diff options
| -rw-r--r-- | include/clang/Basic/DiagnosticASTKinds.td | 8 | ||||
| -rw-r--r-- | include/clang/Basic/DiagnosticIDs.h | 2 | ||||
| -rw-r--r-- | lib/AST/VTableBuilder.cpp | 52 |
3 files changed, 51 insertions, 11 deletions
diff --git a/include/clang/Basic/DiagnosticASTKinds.td b/include/clang/Basic/DiagnosticASTKinds.td index d353b451aa..0b37030d7e 100644 --- a/include/clang/Basic/DiagnosticASTKinds.td +++ b/include/clang/Basic/DiagnosticASTKinds.td @@ -168,6 +168,14 @@ let CategoryName = "Inline Assembly Issue" in { "invalid operand number in inline asm string">; } +// vtable related. +let CategoryName = "VTable ABI Issue" in { + def err_vftable_ambiguous_component : Error< + "ambiguous vftable component for %0 introduced via covariant thunks; " + "this is an inherent limitation of the ABI">; + def note_covariant_thunk : Note< + "covariant thunk required by %0">; +} // Importing ASTs def err_odr_variable_type_inconsistent : Error< diff --git a/include/clang/Basic/DiagnosticIDs.h b/include/clang/Basic/DiagnosticIDs.h index 99b469d70e..a675dfabe4 100644 --- a/include/clang/Basic/DiagnosticIDs.h +++ b/include/clang/Basic/DiagnosticIDs.h @@ -34,7 +34,7 @@ namespace clang { DIAG_START_LEX = DIAG_START_SERIALIZATION + 120, DIAG_START_PARSE = DIAG_START_LEX + 300, DIAG_START_AST = DIAG_START_PARSE + 500, - DIAG_START_COMMENT = DIAG_START_AST + 100, + DIAG_START_COMMENT = DIAG_START_AST + 110, DIAG_START_SEMA = DIAG_START_COMMENT + 100, DIAG_START_ANALYSIS = DIAG_START_SEMA + 3000, DIAG_UPPER_LIMIT = DIAG_START_ANALYSIS + 100 diff --git a/lib/AST/VTableBuilder.cpp b/lib/AST/VTableBuilder.cpp index de0c11a249..5c7b9d2a68 100644 --- a/lib/AST/VTableBuilder.cpp +++ b/lib/AST/VTableBuilder.cpp @@ -13,6 +13,7 @@ #include "clang/AST/VTableBuilder.h" #include "clang/AST/ASTContext.h" +#include "clang/AST/ASTDiagnostic.h" #include "clang/AST/CXXInheritance.h" #include "clang/AST/RecordLayout.h" #include "clang/Basic/TargetInfo.h" @@ -3482,9 +3483,24 @@ static bool findPathForVPtr(ASTContext &Context, CXXBasePaths Paths(/*FindAmbiguities=*/false, /*RecordPaths=*/false, /*DetectVirtual=*/true); +#if 0 + std::vector<const CXXRecordDecl *> BaseLists; + for (const auto &B : RD->bases()) { + const CXXRecordDecl *Base = B.getType()->getAsCXXRecordDecl(); + Paths.clear(); + if (!Base->isDerivedFrom(Info->BaseWithVPtr, Paths)) + continue; + for (const auto &Chain : BaseLists) { + const CXXRecordDecl *MostDerived = Chain.front(); + } + } +#endif // All virtual bases which are on the path to the BaseWithVPtr are not equal. // Specifically, virtual paths which introduce additional covariant thunks // must be preferred over paths which do not introduce such thunks. + const CXXRecordDecl *Base = nullptr; + CharUnits NewOffset; + const CXXMethodDecl *CovariantMD = nullptr; for (const auto *MD : Info->BaseWithVPtr->methods()) { if (!MD->isVirtual()) continue; @@ -3501,10 +3517,10 @@ static bool findPathForVPtr(ASTContext &Context, // Ok, let's iterate through our virtual bases looking for a base which // provides a return adjusting overrider for this method. - const CXXRecordDecl *Base = nullptr; - CharUnits NewOffset; for (const auto &B : RD->bases()) { const CXXRecordDecl *VBase = B.getType()->getAsCXXRecordDecl(); + if (Base == VBase) + continue; // There might be a vbase which derives from a vbase which provides a // covariant override for the method *and* provides its own covariant // override. @@ -3512,7 +3528,7 @@ static bool findPathForVPtr(ASTContext &Context, // looking for the most derived virtual base which provides a covariant // override for the method. Paths.clear(); - if (!VBase->isDerivedFrom(Base ? Base : Info->BaseWithVPtr, Paths) || + if (!VBase->isDerivedFrom(Info->BaseWithVPtr, Paths) || !Paths.getDetectedVirtual()) continue; const CXXMethodDecl *VBaseMD = MD->getCorrespondingMethodInClass(VBase); @@ -3525,17 +3541,33 @@ static bool findPathForVPtr(ASTContext &Context, // Skip any overriders which are not return adjusting. if (BO.isEmpty() || !BO.VirtualBase) continue; - Base = VBase; - NewOffset = VBaseNewOffset; + Paths.clear(); + if (!Base || VBase->isDerivedFrom(Base, Paths)) { + assert(!Base || Paths.getDetectedVirtual()); + Base = VBase; + NewOffset = VBaseNewOffset; + CovariantMD = VBaseMD; + } else { + Paths.clear(); + if (!Base->isDerivedFrom(VBase, Paths)) { + DiagnosticsEngine &Diags = Context.getDiagnostics(); + Diags.Report(RD->getLocation(), diag::err_vftable_ambiguous_component) + << RD; + Diags.Report(CovariantMD->getLocation(), diag::note_covariant_thunk) + << CovariantMD; + Diags.Report(VBaseMD->getLocation(), diag::note_covariant_thunk) + << VBaseMD; + } + } } - - if (Base && Recurse(Base, NewOffset)) - return true; } + if (Base && Recurse(Base, NewOffset)) + return true; + for (const auto &B : RD->bases()) { - const CXXRecordDecl *Base = B.getType()->getAsCXXRecordDecl(); - CharUnits NewOffset = GetBaseOffset(B); + Base = B.getType()->getAsCXXRecordDecl(); + NewOffset = GetBaseOffset(B); if (Recurse(Base, NewOffset)) return true; } |