requires_const_init)
>> + << var << Init->getSourceRange();
>> + for (unsigned I = 0, N = Notes.size(); I != N; ++I)
>> + Diag(Notes[I].first, Notes[I].second);
>> + } else if (GlobalStorage && var->hasAttr<ConstInitAttr>()) {
>> + auto *Attr = var->getAttr<ConstInitAttr>();
>> + Diag(var->getLocation(), diag::err_require_constant_init_failed)
>> + << Init->getSourceRange();
>> + Diag(Attr->getLocation(),
>> diag::note_declared_required_constant_init_here)
>> + << Attr->getRange() << Attr->isConstinit();
>> + for (auto &it : Notes)
>> + Diag(it.first, it.second);
>> + } else if (IsGlobal &&
>> + !getDiagnostics().isIgnored(diag::warn_global_constructor,
>> + var->getLocation())) {
>> // Warn about globals which don't have a constant initializer.
>> Don't
>> // warn about globals with a non-trivial destructor because we
>> already
>> // warned about them.
>> CXXRecordDecl *RD = baseType->getAsCXXRecordDecl();
>> if (!(RD && !RD->hasTrivialDestructor())) {
>> + // checkConstInit() here permits trivial default initialization
>> even in
>> + // C++11 onwards, where such an initializer is not a constant
>> initializer
>> + // but nonetheless doesn't require a global constructor.
>> if (!checkConstInit())
>> Diag(var->getLocation(), diag::warn_global_constructor)
>> - << Init->getSourceRange();
>> + << Init->getSourceRange();
>> }
>> }
>> }
>>
>> // Require the destructor.
>> - if (const RecordType *recordType = baseType->getAs<RecordType>())
>> - FinalizeVarWithDestructor(var, recordType);
>> + if (!type->isDependentType())
>> + if (const RecordType *recordType = baseType->getAs<RecordType>())
>> + FinalizeVarWithDestructor(var, recordType);
>>
>> // If this variable must be emitted, add it as an initializer for the
>> current
>> // module.
>> if (Context.DeclMustBeEmitted(var) && !ModuleScopes.empty())
>> Context.addModuleInitializer(ModuleScopes.back().Module, var);
>> +
>> + // Build the bindings if this is a structured binding declaration.
>> + if (auto *DD = dyn_cast<DecompositionDecl>(var))
>> + CheckCompleteDecompositionDeclaration(DD);
>> }
>>
>> /// Determines if a variable's alignment is dependent.
>>
>> diff --git a/clang/lib/Sema/SemaDeclCXX.cpp
>> b/clang/lib/Sema/SemaDeclCXX.cpp
>> index cbcaf3cc4360..72dfa37c321e 100644
>> --- a/clang/lib/Sema/SemaDeclCXX.cpp
>> +++ b/clang/lib/Sema/SemaDeclCXX.cpp
>> @@ -1250,8 +1250,7 @@ static bool checkTupleLikeDecomposition(Sema &S,
>> if (E.isInvalid())
>> return true;
>> RefVD->setInit(E.get());
>> - if (!E.get()->isValueDependent())
>> - RefVD->checkInitIsICE();
>> + S.CheckCompleteVariableDeclaration(RefVD);
>>
>> E = S.BuildDeclarationNameExpr(CXXScopeSpec(),
>> DeclarationNameInfo(B->getDeclName(),
>> Loc),
>> @@ -11113,8 +11112,8 @@ QualType
>> Sema::CheckComparisonCategoryType(ComparisonCategoryType Kind,
>> // Attempt to diagnose reasons why the STL definition of this type
>> // might be foobar, including it failing to be a constant expression.
>> // TODO Handle more ways the lookup or result can be invalid.
