Name
	n3835, alx-0088r1 - noreturn can't return

Principles
	-  Codify existing practice to address evident deficiencies
	-  Enable secure programming

	And from the old C23 charter:

	-  Trust the programmer, as a goal, is outdated in respect to
	   the security and safety programming communities.

Category
	Earthly demon.

Author
	Alejandro Colomar <alx@kernel.org>

History
	<https://www.alejandro-colomar.es/src/alx/alx/std/wg14/alx-0088.git/>

	r0 (2026-02-14):
	-  Initial draft.

	r1 (2026-02-14; n3845):
	-  wfix

Description
	It makes absolutely no sense to have a [[noreturn]] function
	that contains a return statement.

		[[noreturn]]
		void f(void)
		{
			return;
			// would you mind serving me a dose of Nasal Demons?
		}

	More work would be needed to make sure that [[noreturn]]
	functions can't return.  This is a good start, though.  A low-
	hanging fruit.

Prior art
	Both GCC and Clang diagnose --by default--, even in the case
	where the return statement is unreachable.

		alx@devuan:~/tmp$ cat nr.c
		[[noreturn]]
		void f(void)
		{
			if (0)
				return;

			for (;;)
				continue;
		}
		alx@devuan:~/tmp$ gcc -S -O3 nr.c 
		nr.c: In function ‘f’:
		nr.c:5:17: warning: function declared ‘noreturn’ has a ‘return’ statement
		    5 |                 return;
		      |                 ^~~~~~
		alx@devuan:~/tmp$ clang -S -O3 nr.c 
		nr.c:5:3: warning: function 'f' declared 'noreturn' should
		      not return [-Winvalid-noreturn]
		    5 |                 return;
		      |                 ^
		1 warning generated.

Proposed wording
	Based on N3783.

    6.7.5  Function specifiers
	@@ Constraints, p5+1
	+A function declared with the <b>_Noreturn</b> function specifier
	+shall not contain a return statement.

    6.7.12.7  The noreturn and _Noreturn attributes
	@@ Constraints, p2+1
	+A function declared with the <b>noreturn</b> attribute
	+shall not contain a return statement.