Jonathan Wakely <jwak...@redhat.com> writes:
> [...]
> +void
> +std::breakpoint() noexcept
> +{
> + PROBE(std::breakpoint);
> +
> + if (__gnu_cxx::debugger_signal_for_breakpoint > 0)
> + std::raise(__gnu_cxx::debugger_signal_for_breakpoint);
> +
glib's https://gitlab.gnome.org/GNOME/glib/-/blob/main/glib/gbacktrace.h#L58 is
a useful reference. It has an entry for alpha and also MSVC (though I
can't imagine MSVC matters here).
> +#if _GLIBCXX_HAVE_DEBUGAPI_H && defined(_WIN32) && !defined(__CYGWIN__)
> + DebugBreak();
> +#elif __has_builtin(__builtin_debugtrap)
> + __builtin_debugtrap(); // Clang
> +#elif defined(__i386__) || defined(__x86_64__)
> + __asm__ volatile ("int3; nop");
> +#elifdef __thumb__
> + __asm__ volatile (".inst 0xde01");
> +#elifdef __aarch64__
> + __asm__ volatile (".inst 0xd4200000");
> +#elifdef __arm__
> + __asm__ volatile (".inst 0xe7f001f0");
> +#elifdef __riscv
> + /* section 2.8 in the RISC-V unprivileged ISA manual says for semi-hosted
> + * environments we want the sequence:
> + * slli x0, x0, 0x1f # Entry NOP
> + * ebreak # Break to debugger
> + * srai x0, x0, 7 # NOP encoding the semihosting call number 7
> + */
> + __asm__ volatile (".4byte 0x00100073");
> +#elifdef __powerpc__
> + __asm__ volatile(".4byte 0x7d821008");
> +#else
> + __builtin_trap();
> +#endif
> +} // If the debugger stops here, std::breakpoint() was called.
> +
> [...]