>> - if (!VD->isStaticDataMember() || !VD->isConstexpr() ||
>> !VD->hasInit() ||
>> - VD->isWeak() || !VD->checkInitIsICE())
>> + if (!VD->isStaticDataMember() ||
>> + !VD->isUsableInConstantExpressions(Context))
>> return UnsupportedSTLError(USS_InvalidMember, MemName, VD);
>>
>> // Attempt to evaluate the var decl as a constant expression and
>> extract
>>
>> diff --git a/clang/lib/Serialization/ASTReaderDecl.cpp
>> b/clang/lib/Serialization/ASTReaderDecl.cpp
>> index f5a66dc3c2d1..41f2db1ef5f0 100644
>> --- a/clang/lib/Serialization/ASTReaderDecl.cpp
>> +++ b/clang/lib/Serialization/ASTReaderDecl.cpp
>> @@ -1425,8 +1425,8 @@ ASTDeclReader::RedeclarableResult
>> ASTDeclReader::VisitVarDeclImpl(VarDecl *VD) {
>> VD->setInit(Record.readExpr());
>> if (Val > 1) {
>> EvaluatedStmt *Eval = VD->ensureEvaluatedStmt();
>> - Eval->CheckedICE = true;
>> - Eval->IsICE = (Val & 1) != 0;
>> + Eval->CheckedICE = (Val & 2) != 0;
>> + Eval->IsICE = (Val & 3) == 3;
>> Eval->HasConstantDestruction = (Val & 4) != 0;
>> }
>> }
>> @@ -4438,10 +4438,11 @@ void ASTDeclReader::UpdateDecl(Decl *D,
>> uint64_t Val = Record.readInt();
>> if (Val && !VD->getInit()) {
>> VD->setInit(Record.readExpr());
>> - if (Val > 1) { // IsInitKnownICE = 1, IsInitNotICE = 2,
>> IsInitICE = 3
>> + if (Val != 1) {
>> EvaluatedStmt *Eval = VD->ensureEvaluatedStmt();
>> - Eval->CheckedICE = true;
>> - Eval->IsICE = Val == 3;
>> + Eval->CheckedICE = (Val & 2) != 0;
>> + Eval->IsICE = (Val & 3) == 3;
>> + Eval->HasConstantDestruction = (Val & 4) != 0;
>> }
>> }
>> break;
>>
>> diff --git a/clang/lib/Serialization/ASTWriter.cpp
>> b/clang/lib/Serialization/ASTWriter.cpp
>> index e793e619381b..6056ed623c69 100644
>> --- a/clang/lib/Serialization/ASTWriter.cpp
>> +++ b/clang/lib/Serialization/ASTWriter.cpp
>> @@ -4980,13 +4980,7 @@ void
>> ASTWriter::WriteDeclUpdatesBlocks(RecordDataImpl &OffsetsRecord) {
>> const VarDecl *VD = cast<VarDecl>(D);
>> Record.push_back(VD->isInline());
>> Record.push_back(VD->isInlineSpecified());
>> - if (VD->getInit()) {
>> - Record.push_back(!VD->isInitKnownICE() ? 1
>> - : (VD->isInitICE() ? 3
>> : 2));
>> - Record.AddStmt(const_cast<Expr*>(VD->getInit()));
>> - } else {
>> - Record.push_back(0);
>> - }
>> + Record.AddVarDeclInit(VD);
>> break;
>> }
>>
>> @@ -5746,6 +5740,27 @@ void ASTRecordWriter::AddCXXDefinitionData(const
>> CXXRecordDecl *D) {
>> }
>> }
>>
>> +void ASTRecordWriter::AddVarDeclInit(const VarDecl *VD) {
>> + const Expr *Init = VD->getInit();
>> + if (!Init) {
>> + push_back(0);
>> + return;
>> + }
>> +
>> + // Bottom two bits are as follows:
>> + // 01 -- initializer not checked for ICE
>> + // 10 -- initializer not ICE
>> + // 11 -- initializer ICE
>> + unsigned Val = 1;
>> + if (EvaluatedStmt *ES = VD->getEvaluatedStmt()) {
>> + if (ES->CheckedICE)
>> + Val = 2 | ES->IsICE;
>> + Val |= (ES->HasConstantDestruction ? 4 : 0);
>> + }
>> + push_back(Val);
>> + writeStmtRef(Init);
>> +}
>> +
>> void ASTWriter::ReaderInitialized(ASTReader *Reader) {
>> assert(Reader && "Cannot remove chain");
