Update to 1.69.0

compiler/rustc_target/src/spec/mod.rs

@@ -1194,6 +1194,7 @@ supported_targets! {
     ("x86_64-unknown-hermit", x86_64_unknown_hermit),
 
     ("riscv32i-unknown-none-elf", riscv32i_unknown_none_elf),
+    ("riscv32im-risc0-zkvm-elf", riscv32im_risc0_zkvm_elf),
     ("riscv32im-unknown-none-elf", riscv32im_unknown_none_elf),
     ("riscv32imc-unknown-none-elf", riscv32imc_unknown_none_elf),
     ("riscv32imc-esp-espidf", riscv32imc_esp_espidf),

compiler/rustc_target/src/spec/riscv32im_risc0_zkvm_elf.rs

@@ -0,0 +1,36 @@
+use crate::spec::{Cc, LinkerFlavor, Lld, PanicStrategy, RelocModel};
+use crate::spec::{Target, TargetOptions};
+
+pub fn target() -> Target {
+    Target {
+        data_layout: "e-m:e-p:32:32-i64:64-n32-S128".into(),
+        llvm_target: "riscv32".into(),
+        pointer_width: 32,
+        arch: "riscv32".into(),
+
+        options: TargetOptions {
+            os: "zkvm".into(),
+            vendor: "risc0".into(),
+            linker_flavor: LinkerFlavor::Gnu(Cc::No, Lld::Yes),
+            linker: Some("rust-lld".into()),
+            cpu: "generic-rv32".into(),
+
+            // Some crates (*cough* crossbeam) assume you have 64 bit
+            // atomics if the target name is not in a hardcoded list.
+            // Since zkvm is singlethreaded and all operations are
+            // atomic, I guess we can just say we support 64-bit
+            // atomics.
+            max_atomic_width: Some(64),
+            atomic_cas: true,
+
+            features: "+m".into(),
+            executables: true,
+            panic_strategy: PanicStrategy::Abort,
+            relocation_model: RelocModel::Static,
+            emit_debug_gdb_scripts: false,
+            eh_frame_header: false,
+            singlethread: true,
+            ..Default::default()
+        },
+    }
+}

library/std/build.rs

@@ -32,6 +32,7 @@ fn main() {
         || target.contains("solid")
         || target.contains("nintendo-3ds")
         || target.contains("nto")
+        || target.contains("zkvm")
     {
         // These platforms don't have any special requirements.
     } else {

library/std/src/sys/common/alloc.rs

@@ -15,7 +15,7 @@ use crate::ptr;
     target_arch = "asmjs",
     target_arch = "wasm32",
     target_arch = "hexagon",
-    all(target_arch = "riscv32", not(target_os = "espidf")),
+    all(target_arch = "riscv32", not(any(target_os = "espidf", target_os = "zkvm"))),
     all(target_arch = "xtensa", not(target_os = "espidf")),
 ))]
 pub const MIN_ALIGN: usize = 8;
@@ -29,11 +29,11 @@ pub const MIN_ALIGN: usize = 8;
     target_arch = "wasm64",
 ))]
 pub const MIN_ALIGN: usize = 16;
-// The allocator on the esp-idf platform guarantees 4 byte alignment.
-#[cfg(any(
-    all(target_arch = "riscv32", target_os = "espidf"),
+// The allocator on the esp-idf and zkvm platforms guarantee 4 byte alignment.
+#[cfg(all(any(
+    all(target_arch = "riscv32", any(target_os = "espidf", target_os = "zkvm")),
     all(target_arch = "xtensa", target_os = "espidf"),
-))]
+)))]
 pub const MIN_ALIGN: usize = 4;
 
 pub unsafe fn realloc_fallback(

library/std/src/sys/mod.rs

@@ -43,6 +43,9 @@ cfg_if::cfg_if! {
     } else if #[cfg(target_family = "wasm")] {
         mod wasm;
         pub use self::wasm::*;
+    } else if #[cfg(target_os = "zkvm")] {
+        mod zkvm;
+        pub use self::zkvm::*;
     } else if #[cfg(all(target_vendor = "fortanix", target_env = "sgx"))] {
         mod sgx;
         pub use self::sgx::*;

