llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT--> @llvm/pr-subscribers-clang-modules @llvm/pr-subscribers-clang Author: Alejandro Álvarez Ayllón (alejandro-alvarez-sonarsource) <details> <summary>Changes</summary> ...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. With this commit, we always initialize this trailing pointer, using a `RecoveryExpr` in case of failure to parse. 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. --- Full diff: https://github.com/llvm/llvm-project/pull/121768.diff 2 Files Affected: - (modified) clang/lib/Sema/SemaTemplate.cpp (+16-2) - (added) clang/test/Modules/malformed-constraint-template-non-type-parm-decl.cpp (+54) ``````````diff diff --git a/clang/lib/Sema/SemaTemplate.cpp b/clang/lib/Sema/SemaTemplate.cpp index 20ec2fbeaa6a8b..9b51f973fb2bb8 100644 --- a/clang/lib/Sema/SemaTemplate.cpp +++ b/clang/lib/Sema/SemaTemplate.cpp @@ -1235,6 +1235,10 @@ bool Sema::AttachTypeConstraint(AutoTypeLoc TL, << NewConstrainedParm->getTypeSourceInfo() ->getTypeLoc() .getSourceRange(); + NewConstrainedParm->setPlaceholderTypeConstraint( + RecoveryExpr::Create(Context, OrigConstrainedParm->getType(), + OrigConstrainedParm->getBeginLoc(), + OrigConstrainedParm->getEndLoc(), {})); return true; } // FIXME: Concepts: This should be the type of the placeholder, but this is @@ -1242,8 +1246,13 @@ bool Sema::AttachTypeConstraint(AutoTypeLoc TL, DeclRefExpr *Ref = BuildDeclRefExpr(OrigConstrainedParm, OrigConstrainedParm->getType(), VK_PRValue, OrigConstrainedParm->getLocation()); - if (!Ref) + if (!Ref) { + NewConstrainedParm->setPlaceholderTypeConstraint( + RecoveryExpr::Create(Context, OrigConstrainedParm->getType(), + OrigConstrainedParm->getBeginLoc(), + OrigConstrainedParm->getEndLoc(), {})); return true; + } ExprResult ImmediatelyDeclaredConstraint = formImmediatelyDeclaredConstraint( *this, TL.getNestedNameSpecifierLoc(), TL.getConceptNameInfo(), TL.getNamedConcept(), /*FoundDecl=*/TL.getFoundDecl(), TL.getLAngleLoc(), @@ -1255,8 +1264,13 @@ bool Sema::AttachTypeConstraint(AutoTypeLoc TL, }, EllipsisLoc); if (ImmediatelyDeclaredConstraint.isInvalid() || - !ImmediatelyDeclaredConstraint.isUsable()) + !ImmediatelyDeclaredConstraint.isUsable()) { + NewConstrainedParm->setPlaceholderTypeConstraint( + RecoveryExpr::Create(Context, OrigConstrainedParm->getType(), + OrigConstrainedParm->getBeginLoc(), + OrigConstrainedParm->getEndLoc(), {})); return true; + } NewConstrainedParm->setPlaceholderTypeConstraint( ImmediatelyDeclaredConstraint.get()); 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 00000000000000..cea6404bbebd28 --- /dev/null +++ b/clang/test/Modules/malformed-constraint-template-non-type-parm-decl.cpp @@ -0,0 +1,54 @@ +// 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 + +//--- 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: | | `-RecoveryExpr {{.*}} <col:10, col:34> 'ReferenceOf<angle> auto' contains-errors lvalue +// 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: | | `-RecoveryExpr {{.*}} <col:10, col:34> 'ReferenceOf<angle> auto' contains-errors lvalue +// 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 &' `````````` </details> https://github.com/llvm/llvm-project/pull/121768 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
