Implement DR1330 in C++11 mode, to support libstdc++4.7 which uses it.
We have a new flavor of exception specification, EST_Uninstantiated. A function
type with this exception specification carries a pointer to a FunctionDecl, and
the exception specification for that FunctionDecl is instantiated (if needed)
and used in the place of the function type's exception specification.
When a function template declaration with a non-trivial exception specification
is instantiated, the specialization's exception specification is set to this
new 'uninstantiated' kind rather than being instantiated immediately.
Expr::CanThrow has migrated onto Sema, so it can instantiate exception specs
on-demand. Also, any odr-use of a function triggers the instantiation of its
exception specification (the exception specification could be needed by IRGen).
In passing, fix two places where a DeclRefExpr was created but the corresponding
function was not actually marked odr-used. We used to get away with this, but
don't any more.
Also fix a bug where instantiating an exception specification which refers to
function parameters resulted in a crash. We still have the same bug in default
arguments, which I'll be looking into next.
This, plus a tiny patch to fix libstdc++'s common_type, is enough for clang to
parse (and, in very limited testing, support) all of libstdc++4.7's standard
headers.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@154886 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaTemplateInstantiateDecl.cpp b/lib/Sema/SemaTemplateInstantiateDecl.cpp
index 8d382d1..39c27fc 100644
--- a/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ b/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -2215,6 +2215,194 @@
return NewTInfo;
}
+/// Introduce the instantiated function parameters into the local
+/// instantiation scope, and set the parameter names to those used
+/// in the template.
+static void addInstantiatedParametersToScope(Sema &S, FunctionDecl *Function,
+ const FunctionDecl *PatternDecl,
+ LocalInstantiationScope &Scope,
+ const MultiLevelTemplateArgumentList &TemplateArgs) {
+ unsigned FParamIdx = 0;
+ for (unsigned I = 0, N = PatternDecl->getNumParams(); I != N; ++I) {
+ const ParmVarDecl *PatternParam = PatternDecl->getParamDecl(I);
+ if (!PatternParam->isParameterPack()) {
+ // Simple case: not a parameter pack.
+ assert(FParamIdx < Function->getNumParams());
+ ParmVarDecl *FunctionParam = Function->getParamDecl(FParamIdx);
+ FunctionParam->setDeclName(PatternParam->getDeclName());
+ Scope.InstantiatedLocal(PatternParam, FunctionParam);
+ ++FParamIdx;
+ continue;
+ }
+
+ // Expand the parameter pack.
+ Scope.MakeInstantiatedLocalArgPack(PatternParam);
+ unsigned NumArgumentsInExpansion
+ = S.getNumArgumentsInExpansion(PatternParam->getType(), TemplateArgs);
+ for (unsigned Arg = 0; Arg < NumArgumentsInExpansion; ++Arg) {
+ ParmVarDecl *FunctionParam = Function->getParamDecl(FParamIdx);
+ FunctionParam->setDeclName(PatternParam->getDeclName());
+ Scope.InstantiatedLocalPackArg(PatternParam, FunctionParam);
+ ++FParamIdx;
+ }
+ }
+}
+
+static void InstantiateExceptionSpec(Sema &SemaRef, FunctionDecl *New,
+ const FunctionProtoType *Proto,
+ const MultiLevelTemplateArgumentList &TemplateArgs) {
+ // C++11 [expr.prim.general]p3:
+ // If a declaration declares a member function or member function
+ // template of a class X, the expression this is a prvalue of type
+ // "pointer to cv-qualifier-seq X" between the optional cv-qualifer-seq
+ // and the end of the function-definition, member-declarator, or
+ // declarator.
+ CXXRecordDecl *ThisContext = 0;
+ unsigned ThisTypeQuals = 0;
+ if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(New)) {
+ ThisContext = Method->getParent();
+ ThisTypeQuals = Method->getTypeQualifiers();
+ }
+ Sema::CXXThisScopeRAII ThisScope(SemaRef, ThisContext, ThisTypeQuals,
+ SemaRef.getLangOpts().CPlusPlus0x);
+
+ // The function has an exception specification or a "noreturn"
+ // attribute. Substitute into each of the exception types.
+ SmallVector<QualType, 4> Exceptions;
+ for (unsigned I = 0, N = Proto->getNumExceptions(); I != N; ++I) {
+ // FIXME: Poor location information!
+ if (const PackExpansionType *PackExpansion
+ = Proto->getExceptionType(I)->getAs<PackExpansionType>()) {
+ // We have a pack expansion. Instantiate it.
