From c7cb239f51788dbe3148368942b208934707b6a7 Mon Sep 17 00:00:00 2001 From: Nathan Sidwell Date: Mon, 10 Oct 2022 17:55:04 -0400 Subject: [PATCH] c++: Lambda context mangling VAR and FIELD decls can become part of a lambda context, when the lambda is 'attached' to that entity (It's a C++20 ODR thing that was discovered with modules, but is actually separate.) We were not marking those decls as substitution candidates, leading to demangling failures and variance from other compilers. This patch bumps the ABI, and adds the contexts them to the substitution table. This is the intent of the ABI. gcc/ * common.opt (-fabi-version=): Document 18. * doc/invoke.texi (-fabi-version): Document 18. gcc/c-family/ * c-opts.cc (c_common_post_options): Bump abi to 18. gcc/cp/ * mangle.cc (write_prefix): Add VAR_DECL & FIELD_DECL to substitution table under abi=18. Note possible mismatch. gcc/testsuite/ * g++.dg/abi/lambda-ctx1-17.C: New. * g++.dg/abi/lambda-ctx1-18.C: New. * g++.dg/abi/lambda-ctx1-18vs17.C: New. * g++.dg/abi/lambda-ctx1.h: New. * g++.dg/abi/lambda-vis.C: Adjust expected mangles. * g++.dg/abi/macro0.C: Adjust. --- gcc/c-family/c-opts.cc | 2 +- gcc/common.opt | 3 +++ gcc/cp/mangle.cc | 9 ++++++++- gcc/doc/invoke.texi | 3 +++ gcc/testsuite/g++.dg/abi/lambda-ctx1-17.C | 10 ++++++++++ gcc/testsuite/g++.dg/abi/lambda-ctx1-18.C | 11 ++++++++++ gcc/testsuite/g++.dg/abi/lambda-ctx1-18vs17.C | 9 +++++++++ gcc/testsuite/g++.dg/abi/lambda-ctx1.h | 20 +++++++++++++++++++ gcc/testsuite/g++.dg/abi/lambda-vis.C | 8 +++++--- gcc/testsuite/g++.dg/abi/macro0.C | 2 +- 10 files changed, 71 insertions(+), 6 deletions(-) create mode 100644 gcc/testsuite/g++.dg/abi/lambda-ctx1-17.C create mode 100644 gcc/testsuite/g++.dg/abi/lambda-ctx1-18.C create mode 100644 gcc/testsuite/g++.dg/abi/lambda-ctx1-18vs17.C create mode 100644 gcc/testsuite/g++.dg/abi/lambda-ctx1.h diff --git a/gcc/c-family/c-opts.cc b/gcc/c-family/c-opts.cc index babaa2fc157a..55cebf68f9c3 100644 --- a/gcc/c-family/c-opts.cc +++ b/gcc/c-family/c-opts.cc @@ -975,7 +975,7 @@ c_common_post_options (const char **pfilename) /* Change flag_abi_version to be the actual current ABI level, for the benefit of c_cpp_builtins, and to make comparison simpler. */ - const int latest_abi_version = 17; + const int latest_abi_version = 18; /* Generate compatibility aliases for ABI v13 (8.2) by default. */ const int abi_compat_default = 13; diff --git a/gcc/common.opt b/gcc/common.opt index 3a97e6782ce5..bce3e514f65b 100644 --- a/gcc/common.opt +++ b/gcc/common.opt @@ -1004,6 +1004,9 @@ Driver Undocumented ; member initializers in C++14 and up. ; Default in G++ 12. ; +; 18: Corrects errors in mangling of lambdas with additional context. +; Default in G++ 13. +; ; Additional positive integers will be assigned as new versions of ; the ABI become