chore: upgrade toolchain to nightly-2025-08-18 (#1069)

- upgrade toolchain to nightly-2025-08-18
- upgrade edition to 2024 (some previous used nightly features are
stabilized)

Author: lightsing

.github/workflows/lints.yml

@@ -25,7 +25,7 @@ jobs:
           components: rustfmt, clippy
           targets: riscv32im-unknown-none-elf
           # TODO: figure out way to keep this in sync with rust-toolchain.toml automatically
-          toolchain: nightly-2025-03-25
+          toolchain: nightly-2025-08-18
       - name: Cargo cache
         uses: actions/cache@v4
         with:

.github/workflows/tests.yml

@@ -24,7 +24,7 @@ jobs:
         with:
           targets: riscv32im-unknown-none-elf
           # TODO: figure out way to keep this in sync with rust-toolchain.toml automatically
-          toolchain: nightly-2025-03-25
+          toolchain: nightly-2025-08-18
       - name: Cargo cache
         uses: actions/cache@v4
         with:

Cargo.toml

@@ -13,7 +13,7 @@ resolver = "2"
 
 [workspace.package]
 categories = ["cryptography", "zk", "blockchain", "ceno"]
-edition = "2021"
+edition = "2024"
 keywords = ["cryptography", "zk", "blockchain", "ceno"]
 license = "MIT OR Apache-2.0"
 readme = "README.md"

ceno_cli/example/Cargo.toml

@@ -1,6 +1,6 @@
 [workspace]
 [package]
-edition = "2021"
+edition = "2024"
 license = "MIT OR Apache-2.0"
 name = "ceno_example"
 version = "0.1.0"

ceno_emul/src/addr.rs

@@ -89,7 +89,7 @@ impl ByteAddr {
     }
 
     pub const fn is_aligned(&self) -> bool {
-        self.0 % WORD_SIZE as u32 == 0
+        self.0.is_multiple_of(WORD_SIZE as u32)
     }
 
     pub const fn is_null(&self) -> bool {

ceno_emul/src/elf.rs

@@ -97,7 +97,7 @@ impl Program {
             .e_entry
             .try_into()
             .map_err(|err| anyhow!("e_entry was larger than 32 bits. {err}"))?;
-        if entry >= max_mem || entry % WORD_SIZE as u32 != 0 {
+        if entry >= max_mem || !entry.is_multiple_of(WORD_SIZE as u32) {
             bail!("Invalid entrypoint");
         }
         let segments = elf.segments().ok_or(anyhow!("Missing segment table"))?;
@@ -136,7 +136,7 @@ impl Program {
                     return Err(anyhow!("only support one executable segment"));
                 }
             }
-            if vaddr % WORD_SIZE as u32 != 0 {
+            if !vaddr.is_multiple_of(WORD_SIZE as u32) {
                 bail!("vaddr {vaddr:08x} is unaligned");
             }
             tracing::debug!(
@@ -270,10 +270,11 @@ fn collect_addr_symbols_mapping<'data>(
 
     if let Some((symtab, strtab)) = elf.symbol_table()? {
         for symbol in symtab.iter() {
-            if let Ok(name) = strtab.get(symbol.st_name as usize) {
-                if !name.is_empty() && symbol.st_value != 0 {
-                    symbols.insert(symbol.st_value, name.to_string());
-                }
+            if let Ok(name) = strtab.get(symbol.st_name as usize)
+                && !name.is_empty()
+                && symbol.st_value != 0
+            {
+                symbols.insert(symbol.st_value, name.to_string());
             }
         }
     }
@@ -286,5 +287,5 @@ fn find_max_symbol_in_range(
     start: u64,
     end: u64,
 ) -> Option<(&u64, &String)> {
-    symbols.range(start..end).max_by_key(|(&addr, _)| addr)
+    symbols.range(start..end).max_by_key(|&(addr, _)| addr)
 }

ceno_emul/src/syscalls/keccak_permute.rs

@@ -28,7 +28,7 @@ impl From<[Word; KECCAK_WORDS]> for KeccakState {
         KeccakState(
             words
                 .chunks_exact(2)
-                .map(|chunk| (chunk[0] as u64 | ((chunk[1] as u64) << 32)))
+                .map(|chunk| chunk[0] as u64 | ((chunk[1] as u64) << 32))
                 .collect_vec()
                 .try_into()
                 .expect("failed to parse words into [u64; 25]"),

ceno_emul/src/utils.rs

@@ -13,7 +13,7 @@ impl<'a, const LENGTH: usize> MemoryView<'a, LENGTH> {
     /// Creates a new memory segment view
     /// Asserts that `start` is a multiple of `WORD_SIZE`
     pub fn new(vm: &'a VMState, start: u32) -> Self {
-        assert!(start % WORD_SIZE as u32 == 0);
+        assert!(start.is_multiple_of(WORD_SIZE as u32));
         // TODO: do we need stricter alignment requirements for keccak (u64 array)
         MemoryView {
             vm,

ceno_rt/Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 categories = ["cryptography", "zk", "blockchain", "ceno"]
 description = "Ceno runtime library"
-edition = "2021"
+edition = "2024"
 keywords = ["cryptography", "zk", "blockchain", "ceno"]
 license = "MIT OR Apache-2.0"
 name = "ceno_rt"

ceno_rt/riscv32im-ceno-zkvm-elf.json

@@ -26,7 +26,7 @@
   "panic-strategy": "abort",
   "relocation-model": "static",
   "singlethread": true,
-  "target-c-int-width": "32",
+  "target-c-int-width": 32,
   "target-endian": "little",
   "target-pointer-width": "32"
 }