1 files changed, 80 insertions, 37 deletions

diff --git a/lib/Sema/SemaExceptionSpec.cpp b/lib/Sema/SemaExceptionSpec.cpp
index b92fcbd2a0d9..2387325be435 100644
--- a/lib/Sema/SemaExceptionSpec.cpp
+++ b/lib/Sema/SemaExceptionSpec.cpp
@@ -35,6 +35,33 @@ static const FunctionProtoType *GetUnderlyingFunction(QualType T)
   return T->getAs<FunctionProtoType>();
 }
 
+/// HACK: libstdc++ has a bug where it shadows std::swap with a member
+/// swap function then tries to call std::swap unqualified from the exception
+/// specification of that function. This function detects whether we're in
+/// such a case and turns off delay-parsing of exception specifications.
+bool Sema::isLibstdcxxEagerExceptionSpecHack(const Declarator &D) {
+  auto *RD = dyn_cast<CXXRecordDecl>(CurContext);
+
+  // All the problem cases are member functions named "swap" within class
+  // templates declared directly within namespace std.
+  if (!RD || RD->getEnclosingNamespaceContext() != getStdNamespace() ||
+      !RD->getIdentifier() || !RD->getDescribedClassTemplate() ||
+      !D.getIdentifier() || !D.getIdentifier()->isStr("swap"))
+    return false;
+
+  // Only apply this hack within a system header.
+  if (!Context.getSourceManager().isInSystemHeader(D.getLocStart()))
+    return false;
+
+  return llvm::StringSwitch<bool>(RD->getIdentifier()->getName())
+      .Case("array", true)
+      .Case("pair", true)
+      .Case("priority_queue", true)
+      .Case("stack", true)
+      .Case("queue", true)
+      .Default(false);
+}
+
 /// CheckSpecifiedExceptionType - Check if the given type is valid in an
 /// exception specification. Incomplete types, or pointers to incomplete types
 /// other than void are not allowed.
@@ -112,6 +139,11 @@ bool Sema::CheckDistantExceptionSpec(QualType T) {
 
 const FunctionProtoType *
 Sema::ResolveExceptionSpec(SourceLocation Loc, const FunctionProtoType *FPT) {
+  if (FPT->getExceptionSpecType() == EST_Unparsed) {
+    Diag(Loc, diag::err_exception_spec_not_parsed);
+    return nullptr;
+  }
+
   if (!isUnresolvedExceptionSpec(FPT->getExceptionSpecType()))
     return FPT;
 
@@ -132,21 +164,14 @@ Sema::ResolveExceptionSpec(SourceLocation Loc, const FunctionProtoType *FPT) {
   return SourceDecl->getType()->castAs<FunctionProtoType>();
 }
 
-void Sema::UpdateExceptionSpec(FunctionDecl *FD,
-                               const FunctionProtoType::ExtProtoInfo &EPI) {
-  const FunctionProtoType *Proto = FD->getType()->castAs<FunctionProtoType>();
-
-  // Overwrite the exception spec and rebuild the function type.
-  FunctionProtoType::ExtProtoInfo NewEPI = Proto->getExtProtoInfo();
-  NewEPI.ExceptionSpecType = EPI.ExceptionSpecType;
-  NewEPI.NumExceptions = EPI.NumExceptions;
-  NewEPI.Exceptions = EPI.Exceptions;
-  NewEPI.NoexceptExpr = EPI.NoexceptExpr;
-  FD->setType(Context.getFunctionType(Proto->getReturnType(),
-                                      Proto->getParamTypes(), NewEPI));
+void
+Sema::UpdateExceptionSpec(FunctionDecl *FD,
+                          const FunctionProtoType::ExceptionSpecInfo &ESI) {
+  for (auto *Redecl : FD->redecls())
+    Context.adjustExceptionSpec(cast<FunctionDecl>(Redecl), ESI);
 
