Add Display implementation for newtype wrappers (#301)

Previously the newtype implementations didn't implement the `Display` trait. Now the `Display` trait is implemented on any newtype that uses one of `impl_newtype` or `impl_newtype_for_bytestruct`. Renamed the internal macro `new_type_accessors_impls` to `impl_newtype` for consistency.
mobilecoinfoundation · Mar 22, 2023 · 45d890a · 45d890a
2 parents 5921c23 + 6a993f4
commit 45d890a
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Showing 11 changed files with 148 additions and 46 deletions.
diff --git a/core/types/Cargo.toml b/core/types/Cargo.toml
@@ -13,9 +13,7 @@ rust-version = "1.62.1"
 
 [features]
 default = []
-serde = [
-    "dep:serde"
-]
+serde = ["dep:serde"]
 alloc = []
 
 [dependencies]
@@ -34,4 +32,5 @@ getrandom = { version = "0.2", default-features = false, features = ["custom"] }
 
 [dev-dependencies]
 rand = "0.8.5"
+textwrap = "0.16.0"
 yare = "1.0.1"
diff --git a/core/types/src/attestation_key.rs b/core/types/src/attestation_key.rs
@@ -2,7 +2,7 @@
 //! Attestation Key types
 
 use crate::{
-    new_type_accessors_impls,
+    impl_newtype,
     report::{ExtendedProductId, FamilyId},
     ConfigId, FfiError,
 };
@@ -49,15 +49,15 @@ impl TryFrom<u32> for Algorithm {
 #[repr(transparent)]
 pub struct Version(u16);
 
-new_type_accessors_impls! {
+impl_newtype! {
     Version, u16;
 }
 
 #[derive(Debug, Default, Clone, Hash, PartialEq, Eq)]
 #[repr(transparent)]
 pub struct Id(u16);
 
-new_type_accessors_impls! {
+impl_newtype! {
     Id, u16;
 }
 
@@ -145,7 +145,7 @@ impl AttestationKeyId {
     }
 }
 
-new_type_accessors_impls! {
+impl_newtype! {
     AttestationKeyId, sgx_ql_att_key_id_t;
 }
 
@@ -154,7 +154,7 @@ new_type_accessors_impls! {
 #[repr(transparent)]
 pub struct ServiceProviderId([u8; 16]);
 
-new_type_accessors_impls! {
+impl_newtype! {
     ServiceProviderId, [u8; 16];
 }
 
@@ -180,7 +180,7 @@ impl ExtendedAttestationKeyId {
     }
 }
 
-new_type_accessors_impls! {
+impl_newtype! {
     ExtendedAttestationKeyId, sgx_att_key_id_ext_t;
 }
 

diff --git a/core/types/src/attributes.rs b/core/types/src/attributes.rs
@@ -2,14 +2,14 @@
 
 //! SGX Attributes types
 
-use crate::new_type_accessors_impls;
+use crate::impl_newtype;
 use mc_sgx_core_sys_types::{sgx_attributes_t, sgx_misc_attribute_t, sgx_misc_select_t};
 
 /// Attributes of the enclave
 #[repr(transparent)]
 #[derive(Default, Debug, Clone, Hash, PartialEq, Eq, Copy)]
 pub struct Attributes(sgx_attributes_t);
-new_type_accessors_impls! {
+impl_newtype! {
     Attributes, sgx_attributes_t;
 }
 
@@ -40,7 +40,7 @@ impl Attributes {
 #[derive(Debug, Clone, Copy, Hash, PartialEq, Eq, Default)]
 pub struct MiscellaneousSelect(sgx_misc_select_t);
 
-new_type_accessors_impls! {
+impl_newtype! {
     MiscellaneousSelect, sgx_misc_select_t;
 }
 
@@ -49,7 +49,7 @@ new_type_accessors_impls! {
 #[derive(Debug, Clone, Hash, PartialEq, Eq)]
 pub struct MiscellaneousAttribute(sgx_misc_attribute_t);
 
-new_type_accessors_impls! {
+impl_newtype! {
     MiscellaneousAttribute, sgx_misc_attribute_t;
 }
 

diff --git a/core/types/src/config_id.rs b/core/types/src/config_id.rs
@@ -1,15 +1,15 @@
 // Copyright (c) 2022-2023 The MobileCoin Foundation
 //! SGX Config ID
 
-use crate::new_type_accessors_impls;
+use crate::impl_newtype;
 use mc_sgx_core_sys_types::{sgx_config_id_t, SGX_CONFIGID_SIZE};
 
 /// Config ID
 #[derive(Debug, Clone, Hash, PartialEq, Eq)]
 #[repr(transparent)]
 pub struct ConfigId(sgx_config_id_t);
 
