Newlib exception specification not matching error

[leemagnusson]

Summary
Different exception specifications in different parts of newlib.

To Reproduce
file tmp.cpp

#include <malloc.h>
#include <stdlib.h>

run:

clang++ -c --config=newlib.cfg --target=armv7em-none-eabihf -mfpu=fpv4-sp-d16 -mcpu=cortex-m4 -c tmp.cpp

Expected behavior
Compiles ok

Actual behavior

../lib/clang-runtimes/newlib/arm-none-eabi/armv7m_hard_fpv4_sp_d16_exn_rtti_unaligned/include/stdlib.h:299:8: error: exception specification in declaration does not match previous declaration
  299 | void *  _realloc_r (struct _reent *, void *, size_t) _NOTHROW;
      |         ^
../lib/clang-runtimes/newlib/arm-none-eabi/armv7m_hard_fpv4_sp_d16_exn_rtti_unaligned/include/malloc.h:58:14: note: previous declaration is here
   58 | extern void *_realloc_r (struct _reent *, void *, size_t);
      |              ^
8 errors generated.

Environment
Ubuntu 24.04. x86, with newlib overlay

[leemagnusson]

This is ATfE.

[voltur01]

Thank you for reporting this!

The latest version of newlib seems to have the same issue:

https://github.com/bminor/newlib/blob/7d5c55faa196844260cf6c7e4d51d7e64016ff06/newlib/libc/include/stdlib.h#L299

https://github.com/bminor/newlib/blob/7d5c55faa196844260cf6c7e4d51d7e64016ff06/newlib/libc/include/malloc.h#L58

[voltur01]

Let me check with newlib maintainers.

[voltur01]

I can reproduce this with main line ATfE, however not with gcc:

$ arm-none-eabi-g++ --version
arm-none-eabi-g++ (Arm GNU Toolchain 14.2.Rel1 (Build arm-14.52)) 14.2.1 20241119

[voltur01]

Reported in upstream newlib Bugzilla: https://sourceware.org/bugzilla/show_bug.cgi?id=33250