Re-enable testing of WASI on CI

.github/workflows/full_ci.yml

@@ -118,11 +118,7 @@ jobs:
           powerpc64le-unknown-linux-gnu,
           s390x-unknown-linux-gnu,
           riscv64gc-unknown-linux-gnu,
-          # FIXME: A recent nightly causes a linker failure:
-          # https://github.com/rust-lang/rust/issues/76679
-          # See this comment for more details:
-          # https://github.com/rust-lang/libc/pull/2225#issuecomment-880696737
-          #wasm32-wasi,
+          wasm32-wasip1,
           sparc64-unknown-linux-gnu,
           wasm32-unknown-emscripten,
           x86_64-linux-android,

build.rs

@@ -17,6 +17,7 @@ const ALLOWED_CFGS: &'static [&'static str] = &[
     "libc_const_extern_fn",
     "libc_const_extern_fn_unstable",
     "libc_deny_warnings",
+    "libc_ctest",
 ];
 
 // Extra values to allow for check-cfg.

ci/docker/wasm32-wasip1/Dockerfile

@@ -0,0 +1,32 @@
+FROM ubuntu:24.04
+
+RUN apt-get update && \
+    apt-get install -y --no-install-recommends \
+    ca-certificates \
+    curl \
+    clang \
+    xz-utils
+
+# Wasmtime is used to execute tests and wasi-sdk is used to compile tests.
+# Download appropriate versions here and configure various flags below.
+ENV WASMTIME 24.0.0
+ENV WASI_SDK 24
+
+RUN curl -L https://github.com/bytecodealliance/wasmtime/releases/download/v$WASMTIME/wasmtime-v$WASMTIME-x86_64-linux.tar.xz | \
+  tar xJf -
+ENV PATH=$PATH:/wasmtime-v$WASMTIME-x86_64-linux
+
+RUN curl -LO https://github.com/WebAssembly/wasi-sdk/releases/download/wasi-sdk-$WASI_SDK/wasi-sdk-$WASI_SDK.0-x86_64-linux.deb
+RUN dpkg -i ./wasi-sdk-*.deb
+
+# Note that `-D_WASI_EMULATED_PROCESS_CLOCKS` is used to enable access to
+# clock-related defines even though they're emulated. Also note that the usage
+# of `-Ctarget-feature=-crt-static` here forces usage of the external wasi-libc
+# installed via `wasi-sdk` instead of the version that comes with the standard
+# library.
+ENV CARGO_TARGET_WASM32_WASIP1_RUNNER=wasmtime \
+    CARGO_TARGET_WASM32_WASIP1_LINKER=/opt/wasi-sdk/bin/clang \
+    CARGO_TARGET_WASM32_WASIP1_RUSTFLAGS="-lwasi-emulated-process-clocks -Ctarget-feature=-crt-static" \
+    CC_wasm32_wasip1=/opt/wasi-sdk/bin/clang \
+    CFLAGS_wasm32_wasip1=-D_WASI_EMULATED_PROCESS_CLOCKS \
+    PATH=$PATH:/rust/bin

libc-test/build.rs

@@ -1437,6 +1437,7 @@ fn test_wasi(target: &str) {
         "dirent.h",
         "errno.h",
         "fcntl.h",
+        "langinfo.h",
         "limits.h",
         "locale.h",
         "malloc.h",
@@ -1448,6 +1449,7 @@ fn test_wasi(target: &str) {
         "stdio.h",
         "stdlib.h",
         "string.h",
+        "sys/ioctl.h",
         "sys/resource.h",
         "sys/select.h",
         "sys/socket.h",
@@ -1456,16 +1458,20 @@ fn test_wasi(target: &str) {
         "sys/types.h",
         "sys/uio.h",
         "sys/utsname.h",
-        "sys/ioctl.h",
         "time.h",
         "unistd.h",
         "wasi/api.h",
-        "wasi/libc.h",
         "wasi/libc-find-relpath.h",
         "wasi/libc-nocwd.h",
+        "wasi/libc.h",
         "wchar.h",
     }
 
+    // Currently `ctest2` doesn't support macros-in-static-expressions and will
+    // panic on them. That affects `CLOCK_*` defines in wasi to set this here
+    // to omit them.
+    cfg.cfg("libc_ctest", None);
+
     cfg.type_name(move |ty, is_struct, is_union| match ty {
         "FILE" | "fd_set" | "DIR" => ty.to_string(),
         t if is_union => format!("union {}", t),
@@ -1484,20 +1490,27 @@ fn test_wasi(target: &str) {
         }
     });
 