-new_type_accessors_impls! {
+impl_newtype! {
     ConfigId, sgx_config_id_t;
 }
 

diff --git a/core/types/src/key_request.rs b/core/types/src/key_request.rs
@@ -2,7 +2,7 @@
 //! SGX key request rust types
 
 use crate::{
-    impl_newtype_for_bytestruct, new_type_accessors_impls, Attributes, ConfigSvn, CpuSvn, IsvSvn,
+    impl_newtype, impl_newtype_for_bytestruct, Attributes, ConfigSvn, CpuSvn, IsvSvn,
     MiscellaneousSelect,
 };
 use bitflags::bitflags;
@@ -73,7 +73,7 @@ bitflags! {
 #[derive(Debug, Clone, Hash, PartialEq, Eq)]
 #[repr(transparent)]
 pub struct KeyRequest(sgx_key_request_t);
-new_type_accessors_impls! {
+impl_newtype! {
     KeyRequest, sgx_key_request_t;
 }
 
@@ -189,7 +189,7 @@ impl KeyRequestBuilder {
 #[derive(Default, Debug, Clone, Hash, PartialEq, Eq)]
 pub struct Key128bit(sgx_key_128bit_t);
 
-new_type_accessors_impls! {
+impl_newtype! {
     Key128bit, sgx_key_128bit_t;
 }
 

diff --git a/core/types/src/macros.rs b/core/types/src/macros.rs
@@ -7,7 +7,7 @@ pub(crate) use alloc::vec::Vec;
 /// an SgxWrapperType that don't depend on the contents of the inner
 /// type.
 #[macro_export]
-macro_rules! new_type_accessors_impls {
+macro_rules! newtype_accessors_impls {
     ($($wrapper:ident, $inner:ty;)*) => {$(
         impl AsMut<$inner> for $wrapper {
             fn as_mut(&mut self) -> &mut $inner {
@@ -42,6 +42,23 @@ macro_rules! new_type_accessors_impls {
     )*}
 }
 
+/// Newtype wrapper for a primitive or struct type
+#[macro_export]
+macro_rules! impl_newtype {
+    ($($wrapper:ident, $inner:ty;)*) => {$(
+        $crate::newtype_accessors_impls! {
+            $wrapper, $inner;
+        }
+
+        impl ::core::fmt::Display for $wrapper {
+            fn fmt(&self, f: &mut ::core::fmt::Formatter) -> ::core::fmt::Result {
+                ::core::fmt::Debug::fmt(&self.0, f)
+            }
+        }
+
+    )*}
+}
+
 /// This macro provides common byte-handling operations when the type being
 /// wrapped is a struct containing a single fixed-size array of bytes.
 ///
@@ -50,7 +67,7 @@ macro_rules! new_type_accessors_impls {
 macro_rules! impl_newtype_for_bytestruct {
     ($($wrapper:ident, $inner:ident, $size:ident, $fieldname:ident;)*) => {$(
 
-        $crate::new_type_accessors_impls! {
+        $crate::newtype_accessors_impls! {
             $wrapper, $inner;
         }
 
@@ -74,7 +91,7 @@ macro_rules! impl_newtype_for_bytestruct {
         impl<'bytes> TryFrom<&'bytes [u8]> for $wrapper {
             type Error = $crate::FfiError;
 
-            fn try_from(src: &[u8]) -> core::result::Result<Self, Self::Error> {
+            fn try_from(src: &[u8]) -> ::core::result::Result<Self, Self::Error> {
                 if src.len() < $size {
                     return Err($crate::FfiError::InvalidInputLength);
                 }
@@ -89,7 +106,7 @@ macro_rules! impl_newtype_for_bytestruct {
         impl TryFrom<$crate::macros::Vec<u8>> for $wrapper {
             type Error = $crate::FfiError;
 
-            fn try_from(src: $crate::macros::Vec<u8>) -> core::result::Result<Self, Self::Error> {
+            fn try_from(src: $crate::macros::Vec<u8>) -> ::core::result::Result<Self, Self::Error> {
                 Self::try_from(src.as_slice())
             }
         }
@@ -100,22 +117,48 @@ macro_rules! impl_newtype_for_bytestruct {
             }
         }
 
+        impl ::core::fmt::UpperHex for $wrapper {
+            fn fmt(&self, f: &mut ::core::fmt::Formatter) -> ::core::fmt::Result {
+                let inner: &[u8] = self.as_ref();
+                let prefix = if f.alternate() { "0x" } else { "" };
+                let separators = ::core::iter::once(prefix).chain(::core::iter::repeat("_"));
+                let segments = separators.zip(inner.chunks(2));
+                for (separator, chunk) in segments {
+                    write!(f, "{separator}")?;
+                    for byte in chunk {
+                        write!(f, "{:02X}", byte)?;
+                    }
+                }
+                Ok(())
+            }
+        }
+
+        impl ::core::fmt::Display for $wrapper {
+            fn fmt(&self, f: &mut ::core::fmt::Formatter) -> ::core::fmt::Result {
+                write!(f, "{:#X}", self)
+            }
+        }
+
     )*}
 }
 