library/std/src/sys/zkvm/abi.rs

@@ -0,0 +1,52 @@
+//! ABI definitions for symbols exported by risc0-zkvm-platform.
+
+// Included here so we don't have to depend on risc0-zkvm-platform.
+//
+// FIXME: Should we move this to the "libc" crate?  It seems like other
+// architectures put a lot of this kind of stuff there.  But there's
+// currently no risc0 fork of the libc crate, so we'd either have to
+// fork it or upstream it.
+
+#![allow(dead_code)]
+pub const DIGEST_WORDS: usize = 8;
+
+/// Standard IO file descriptors for use with sys_read and sys_write.
+pub mod fileno {
+    pub const STDIN: u32 = 0;
+    pub const STDOUT: u32 = 1;
+    pub const STDERR: u32 = 2;
+    pub const JOURNAL: u32 = 3;
+}
+
+extern "C" {
+    // Wrappers around syscalls provided by risc0-zkvm-platform:
+    pub fn sys_halt();
+    pub fn sys_output(output_id: u32, output_value: u32);
+    pub fn sys_sha_compress(
+        out_state: *mut [u32; DIGEST_WORDS],
+        in_state: *const [u32; DIGEST_WORDS],
+        block1_ptr: *const [u32; DIGEST_WORDS],
+        block2_ptr: *const [u32; DIGEST_WORDS],
+    );
+    pub fn sys_sha_buffer(
+        out_state: *mut [u32; DIGEST_WORDS],
+        in_state: *const [u32; DIGEST_WORDS],
+        buf: *const u8,
+        count: u32,
+    );
+    pub fn sys_rand(recv_buf: *mut u32, words: usize);
+    pub fn sys_panic(msg_ptr: *const u8, len: usize) -> !;
+    pub fn sys_log(msg_ptr: *const u8, len: usize);
+    pub fn sys_cycle_count() -> usize;
+    pub fn sys_read(fd: u32, recv_buf: *mut u8, nrequested: usize) -> usize;
+    pub fn sys_write(fd: u32, write_buf: *const u8, nbytes: usize);
+    pub fn sys_getenv(
+        recv_buf: *mut u32,
+        words: usize,
+        varname: *const u8,
+        varname_len: usize,
+    ) -> usize;
+
+    // Allocate memory from global HEAP.
+    pub fn sys_alloc_words(nwords: usize) -> *mut u32;
+}

library/std/src/sys/zkvm/alloc.rs

@@ -0,0 +1,22 @@
+use super::{abi, WORD_SIZE};
+use crate::alloc::{GlobalAlloc, Layout, System};
+
+#[stable(feature = "alloc_system_type", since = "1.28.0")]
+unsafe impl GlobalAlloc for System {
+    #[inline]
+    unsafe fn alloc(&self, layout: Layout) -> *mut u8 {
+        let nwords = layout
+            .align_to(WORD_SIZE)
+            .expect("Unable to align allocation to word size")
+            .pad_to_align()
+            .size()
+            / WORD_SIZE;
+
+        abi::sys_alloc_words(nwords) as *mut u8
+    }
+
+    #[inline]
+    unsafe fn dealloc(&self, _ptr: *mut u8, _layout: Layout) {
+        // this allocator never deallocates memory
+    }
+}

library/std/src/sys/zkvm/env.rs

@@ -0,0 +1,9 @@
+pub mod os {
+    pub const FAMILY: &str = "";
+    pub const OS: &str = "";
+    pub const DLL_PREFIX: &str = "";
+    pub const DLL_SUFFIX: &str = ".elf";
+    pub const DLL_EXTENSION: &str = "elf";
+    pub const EXE_SUFFIX: &str = ".elf";
+    pub const EXE_EXTENSION: &str = "elf";
+}

library/std/src/sys/zkvm/mod.rs

@@ -0,0 +1,50 @@
+//! System bindings for the risc0 zkvm platform
+//!
+//! This module contains the facade (aka platform-specific) implementations of
+//! OS level functionality for zkvm.
+//!
+//! This is all super highly experimental and not actually intended for
+//! wide/production use yet, it's still all in the experimental category. This
+//! will likely change over time.
+
+const WORD_SIZE: usize = core::mem::size_of::<u32>();
+
+pub mod alloc;
+#[path = "../unsupported/args.rs"]
+pub mod args;
+#[path = "../unix/cmath.rs"]
+pub mod cmath;
+pub mod env;
+#[path = "../unsupported/fs.rs"]
+pub mod fs;
+#[path = "../unsupported/io.rs"]
+pub mod io;
+#[path = "../unsupported/net.rs"]
+pub mod net;
+#[path = "../unsupported/once.rs"]
+pub mod once;
+pub mod os;
+#[path = "../unix/os_str.rs"]
+pub mod os_str;
+#[path = "../unix/path.rs"]
+pub mod path;
+#[path = "../unsupported/pipe.rs"]
+pub mod pipe;
+#[path = "../unsupported/process.rs"]
+pub mod process;
+pub mod stdio;
+pub mod thread_local_key;
+#[path = "../unsupported/time.rs"]
+pub mod time;
+
+#[path = "../unsupported/locks/mod.rs"]
+pub mod locks;
+#[path = "../unsupported/thread.rs"]
+pub mod thread;
+
+#[path = "../unsupported/common.rs"]
+#[deny(unsafe_op_in_unsafe_fn)]
+mod common;
+pub use common::*;
+
+mod abi;