>> assert((!Chain || Chain == Reader) && "Cannot replace chain");
>>
>> diff --git a/clang/lib/Serialization/ASTWriterDecl.cpp
>> b/clang/lib/Serialization/ASTWriterDecl.cpp
>> index 911fcb409547..8778f0c02671 100644
>> --- a/clang/lib/Serialization/ASTWriterDecl.cpp
>> +++ b/clang/lib/Serialization/ASTWriterDecl.cpp
>> @@ -1000,19 +1000,7 @@ void ASTDeclWriter::VisitVarDecl(VarDecl *D) {
>> }
>> Record.push_back(D->getLinkageInternal());
>>
>> - if (D->getInit()) {
>> - if (!D->isInitKnownICE())
>> - Record.push_back(1);
>> - else {
>> - Record.push_back(
>> - 2 |
>> - (D->isInitICE() ? 1 : 0) |
>> - (D->ensureEvaluatedStmt()->HasConstantDestruction ? 4 : 0));
>> - }
>> - Record.AddStmt(D->getInit());
>> - } else {
>> - Record.push_back(0);
>> - }
>> + Record.AddVarDeclInit(D);
>>
>> if (D->hasAttr<BlocksAttr>() && D->getType()->getAsCXXRecordDecl()) {
>> BlockVarCopyInit Init = Writer.Context->getBlockVarCopyInit(D);
>>
>> diff --git a/clang/test/CodeGen/enable_if.c
>> b/clang/test/CodeGen/enable_if.c
>> index 5e9f904fdd3f..1d830ae68f54 100644
>> --- a/clang/test/CodeGen/enable_if.c
>> +++ b/clang/test/CodeGen/enable_if.c
>> @@ -65,19 +65,19 @@ void test3() {
>> }
>>
>>
>> -const int TRUEFACTS = 1;
>> +enum { TRUEFACTS = 1 };
>> void qux(int m) __attribute__((overloadable, enable_if(1, ""),
>> enable_if(TRUEFACTS, "")));
>> void qux(int m) __attribute__((overloadable, enable_if(1, "")));
>> // CHECK-LABEL: define void @test4
>> void test4() {
>> - // CHECK: store void (i32)*
>> @_Z3quxUa9enable_ifIXLi1EEXL_Z9TRUEFACTSEEEi
>> + // CHECK: store void (i32)* @_Z3quxUa9enable_ifIXLi1EEXLi1EEEi
>> void (*p)(int) = qux;
>> - // CHECK: store void (i32)*
>> @_Z3quxUa9enable_ifIXLi1EEXL_Z9TRUEFACTSEEEi
>> + // CHECK: store void (i32)* @_Z3quxUa9enable_ifIXLi1EEXLi1EEEi
>> void (*p2)(int) = &qux;
>> - // CHECK: store void (i32)*
>> @_Z3quxUa9enable_ifIXLi1EEXL_Z9TRUEFACTSEEEi
>> + // CHECK: store void (i32)* @_Z3quxUa9enable_ifIXLi1EEXLi1EEEi
>> p = qux;
>> - // CHECK: store void (i32)*
>> @_Z3quxUa9enable_ifIXLi1EEXL_Z9TRUEFACTSEEEi
>> + // CHECK: store void (i32)* @_Z3quxUa9enable_ifIXLi1EEXLi1EEEi
>> p = &qux;
>> }
>>
>>
>> diff --git a/clang/test/OpenMP/threadprivate_codegen.cpp
>> b/clang/test/OpenMP/threadprivate_codegen.cpp
>> index a46bb6907015..2ef6522760ab 100644
>> --- a/clang/test/OpenMP/threadprivate_codegen.cpp
>> +++ b/clang/test/OpenMP/threadprivate_codegen.cpp
>> @@ -598,8 +598,8 @@ int main() {
>> // CHECK-DEBUG-NEXT: [[RES:%.*]] = load [[INT]], [[INT]]* [[RES_ADDR]]
>> // CHECK-DEBUG-NEXT: [[ADD:%.*]] = add {{.*}} [[INT]] [[RES]],
>> [[ST_INT_ST_VAL]]
>> // CHECK-DEBUG-NEXT: store [[INT]] [[ADD]], [[INT]]* [[RES:.+]]
>> - // CHECK-TLS: [[ST_INT_ST_ADDR:%.*]] = call i32*
>> [[ST_INT_ST_TLS_INITD:[^,]+]]
>> - // CHECK-TLS-NEXT: [[ST_INT_ST_VAL:%.*]] = load i32, i32*
>> [[ST_INT_ST_ADDR]]
>> + //
>> + // CHECK-TLS: [[ST_INT_ST_VAL:%.*]] = load i32, i32*
>> [[ST_INT_ST_ADDR:[^,]+]]
>> // CHECK-TLS-NEXT: [[RES:%.*]] = load i32, i32* [[RES_ADDR]]
>> // CHECK-TLS-NEXT: [[ADD:%.*]] = add {{.*}} i32 [[RES]],