+ SmallVector<UnexpandedParameterPack, 2> Unexpanded;
+ SemaRef.collectUnexpandedParameterPacks(PackExpansion->getPattern(),
+ Unexpanded);
+ assert(!Unexpanded.empty() &&
+ "Pack expansion without parameter packs?");
+
+ bool Expand = false;
+ bool RetainExpansion = false;
+ llvm::Optional<unsigned> NumExpansions
+ = PackExpansion->getNumExpansions();
+ if (SemaRef.CheckParameterPacksForExpansion(New->getLocation(),
+ SourceRange(),
+ Unexpanded,
+ TemplateArgs,
+ Expand,
+ RetainExpansion,
+ NumExpansions))
+ break;
+
+ if (!Expand) {
+ // We can't expand this pack expansion into separate arguments yet;
+ // just substitute into the pattern and create a new pack expansion
+ // type.
+ Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, -1);
+ QualType T = SemaRef.SubstType(PackExpansion->getPattern(),
+ TemplateArgs,
+ New->getLocation(), New->getDeclName());
+ if (T.isNull())
+ break;
+
+ T = SemaRef.Context.getPackExpansionType(T, NumExpansions);
+ Exceptions.push_back(T);
+ continue;
+ }
+
+ // Substitute into the pack expansion pattern for each template
+ bool Invalid = false;
+ for (unsigned ArgIdx = 0; ArgIdx != *NumExpansions; ++ArgIdx) {
+ Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, ArgIdx);
+
+ QualType T = SemaRef.SubstType(PackExpansion->getPattern(),
+ TemplateArgs,
+ New->getLocation(), New->getDeclName());
+ if (T.isNull()) {
+ Invalid = true;
+ break;
+ }
+
+ Exceptions.push_back(T);
+ }
+
+ if (Invalid)
+ break;
+
+ continue;
+ }
+
+ QualType T
+ = SemaRef.SubstType(Proto->getExceptionType(I), TemplateArgs,
+ New->getLocation(), New->getDeclName());
+ if (T.isNull() ||
+ SemaRef.CheckSpecifiedExceptionType(T, New->getLocation()))
+ continue;
+
+ Exceptions.push_back(T);
+ }
+ Expr *NoexceptExpr = 0;
+ if (Expr *OldNoexceptExpr = Proto->getNoexceptExpr()) {
+ EnterExpressionEvaluationContext Unevaluated(SemaRef,
+ Sema::ConstantEvaluated);
+ ExprResult E = SemaRef.SubstExpr(OldNoexceptExpr, TemplateArgs);
+ if (E.isUsable())
+ E = SemaRef.CheckBooleanCondition(E.get(), E.get()->getLocStart());
+
+ if (E.isUsable()) {
+ NoexceptExpr = E.take();
+ if (!NoexceptExpr->isTypeDependent() &&
+ !NoexceptExpr->isValueDependent())
+ NoexceptExpr = SemaRef.VerifyIntegerConstantExpression(NoexceptExpr,
+ 0, SemaRef.PDiag(diag::err_noexcept_needs_constant_expression),
+ /*AllowFold*/ false).take();
+ }
+ }
+
+ // Rebuild the function type
+ const FunctionProtoType *NewProto
+ = New->getType()->getAs<FunctionProtoType>();
+ assert(NewProto && "Template instantiation without function prototype?");
+
+ FunctionProtoType::ExtProtoInfo EPI = NewProto->getExtProtoInfo();
+ EPI.ExceptionSpecType = Proto->getExceptionSpecType();
+ EPI.NumExceptions = Exceptions.size();
+ EPI.Exceptions = Exceptions.data();
+ EPI.NoexceptExpr = NoexceptExpr;
+
+ New->setType(SemaRef.Context.getFunctionType(NewProto->getResultType(),
+ NewProto->arg_type_begin(),
+ NewProto->getNumArgs(),
+ EPI));
+}
+
+void Sema::InstantiateExceptionSpec(SourceLocation PointOfInstantiation,
+ FunctionDecl *Decl) {
+ FunctionDecl *Tmpl = Decl->getTemplateInstantiationPattern();
+ assert(Tmpl && "can't instantiate non-template");
+
+ if (Decl->getType()->castAs<FunctionProtoType>()->getExceptionSpecType()
+ != EST_Uninstantiated)
+ return;
+
+ InstantiatingTemplate Inst(*this, PointOfInstantiation, Decl,
+ InstantiatingTemplate::ExceptionSpecification());
+ if (Inst)
+ return;
+
+ // Enter the scope of this instantiation. We don't use
+ // PushDeclContext because we don't have a scope.