 #[cfg(test)]
 mod test {
+    extern crate std;
+
     use crate::FfiError;
+    use std::format;
+    use std::string::ToString;
     use yare::parameterized;
 
     const FIELD_SIZE: usize = 24;
 
-    #[derive(Default, Debug, Clone, Copy, Eq, PartialEq)]
+    #[derive(Default, Debug, Clone, Copy, PartialEq)]
     struct Inner {
         field: [u8; FIELD_SIZE],
     }
 
-    #[derive(Default, Debug, Clone, Copy, Eq, PartialEq)]
+    #[derive(Default, Debug, Clone, PartialEq)]
     #[repr(transparent)]
     struct Outer(Inner);
 
@@ -178,4 +221,65 @@ mod test {
         let outer = Outer::default();
         assert_eq!(outer.0.field, [0u8; Outer::SIZE]);
     }
+
+    #[test]
+    fn newtype_byte_array_display() {
+        let outer = Outer::from([
+            0xABu8, 0x00, 0xcd, 0x12, 0xfe, 0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7, 0x8, 0x9, 0x0a,
+            0x0B, 0x0C, 0x0D, 0x0E, 0x0F, 0x10, 0x11, 0x12, 0x13,
+        ]);
+        assert_eq!(
+            outer.to_string(),
+            "0xAB00_CD12_FE01_0203_0405_0607_0809_0A0B_0C0D_0E0F_1011_1213"
+        );
+    }
+
+    #[derive(Debug, Clone, Copy, PartialEq)]
+    struct StructInner {
+        field: u32,
+    }
+
+    #[repr(transparent)]
+    struct StructOuter(StructInner);
+    impl_newtype! {
+        StructOuter, StructInner;
+    }
+
+    #[repr(transparent)]
+    struct PrimitiveOuter(u32);
+    impl_newtype! {
+        PrimitiveOuter, u32;
+    }
+
+    #[test]
+    fn newtype_for_struct() {
+        let inner = StructInner { field: 30 };
+        let outer: StructOuter = inner.into();
+        assert_eq!(outer.0, inner);
+    }
+
+    #[test]
+    fn display_newtype_for_struct() {
+        let inner = StructInner { field: 20 };
+        let outer: StructOuter = inner.into();
+        assert_eq!(outer.to_string(), "StructInner { field: 20 }");
+    }
+
+    #[test]
+    fn display_newtype_for_struct_alternate() {
+        let inner = StructInner { field: 20 };
+        let outer: StructOuter = inner.into();
+        let expected = r#"
+            StructInner {
+                field: 20,
+            }"#;
+        assert_eq!(format!("\n{outer:#}"), textwrap::dedent(expected));
+    }
+
+    #[test]
+    fn display_newtype_for_primitive() {
+        let inner = 42;
+        let outer: PrimitiveOuter = inner.into();
+        assert_eq!(outer.to_string(), "42");
+    }
 }
diff --git a/core/types/src/quote.rs b/core/types/src/quote.rs
@@ -2,8 +2,8 @@
 //! Quote types
 
 use crate::{
-    attestation_key::QuoteSignatureKind, impl_newtype_for_bytestruct, new_type_accessors_impls,
-    report::Report, FfiError, IsvSvn, ReportBody, TargetInfo,
+    attestation_key::QuoteSignatureKind, impl_newtype, impl_newtype_for_bytestruct, report::Report,
+    FfiError, IsvSvn, ReportBody, TargetInfo,
 };
 use mc_sgx_core_sys_types::{
     sgx_basename_t, sgx_epid_group_id_t, sgx_platform_info_t, sgx_qe_report_info_t,
@@ -32,7 +32,7 @@ impl QuotingEnclaveReportInfo {
     }
 }
 
-new_type_accessors_impls! {
+impl_newtype! {
     QuotingEnclaveReportInfo, sgx_qe_report_info_t;
 }
 
@@ -50,7 +50,7 @@ impl_newtype_for_bytestruct! {
 #[repr(transparent)]
 pub struct UpdateInfoBit(sgx_update_info_bit_t);
 
-new_type_accessors_impls! {
+impl_newtype! {
     UpdateInfoBit, sgx_update_info_bit_t;
 }
 
@@ -76,7 +76,7 @@ impl UpdateInfoBit {
 #[repr(transparent)]
 pub struct EpidGroupId(sgx_epid_group_id_t);
 
-new_type_accessors_impls! {
+impl_newtype! {
     EpidGroupId, sgx_epid_group_id_t;
 }
 
@@ -114,7 +114,7 @@ pub struct RawQuote<'a> {
 #[repr(transparent)]
 pub struct Version(u16);
 
-new_type_accessors_impls! {
+impl_newtype! {
     Version, u16;
 }