https://github.com/Serosh-commits updated https://github.com/llvm/llvm-project/pull/180407
>From c729125b2ec86757c3d1cf2c6b54bcf778f0ed8a Mon Sep 17 00:00:00 2001 From: Serosh-commits <[email protected]> Date: Sun, 8 Feb 2026 17:40:06 +0530 Subject: [PATCH] [clang][sema] fix crash on builtin template ids with dependent packs (gh180307) --- clang/lib/Sema/SemaTemplate.cpp | 25 +++++++----- .../builtin_templates_invalid_parameters.cpp | 40 +++++++++++++++++++ 2 files changed, 54 insertions(+), 11 deletions(-) create mode 100644 clang/test/SemaCXX/builtin_templates_invalid_parameters.cpp diff --git a/clang/lib/Sema/SemaTemplate.cpp b/clang/lib/Sema/SemaTemplate.cpp index 3497ff7856eed..ab0d74abfcbf0 100644 --- a/clang/lib/Sema/SemaTemplate.cpp +++ b/clang/lib/Sema/SemaTemplate.cpp @@ -3406,25 +3406,29 @@ static QualType checkBuiltinTemplateIdType( Sema &SemaRef, ElaboratedTypeKeyword Keyword, BuiltinTemplateDecl *BTD, ArrayRef<TemplateArgument> Converted, SourceLocation TemplateLoc, TemplateArgumentListInfo &TemplateArgs) { + if (Converted.size() < + BTD->getTemplateParameters()->getMinRequiredArguments()) + return QualType(); + ASTContext &Context = SemaRef.getASTContext(); switch (BTD->getBuiltinTemplateKind()) { case BTK__make_integer_seq: { - // Specializations of __make_integer_seq<S, T, N> are treated like - // S<T, 0, ..., N-1>. + assert(Converted.size() == 3); + if (Converted[1].isDependent() || Converted[2].isDependent()) + return QualType(); QualType OrigType = Converted[1].getAsType(); + assert(!OrigType->isDependentType()); // C++14 [inteseq.intseq]p1: // T shall be an integer type. - if (!OrigType->isDependentType() && !OrigType->isIntegralType(Context)) { + if (!OrigType->isIntegralType(Context)) { SemaRef.Diag(TemplateArgs[1].getLocation(), diag::err_integer_sequence_integral_element_type); return QualType(); } TemplateArgument NumArgsArg = Converted[2]; - if (NumArgsArg.isDependent()) - return QualType(); TemplateArgumentListInfo SyntheticTemplateArgs; // The type argument, wrapped in substitution sugar, gets reused as the @@ -3459,15 +3463,12 @@ static QualType checkBuiltinTemplateIdType( } case BTK__type_pack_element: { - // Specializations of - // __type_pack_element<Index, T_1, ..., T_N> - // are treated like T_Index. assert(Converted.size() == 2 && "__type_pack_element should be given an index and a parameter pack"); + if (Converted[0].isDependent() || Converted[1].isDependent()) + return QualType(); TemplateArgument IndexArg = Converted[0], Ts = Converted[1]; - if (IndexArg.isDependent() || Ts.isDependent()) - return QualType(); llvm::APSInt Index = IndexArg.getAsIntegral(); assert(Index >= 0 && "the index used with __type_pack_element should be of " @@ -3486,7 +3487,7 @@ static QualType checkBuiltinTemplateIdType( case BTK__builtin_common_type: { assert(Converted.size() == 4); - if (llvm::any_of(Converted, [](auto &C) { return C.isDependent(); })) + if (Converted[3].isDependent()) return QualType(); TemplateName BaseTemplate = Converted[0].getAsTemplate(); @@ -3509,6 +3510,8 @@ static QualType checkBuiltinTemplateIdType( case BTK__hlsl_spirv_type: { assert(Converted.size() == 4); + if (llvm::any_of(Converted, [](const TemplateArgument &A) { return A.isDependent(); })) + return QualType(); if (!Context.getTargetInfo().getTriple().isSPIRV()) { SemaRef.Diag(TemplateLoc, diag::err_hlsl_spirv_only) << BTD; diff --git a/clang/test/SemaCXX/builtin_templates_invalid_parameters.cpp b/clang/test/SemaCXX/builtin_templates_invalid_parameters.cpp new file mode 100644 index 0000000000000..814ee2a756bcc --- /dev/null +++ b/clang/test/SemaCXX/builtin_templates_invalid_parameters.cpp @@ -0,0 +1,40 @@ +// RUN: %clang_cc1 -fsyntax-only -verify -std=c++11 %s + +using SizeT = decltype(sizeof(int)); + +// Test insufficient parameters for built-in templates. +// These should be caught even if arguments are dependent. + +template <SizeT... Seq> +void test_type_pack_element_insufficient(__type_pack_element<Seq...>) {} + +template <typename T> +void test_make_integer_seq_insufficient(__make_integer_seq<T>) {} + +template <typename T> +using test_common_type_insufficient = __builtin_common_type<T>; + +// Standard usage checks for non-dependent cases that are still broken. +using t1 = __type_pack_element<0>; // expected-error {{a parameter pack may not be accessed at an out of bounds index}} +using t2 = __make_integer_seq<int>; // expected-error {{too few template arguments for class template '__make_integer_seq'}} +using t3 = __builtin_common_type<int>; // expected-error {{too few template arguments for class template '__builtin_common_type'}} +// expected-error@-1 {{template argument for template template parameter must be a class template or type alias template}} + +// Dependent cases that previously crashed but now return QualType() gracefully. +template <SizeT... Seq> +using gh180307 = __type_pack_element<Seq...>; + +template <typename T> +using gh180307_bis = __make_integer_seq<gh180307, T>; +// expected-error@-1 {{too few template arguments for class template '__make_integer_seq'}} +// expected-note@-2 {{template template argument has different template parameters than its corresponding template template parameter}} +// expected-note@24 {{template parameter is declared here}} + +// Eager expansion checks: Built-in templates should expand even if the +// destination template is dependent, provided the other arguments are known. +template <template <typename T, T... Ints> class Seq> +using test_make_integer_seq_eager = __make_integer_seq<Seq, int, 2>; + +template <typename T, T... Ints> struct MySeq; +using check_eager = test_make_integer_seq_eager<MySeq>; +using check_eager = MySeq<int, 0, 1>; // should match _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
