Build does not work with GCC 15+

[pinskia]

With GCC 15, the build fails due to missing cstdint include. GCC 15 removed some extra includes in the standard headers and caused the issue. See https://gcc.gnu.org/gcc-15/porting_to.html for more information.

GCC 15 output:

In file included from ./src/common/cpuinfo/CpuModel.h:27,
                 from src/common/cpuinfo/CpuModel.cpp:24:
./arm_compute/core/CPP/CPPTypes.h:183:5: error: ‘uint64_t’ does not name a type
  183 |     uint64_t get_sme2_vector_length() const;
      |     ^~~~~~~~
./arm_compute/core/CPP/CPPTypes.h:30:1: note: ‘uint64_t’ is defined in header ‘<cstdint>’; this is probably fixable by adding ‘#include <cstdint>’
   29 | #include <memory>
  +++ |+#include <cstdint>
   30 |

[pinskia]

Some more errors similar after fixing the above one:

In file included from src/runtime/Allocator.cpp:27:
./arm_compute/runtime/MemoryRegion.h:99:21: error: ‘uint8_t’ was not declared in this scope
   99 |     std::shared_ptr<uint8_t> _mem;
      |                     ^~~~~~~
./arm_compute/runtime/MemoryRegion.h:31:1: note: ‘uint8_t’ is defined in header ‘<cstdint>’; this is probably fixable by adding ‘#include <cstdint>’
   30 | #include <cstddef>
  +++ |+#include <cstdint>
   31 |

[morgolock]

Hi @pinskia

Could you please share these details?

1. What is the full build command you are using?
2. The output of g++ --version or the corresponding cross-compiler you are using

[pinskia]

The version of GCC I am using:

[apinski@xeond2 upstream-cross-aarch64]$ ./install/bin/aarch64-linux-gnu-g++ -v
Using built-in specs.
COLLECT_GCC=./install/bin/aarch64-linux-gnu-g++
COLLECT_LTO_WRAPPER=/bajas/pinskia/src/upstream-cross-aarch64/install/bin/../libexec/gcc/aarch64-linux-gnu/15.0.0/lto-wrapper
Target: aarch64-linux-gnu
Configured with: ../configure --target=aarch64-linux-gnu --prefix=/home/apinski/src/upstream-cross-aarch64/install --enable-languages=c,c++,fortran --with-sysroot=/home/apinski/src/upstream-cross-aarch64/install/aarch64-linux-gnu/sysroot
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 15.0.0 20240903 (experimental) [trunk 4beaa1846dc] (GCC)

This was the trunk version as of last week. as I should have mention adding #include <cstdint> to the following files allowed me to do the testing I needed to do:

arm_compute/core/CPP/CPPTypes.h
arm_compute/runtime/MemoryRegion.h
tests/framework/instruments/hwc_names.hpp

The testing I needed to do was reduce a testcase for GCC where GCC had an internal compiler error due to -flto usage.

[morgolock]

Hi @pinskia

Could you please share the command used to compile the library ?

[jwakely]

It doesn't matter: your code is wrong. You need to include the relevant header before using those types. That's how C++ works. Maybe you've got away with it until now with some compilers, but the code is still wrong.

This is documented as a change that might be needed when using GCC 15: https://gcc.gnu.org/gcc-15/porting_to.html#header-dep-changes

But the bottom line is you need to include the right header for anything in the C++ standard library that you rely on.

[morgolock]

Hi @jwakely

Many thanks for raising this, we'll have a look at it and fix it

[morgolock]

Hi @pinskia

Since GCC15 has not yet been released I'm struggling to reproduce the problem. I'm building ACL main branch with GCC 15.0.0 20240514 (experimental) and I can't see the errors mentioned above.

~/ComputeLibrary$ //aarch64-none-linux-gnu/bin/aarch64-none-linux-gnu-gcc --version -v
Using built-in specs.
COLLECT_AS_OPTIONS='--version'
COLLECT_GCC=/arm/pdtl/snapshots/fsf-trunk.3697/installed/rhe8x86_64/aarch64-none-linux-gnu/bin/aarch64-none-linux-gnu-gcc
COLLECT_LTO_WRAPPER=/arm/pdtl/snapshots/fsf-trunk.3697/installed/rhe8x86_64/aarch64-none-linux-gnu/bin/../libexec/gcc/aarch64-none-linux-gnu/15.0.0/lto-wrapper
aarch64-none-linux-gnu-gcc (fsf-trunk.3697) 15.0.0 20240514 (experimental)
Copyright (C) 2024 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

It would help if you could either:

• Contribute directly to ACL. Please submit a patch for review fixing this specific problem, we would be happy to take your contribution.
• Provide more details as to how to reproduce this: ACL branch you are building, the command you're using to build the library. Once I can reproduce it I'll be happy to fix it myself.

Hope this helps

[jwakely]

aarch64-none-linux-gnu-gcc (fsf-trunk.3697) 15.0.0 20240514 (experimental)

The relevant change was committed to GCC trunk on 2024-08-01 so this build won't have it.

There are RPMs of a recent gcc 15 at https://copr.fedorainfracloud.org/coprs/jwakely/gcc-latest/ or you could use the scripts at https://github.com/jwakely/pkg-gcc-latest/ to build a .deb (I only provide a pre-built .deb for x86_64 not aarch64).