the default version of the ABI. fabi-version= diff --git a/gcc/cp/mangle.cc b/gcc/cp/mangle.cc index f051e76466a3..1215463089b5 100644 --- a/gcc/cp/mangle.cc +++ b/gcc/cp/mangle.cc @@ -1252,7 +1252,14 @@ write_prefix (const tree node) { /* := M */ write_char ('M'); - return; + + /* Before ABI 18, we did not count these as substitution + candidates. This leads to incorrect demanglings (and + ABI divergence to other compilers). */ + if (abi_warn_or_compat_version_crosses (18)) + G.need_abi_warning = true; + if (!abi_version_at_least (18)) + return; } } diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi index 278c55d5a19a..271c8bb84685 100644 --- a/gcc/doc/invoke.texi +++ b/gcc/doc/invoke.texi @@ -2973,6 +2973,9 @@ Version 17, which first appeared in G++ 12, fixes layout of classes that inherit from aggregate classes with default member initializers in C++14 and up. +Version 18, which first appeard in G++ 13, fixes manglings of lambdas +that have additional context. + See also @option{-Wabi}. @item -fabi-compat-version=@var{n} diff --git a/gcc/testsuite/g++.dg/abi/lambda-ctx1-17.C b/gcc/testsuite/g++.dg/abi/lambda-ctx1-17.C new file mode 100644 index 000000000000..42f277a21170 --- /dev/null +++ b/gcc/testsuite/g++.dg/abi/lambda-ctx1-17.C @@ -0,0 +1,10 @@ +// { dg-do compile { target c++20 } } +// { dg-options -fabi-version=17 } + +#include "lambda-ctx1.h" + +// These demangle incorrectly, due to a missed substitution candidate +// { dg-final { scan-assembler {_ZNK1C1fMUlT_E_clIMS_iEEDaS0_:} } } +// { dg-final { scan-assembler {_ZNK2L2MUlT_T0_E_clIifEEvS_S0_:} } } +// { dg-final { scan-assembler {_ZNK1B2L3MUlT_T0_E_clIjdEEvS0_S1_:} } } +// { dg-final { scan-assembler {_Z3fooIN1qMUlvE_EN1qMUlvE0_EEiOT_OT0_:} } } diff --git a/gcc/testsuite/g++.dg/abi/lambda-ctx1-18.C b/gcc/testsuite/g++.dg/abi/lambda-ctx1-18.C new file mode 100644 index 000000000000..c1c9e274d7f3 --- /dev/null +++ b/gcc/testsuite/g++.dg/abi/lambda-ctx1-18.C @@ -0,0 +1,11 @@ +// { dg-do compile { target c++20 } } +// { dg-options -fabi-version=18 } + +#include "lambda-ctx1.h" + +// These correctly include the lambda's extra context as a +// substitution candidate, and thus demangle as expected +// { dg-final { scan-assembler {_ZNK1C1fMUlT_E_clIMS_iEEDaS1_:} } } +// { dg-final { scan-assembler {_ZNK2L2MUlT_T0_E_clIifEEvS0_S1_:} } } +// { dg-final { scan-assembler {_ZNK1B2L3MUlT_T0_E_clIjdEEvS1_S2_:} } } +// { dg-final { scan-assembler {_Z3fooIN1qMUlvE_ENS0_UlvE0_EEiOT_OT0_:} } } diff --git a/gcc/testsuite/g++.dg/abi/lambda-ctx1-18vs17.C b/gcc/testsuite/g++.dg/abi/lambda-ctx1-18vs17.C new file mode 100644 index 000000000000..f5ec905dec3a --- /dev/null +++ b/gcc/testsuite/g++.dg/abi/lambda-ctx1-18vs17.C @@ -0,0 +1,9 @@ +// { dg-do compile { target c++20 } } +// { dg-options {-fabi-version=18 -Wabi=17} } + +#include "lambda-ctx1.h" + +// { dg-regexp {[^\n]*lambda-ctx1.h:[:0-9]* warning: the mangled name [^\n]* \('_ZNK1B2L3MUlT_T0_E_clIjdEEvS0_S1_'\) and '-fabi-version=18' \('_ZNK1B2L3MUlT_T0_E_clIjdEEvS1_S2_'\) [^\n]*\n} } +// { dg-regexp {[^\n]*lambda-ctx1.h:[:0-9]* warning: the mangled name [^\n]* \('_ZNK2L2MUlT_T0_E_clIifEEvS_S0_'\) and '-fabi-version=18' \('_ZNK2L2MUlT_T0_E_clIifEEvS0_S1_'\) [^\n]*\n} } +// { dg-regexp {[^\n]*lambda-ctx1.h:[:0-9]* warning: the mangled name [^\n]* \('_ZNK1C1fMUlT_E_clIMS_iEEDaS0_'\) and '-fabi-version=18' \('_ZNK1C1fMUlT_E_clIMS_iEEDaS1_'\) [^\n]*\n} } +// { dg-regexp {[^\n]*lambda-ctx1.h:[:0-9]* warning: the mangled name [^\n]* \('_Z3fooIN1qMUlvE_EN1qMUlvE0_EEiOT_OT0_'\) and '-fabi-version=18' \('_Z3fooIN1qMUlvE_ENS0_UlvE0_EEiOT_OT0_'\) [^\n]*\n} } diff --git a/gcc/testsuite/g++.dg/abi/lambda-ctx1.h b/gcc/testsuite/g++.dg/abi/lambda-ctx1.h new file mode 100644 index 000000000000..9afb66aae76a --- /dev/null +++ b/gcc/testsuite/g++.dg/abi/lambda-ctx1.h @@ -0,0 +1,20 @@ +inline auto L2 = [] (T, U) -> void {}; +namespace B +{ + inline auto L3 = [] (T, U) -> void {}; +} + +struct C +{ + int f = [] (auto){ return 1;}(&C::f); + C (); +}; + +C::C () +{ + L2 (1, 1.2f); + B::L3 (1u, 1.2); +} + +template int foo (A&&, B&&) {return 0;} +inline int q = foo ([](){}, [](){}); diff --git a/gcc/testsuite/g++.dg/abi/lambda-vis.C b/gcc/testsuite/g++.dg/abi/lambda-vis.C index c1033f501a3c..81cffcbe5a6d 100644 --- a/gcc/testsuite/g++.dg/abi/lambda-vis.C +++ b/gcc/testsuite/g++.dg/abi/lambda-vis.C @@ -13,9 +13,11 @@ int gvar = gfoo (capture ([]{})); inline int ivar = ifoo (capture ([]{})); -// { dg-final { scan-assembler {_?_Z7captureINL4svarMUlvE_EE7WrapperIT_EOS2_:} } } -// { dg-final { scan-assembler {_?_Z7captureIN4gvarMUlvE_EE7WrapperIT_EOS2_:} } } -// { dg-final { scan-assembler {_?_Z7captureIN4ivarMUlvE_EE7WrapperIT_EOS2_:} } } +// These manglings change between ABIs 17 and 18 (the final +// substitution number). +// { dg-final { scan-assembler {_?_Z7captureINL4svarMUlvE_EE7WrapperIT_EOS3_:} } } +// { dg-final { scan-assembler {_?_Z7captureIN4gvarMUlvE_EE7WrapperIT_EOS3_:} } } +// { dg-final { scan-assembler {_?_Z7captureIN4ivarMUlvE_EE7WrapperIT_EOS3_:} } } // Calls to the foos are emitted. // { dg-final { scan-assembler {call[ \t]*_?_Z4sfooI7WrapperINL4svarMUlvE_EEEiT_} { target { i?86-*-* x86_64-*-* } } } } diff --git a/gcc/testsuite/g++.dg/abi/macro0.C b/gcc/testsuite/g++.dg/abi/macro0.C index 2d07fcdc631c..4a0e9d06ca0f 100644 --- a/gcc/testsuite/g++.dg/abi/macro0.C +++ b/gcc/testsuite/g++.dg/abi/macro0.C @@ -1,6 +1,6 @@ // This testcase will need to be kept in sync with c_common_post_options. // { dg-options "-fabi-version=0" } -#if __GXX_ABI_VERSION != 1017 +#if __GXX_ABI_VERSION != 1018 #error "Incorrect value of __GXX_ABI_VERSION" #endif