+ Sema::ContextRAII savedContext(*this, Decl);
+ LocalInstantiationScope Scope(*this);
+
+ MultiLevelTemplateArgumentList TemplateArgs =
+ getTemplateInstantiationArgs(Decl, 0, /*RelativeToPrimary*/true);
+
+ addInstantiatedParametersToScope(*this, Decl, Tmpl, Scope, TemplateArgs);
+
+ const FunctionProtoType *Proto = Tmpl->getType()->castAs<FunctionProtoType>();
+ ::InstantiateExceptionSpec(*this, Decl, Proto, TemplateArgs);
+}
+
/// \brief Initializes the common fields of an instantiation function
/// declaration (New) from the corresponding fields of its template (Tmpl).
///
@@ -2252,135 +2440,32 @@
assert(Proto && "Function template without prototype?");
if (Proto->hasExceptionSpec() || Proto->getNoReturnAttr()) {
- // C++11 [expr.prim.general]p3:
- // If a declaration declares a member function or member function
- // template of a class X, the expression this is a prvalue of type
- // "pointer to cv-qualifier-seq X" between the optional cv-qualifer-seq
- // and the end of the function-definition, member-declarator, or
- // declarator.
- CXXRecordDecl *ThisContext = 0;
- unsigned ThisTypeQuals = 0;
- if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(New)) {
- ThisContext = Method->getParent();
- ThisTypeQuals = Method->getTypeQualifiers();
- }
- Sema::CXXThisScopeRAII ThisScope(SemaRef, ThisContext, ThisTypeQuals,
- SemaRef.getLangOpts().CPlusPlus0x);
-
-
- // The function has an exception specification or a "noreturn"
- // attribute. Substitute into each of the exception types.
- SmallVector<QualType, 4> Exceptions;
- for (unsigned I = 0, N = Proto->getNumExceptions(); I != N; ++I) {
- // FIXME: Poor location information!
- if (const PackExpansionType *PackExpansion
- = Proto->getExceptionType(I)->getAs<PackExpansionType>()) {
- // We have a pack expansion. Instantiate it.
- SmallVector<UnexpandedParameterPack, 2> Unexpanded;
- SemaRef.collectUnexpandedParameterPacks(PackExpansion->getPattern(),
- Unexpanded);
- assert(!Unexpanded.empty() &&
- "Pack expansion without parameter packs?");
-
- bool Expand = false;
- bool RetainExpansion = false;
- llvm::Optional<unsigned> NumExpansions
- = PackExpansion->getNumExpansions();
- if (SemaRef.CheckParameterPacksForExpansion(New->getLocation(),
- SourceRange(),
- Unexpanded,
- TemplateArgs,
- Expand,
- RetainExpansion,
- NumExpansions))
- break;
-
- if (!Expand) {
- // We can't expand this pack expansion into separate arguments yet;
- // just substitute into the pattern and create a new pack expansion
- // type.
- Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, -1);
- QualType T = SemaRef.SubstType(PackExpansion->getPattern(),
- TemplateArgs,
- New->getLocation(), New->getDeclName());
- if (T.isNull())
- break;
-
- T = SemaRef.Context.getPackExpansionType(T, NumExpansions);
- Exceptions.push_back(T);
- continue;
- }
-
- // Substitute into the pack expansion pattern for each template
- bool Invalid = false;
- for (unsigned ArgIdx = 0; ArgIdx != *NumExpansions; ++ArgIdx) {
- Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, ArgIdx);
-
- QualType T = SemaRef.SubstType(PackExpansion->getPattern(),
- TemplateArgs,
- New->getLocation(), New->getDeclName());
- if (T.isNull()) {
- Invalid = true;
- break;
- }
-
- Exceptions.push_back(T);
- }
-
- if (Invalid)
- break;
-
- continue;
- }
-
- QualType T
- = SemaRef.SubstType(Proto->getExceptionType(I), TemplateArgs,
- New->getLocation(), New->getDeclName());
- if (T.isNull() ||
- SemaRef.CheckSpecifiedExceptionType(T, New->getLocation()))
- continue;
-
- Exceptions.push_back(T);
- }
- Expr *NoexceptExpr = 0;
- if (Expr *OldNoexceptExpr = Proto->getNoexceptExpr()) {
