Author: Alejandro Álvarez Ayllón Date: 2025-02-19T07:19:31-08:00 New Revision: 26a83994176fcdca6e77be4f221a15f561681621
URL: https://github.com/llvm/llvm-project/commit/26a83994176fcdca6e77be4f221a15f561681621 DIFF: https://github.com/llvm/llvm-project/commit/26a83994176fcdca6e77be4f221a15f561681621.diff LOG: [clang][Sema] Fix initialization of `NonTypeTemplateParmDecl`... (#121768) ...when there are invalid constraints. When attaching a `TypeConstraint`, in case of error, the trailing pointer that is supposed to point to the constraint is left uninitialized. Sometimes the uninitialized value will be a `nullptr`, but at other times it will not. If we traverse the AST (for instance, dumping it, or when writing the BMI), we may get a crash depending on the value that was left. The serialization may also contain a bogus value. In this commit, we always initialize the `PlaceholderTypeConstraint` with `nullptr`, to avoid accessing this uninitialized memory. This does not affect only modules, but it causes a segfault more consistently when they are involved. The test case was reduced from `mp-units`. --------- Co-authored-by: Erich Keane <eke...@nvidia.com> Added: clang/test/Modules/malformed-constraint-template-non-type-parm-decl.cpp Modified: clang/lib/AST/DeclTemplate.cpp clang/lib/Serialization/ASTWriterDecl.cpp Removed: ################################################################################ diff --git a/clang/lib/AST/DeclTemplate.cpp b/clang/lib/AST/DeclTemplate.cpp index 7fb89bf5b499f..63caf04f7ef38 100644 --- a/clang/lib/AST/DeclTemplate.cpp +++ b/clang/lib/AST/DeclTemplate.cpp @@ -786,12 +786,16 @@ NonTypeTemplateParmDecl *NonTypeTemplateParmDecl::Create( QualType T, bool ParameterPack, TypeSourceInfo *TInfo) { AutoType *AT = C.getLangOpts().CPlusPlus20 ? T->getContainedAutoType() : nullptr; - return new (C, DC, - additionalSizeToAlloc<std::pair<QualType, TypeSourceInfo *>, - Expr *>(0, - AT && AT->isConstrained() ? 1 : 0)) - NonTypeTemplateParmDecl(DC, StartLoc, IdLoc, D, P, Id, T, ParameterPack, - TInfo); + const bool HasConstraint = AT && AT->isConstrained(); + auto *NTTP = + new (C, DC, + additionalSizeToAlloc<std::pair<QualType, TypeSourceInfo *>, Expr *>( + 0, HasConstraint ? 1 : 0)) + NonTypeTemplateParmDecl(DC, StartLoc, IdLoc, D, P, Id, T, + ParameterPack, TInfo); + if (HasConstraint) + NTTP->setPlaceholderTypeConstraint(nullptr); + return NTTP; } NonTypeTemplateParmDecl *NonTypeTemplateParmDecl::Create( @@ -800,23 +804,30 @@ NonTypeTemplateParmDecl *NonTypeTemplateParmDecl::Create( QualType T, TypeSourceInfo *TInfo, ArrayRef<QualType> ExpandedTypes, ArrayRef<TypeSourceInfo *> ExpandedTInfos) { AutoType *AT = TInfo->getType()->getContainedAutoType(); - return new (C, DC, - additionalSizeToAlloc<std::pair<QualType, TypeSourceInfo *>, - Expr *>( - ExpandedTypes.size(), AT && AT->isConstrained() ? 1 : 0)) - NonTypeTemplateParmDecl(DC, StartLoc, IdLoc, D, P, Id, T, TInfo, - ExpandedTypes, ExpandedTInfos); + const bool HasConstraint = AT && AT->isConstrained(); + auto *NTTP = + new (C, DC, + additionalSizeToAlloc<std::pair<QualType, TypeSourceInfo *>, Expr *>( + ExpandedTypes.size(), HasConstraint ? 