   // If we've fully resolved the exception specification, notify listeners.
-  if (!isUnresolvedExceptionSpec(EPI.ExceptionSpecType))
+  if (!isUnresolvedExceptionSpec(ESI.Type))
     if (auto *Listener = getASTMutationListener())
       Listener->ResolvedExceptionSpec(FD);
 }
@@ -227,32 +252,28 @@ bool Sema::CheckEquivalentExceptionSpec(FunctionDecl *Old, FunctionDecl *New) {
       (Old->getLocation().isInvalid() ||
        Context.getSourceManager().isInSystemHeader(Old->getLocation())) &&
       Old->isExternC()) {
-    FunctionProtoType::ExtProtoInfo EPI = NewProto->getExtProtoInfo();
-    EPI.ExceptionSpecType = EST_DynamicNone;
-    QualType NewType = Context.getFunctionType(NewProto->getReturnType(),
-                                               NewProto->getParamTypes(), EPI);
-    New->setType(NewType);
+    New->setType(Context.getFunctionType(
+        NewProto->getReturnType(), NewProto->getParamTypes(),
+        NewProto->getExtProtoInfo().withExceptionSpec(EST_DynamicNone)));
     return false;
   }
 
   const FunctionProtoType *OldProto =
     Old->getType()->castAs<FunctionProtoType>();
 
-  FunctionProtoType::ExtProtoInfo EPI = NewProto->getExtProtoInfo();
-  EPI.ExceptionSpecType = OldProto->getExceptionSpecType();
-  if (EPI.ExceptionSpecType == EST_Dynamic) {
-    EPI.NumExceptions = OldProto->getNumExceptions();
-    EPI.Exceptions = OldProto->exception_begin();
-  } else if (EPI.ExceptionSpecType == EST_ComputedNoexcept) {
+  FunctionProtoType::ExceptionSpecInfo ESI = OldProto->getExceptionSpecType();
+  if (ESI.Type == EST_Dynamic) {
+    ESI.Exceptions = OldProto->exceptions();
+  } else if (ESI.Type == EST_ComputedNoexcept) {
     // FIXME: We can't just take the expression from the old prototype. It
     // likely contains references to the old prototype's parameters.
   }
 
   // Update the type of the function with the appropriate exception
   // specification.
-  QualType NewType = Context.getFunctionType(NewProto->getReturnType(),
-                                             NewProto->getParamTypes(), EPI);
-  New->setType(NewType);
+  New->setType(Context.getFunctionType(
+      NewProto->getReturnType(), NewProto->getParamTypes(),
+      NewProto->getExtProtoInfo().withExceptionSpec(ESI)));
 
   // Warn about the lack of exception specification.
   SmallString<128> ExceptionSpecString;
@@ -723,10 +744,11 @@ static bool CheckSpecForTypesEquivalent(Sema &S,
 /// assignment and override compatibility check. We do not check the parameters
 /// of parameter function pointers recursively, as no sane programmer would
 /// even be able to write such a function type.
-bool Sema::CheckParamExceptionSpec(const PartialDiagnostic & NoteID,
-    const FunctionProtoType *Target, SourceLocation TargetLoc,
-    const FunctionProtoType *Source, SourceLocation SourceLoc)
-{
+bool Sema::CheckParamExceptionSpec(const PartialDiagnostic &NoteID,
+                                   const FunctionProtoType *Target,
+                                   SourceLocation TargetLoc,
+                                   const FunctionProtoType *Source,
+                                   SourceLocation SourceLoc) {
   if (CheckSpecForTypesEquivalent(
           *this, PDiag(diag::err_deep_exception_specs_differ) << 0, PDiag(),
           Target->getReturnType(), TargetLoc, Source->getReturnType(),
@@ -747,23 +769,30 @@ bool Sema::CheckParamExceptionSpec(const PartialDiagnostic & NoteID,
   return false;
 }
 
