Xen: Update compiler baseline checks

We have checks in both xen/compiler.h, and Config.mk.  Both are incomplete.

The check in Config.mk sees $(CC) in system and cross-compiler form, so cannot
express anything more than the global baseline.  Change it to simply 5.1.

In xen/compiler.h, rewrite the expression for clarity/brevity.

Include a GCC 12.2 check for RISCV, and include a Clang 11 baseline check.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>

Config.mk

@@ -125,8 +125,8 @@ define cc-ver-check-closure
     endif
 endef
 
-# Require GCC v4.1+
+# Require GCC v5.1 as the project global baseline
-check-$(gcc) = $(call cc-ver-check,CC,0x040100,"Xen requires at least gcc-4.1")
+check-$(gcc) = $(call cc-ver-check,CC,0x050100,"Xen requires at least GCC 5.1")
 $(eval $(check-y))
 
 ld-ver-build-id = $(shell $(1) --build-id 2>&1 | \

xen/include/xen/compiler.h

@@ -1,19 +1,21 @@
 #ifndef __LINUX_COMPILER_H
 #define __LINUX_COMPILER_H
 
-#if !defined(__GNUC__) || (__GNUC__ < 4)
+#if CONFIG_CC_IS_GCC
-#error Sorry, your compiler is too old/not recognized.
+
-#elif CONFIG_CC_IS_GCC
+# if defined(CONFIG_RISCV) && CONFIG_GCC_VERSION < 120200
-# if defined(CONFIG_ARM_32) && CONFIG_GCC_VERSION < 40900
+#  error Sorry, please use GCC >= 12.2
-#  error Sorry, your version of GCC is too old - please use 4.9 or newer.
+# elif CONFIG_GCC_VERSION < 50100
-# elif defined(CONFIG_ARM_64) && CONFIG_GCC_VERSION < 50100
+#  error Sorry, please use GCC >= 5.1
-/*
- * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63293
- * https://lore.kernel.org/r/20210107111841.GN1551@shell.armlinux.org.uk
- */
-#  error Sorry, your version of GCC is too old - please use 5.1 or newer.
 # endif
-#endif
+
+#elif CONFIG_CC_IS_CLANG
+
+# if CONFIG_CLANG_VERSION < 110000
+#  error Sorry, please use Clang >= 11
+# endif
+
+#endif /* Compiler checks. */
 
 #ifdef CONFIG_CC_HAS_VISIBILITY_ATTRIBUTE
 /* Results in more efficient PIC code (no indirections through GOT or PLT). */