git: f29905cab576 - main - makesyscalls: deprecate cpp other than includes

The branch main has been updated by brooks:

URL: https://cgit.FreeBSD.org/src/commit/?id=f29905cab576a0ccf454ee2e215f590e0e656d70

commit f29905cab576a0ccf454ee2e215f590e0e656d70
Author:     Brooks Davis <brooks@FreeBSD.org>
AuthorDate: 2025-02-18 22:02:19 +0000
Commit:     Brooks Davis <brooks@FreeBSD.org>
CommitDate: 2025-02-18 22:03:26 +0000

    makesyscalls: deprecate cpp other than includes
    
    Warn that C preprocessor directives in the config file are deprecated.
    They are unsound and support has a number of potential pitfalls.  They
    should be replaced by compile-time generation of files plus an overlay
    framework to allow things like per-arch variation.
    
    Reviewed by:    kevans
    Sponsored by:   DARPA, AFRL
    Pull Request:   https://github.com/freebsd/freebsd-src/pull/1575
---
 sys/kern/syscalls.master                    | 1 +
 sys/tools/syscalls/core/freebsd-syscall.lua | 6 ++++++
 2 files changed, 7 insertions(+)

diff --git a/sys/kern/syscalls.master b/sys/kern/syscalls.master
index fbd2ffb60cae..67396a4cabc5 100644
--- a/sys/kern/syscalls.master
+++ b/sys/kern/syscalls.master
@@ -111,6 +111,7 @@
 ; limited set of output files.  Before the first syscalls, #include lines will
 ; be copied and %%ABI_HEADERS%% expanded.  Between system call entries,
 ; all lines beginning with # will be copied.  Caveat Emptor.
+; WARNING: this functionality is deprecated.
 
 #include <sys/param.h>
 #include <sys/sysent.h>
diff --git a/sys/tools/syscalls/core/freebsd-syscall.lua b/sys/tools/syscalls/core/freebsd-syscall.lua
index fdd3a9011b7a..2ef0fdea6401 100644
--- a/sys/tools/syscalls/core/freebsd-syscall.lua
+++ b/sys/tools/syscalls/core/freebsd-syscall.lua
@@ -50,6 +50,7 @@ function FreeBSDSyscall:parseSysfile()
 	local incs = ""
 	local prolog = ""
 	local first = true
+	local cpp_warned = false
 	local s
 	for line in fh:lines() do
 		line = line:gsub(commentExpr, "") -- Strip any comments.
@@ -82,6 +83,11 @@ function FreeBSDSyscall:parseSysfile()
 				incs = incs .. h .. "\n"
 			end
 		elseif line:match("^#") then
+			if not cpp_warned then
+				util.warn("use of non-include cpp " ..
+				    "directives is deprecated")
+				cpp_warned = true
+			end
 			prolog = prolog .. line .. "\n"
 		else
 			s = syscall:new()