commit 91be1905f4dc7c4a5236715759c65de55c90fbb8
author Pierre-Clément Tosi <ptosi@google.com> Mon Jan 22 21:15:19 2024 +0000
committer Pierre-Clément Tosi <ptosi@google.com> Fri Feb 16 14:52:18 2024 +0000
tree 530571fa205dbd58bac0ac7dcc59f091cd5dbd75
parent 38304eb3b4e2c1c6d3f3499570478302018bdcbb

libfdt: Replace helper functions with FdtRawResult

Move all FFI interfaces to the newly-introduced FdtRawResult,
implementing TryFrom<FdtRawResult> as needed, and remove the
now-obsolete helper functions.

Note that all low-level libfdt wrappers now simply return

    FdtRawResult::from(ret).try_into()

Test: m pvmfw
Test: atest liblibfdt.integration_test
Change-Id: I54ee0330556533a7a8d0ce07f15fed50849260eb

libs/libfdt/src/result.rs

diff --git a/libs/libfdt/src/result.rs b/libs/libfdt/src/result.rs
index 65ef55d..52291ca 100644
--- a/libs/libfdt/src/result.rs
+++ b/libs/libfdt/src/result.rs
@@ -14,7 +14,7 @@
 
 //! Rust types related to the libfdt C integer results.
 
-use core::ffi::c_int;
+use core::ffi::{c_int, c_uint};
 use core::fmt;
 use core::result;
 
@@ -94,18 +94,6 @@
 /// Result type with FdtError enum.
 pub type Result<T> = result::Result<T, FdtError>;
 
-pub(crate) fn fdt_err(val: c_int) -> Result<c_int> {
-    FdtRawResult::from(val).try_into()
-}
-
-pub(crate) fn fdt_err_expect_zero(val: c_int) -> Result<()> {
-    FdtRawResult::from(val).try_into()
-}
-
-pub(crate) fn fdt_err_or_option(val: c_int) -> Result<Option<c_int>> {
-    FdtRawResult::from(val).try_into()
-}
-
 #[derive(Clone, Copy, Debug, Eq, PartialEq)]
 pub(crate) struct FdtRawResult(c_int);
 
@@ -164,6 +152,34 @@
     }
 }
 
+impl TryFrom<FdtRawResult> for c_uint {
+    type Error = FdtError;
+
+    fn try_from(res: FdtRawResult) -> Result<Self> {
+        Ok(c_int::try_from(res)?.try_into().unwrap())
+    }
+}
+
+impl TryFrom<FdtRawResult> for usize {
+    type Error = FdtError;
+
+    fn try_from(res: FdtRawResult) -> Result<Self> {
+        Ok(c_int::try_from(res)?.try_into().unwrap())
+    }
+}
+
+impl TryFrom<FdtRawResult> for Option<usize> {
+    type Error = FdtError;
+
+    fn try_from(res: FdtRawResult) -> Result<Self> {
+        match res.try_into() {
+            Ok(n) => Ok(Some(n)),
+            Err(FdtError::NotFound) => Ok(None),
+            Err(e) => Err(e),
+        }
+    }
+}
+
 impl TryFrom<FdtRawResult> for () {
     type Error = FdtError;