[PATCH v2] x86/syscalls: shrink entry/syscall_32.i via IWYU

[Tanzir Hasan <tanzirh@google.com>]

This diff uses an open source tool include-what-you-use (IWYU) to modify
the include list, changing indirect includes to direct includes. IWYU is
implemented using the IWYUScripts github repository which is a tool that
is currently undergoing development. These changes seek to improve build
times.

pt_regs has been used because it is the only part of ptrace that is
necessary for the build of this file.

This change to entry/syscall_32.c resulted in a preprocessed size of
entry/syscall_32.i from 64002 lines to 24506 lines (-62%) for the x86
defconfig.

Suggested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Tanzir Hasan <tanzirh@google.com>
---
Changes in v2:
- added pt_regs which was all that was needed from ptrace
- Link to v1: https://lore.kernel.org/r/20231227-syscall32-v1-1-9621140d33bd@google.com
---
 arch/x86/entry/syscall_32.c | 18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/arch/x86/entry/syscall_32.c b/arch/x86/entry/syscall_32.c
index 8cfc9bc73e7f..6ed862eb3b80 100644
--- a/arch/x86/entry/syscall_32.c
+++ b/arch/x86/entry/syscall_32.c
@@ -1,12 +1,22 @@
 // SPDX-License-Identifier: GPL-2.0
 /* System call table for i386. */
 
-#include <linux/linkage.h>
-#include <linux/sys.h>
-#include <linux/cache.h>
-#include <linux/syscalls.h>
 #include <asm/syscall.h>
 
+struct pt_regs;
+typedef long (*sys_call_ptr_t)(const struct pt_regs *);
+extern const sys_call_ptr_t sys_call_table[];
+#if defined(CONFIG_X86_32)
+#define ia32_sys_call_table sys_call_table
+#else
+/*
+ * These may not exist, but still put the prototypes in so we
+ * can use IS_ENABLED().
+ */
+extern const sys_call_ptr_t ia32_sys_call_table[];
+extern const sys_call_ptr_t x32_sys_call_table[];
+#endif
+
 #ifdef CONFIG_IA32_EMULATION
 #define __SYSCALL_WITH_COMPAT(nr, native, compat)	__SYSCALL(nr, compat)
 #else

---
base-commit: fbafc3e621c3f4ded43720fdb1d6ce1728ec664e
change-id: 20231227-syscall32-2c6d62fe51c9

Best regards,
-- 
Tanzir Hasan <tanzirh@google.com>