From b6dbda67d8f687350de66e68a7fd61433fac7107 Mon Sep 17 00:00:00 2001 From: Ahmed Bougacha Date: Mon, 22 Jul 2024 16:41:22 -0700 Subject: [clang] Implement type/address discrimination of type_info vtable. (#99726) We want to be able to support full type and address discrimination of type_info on targets that don't have existing ABI compatibility constraints. This patch does not enable such behavior on any platform, it just adds the necessary machinery. In clang we add a new commandline argument to control the type_info vtable ABI: -fptrauth-type-info-vtable-pointer-discrimination and a feature flag to allow source level detection of the ABI: __has_feature(ptrauth_type_info_vtable_pointer_discrimination) Co-authored-by: Oliver Hunt --- clang/lib/Frontend/CompilerInvocation.cpp | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) (limited to 'clang/lib/Frontend/CompilerInvocation.cpp') diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp index bf57add..424fe53 100644 --- a/clang/lib/Frontend/CompilerInvocation.cpp +++ b/clang/lib/Frontend/CompilerInvocation.cpp @@ -1488,8 +1488,15 @@ void CompilerInvocation::setDefaultPointerAuthOptions( Key::ASDA, LangOpts.PointerAuthVTPtrAddressDiscrimination, LangOpts.PointerAuthVTPtrTypeDiscrimination ? Discrimination::Type : Discrimination::None); - Opts.CXXTypeInfoVTablePointer = - PointerAuthSchema(Key::ASDA, false, Discrimination::None); + + if (LangOpts.PointerAuthTypeInfoVTPtrDiscrimination) + Opts.CXXTypeInfoVTablePointer = + PointerAuthSchema(Key::ASDA, true, Discrimination::Constant, + StdTypeInfoVTablePointerConstantDiscrimination); + else + Opts.CXXTypeInfoVTablePointer = + PointerAuthSchema(Key::ASDA, false, Discrimination::None); + Opts.CXXVTTVTablePointers = PointerAuthSchema(Key::ASDA, false, Discrimination::None); Opts.CXXVirtualFunctionPointers = Opts.CXXVirtualVariadicFunctionPointers = @@ -3411,6 +3418,9 @@ static void GeneratePointerAuthArgs(const LangOptions &Opts, GenerateArg(Consumer, OPT_fptrauth_vtable_pointer_address_discrimination); if (Opts.PointerAuthVTPtrTypeDiscrimination) GenerateArg(Consumer, OPT_fptrauth_vtable_pointer_type_discrimination); + if (Opts.PointerAuthTypeInfoVTPtrDiscrimination) + GenerateArg(Consumer, OPT_fptrauth_type_info_vtable_pointer_discrimination); + if (Opts.PointerAuthInitFini) GenerateArg(Consumer, OPT_fptrauth_init_fini); if (Opts.PointerAuthFunctionTypeDiscrimination) @@ -3427,6 +3437,9 @@ static void ParsePointerAuthArgs(LangOptions &Opts, ArgList &Args, Args.hasArg(OPT_fptrauth_vtable_pointer_address_discrimination); Opts.PointerAuthVTPtrTypeDiscrimination = Args.hasArg(OPT_fptrauth_vtable_pointer_type_discrimination); + Opts.PointerAuthTypeInfoVTPtrDiscrimination = + Args.hasArg(OPT_fptrauth_type_info_vtable_pointer_discrimination); + Opts.PointerAuthInitFini = Args.hasArg(OPT_fptrauth_init_fini); Opts.PointerAuthFunctionTypeDiscrimination = Args.hasArg(OPT_fptrauth_function_pointer_type_discrimination); -- cgit v1.1