From 5afb34b2487cf0fc0ebe20cd127a575f0624e7d5 Mon Sep 17 00:00:00 2001
From: Andrew Walbran <qwandor@google.com>
Date: Wed, 3 Aug 2022 09:51:02 +0000
Subject: Add methods to construct errors from Rust strings.

This is more convenient in most cases than a CStr, and will let callers
stop duplicating the code to convert it.

Bug: 234019127
Test: atest compos_key_tests MicrodroidHostTestCases MicrodroidTestApp libbinder_rs-internal_test
Change-Id: Idc6684f22f33d4ff79d2326499d089dc85e213ea
---
 libs/binder/rust/src/error.rs | 57 ++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 56 insertions(+), 1 deletion(-)

diff --git a/libs/binder/rust/src/error.rs b/libs/binder/rust/src/error.rs
index 2598ebc804..f6b09ed8fe 100644
--- a/libs/binder/rust/src/error.rs
+++ b/libs/binder/rust/src/error.rs
@@ -18,7 +18,7 @@ use crate::binder::AsNative;
 use crate::sys;
 
 use std::error;
-use std::ffi::CStr;
+use std::ffi::{CStr, CString};
 use std::fmt::{Debug, Display, Formatter, Result as FmtResult};
 use std::result;
 
@@ -104,6 +104,10 @@ unsafe impl Sync for Status {}
 // A thread-local `AStatus` would not be valid.
 unsafe impl Send for Status {}
 
+fn to_cstring<T: AsRef<str>>(message: T) -> Option<CString> {
+    CString::new(message.as_ref()).ok()
+}
+
 impl Status {
     /// Create a status object representing a successful transaction.
     pub fn ok() -> Self {
@@ -146,6 +150,11 @@ impl Status {
         Self(ptr)
     }
 
+    /// Creates a status object from a service specific error.
+    pub fn new_service_specific_error_str<T: AsRef<str>>(err: i32, message: Option<T>) -> Status {
+        Self::new_service_specific_error(err, message.and_then(to_cstring).as_deref())
+    }
+
     /// Create a status object from an exception code
     pub fn new_exception(exception: ExceptionCode, message: Option<&CStr>) -> Status {
         if let Some(message) = message {
@@ -158,6 +167,14 @@ impl Status {
         }
     }
 
+    /// Creates a status object from an exception code and message.
+    pub fn new_exception_str<T: AsRef<str>>(
+        exception: ExceptionCode,
+        message: Option<T>,
+    ) -> Status {
+        Self::new_exception(exception, message.and_then(to_cstring).as_deref())
+    }
+
     /// Create a status object from a raw `AStatus` pointer.
     ///
     /// # Safety
@@ -371,3 +388,41 @@ unsafe impl AsNative<sys::AStatus> for Status {
         self.0
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn make_service_specific_error() {
+        let status = Status::new_service_specific_error_str(-42, Some("message"));
+
+        assert!(!status.is_ok());
+        assert_eq!(status.exception_code(), ExceptionCode::SERVICE_SPECIFIC);
+        assert_eq!(status.service_specific_error(), -42);
+        assert_eq!(
+            status.get_description(),
+            "Status(-8, EX_SERVICE_SPECIFIC): '-42: message'".to_string()
+        );
+    }
+
+    #[test]
+    fn make_exception() {
+        let status = Status::new_exception_str(ExceptionCode::ILLEGAL_STATE, Some("message"));
+
+        assert!(!status.is_ok());
+        assert_eq!(status.exception_code(), ExceptionCode::ILLEGAL_STATE);
+        assert_eq!(status.service_specific_error(), 0);
+        assert_eq!(status.get_description(), "Status(-5, EX_ILLEGAL_STATE): 'message'".to_string());
+    }
+
+    #[test]
+    fn make_exception_null() {
+        let status = Status::new_exception_str(ExceptionCode::ILLEGAL_STATE, Some("one\0two"));
+
+        assert!(!status.is_ok());
+        assert_eq!(status.exception_code(), ExceptionCode::ILLEGAL_STATE);
+        assert_eq!(status.service_specific_error(), 0);
+        assert_eq!(status.get_description(), "Status(-5, EX_ILLEGAL_STATE): ''".to_string());
+    }
+}
-- 
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