[Bug]: GCC 14.2.0 ICE on Debian AArch64 when compiling GoogleTest 1.18.0 parameterized tests

Describe the issue

Summary

GCC 14.2.0 crashes with an internal compiler error while compiling a GoogleTest value-parameterized test on Debian AArch64.

The failure occurs during template instantiation in GoogleTest 1.18.0, specifically in:

testing::internal::CheckedDowncastToActualType()

called by:

ValuesInIteratorRangeGenerator::Iterator::Equals()

The same project and source code compile successfully in the following configurations:

GCC 14.2.0 on Ubuntu 24.04 AMD64 with GoogleTest 1.18.0 GCC 14.2.0 on Debian AArch64 with GoogleTest 1.17.0

The failure is reproducible only with the combination of:

GCC 14.2.0 Debian AArch64 GoogleTest 1.18.0

This appears to be an AArch64-specific GCC 14.2 compiler issue exposed by changes introduced in GoogleTest 1.18.0. GCC should report a normal diagnostic for invalid source code, if any, rather than terminate with a segmentation fault.

Reproduction matrix

GCC 14.2.0 | Ubuntu 24.04 | AMD64  | GoogleTest 1.18.0 | PASS
GCC 14.2.0 | Debian       | ARM64  | GoogleTest 1.17.0 | PASS
GCC 14.2.0 | Debian       | ARM64  | GoogleTest 1.18.0 | ICE

Affected parameter type

The GoogleTest parameter type involved in the failure is:

std::tuple<
    signed char,
    unsigned int,
    std::filesystem::path,
    std::filesystem::path
>

The compiler crashes while instantiating:

testing::internal::ValuesInIteratorRangeGenerator<
    std::tuple<
        signed char,
        unsigned int,
        std::filesystem::path,
        std::filesystem::path
    >
>::Iterator::Equals()

Steps to reproduce the problem

Minimal reproduction candidate

The following test case approximates the structure that triggers the issue:

#include <filesystem>
#include <tuple>

#include <gtest/gtest.h>

using Param = std::tuple<
    signed char,
    unsigned int,
    std::filesystem::path,
    std::filesystem::path
>;

class ReproTest : public testing::TestWithParam<Param> {};

TEST_P(ReproTest, CompilesParameterizedTest) {
    EXPECT_TRUE(true);
}

INSTANTIATE_TEST_SUITE_P(
    Repro,
    ReproTest,
    testing::Values(
        Param{
            1,
            2U,
            std::filesystem::path{"input.bin"},
            std::filesystem::path{"output.bin"}
        }
    )
);

Example compilation command:

g++ \
    -std=c++20 \
    -O3 \
    -isystem /home/gene/.conan2/p/b/gtestc6cac63e9157e/p/include \
    -L /home/gene/.conan2/p/b/gtestc6cac63e9157e/p/lib \
    -flto=auto \
    -fno-fat-lto-objects \
    report.cpp \
    -lgtest \
    -lgtest_main \
    -pthread \
    -o report

gene@raspberrypi:~/proj/gtest_failed $ g++
-std=c++20
-O3
-isystem /home/gene/.conan2/p/b/gtestc6cac63e9157e/p/include
-L /home/gene/.conan2/p/b/gtestc6cac63e9157e/p/lib
-flto=auto
-fno-fat-lto-objects
report.cpp
-lgtest
-lgtest_main
-pthread
-o report In file included from /home/gene/.conan2/p/b/gtestc6cac63e9157e/p/include/gtest/gtest-message.h:57, from /home/gene/.conan2/p/b/gtestc6cac63e9157e/p/include/gtest/gtest-assertion-result.h:46, from /home/gene/.conan2/p/b/gtestc6cac63e9157e/p/include/gtest/gtest.h:64, from report.cpp:4: /home/gene/.conan2/p/b/gtestc6cac63e9157e/p/include/gtest/internal/gtest-port.h: In instantiation of ‘Derived* testing::internal::CheckedDowncastToActualType(Base*) [with Derived = const ValuesInIteratorRangeGenerator<std::tuple<signed char, unsigned int, std::filesystem::_cxx11::path, std::filesystem::__cxx11::path> >::Iterator; Base = const ParamIteratorInterface<std::tuple<signed char, unsigned int, std::filesystem::__cxx11::path, std::filesystem::__cxx11::path> >]’: /home/gene/.conan2/p/b/gtestc6cac63e9157e/p/include/gtest/internal/gtest-param-util.h:352:57: required from ‘bool testing::internal::ValuesInIteratorRangeGenerator::Iterator::Equals(const testing::internal::ParamIteratorInterface&) const [with T = std::tuple<signed char, unsigned int, std::filesystem::__cxx11::path, std::filesystem::__cxx11::path>]’ 352 | CheckedDowncastToActualType(&other)->iterator; | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~ /home/gene/.conan2/p/b/gtestc6cac63e9157e/p/include/gtest/internal/gtest-param-util.h:345:10: required from here 345 | bool Equals(const ParamIteratorInterface& other) const override { | ^~~~~~ /home/gene/.conan2/p/b/gtestc6cac63e9157e/p/include/gtest/internal/gtest-port.h:1171:10: internal compiler error: Segmentation fault 1171 | return static_cast<Derived*>(base); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~ 0xd5061f internal_error(char const*, ...) ???:0 0xe77ee3 comp_type_attributes(tree_node const*, tree_node const*) ???:0 0x114c523 perform_direct_initialization_if_possible(tree_node*, tree_node*, bool, int) ???:0 0x13a5123 build_static_cast(unsigned int, tree_node*, tree_node*, int) ???:0 0x12a455f tsubst_expr(tree_node*, tree_node*, int, tree_node*) ???:0 0x13c1f9f instantiate_decl(tree_node*, bool, bool) ???:0 0xf762a7 instantiate_pending_templates(int) ???:0 0xf6b497 c_parse_final_cleanups() ???:0 0x178a953 c_common_parse_file() ???:0 Please submit a full bug report, with preprocessed source (by using -freport-bug). Please include the complete backtrace with any bug report. See file:///usr/share/doc/gcc-14/README.Bugs for instructions.

What version of GoogleTest are you using?

Installed gtest package

    gtest/1.18.0
      revisions
        e2507fc4efe2ec9e2db9e5c91eefab9f (2026-08-11 11:14:07 UTC)
          packages
            919b3575c3d845dc9ef564f9dbf7b05101a8e69d
              info
                settings
                  arch: armv8
                  build_type: Release
                  compiler: gcc
                  compiler.cppstd: 20
                  compiler.libcxx: libstdc++11
                  compiler.version: 14.2
                  os: Linux
                options
                  build_gmock: True
                  disable_pthreads: False
                  fPIC: True
                  hide_symbols: False
                  shared: False

What operating system and version are you using?

Environment

Failing environment

Operating system: Debian Linux
Architecture: AArch64 / ARM64
Compiler: GCC 14.2.0
C++ standard: C++20
Build system: CMake with Ninja
Dependency manager: Conan 2
GoogleTest version: 1.18.0
Build type: Release

Passing configurations

Configuration 1

Operating system: Ubuntu 24.04
Architecture: AMD64 / x86_64
Compiler: GCC 14.2.0
GoogleTest version: 1.18.0
Result: PASS

Configuration 2

Operating system: Debian Linux
Architecture: AArch64 / ARM64
Compiler: GCC 14.2.0
GoogleTest version: 1.17.0
Result: PASS

What compiler and version are you using?

The same as before.

What build system are you using?

The same as before.

Additional context

No response