1 : 0)) + NonTypeTemplateParmDecl(DC, StartLoc, IdLoc, D, P, Id, T, TInfo, + ExpandedTypes, ExpandedTInfos); + if (HasConstraint) + NTTP->setPlaceholderTypeConstraint(nullptr); + return NTTP; } NonTypeTemplateParmDecl * NonTypeTemplateParmDecl::CreateDeserialized(ASTContext &C, GlobalDeclID ID, bool HasTypeConstraint) { - return new (C, ID, additionalSizeToAlloc<std::pair<QualType, - TypeSourceInfo *>, - Expr *>(0, - HasTypeConstraint ? 1 : 0)) + auto *NTTP = + new (C, ID, + additionalSizeToAlloc<std::pair<QualType, TypeSourceInfo *>, Expr *>( + 0, HasTypeConstraint ? 1 : 0)) NonTypeTemplateParmDecl(nullptr, SourceLocation(), SourceLocation(), 0, 0, nullptr, QualType(), false, nullptr); + if (HasTypeConstraint) + NTTP->setPlaceholderTypeConstraint(nullptr); + return NTTP; } NonTypeTemplateParmDecl * @@ -830,6 +841,8 @@ NonTypeTemplateParmDecl::CreateDeserialized(ASTContext &C, GlobalDeclID ID, NonTypeTemplateParmDecl(nullptr, SourceLocation(), SourceLocation(), 0, 0, nullptr, QualType(), nullptr, {}, {}); NTTP->NumExpandedTypes = NumExpandedTypes; + if (HasTypeConstraint) + NTTP->setPlaceholderTypeConstraint(nullptr); return NTTP; } diff --git a/clang/lib/Serialization/ASTWriterDecl.cpp b/clang/lib/Serialization/ASTWriterDecl.cpp index b25dadab656b0..ac80bb46afa2d 100644 --- a/clang/lib/Serialization/ASTWriterDecl.cpp +++ b/clang/lib/Serialization/ASTWriterDecl.cpp @@ -2016,8 +2016,7 @@ void ASTDeclWriter::VisitNonTypeTemplateParmDecl(NonTypeTemplateParmDecl *D) { // For an expanded parameter pack, record the number of expansion types here // so that it's easier for deserialization to allocate the right amount of // memory. - Expr *TypeConstraint = D->getPlaceholderTypeConstraint(); - Record.push_back(!!TypeConstraint); + Record.push_back(D->hasPlaceholderTypeConstraint()); if (D->isExpandedParameterPack()) Record.push_back(D->getNumExpansionTypes()); @@ -2025,8 +2024,9 @@ void ASTDeclWriter::VisitNonTypeTemplateParmDecl(NonTypeTemplateParmDecl *D) { // TemplateParmPosition. Record.push_back(D->getDepth()); Record.push_back(D->getPosition()); - if (TypeConstraint) - Record.AddStmt(TypeConstraint); + + if (D->hasPlaceholderTypeConstraint()) + Record.AddStmt(D->getPlaceholderTypeConstraint()); if (D->isExpandedParameterPack()) { for (unsigned I = 0, N = D->getNumExpansionTypes(); I != N; ++I) { diff --git a/clang/test/Modules/malformed-constraint-template-non-type-parm-decl.cpp b/clang/test/Modules/malformed-constraint-template-non-type-parm-decl.cpp new file mode 100644 index 0000000000000..73dff88e506b4 --- /dev/null +++ b/clang/test/Modules/malformed-constraint-template-non-type-parm-decl.cpp @@ -0,0 +1,55 @@ +// RUN: rm -rf %t +// RUN: split-file %s %t +// RUN: cd %t + +// RUN: %clang_cc1 -std=c++20 mod.cppm -emit-module-interface -o mod.pcm -fallow-pcm-with-compiler-errors -verify +// RUN: %clang_cc1 -std=c++20 main.cpp -fmodule-file=mod=mod.pcm -verify -fallow-pcm-with-compiler-errors -fsyntax-only -ast-dump-all | FileCheck %s + +// RUN: %clang_cc1 -std=c++20 mod.cppm -emit-reduced-module-interface -o mod.pcm -fallow-pcm-with-compiler-errors -verify +// RUN: %clang_cc1 -std=c++20 main.cpp -fmodule-file=mod=mod.pcm -verify -fallow-pcm-with-compiler-errors -fsyntax-only -ast-dump-all | FileCheck %s + +//--- mod.cppm +export module mod; + +template <typename T, auto Q> +concept ReferenceOf = Q; + +// expected-error@+2 {{unknown type name 'AngleIsInvalidNow'}} +// expected-error@+1 {{constexpr variable 'angle' must be initialized by a constant expression}} +constexpr struct angle {AngleIsInvalidNow e;} angle; + +// expected-error@+1 {{non-type template argument is not a constant expression}} +template<ReferenceOf<angle> auto R, typename Rep> requires requires(Rep v) {cos(v);} +auto cos(const Rep& q); + +// expected-error@+1 {{non-type template argument is not a constant expression}} +template<ReferenceOf<angle> auto R, typename Rep> requires requires(Rep v) {tan(v);} +auto tan(const Rep& q); + +//--- main.cpp +// expected-no-diagnostics +import mod; + +// CHECK: |-FunctionTemplateDecl {{.*}} <line:11:1, line:12:22> col:6 imported in mod hidden invalid cos +// CHECK-NEXT: | |-NonTypeTemplateParmDecl {{.*}} <line:11:10, col:34> col:34 imported in mod hidden referenced invalid 'ReferenceOf<angle> auto' depth 0 index 0 R +// CHECK-NEXT: | |-TemplateTypeParmDecl {{.*}} <col:37, col:46> col:46 imported in mod hidden referenced typename depth 0 index 1 Rep +// CHECK-NEXT: | |-RequiresExpr {{.*}} <col:60, col:84> 'bool' +// CHECK-NEXT: | | |-ParmVarDecl {{.*}} <col:69, col:73> col:73 imported in mod hidden referenced v 'Rep' +// CHECK-NEXT: | | `-SimpleRequirement {{.*}} dependent +// CHECK-NEXT: | | `-CallExpr {{.*}} <col:77, col:82> '<dependent type>' +// CHECK-NEXT: | | |-UnresolvedLookupExpr {{.*}} <col:77> '<overloaded function type>' lvalue (ADL) = 'cos' empty +// CHECK-NEXT: | | `-DeclRefExpr {{.*}} <col:81> 'Rep' lvalue ParmVar {{.*}} 'v' 'Rep' non_odr_use_unevaluated +// CHECK-NEXT: | `-FunctionDecl {{.*}} <line:12:1, col:22> col:6 imported in mod hidden cos 'auto (const Rep &)' +// CHECK-NEXT: | `-ParmVarDecl {{.*}} <col:10, col:21> col:21 imported in mod hidden q 'const Rep &' + +// CHECK: |-FunctionTemplateDecl {{.*}} <line:15:1, line:16:22> col:6 imported in mod hidden invalid tan +// CHECK-NEXT: | |-NonTypeTemplateParmDecl {{.*}} <line:15:10, col:34> col:34 imported in mod hidden referenced invalid 'ReferenceOf<angle> auto' depth 0 index 0 R +// CHECK-NEXT: | |-TemplateTypeParmDecl {{.*}} <col:37, col:46> col:46 imported in mod hidden referenced typename depth 0 index 1 Rep +// CHECK-NEXT: | |-RequiresExpr {{.*}} <col:60, col:84> 'bool' +// CHECK-NEXT: | | |-ParmVarDecl {{.*}} <col:69, col:73> col:73 imported in mod hidden referenced v 'Rep' +// CHECK-NEXT: | | `-SimpleRequirement {{.*}} dependent +// CHECK-NEXT: | | `-CallExpr {{.*}} <col:77, col:82> '<dependent type>' +// CHECK-NEXT: | | |-UnresolvedLookupExpr {{.*}} <col:77> '<overloaded function type>' lvalue (ADL) = 'tan' empty +// CHECK-NEXT: | | `-DeclRefExpr {{.*}} <col:81> 'Rep' lvalue ParmVar {{.*}} 'v' 'Rep' non_odr_use_unevaluated +// CHECK-NEXT: | `-FunctionDecl {{.*}} <line:16:1, col:22> col:6 imported in mod hidden tan 'auto (const Rep &)' +// CHECK-NEXT: | `-ParmVarDecl {{.*}} <col:10, col:21> col:21 imported in mod hidden q 'const Rep &' _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