-    // Looks like LLD doesn't merge duplicate imports, so if the Rust
-    // code imports from a module and the C code also imports from a
-    // module we end up with two imports of function pointers which
-    // import the same thing but have different function pointers
-    cfg.skip_fn_ptrcheck(|f| f.starts_with("__wasi"));
+    // These have a different and internal type in header files and are only
+    // used here to generate a pointer to them in bindings so skip these tests.
+    cfg.skip_static(|c| c.starts_with("_CLOCK_"));
+
+    cfg.skip_fn(|f| match f {
+        // This function doesn't actually exist in libc's header files
+        "__errno_location" => true,
+
+        // The `timeout` argument to this function is `*const` in Rust but
+        // mutable in C which causes a mismatch. Avoiding breakage by changing
+        // this in wasi-libc and instead accepting that this is slightly
+        // different.
+        "select" => true,
+
+        _ => false,
+    });
 
     // d_name is declared as a flexible array in WASI libc, so it
     // doesn't support sizeof.
     cfg.skip_field(|s, field| s == "dirent" && field == "d_name");
 
-    // Currently Rust/clang disagree on function argument ABI, so skip these
-    // tests. For more info see WebAssembly/tool-conventions#88
-    cfg.skip_roundtrip(|_| true);
-
     cfg.generate("../src/lib.rs", "main.rs");
 }
 

src/wasi.rs

@@ -248,14 +248,14 @@ pub const AT_SYMLINK_FOLLOW: c_int = 0x2;
 pub const AT_REMOVEDIR: c_int = 0x4;
 pub const UTIME_OMIT: c_long = 0xfffffffe;
 pub const UTIME_NOW: c_long = 0xffffffff;
-pub const S_IFIFO: mode_t = 0o14_0000;
+pub const S_IFIFO: mode_t = 0o1_0000;
 pub const S_IFCHR: mode_t = 0o2_0000;
 pub const S_IFBLK: mode_t = 0o6_0000;
 pub const S_IFDIR: mode_t = 0o4_0000;
 pub const S_IFREG: mode_t = 0o10_0000;
 pub const S_IFLNK: mode_t = 0o12_0000;
 pub const S_IFSOCK: mode_t = 0o14_0000;
-pub const S_IFMT: mode_t = 0o16_0000;
+pub const S_IFMT: mode_t = 0o17_0000;
 pub const S_IRWXO: mode_t = 0o0007;
 pub const S_IXOTH: mode_t = 0o0001;
 pub const S_IWOTH: mode_t = 0o0002;
@@ -375,17 +375,26 @@ pub const _SC_PAGE_SIZE: ::c_int = _SC_PAGESIZE;
 pub const _SC_IOV_MAX: c_int = 60;
 pub const _SC_SYMLOOP_MAX: c_int = 173;
 
-// unsafe code here is required in the stable, but not in nightly
-#[allow(unused_unsafe)]
-pub static CLOCK_MONOTONIC: clockid_t = unsafe { clockid_t(ptr_addr_of!(_CLOCK_MONOTONIC)) };
-#[allow(unused_unsafe)]
-pub static CLOCK_PROCESS_CPUTIME_ID: clockid_t =
-    unsafe { clockid_t(ptr_addr_of!(_CLOCK_PROCESS_CPUTIME_ID)) };
-#[allow(unused_unsafe)]
-pub static CLOCK_REALTIME: clockid_t = unsafe { clockid_t(ptr_addr_of!(_CLOCK_REALTIME)) };
-#[allow(unused_unsafe)]
-pub static CLOCK_THREAD_CPUTIME_ID: clockid_t =
-    unsafe { clockid_t(ptr_addr_of!(_CLOCK_THREAD_CPUTIME_ID)) };
+cfg_if! {
+    if #[cfg(libc_ctest)] {
+        // skip these constants when this is active because `ctest` currently
+        // panics on parsing the constants below
+    } else {
+        // unsafe code here is required in the stable, but not in nightly
+        #[allow(unused_unsafe)]
+        pub static CLOCK_MONOTONIC: clockid_t =
+            unsafe { clockid_t(ptr_addr_of!(_CLOCK_MONOTONIC)) };
+        #[allow(unused_unsafe)]
+        pub static CLOCK_PROCESS_CPUTIME_ID: clockid_t =
+            unsafe { clockid_t(ptr_addr_of!(_CLOCK_PROCESS_CPUTIME_ID)) };
+        #[allow(unused_unsafe)]
+        pub static CLOCK_REALTIME: clockid_t =
+            unsafe { clockid_t(ptr_addr_of!(_CLOCK_REALTIME)) };
+        #[allow(unused_unsafe)]
+        pub static CLOCK_THREAD_CPUTIME_ID: clockid_t =
+            unsafe { clockid_t(ptr_addr_of!(_CLOCK_THREAD_CPUTIME_ID)) };
+    }
+}
 
 pub const ABDAY_1: ::nl_item = 0x20000;
 pub const ABDAY_2: ::nl_item = 0x20001;