>> [[ST_INT_ST_VAL]]
>> // CHECK-TLS-NEXT: store i32 [[ADD]], i32* [[RES_ADDR]]
>> @@ -620,8 +620,8 @@ int main() {
>> // CHECK-DEBUG-NEXT: [[RES:%.*]] = load [[INT]], [[INT]]* [[RES_ADDR]]
>> // CHECK-DEBUG-NEXT: [[ADD:%.*]] = add {{.*}} [[INT]] [[RES]],
>> [[FLOAT_TO_INT_CONV]]
>> // CHECK-DEBUG-NEXT: store [[INT]] [[ADD]], [[INT]]* [[RES:.+]]
>> - // CHECK-TLS: [[ST_FLOAT_ST_ADDR:%.*]] = call float*
>> [[ST_FLOAT_ST_TLS_INITD:[^,]+]]
>> - // CHECK-TLS-NEXT: [[ST_FLOAT_ST_VAL:%.*]] = load float, float*
>> [[ST_FLOAT_ST_ADDR]]
>> + //
>> + // CHECK-TLS: [[ST_FLOAT_ST_VAL:%.*]] = load float, float*
>> [[ST_FLOAT_ST_ADDR:[^,]+]]
>> // CHECK-TLS-NEXT: [[FLOAT_TO_INT_CONV:%.*]] = fptosi float
>> [[ST_FLOAT_ST_VAL]] to i32
>> // CHECK-TLS-NEXT: [[RES:%.*]] = load i32, i32* [[RES_ADDR]]
>> // CHECK-TLS-NEXT: [[ADD:%.*]] = add {{.*}} i32 [[RES]],
>> [[FLOAT_TO_INT_CONV]]
>> @@ -727,14 +727,14 @@ int main() {
>> // CHECK-TLS: call void [[ARR_X_TLS_INIT]]
>> // CHECK-TLS: ret [2 x [3 x [[S1]]]]* [[ARR_X]]
>> // CHECK-TLS: }
>> -// CHECK-TLS: define {{.*}} i32* [[ST_INT_ST_TLS_INITD]] {{#[0-9]+}}
>> comdat {
>> -// CHECK-TLS-NOT: call
>> -// CHECK-TLS: ret i32* [[ST_INT_ST]]
>> -// CHECK-TLS: }
>> -// CHECK-TLS: define {{.*}} float* [[ST_FLOAT_ST_TLS_INITD]] {{#[0-9]+}}
>> comdat {
>> -// CHECK-TLS-NOT: call
>> -// CHECK-TLS: ret float* [[ST_FLOAT_ST]]
>> -// CHECK-TLS: }
>> +//
>> +//
>> +//
>> +//
>> +//
>> +//
>> +//
>> +//
>> // CHECK-TLS: define {{.*}} [[S4]]* [[ST_S4_ST_TLS_INITD]] {{#[0-9]+}}
>> comdat {
>> // CHECK-TLS: call void [[ST_S4_ST_TLS_INIT]]
>> // CHECK-TLS: ret [[S4]]* [[ST_S4_ST]]
>> @@ -874,8 +874,8 @@ int foobar() {
>> // CHECK-DEBUG-NEXT: [[RES:%.*]] = load [[INT]], [[INT]]* [[RES_ADDR]]
>> // CHECK-DEBUG-NEXT: [[ADD:%.*]] = add {{.*}} [[INT]] [[RES]],
>> [[ST_INT_ST_VAL]]
>> // CHECK-DEBUG-NEXT: store [[INT]] [[ADD]], [[INT]]* [[RES:.+]]
>> - // OMP45-TLS: [[ST_INT_ST_ADDR:%.*]] = call i32*
>> [[ST_INT_ST_TLS_INITD]]
>> - // OMP45-TLS-NEXT: [[ST_INT_ST_VAL:%.*]] = load [[INT]], [[INT]]*
>> [[ST_INT_ST_ADDR]]
>> + //
>> + // OMP45-TLS: [[ST_INT_ST_VAL:%.*]] = load [[INT]], [[INT]]*
>> [[ST_INT_ST_ADDR:[^,]+]]
>> // OMP45-TLS-NEXT: [[RES:%.*]] = load [[INT]], [[INT]]* [[RES_ADDR]]
>> // OMP45-TLS-NEXT: [[ADD:%.*]] = add {{.*}} [[INT]] [[RES]],
>> [[ST_INT_ST_VAL]]
>> // OMP45-TLS-NEXT: store [[INT]] [[ADD]], [[INT]]* [[RES:.+]]
>> @@ -896,8 +896,8 @@ int foobar() {
>> // CHECK-DEBUG-NEXT: [[RES:%.*]] = load [[INT]], [[INT]]* [[RES_ADDR]]
>> // CHECK-DEBUG-NEXT: [[ADD:%.*]] = add {{.*}} [[INT]] [[RES]],
>> [[FLOAT_TO_INT_CONV]]
>> // CHECK-DEBUG-NEXT: store [[INT]] [[ADD]], [[INT]]* [[RES:.+]]
>> - // OMP45-TLS: [[ST_FLOAT_ST_ADDR:%.*]] = call float*
>> [[ST_FLOAT_ST_TLS_INITD]]
>> - // OMP45-TLS-NEXT: [[ST_FLOAT_ST_VAL:%.*]] = load float, float*
>> [[ST_FLOAT_ST_ADDR]]
>> + //
>> + // OMP45-TLS: [[ST_FLOAT_ST_VAL:%.*]] = load float, float*
>> [[ST_FLOAT_ST_ADDR:[^,]+]]
>> // OMP45-TLS-NEXT: [[FLOAT_TO_INT_CONV:%.*]] = fptosi float
>> [[ST_FLOAT_ST_VAL]] to [[INT]]