- EnterExpressionEvaluationContext Unevaluated(SemaRef,
- Sema::ConstantEvaluated);
- ExprResult E = SemaRef.SubstExpr(OldNoexceptExpr, TemplateArgs);
- if (E.isUsable())
- E = SemaRef.CheckBooleanCondition(E.get(), E.get()->getLocStart());
-
- if (E.isUsable()) {
- NoexceptExpr = E.take();
- if (!NoexceptExpr->isTypeDependent() &&
- !NoexceptExpr->isValueDependent())
- NoexceptExpr = SemaRef.VerifyIntegerConstantExpression(NoexceptExpr,
- 0, SemaRef.PDiag(diag::err_noexcept_needs_constant_expression),
- /*AllowFold*/ false).take();
- }
- }
-
- // Rebuild the function type
-
FunctionProtoType::ExtProtoInfo EPI = Proto->getExtProtoInfo();
- EPI.ExceptionSpecType = Proto->getExceptionSpecType();
- EPI.NumExceptions = Exceptions.size();
- EPI.Exceptions = Exceptions.data();
- EPI.NoexceptExpr = NoexceptExpr;
- EPI.ExtInfo = Proto->getExtInfo();
- const FunctionProtoType *NewProto
- = New->getType()->getAs<FunctionProtoType>();
- assert(NewProto && "Template instantiation without function prototype?");
- New->setType(SemaRef.Context.getFunctionType(NewProto->getResultType(),
- NewProto->arg_type_begin(),
- NewProto->getNumArgs(),
- EPI));
+ // DR1330: In C++11, defer instantiation of a non-trivial
+ // exception specification.
+ if (SemaRef.getLangOpts().CPlusPlus0x &&
+ EPI.ExceptionSpecType != EST_None &&
+ EPI.ExceptionSpecType != EST_DynamicNone &&
+ EPI.ExceptionSpecType != EST_BasicNoexcept) {
+ // Mark the function has having an uninstantiated exception specification.
+ const FunctionProtoType *NewProto
+ = New->getType()->getAs<FunctionProtoType>();
+ assert(NewProto && "Template instantiation without function prototype?");
+ EPI = NewProto->getExtProtoInfo();
+ EPI.ExceptionSpecType = EST_Uninstantiated;
+ EPI.ExceptionSpecDecl = New;
+ New->setType(SemaRef.Context.getFunctionType(NewProto->getResultType(),
+ NewProto->arg_type_begin(),
+ NewProto->getNumArgs(),
+ EPI));
+ } else {
+ ::InstantiateExceptionSpec(SemaRef, New, Proto, TemplateArgs);
+ }
}
- const FunctionDecl* Definition = Tmpl;
-
// Get the definition. Leaves the variable unchanged if undefined.
+ const FunctionDecl *Definition = Tmpl;
Tmpl->isDefined(Definition);
SemaRef.InstantiateAttrs(TemplateArgs, Definition, New,
@@ -2538,33 +2623,8 @@
MultiLevelTemplateArgumentList TemplateArgs =
getTemplateInstantiationArgs(Function, 0, false, PatternDecl);
- // Introduce the instantiated function parameters into the local
- // instantiation scope, and set the parameter names to those used
- // in the template.
- unsigned FParamIdx = 0;
- for (unsigned I = 0, N = PatternDecl->getNumParams(); I != N; ++I) {
- const ParmVarDecl *PatternParam = PatternDecl->getParamDecl(I);
- if (!PatternParam->isParameterPack()) {
- // Simple case: not a parameter pack.
- assert(FParamIdx < Function->getNumParams());
- ParmVarDecl *FunctionParam = Function->getParamDecl(FParamIdx);
- FunctionParam->setDeclName(PatternParam->getDeclName());
- Scope.InstantiatedLocal(PatternParam, FunctionParam);
- ++FParamIdx;
- continue;
- }
-
- // Expand the parameter pack.
- Scope.MakeInstantiatedLocalArgPack(PatternParam);
- unsigned NumArgumentsInExpansion
- = getNumArgumentsInExpansion(PatternParam->getType(), TemplateArgs);
- for (unsigned Arg = 0; Arg < NumArgumentsInExpansion; ++Arg) {
- ParmVarDecl *FunctionParam = Function->getParamDecl(FParamIdx);
- FunctionParam->setDeclName(PatternParam->getDeclName());
- Scope.InstantiatedLocalPackArg(PatternParam, FunctionParam);
- ++FParamIdx;
- }
- }
+ addInstantiatedParametersToScope(*this, Function, PatternDecl, Scope,
+ TemplateArgs);
if (PatternDecl->isDefaulted()) {
ActOnFinishFunctionBody(Function, 0, /*IsInstantiation=*/true);