Compile error on i386 with `-Werror=free-nonheap-object`

[Harry-Chen]

Describe the bug

The following build error occurred when building for i386 on Debian with GCC 15.2.0:

[3/147] /usr/lib/ccache/c++  -I/build/package/package/include -I/build/package/package/test -I/build/package/package/test/thirdparty -I/build/package/package/test/thirdparty/catch -g -O2 -ffile-prefix-map=/build/package/package=. -fstack-protector-strong -Wformat -Werror=format-security -Wdate-time -D_FORTIFY_SOURCE=2 -Werror=maybe-uninitialized -Wnon-virtual-dtor -Werror=stringop-overflow -Werror -Wall -Wextra -Wcast-align -Wcast-qual -Wimplicit-fallthrough -Wsign-compare -pedantic -Wnonnull -Wnull-dereference -Werror=nonnull -MD -MT test/CMakeFiles/unit_tests.dir/bson/src/bson_cursor_tests.cpp.o -MF test/CMakeFiles/unit_tests.dir/bson/src/bson_cursor_tests.cpp.o.d -o test/CMakeFiles/unit_tests.dir/bson/src/bson_cursor_tests.cpp.o -c /build/package/package/test/bson/src/bson_cursor_tests.cpp
FAILED: test/CMakeFiles/unit_tests.dir/bson/src/bson_cursor_tests.cpp.o 
/usr/lib/ccache/c++  -I/build/package/package/include -I/build/package/package/test -I/build/package/package/test/thirdparty -I/build/package/package/test/thirdparty/catch -g -O2 -ffile-prefix-map=/build/package/package=. -fstack-protector-strong -Wformat -Werror=format-security -Wdate-time -D_FORTIFY_SOURCE=2 -Werror=maybe-uninitialized -Wnon-virtual-dtor -Werror=stringop-overflow -Werror -Wall -Wextra -Wcast-align -Wcast-qual -Wimplicit-fallthrough -Wsign-compare -pedantic -Wnonnull -Wnull-dereference -Werror=nonnull -MD -MT test/CMakeFiles/unit_tests.dir/bson/src/bson_cursor_tests.cpp.o -MF test/CMakeFiles/unit_tests.dir/bson/src/bson_cursor_tests.cpp.o.d -o test/CMakeFiles/unit_tests.dir/bson/src/bson_cursor_tests.cpp.o -c /build/package/package/test/bson/src/bson_cursor_tests.cpp
In file included from /usr/include/i386-linux-gnu/c++/15/bits/c++allocator.h:33,
                 from /usr/include/c++/15/bits/allocator.h:46,
                 from /usr/include/c++/15/bits/alloc_traits.h:39,
                 from /usr/include/c++/15/ext/alloc_traits.h:36,
                 from /usr/include/c++/15/bits/hashtable_policy.h:39,
                 from /usr/include/c++/15/bits/hashtable.h:37,
                 from /usr/include/c++/15/bits/unordered_map.h:33,
                 from /usr/include/c++/15/unordered_map:43,
                 from /usr/include/c++/15/functional:65,
                 from /build/package/package/include/jsoncons_ext/bson/bson_cursor.hpp:11,
                 from /build/package/package/test/bson/src/bson_cursor_tests.cpp:8:
In member function ‘void std::__new_allocator<_Tp>::deallocate(_Tp*, size_type) [with _Tp = long long unsigned int]’,
    inlined from ‘static void std::allocator_traits<std::allocator<_Tp1> >::deallocate(allocator_type&, pointer, size_type) [with _Tp = long long unsigned int]’ at /usr/include/c++/15/bits/alloc_traits.h:649:23,
    inlined from ‘void jsoncons::basic_bigint<Allocator>::dynamic_storage::destroy(const real_allocator_type&) [with Allocator = std::allocator<unsigned char>]’ at /build/package/package/include/jsoncons/utility/bigint.hpp:275:71,
    inlined from ‘void jsoncons::basic_bigint<Allocator>::destroy() [with Allocator = std::allocator<unsigned char>]’ at /build/package/package/include/jsoncons/utility/bigint.hpp:1545:34,
    inlined from ‘jsoncons::basic_bigint<Allocator>::~basic_bigint() [with Allocator = std::allocator<unsigned char>]’ at /build/package/package/include/jsoncons/utility/bigint.hpp:359:16,
    inlined from ‘void jsoncons::basic_bigint<Allocator>::unnormalize(jsoncons::basic_bigint<Allocator>&, int, int) const [with Allocator = std::allocator<unsigned char>]’ at /build/package/package/include/jsoncons/utility/bigint.hpp:1668:20,
    inlined from ‘void jsoncons::basic_bigint<Allocator>::divide(jsoncons::basic_bigint<Allocator>, jsoncons::basic_bigint<Allocator>&, jsoncons::basic_bigint<Allocator>&, bool) const [with Allocator = std::allocator<unsigned char>]’ at /build/package/package/include/jsoncons/utility/bigint.hpp:1536:24:
/usr/include/c++/15/bits/new_allocator.h:172:66: error: ‘void operator delete(void*, std::size_t)’ called on a pointer to an unallocated object ‘4294967295’ [-Werror=free-nonheap-object]
  172 |         _GLIBCXX_OPERATOR_DELETE(_GLIBCXX_SIZED_DEALLOC(__p, __n));
      |                                                                  ^
cc1plus: all warnings being treated as errors

Looks like there is a delete operator called on address -1 (which equals UINT32_MAX, i.e. 4294967295). I tried to read the code from bigint.hpp, but have not discovered anything obvious. Please investigate whether there is an architecture-related issue.

The full log could be obtained here.

Enumerate the steps to reproduce the bug

Just build with the specified configuration.

What compiler, architecture, and operating system?

• Compiler: GCC 15.2.0
• Architecture: i386
• Operating system: Debian sid

What jsoncons library version?

• Latest release 1.4.3
• Other release ______
• master

[danielaparker]

Thanks for reporting this, we'll have a look.

[danielaparker]

I can't replicate this on any of the environments we test on, but we've made some changes to the bigint class, can you repeat the test using the code on master? To see if anything has changed? Thanks.

[Harry-Chen]

@danielaparker The issue persists in the latest master commit (ce44fe6). You could try these steps to reproduce:

• install g++-i686-linux-gnu in debian trixie
• configure project by CC=i686-linux-gnu-gcc CXX=i686-linux-gnu-g++ CXXFLAGS='-fstack-protector-strong -Wformat -Werror=format-security -Wdate-time -D_FORTIFY_SOURCE=2 -Werror=maybe-uninitialized -Wnon-virtual-dtor -Werror=stringop-overflow -Werror -Wall -Wextra -Wcast-align -Wcast-qual -Wimplicit-fallthrough -Wsign-compare -pedantic -Wnonnull -Wnull-dereference -Werror=nonnull' cmake .. -DCMAKE_BUILD_TYPE=RelWithDebInfo
• build the project by cmake --build .

Still same errors: /usr/i686-linux-gnu/include/c++/14/bits/new_allocator.h:172:33: error: ‘void operator delete(void*, std::size_t)’ called on a pointer to an unallocated object ‘4294967295’ [-Werror=free-nonheap-object]