libfdt: Introduce FdtRawResult abstraction type
Introduce a type representing the raw result of a libfdt function call,
so that we can implement traits (in particular From and TryFrom) on the
result in order to centralize and abstract away operations such as
trivial type casting.
Test: m pvmfw
Test: atest liblibfdt.integration_test
Change-Id: I26e77cc17e7aa2d5cc437ceed131dca84f6936e8
diff --git a/libs/libfdt/src/result.rs b/libs/libfdt/src/result.rs
index 9643e1e..65ef55d 100644
--- a/libs/libfdt/src/result.rs
+++ b/libs/libfdt/src/result.rs
@@ -95,45 +95,82 @@
pub type Result<T> = result::Result<T, FdtError>;
pub(crate) fn fdt_err(val: c_int) -> Result<c_int> {
- if val >= 0 {
- Ok(val)
- } else {
- Err(match -val as _ {
- libfdt_bindgen::FDT_ERR_NOTFOUND => FdtError::NotFound,
- libfdt_bindgen::FDT_ERR_EXISTS => FdtError::Exists,
- libfdt_bindgen::FDT_ERR_NOSPACE => FdtError::NoSpace,
- libfdt_bindgen::FDT_ERR_BADOFFSET => FdtError::BadOffset,
- libfdt_bindgen::FDT_ERR_BADPATH => FdtError::BadPath,
- libfdt_bindgen::FDT_ERR_BADPHANDLE => FdtError::BadPhandle,
- libfdt_bindgen::FDT_ERR_BADSTATE => FdtError::BadState,
- libfdt_bindgen::FDT_ERR_TRUNCATED => FdtError::Truncated,
- libfdt_bindgen::FDT_ERR_BADMAGIC => FdtError::BadMagic,
- libfdt_bindgen::FDT_ERR_BADVERSION => FdtError::BadVersion,
- libfdt_bindgen::FDT_ERR_BADSTRUCTURE => FdtError::BadStructure,
- libfdt_bindgen::FDT_ERR_BADLAYOUT => FdtError::BadLayout,
- libfdt_bindgen::FDT_ERR_INTERNAL => FdtError::Internal,
- libfdt_bindgen::FDT_ERR_BADNCELLS => FdtError::BadNCells,
- libfdt_bindgen::FDT_ERR_BADVALUE => FdtError::BadValue,
- libfdt_bindgen::FDT_ERR_BADOVERLAY => FdtError::BadOverlay,
- libfdt_bindgen::FDT_ERR_NOPHANDLES => FdtError::NoPhandles,
- libfdt_bindgen::FDT_ERR_BADFLAGS => FdtError::BadFlags,
- libfdt_bindgen::FDT_ERR_ALIGNMENT => FdtError::Alignment,
- _ => FdtError::Unknown(val),
- })
- }
+ FdtRawResult::from(val).try_into()
}
pub(crate) fn fdt_err_expect_zero(val: c_int) -> Result<()> {
- match fdt_err(val)? {
- 0 => Ok(()),
- _ => Err(FdtError::Unknown(val)),
- }
+ FdtRawResult::from(val).try_into()
}
pub(crate) fn fdt_err_or_option(val: c_int) -> Result<Option<c_int>> {
- match fdt_err(val) {
- Ok(val) => Ok(Some(val)),
- Err(FdtError::NotFound) => Ok(None),
- Err(e) => Err(e),
+ FdtRawResult::from(val).try_into()
+}
+
+#[derive(Clone, Copy, Debug, Eq, PartialEq)]
+pub(crate) struct FdtRawResult(c_int);
+
+impl From<c_int> for FdtRawResult {
+ fn from(value: c_int) -> Self {
+ Self(value)
+ }
+}
+
+impl TryFrom<FdtRawResult> for c_int {
+ type Error = FdtError;
+
+ fn try_from(res: FdtRawResult) -> Result<Self> {
+ use libfdt_bindgen::{
+ FDT_ERR_ALIGNMENT, FDT_ERR_BADFLAGS, FDT_ERR_BADLAYOUT, FDT_ERR_BADMAGIC,
+ FDT_ERR_BADNCELLS, FDT_ERR_BADOFFSET, FDT_ERR_BADOVERLAY, FDT_ERR_BADPATH,
+ FDT_ERR_BADPHANDLE, FDT_ERR_BADSTATE, FDT_ERR_BADSTRUCTURE, FDT_ERR_BADVALUE,
+ FDT_ERR_BADVERSION, FDT_ERR_EXISTS, FDT_ERR_INTERNAL, FDT_ERR_NOPHANDLES,
+ FDT_ERR_NOSPACE, FDT_ERR_NOTFOUND, FDT_ERR_TRUNCATED,
+ };
+ match res.0 {
+ x if x >= 0 => Ok(x),
+ x if x == -(FDT_ERR_NOTFOUND as c_int) => Err(FdtError::NotFound),
+ x if x == -(FDT_ERR_EXISTS as c_int) => Err(FdtError::Exists),
+ x if x == -(FDT_ERR_NOSPACE as c_int) => Err(FdtError::NoSpace),
+ x if x == -(FDT_ERR_BADOFFSET as c_int) => Err(FdtError::BadOffset),
+ x if x == -(FDT_ERR_BADPATH as c_int) => Err(FdtError::BadPath),
+ x if x == -(FDT_ERR_BADPHANDLE as c_int) => Err(FdtError::BadPhandle),
+ x if x == -(FDT_ERR_BADSTATE as c_int) => Err(FdtError::BadState),
+ x if x == -(FDT_ERR_TRUNCATED as c_int) => Err(FdtError::Truncated),
+ x if x == -(FDT_ERR_BADMAGIC as c_int) => Err(FdtError::BadMagic),
+ x if x == -(FDT_ERR_BADVERSION as c_int) => Err(FdtError::BadVersion),
+ x if x == -(FDT_ERR_BADSTRUCTURE as c_int) => Err(FdtError::BadStructure),
+ x if x == -(FDT_ERR_BADLAYOUT as c_int) => Err(FdtError::BadLayout),
+ x if x == -(FDT_ERR_INTERNAL as c_int) => Err(FdtError::Internal),
+ x if x == -(FDT_ERR_BADNCELLS as c_int) => Err(FdtError::BadNCells),
+ x if x == -(FDT_ERR_BADVALUE as c_int) => Err(FdtError::BadValue),
+ x if x == -(FDT_ERR_BADOVERLAY as c_int) => Err(FdtError::BadOverlay),
+ x if x == -(FDT_ERR_NOPHANDLES as c_int) => Err(FdtError::NoPhandles),
+ x if x == -(FDT_ERR_BADFLAGS as c_int) => Err(FdtError::BadFlags),
+ x if x == -(FDT_ERR_ALIGNMENT as c_int) => Err(FdtError::Alignment),
+ x => Err(FdtError::Unknown(x)),
+ }
+ }
+}
+
+impl TryFrom<FdtRawResult> for Option<c_int> {
+ 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;
+
+ fn try_from(res: FdtRawResult) -> Result<Self> {
+ match res.try_into()? {
+ 0 => Ok(()),
+ n => Err(FdtError::Unknown(n)),
+ }
}
}