[PATCH v1 05/35] Assume GCC 4.2 or later

[Alejandro Colomar]

This is what Clang claims to support.

	$ clang --version;
	Debian clang version 19.1.7 (3+b1)
	Target: x86_64-pc-linux-gnu
	Thread model: posix
	InstalledDir: /usr/lib/llvm-19/bin
	$ echo __GNUC__ __GNUC_MINOR__ \
		| clang -E -x c /dev/stdin \
		| tail -n1;
	4 2

Signed-off-by: Alejandro Colomar <alx@kernel.org>
---
 include/features.h | 2 --
 misc/sys/cdefs.h   | 4 ----
 2 files changed, 6 deletions(-)

diff --git a/include/features.h b/include/features.h
index 7d8095c682..c067077139 100644
--- a/include/features.h
+++ b/include/features.h
@@ -433,8 +433,6 @@
 #if defined _FORTIFY_SOURCE && _FORTIFY_SOURCE > 0
 # if !defined __OPTIMIZE__ || __OPTIMIZE__ <= 0
 #  warning _FORTIFY_SOURCE requires compiling with optimization (-O)
-# elif !__GNUC_PREREQ (4, 1)
-#  warning _FORTIFY_SOURCE requires GCC 4.1 or later
 # elif _FORTIFY_SOURCE > 2 && (__glibc_clang_prereq (9, 0)		      \
 			       || __GNUC_PREREQ (12, 0))
 
diff --git a/misc/sys/cdefs.h b/misc/sys/cdefs.h
index 53e4355862..6a680adcde 100644
--- a/misc/sys/cdefs.h
+++ b/misc/sys/cdefs.h
@@ -716,11 +716,7 @@ _Static_assert (0, "IEEE 128-bits long double requires redirection on this platf
 
 /* Specify that a function such as setjmp or vfork may return
    twice.  */
-#if __GNUC_PREREQ (4, 1)
 # define __attribute_returns_twice__ __attribute__ ((__returns_twice__))
-#else
-# define __attribute_returns_twice__ /* Ignore.  */
-#endif
 
 /* Mark struct types as aliasable.  Restricted to compilers that
    support forward declarations of structs in the presence of the
-- 
2.51.0