46         // could have reached a dependent parameter pack.  in addUnexpanded()
116     /// elements that are pack expansions.
167       // A function parameter pack is a pack expansion, so cannot contain  in TraverseDecl()
168       // an unexpanded parameter pack. Likewise for a template parameter  in TraverseDecl()
169       // pack that contains any references to other packs.  in TraverseDecl()
176     /// Suppress traversal of pack-expanded attributes.
184     /// Suppress traversal of pack expansion expressions and types.
202     /// Suppress traversal of using-declaration pack expansion.
210     /// Suppress traversal of using-declaration pack expansion.
218     /// Suppress traversal of template argument pack expansions.
226     /// Suppress traversal of template argument pack expansions.
234     /// Suppress traversal of base specifier pack expansions.
242     /// Suppress traversal of mem-initializer pack expansions.
251     /// parameter pack. In this case, the unexpanded pack can occur anywhere,
253     /// lambda, we don't propagate the 'contains unexpanded parameter pack' bit
275     /// Suppress traversal within pack expansions in lambda captures.
286 /// Determine whether it's possible for an unexpanded parameter pack to
309   // If we are within a lambda expression and referencing a pack that is not  in DiagnoseUnexpandedParameterPacks()
311   // parameter pack, and we are done.  in DiagnoseUnexpandedParameterPacks()
316     for (auto &Pack : Unexpanded) {  in DiagnoseUnexpandedParameterPacks()  local
318         if (auto *TTPT = Pack.first.dyn_cast<const TemplateTypeParmType *>()) {  in DiagnoseUnexpandedParameterPacks()
322         return declaresSameEntity(Pack.first.get<NamedDecl *>(), LocalPack);  in DiagnoseUnexpandedParameterPacks()
325         LambdaParamPackReferences.push_back(Pack);  in DiagnoseUnexpandedParameterPacks()
331       // unexpanded pack in this case, which will require expansion outside the  in DiagnoseUnexpandedParameterPacks()
334       // We do not permit pack expansion that would duplicate a statement  in DiagnoseUnexpandedParameterPacks()
339       //   f( ({ bad: 0; }) + pack ... );  in DiagnoseUnexpandedParameterPacks()
397   //   An appearance of a name of a parameter pack that is not expanded is  in DiagnoseUnexpandedParameterPack()
412   //   An appearance of a name of a parameter pack that is not expanded is  in DiagnoseUnexpandedParameterPack()
456   //   An appearance of a name of a parameter pack that is not expanded is  in DiagnoseUnexpandedParameterPack()
473   //   An appearance of a name of a parameter pack that is not expanded is  in DiagnoseUnexpandedParameterPack()
632   // Create the pack expansion type and source-location information.  in CheckPackExpansion()
651   //   The pattern of a pack expansion shall name one or more  in CheckPackExpansion()
652   //   parameter packs that are not expanded by a nested pack  in CheckPackExpansion()
656   // the desugaring of an init-capture pack.  in CheckPackExpansion()
678   //   The pattern of a pack expansion shall name one or more  in CheckPackExpansion()
679   //   parameter packs that are not expanded by a nested pack  in CheckPackExpansion()
688   // Create the pack expansion expression and source-location information.  in CheckPackExpansion()
706     // Compute the depth and index for this parameter pack.  in CheckParameterPacksForExpansion()
726     // Determine the size of this argument pack.  in CheckParameterPacksForExpansion()
729       // Figure out whether we're instantiating to an argument pack or not.  in CheckParameterPacksForExpansion()
736         // We could expand this function parameter pack.  in CheckParameterPacksForExpansion()
739         // We can't expand this function parameter pack, so we can't expand  in CheckParameterPacksForExpansion()
740         // the pack expansion.  in CheckParameterPacksForExpansion()
746       // cannot expand the pack expansion. Make a note of this, but we still  in CheckParameterPacksForExpansion()
754       // Determine the size of the argument pack.  in CheckParameterPacksForExpansion()
760     //   arguments corresponding to a template parameter pack, even when the  in CheckParameterPacksForExpansion()
769           // We don't actually know the new pack size yet.  in CheckParameterPacksForExpansion()
778       // The is the first pack we've seen for which we have an argument.  in CheckParameterPacksForExpansion()
789       //   All of the parameter packs expanded by a pack expansion shall have  in CheckParameterPacksForExpansion()
810   // ... a call to 'A<int, int>().f<int>' should expand the pack once and  in CheckParameterPacksForExpansion()
836     // Compute the depth and index for this parameter pack.  in getNumArgumentsInExpansion()
847         // Function parameter pack or init-capture pack.  in getNumArgumentsInExpansion()
854           // The pattern refers to an unexpanded pack. We're not ready to expand  in getNumArgumentsInExpansion()
855           // this pack yet.  in getNumArgumentsInExpansion()
859         assert((!Result || *Result == Size) && "inconsistent pack sizes");  in getNumArgumentsInExpansion()
869       // expand this pack yet.  in getNumArgumentsInExpansion()
872     // Determine the size of the argument pack.  in getNumArgumentsInExpansion()
874     assert((!Result || *Result == Size) && "inconsistent pack sizes");  in getNumArgumentsInExpansion()
1023   //   The identifier in a sizeof... expression shall name a parameter pack.  in ActOnSizeofParameterPackExpr()
1179   case TemplateArgument::Pack:  in getTemplateArgumentPackExpansionPattern()
1190   // If this is a substituted pack, grab that pack. If not, we don't know  in getFullyPackExpandedSize()
1193   // pack anywhere within this argument, but that's not necessary in the common  in getFullyPackExpandedSize()
1195   TemplateArgument Pack;  in getFullyPackExpandedSize()  local
1199       Pack = Subst->getArgumentPack();  in getFullyPackExpandedSize()
1207       Pack = Subst->getArgumentPack();  in getFullyPackExpandedSize()
1220       Pack = Subst->getArgumentPack();  in getFullyPackExpandedSize()
1230   case TemplateArgument::Pack:  in getFullyPackExpandedSize()
1235   // Check that no argument in the pack is itself a pack expansion.  in getFullyPackExpandedSize()
1236   for (TemplateArgument Elem : Pack.pack_elements()) {  in getFullyPackExpandedSize()
1238     // expanded this pack expansion into the enclosing pack if we could.  in getFullyPackExpandedSize()
1241     // Don't guess the size of unexpanded packs. The pack within a template  in getFullyPackExpandedSize()
1246     // unexpanded pack regardless of Elem's dependence. For instance,  in getFullyPackExpandedSize()
1253   return Pack.pack_size();  in getFullyPackExpandedSize()
1287   //   either e1 shall contain an unexpanded parameter pack or e2 shall contain  in ActOnCXXFoldExpr()
1288   //   an unexpanded parameter pack, but not both.  in ActOnCXXFoldExpr()
1302   //   parameter pack.  in ActOnCXXFoldExpr()
1304     Expr *Pack = LHS ? LHS : RHS;  in ActOnCXXFoldExpr()  local
1305     assert(Pack && "fold expression with neither LHS nor RHS");  in ActOnCXXFoldExpr()
1306     if (!Pack->containsUnexpandedParameterPack()) {  in ActOnCXXFoldExpr()
1309              << Pack->getSourceRange();  in ActOnCXXFoldExpr()