>> // OMP45-TLS-NEXT: [[RES:%.*]] = load [[INT]], [[INT]]* [[RES_ADDR]]
>> // OMP45-TLS-NEXT: [[ADD:%.*]] = add {{.*}} [[INT]] [[RES]],
>> [[FLOAT_TO_INT_CONV]]
>>
>> diff --git a/clang/test/Sema/enable_if.c b/clang/test/Sema/enable_if.c
>> index b4bb2ecd0d20..d96a53d94e1e 100644
>> --- a/clang/test/Sema/enable_if.c
>> +++ b/clang/test/Sema/enable_if.c
>> @@ -5,7 +5,7 @@
>> typedef int mode_t;
>> typedef unsigned long size_t;
>>
>> -const int TRUE = 1;
>> +enum { TRUE = 1 };
>>
>> int open(const char *pathname, int flags)
>> __attribute__((enable_if(!(flags & O_CREAT), "must specify mode when using
>> O_CREAT"))) __attribute__((overloadable)); // expected-note{{candidate
>> disabled: must specify mode when using O_CREAT}}
>> int open(const char *pathname, int flags, mode_t mode)
>> __attribute__((overloadable)); // expected-note{{candidate function not
>> viable: requires 3 arguments, but 2 were provided}}
>> @@ -114,7 +114,7 @@ void f(int n) __attribute__((enable_if(unresolvedid,
>> "chosen when 'unresolvedid'
>> int global;
>> void f(int n) __attribute__((enable_if(global == 0, "chosen when
>> 'global' is zero"))); // expected-error{{'enable_if' attribute expression
>> never produces a constant expression}} // expected-note{{subexpression not
>> valid in a constant expression}}
>>
>> -const int cst = 7;
>> +enum { cst = 7 };
>> void return_cst(void) __attribute__((overloadable))
>> __attribute__((enable_if(cst == 7, "chosen when 'cst' is 7")));
>> void test_return_cst() { return_cst(); }
>>
>>
>> diff --git a/clang/test/SemaCXX/constant-expression.cpp
>> b/clang/test/SemaCXX/constant-expression.cpp
>> index 2bec62f46b66..a5e571a97eb2 100644
>> --- a/clang/test/SemaCXX/constant-expression.cpp
>> +++ b/clang/test/SemaCXX/constant-expression.cpp
>> @@ -98,9 +98,9 @@ void diags(int n) {
>>
>> namespace IntOrEnum {
>> const int k = 0;
>> - const int &p = k;
>> + const int &p = k; // expected-note {{declared here}}
>> template<int n> struct S {};
>> - S<p> s; // expected-error {{not an integral constant expression}}
>> + S<p> s; // expected-error {{not an integral constant expression}}
>> expected-note {{read of variable 'p' of non-integral, non-enumeration type
>> 'const int &'}}
>> }
>>
>> extern const int recurse1;
>>
>> diff --git a/clang/test/SemaCXX/i-c-e-cxx.cpp
>> b/clang/test/SemaCXX/i-c-e-cxx.cpp
>> index a09ff5ac8d9f..da9be1229a54 100644
>> --- a/clang/test/SemaCXX/i-c-e-cxx.cpp
>> +++ b/clang/test/SemaCXX/i-c-e-cxx.cpp
>> @@ -19,9 +19,6 @@ void f() {
>>
>> int a() {
>> const int t=t; // expected-note {{declared here}}
>> -#if __cplusplus <= 199711L
>> - // expected-note at -2 {{read of object outside its lifetime}}
>> -#endif
>>
>> switch(1) { // do not warn that 1 is not a case value;
>> // 't' might have been expected to evalaute to 1
>>
>>
>>
>> _______________________________________________
>> cfe-commits mailing list
>> cfe-commits at lists.llvm.org
>> https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
>>
>
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