[PATCH RESEND 1/1] rust: error: auto-generate error declarations

Yiyang Wu
2024-09-20T02:49:47Z

This patch adds a new cmd_errno to convert the include/linux/errno.h
content into declare_err! macros for better maintainability and readability.

Signed-off-by: Yiyang Wu <toolmanp@tlmp.cc>
---
rust/.gitignore | 1 +
rust/Makefile | 14 ++++++++++-
rust/kernel/error.rs | 58 +++-----------------------------------------
3 files changed, 18 insertions(+), 55 deletions(-)

diff --git a/rust/.gitignore b/rust/.gitignore
index d3829ffab80b..ba71ef4a9239 100644
--- a/rust/.gitignore
+++ b/rust/.gitignore
@@ -5,6 +5,7 @@ bindings_helpers_generated.rs
doctests_kernel_generated.rs
doctests_kernel_generated_kunit.c
uapi_generated.rs
+errno_generated.rs
exports_*_generated.h
doc/
test/
diff --git a/rust/Makefile b/rust/Makefile
index dd76dc27d666..f5a1680fe59c 100644
--- a/rust/Makefile
+++ b/rust/Makefile
@@ -22,6 +22,8 @@ always-$(CONFIG_RUST) += exports_alloc_generated.h exports_helpers_generated.h \
always-$(CONFIG_RUST) += uapi/uapi_generated.rs
obj-$(CONFIG_RUST) += uapi.o

+always-$(CONFIG_RUST) += kernel/errno_generated.rs
+
ifdef CONFIG_RUST_BUILD_ASSERT_ALLOW
obj-$(CONFIG_RUST) += build_error.o
else
@@ -289,6 +291,15 @@ $(obj)/uapi/uapi_generated.rs: $(src)/uapi/uapi_helper.h \
$(src)/bindgen_parameters FORCE
$(call if_changed_dep,bindgen)

+quiet_cmd_errno = EXPORTS $@
+ cmd_errno = \
+ $(CC) $(c_flags) -E -CC -dD $< \
+ | sed -E 's/\#define\s*([A-Z0-9]+)\s+([0-9]+)\s+\/\*\s*(.*)\s\*\//declare_err!(\1, "\3.");/' \
+ | grep -E '^declare_err.*$$' > $@
+
+$(obj)/kernel/errno_generated.rs: $(srctree)/include/linux/errno.h FORCE
+ $(call if_changed,errno)
+
# See `CFLAGS_REMOVE_helpers.o` above. In addition, Clang on C does not warn
# with `-Wmissing-declarations` (unlike GCC), so it is not strictly needed here
# given it is `libclang`; but for consistency, future Clang changes and/or
@@ -420,7 +431,8 @@ $(obj)/uapi.o: $(src)/uapi/lib.rs \

$(obj)/kernel.o: private rustc_target_flags = --extern alloc \
--extern build_error --extern macros --extern bindings --extern uapi
-$(obj)/kernel.o: $(src)/kernel/lib.rs $(obj)/alloc.o $(obj)/build_error.o \
+$(obj)/kernel.o: $(src)/kernel/lib.rs $(obj)/kernel/errno_generated.rs \
+ $(obj)/alloc.o $(obj)/build_error.o \
$(obj)/libmacros.so $(obj)/bindings.o $(obj)/uapi.o FORCE
+$(call if_changed_rule,rustc_library)

diff --git a/rust/kernel/error.rs b/rust/kernel/error.rs
index 6f1587a2524e..bb16b40a8d19 100644
--- a/rust/kernel/error.rs
+++ b/rust/kernel/error.rs
@@ -23,60 +23,10 @@ macro_rules! declare_err {
pub const $err: super::Error = super::Error(-(crate::bindings::$err as i32));
};
}
-
- declare_err!(EPERM, "Operation not permitted.");
- declare_err!(ENOENT, "No such file or directory.");
- declare_err!(ESRCH, "No such process.");
- declare_err!(EINTR, "Interrupted system call.");
- declare_err!(EIO, "I/O error.");
- declare_err!(ENXIO, "No such device or address.");
- declare_err!(E2BIG, "Argument list too long.");
- declare_err!(ENOEXEC, "Exec format error.");
- declare_err!(EBADF, "Bad file number.");
- declare_err!(ECHILD, "No child processes.");
- declare_err!(EAGAIN, "Try again.");
- declare_err!(ENOMEM, "Out of memory.");
- declare_err!(EACCES, "Permission denied.");
- declare_err!(EFAULT, "Bad address.");
- declare_err!(ENOTBLK, "Block device required.");
- declare_err!(EBUSY, "Device or resource busy.");
- declare_err!(EEXIST, "File exists.");
- declare_err!(EXDEV, "Cross-device link.");
- declare_err!(ENODEV, "No such device.");
- declare_err!(ENOTDIR, "Not a directory.");
- declare_err!(EISDIR, "Is a directory.");
- declare_err!(EINVAL, "Invalid argument.");
- declare_err!(ENFILE, "File table overflow.");
- declare_err!(EMFILE, "Too many open files.");
- declare_err!(ENOTTY, "Not a typewriter.");
- declare_err!(ETXTBSY, "Text file busy.");
- declare_err!(EFBIG, "File too large.");
- declare_err!(ENOSPC, "No space left on device.");
- declare_err!(ESPIPE, "Illegal seek.");
- declare_err!(EROFS, "Read-only file system.");
- declare_err!(EMLINK, "Too many links.");
- declare_err!(EPIPE, "Broken pipe.");
- declare_err!(EDOM, "Math argument out of domain of func.");
- declare_err!(ERANGE, "Math result not representable.");
- declare_err!(ERESTARTSYS, "Restart the system call.");
- declare_err!(ERESTARTNOINTR, "System call was interrupted by a signal and will be restarted.");
- declare_err!(ERESTARTNOHAND, "Restart if no handler.");
- declare_err!(ENOIOCTLCMD, "No ioctl command.");
- declare_err!(ERESTART_RESTARTBLOCK, "Restart by calling sys_restart_syscall.");
- declare_err!(EPROBE_DEFER, "Driver requests probe retry.");
- declare_err!(EOPENSTALE, "Open found a stale dentry.");
- declare_err!(ENOPARAM, "Parameter not supported.");
- declare_err!(EBADHANDLE, "Illegal NFS file handle.");
- declare_err!(ENOTSYNC, "Update synchronization mismatch.");
- declare_err!(EBADCOOKIE, "Cookie is stale.");
- declare_err!(ENOTSUPP, "Operation is not supported.");
- declare_err!(ETOOSMALL, "Buffer or request is too small.");
- declare_err!(ESERVERFAULT, "An untranslatable error occurred.");
- declare_err!(EBADTYPE, "Type not supported by server.");
- declare_err!(EJUKEBOX, "Request initiated, but will not complete before timeout.");
- declare_err!(EIOCBQUEUED, "iocb queued, will get completion event.");
- declare_err!(ERECALLCONFLICT, "Conflict with recalled state.");
- declare_err!(ENOGRACE, "NFS file lock reclaim refused.");
+ include!(concat!(
+ env!("OBJTREE"),
+ "/rust/kernel/errno_generated.rs"
+ ));
}

/// Generic integer kernel error.
--
2.46.0