-bool Sema::CheckExceptionSpecCompatibility(Expr *From, QualType ToType)
-{
+bool Sema::CheckExceptionSpecCompatibility(Expr *From, QualType ToType) {
   // First we check for applicability.
   // Target type must be a function, function pointer or function reference.
   const FunctionProtoType *ToFunc = GetUnderlyingFunction(ToType);
-  if (!ToFunc)
+  if (!ToFunc || ToFunc->hasDependentExceptionSpec())
     return false;
 
   // SourceType must be a function or function pointer.
   const FunctionProtoType *FromFunc = GetUnderlyingFunction(From->getType());
-  if (!FromFunc)
+  if (!FromFunc || FromFunc->hasDependentExceptionSpec())
     return false;
 
   // Now we've got the correct types on both sides, check their compatibility.
   // This means that the source of the conversion can only throw a subset of
   // the exceptions of the target, and any exception specs on arguments or
   // return types must be equivalent.
+  //
+  // FIXME: If there is a nested dependent exception specification, we should
+  // not be checking it here. This is fine:
+  //   template<typename T> void f() {
+  //     void (*p)(void (*) throw(T));
+  //     void (*q)(void (*) throw(int)) = p;
+  //   }
+  // ... because it might be instantiated with T=int.
   return CheckExceptionSpecSubset(PDiag(diag::err_incompatible_exception_specs),
                                   PDiag(), ToFunc, 
                                   From->getSourceRange().getBegin(),
@@ -772,6 +801,11 @@ bool Sema::CheckExceptionSpecCompatibility(Expr *From, QualType ToType)
 
 bool Sema::CheckOverridingFunctionExceptionSpec(const CXXMethodDecl *New,
                                                 const CXXMethodDecl *Old) {
+  // If the new exception specification hasn't been parsed yet, skip the check.
+  // We'll get called again once it's been parsed.
+  if (New->getType()->castAs<FunctionProtoType>()->getExceptionSpecType() ==
+      EST_Unparsed)
+    return false;
   if (getLangOpts().CPlusPlus11 && isa<CXXDestructorDecl>(New)) {
     // Don't check uninstantiated template destructors at all. We can only
     // synthesize correct specs after the template is instantiated.
@@ -780,11 +814,18 @@ bool Sema::CheckOverridingFunctionExceptionSpec(const CXXMethodDecl *New,
     if (New->getParent()->isBeingDefined()) {
       // The destructor might be updated once the definition is finished. So
       // remember it and check later.
-      DelayedDestructorExceptionSpecChecks.push_back(std::make_pair(
-        cast<CXXDestructorDecl>(New), cast<CXXDestructorDecl>(Old)));
+      DelayedExceptionSpecChecks.push_back(std::make_pair(New, Old));
       return false;
     }
   }
+  // If the old exception specification hasn't been parsed yet, remember that
+  // we need to perform this check when we get to the end of the outermost
+  // lexically-surrounding class.
+  if (Old->getType()->castAs<FunctionProtoType>()->getExceptionSpecType() ==
+      EST_Unparsed) {
+    DelayedExceptionSpecChecks.push_back(std::make_pair(New, Old));
+    return false;
+  }
   unsigned DiagID = diag::err_override_exception_spec;
   if (getLangOpts().MicrosoftExt)
     DiagID = diag::ext_override_exception_spec;
@@ -1051,6 +1092,7 @@ CanThrowResult Sema::canThrow(const Expr *E) {
   case Expr::CXXDependentScopeMemberExprClass:
   case Expr::CXXUnresolvedConstructExprClass:
   case Expr::DependentScopeDeclRefExprClass:
+  case Expr::CXXFoldExprClass:
     return CT_Dependent;
 
   case Expr::AsTypeExprClass:
@@ -1071,6 +1113,7 @@ CanThrowResult Sema::canThrow(const Expr *E) {
   case Expr::UnaryExprOrTypeTraitExprClass:
   case Expr::UnresolvedLookupExprClass:
   case Expr::UnresolvedMemberExprClass:
+  case Expr::TypoExprClass:
     // FIXME: Can any of the above throw?  If so, when?
     return CT_Cannot;