library/std/src/sys/zkvm/os.rs

@@ -0,0 +1,125 @@
+use super::{abi, unsupported, WORD_SIZE};
+use crate::error::Error as StdError;
+use crate::ffi::{OsStr, OsString};
+use crate::fmt;
+use crate::io;
+use crate::marker::PhantomData;
+use crate::path::{self, PathBuf};
+use crate::sys_common::FromInner;
+
+pub fn errno() -> i32 {
+    0
+}
+
+pub fn error_string(_errno: i32) -> String {
+    "operation successful".to_string()
+}
+
+pub fn getcwd() -> io::Result<PathBuf> {
+    unsupported()
+}
+
+pub fn chdir(_: &path::Path) -> io::Result<()> {
+    unsupported()
+}
+
+pub struct SplitPaths<'a>(!, PhantomData<&'a ()>);
+
+pub fn split_paths(_unparsed: &OsStr) -> SplitPaths<'_> {
+    panic!("unsupported")
+}
+
+impl<'a> Iterator for SplitPaths<'a> {
+    type Item = PathBuf;
+    fn next(&mut self) -> Option<PathBuf> {
+        self.0
+    }
+}
+
+#[derive(Debug)]
+pub struct JoinPathsError;
+
+pub fn join_paths<I, T>(_paths: I) -> Result<OsString, JoinPathsError>
+where
+    I: Iterator<Item = T>,
+    T: AsRef<OsStr>,
+{
+    Err(JoinPathsError)
+}
+
+impl fmt::Display for JoinPathsError {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        "not supported on this platform yet".fmt(f)
+    }
+}
+
+impl StdError for JoinPathsError {
+    #[allow(deprecated)]
+    fn description(&self) -> &str {
+        "not supported on this platform yet"
+    }
+}
+
+pub fn current_exe() -> io::Result<PathBuf> {
+    unsupported()
+}
+
+pub struct Env(!);
+
+impl Iterator for Env {
+    type Item = (OsString, OsString);
+    fn next(&mut self) -> Option<(OsString, OsString)> {
+        self.0
+    }
+}
+
+pub fn env() -> Env {
+    panic!("not supported on this platform")
+}
+
+pub fn getenv(varname: &OsStr) -> Option<OsString> {
+    let varname = varname.bytes();
+    let nbytes =
+        unsafe { abi::sys_getenv(crate::ptr::null_mut(), 0, varname.as_ptr(), varname.len()) };
+    if nbytes == usize::MAX {
+        return None;
+    }
+
+    let nwords = (nbytes + WORD_SIZE - 1) / WORD_SIZE;
+    let words = unsafe { abi::sys_alloc_words(nwords) };
+
+    let nbytes2 = unsafe { abi::sys_getenv(words, nwords, varname.as_ptr(), varname.len()) };
+    debug_assert_eq!(nbytes, nbytes2);
+
+    // Convert to OsString.
+    //
+    // FIXME: We can probably get rid of the extra copy here if we
+    // reimplement "os_str" instead of just using the generic unix
+    // "os_str".
+    let u8s: &[u8] = unsafe { crate::slice::from_raw_parts(words.cast() as *const u8, nbytes) };
+    Some(OsString::from_inner(super::os_str::Buf { inner: u8s.to_vec() }))
+}
+
+pub fn setenv(_: &OsStr, _: &OsStr) -> io::Result<()> {
+    Err(io::const_io_error!(io::ErrorKind::Unsupported, "cannot set env vars on this platform"))
+}
+
+pub fn unsetenv(_: &OsStr) -> io::Result<()> {
+    Err(io::const_io_error!(io::ErrorKind::Unsupported, "cannot unset env vars on this platform"))
+}
+
+pub fn temp_dir() -> PathBuf {
+    panic!("no filesystem on this platform")
+}
+
+pub fn home_dir() -> Option<PathBuf> {
+    None
+}
+
+pub fn exit(_code: i32) -> ! {
+    crate::intrinsics::abort()
+}
+
+pub fn getpid() -> u32 {
+    panic!("no pids on this platform")
+}