Auto merge of #123402 - workingjubilee:rollup-0j5ihn6, r=workingjubilee

Rollup of 4 pull requests

Successful merges:

 - #122411 ( Provide cabi_realloc on wasm32-wasip2 by default )
 - #123349 (Fix capture analysis for by-move closure bodies)
 - #123359 (Link against libc++abi and libunwind as well when building LLVM wrappers on AIX)
 - #123388 (use a consistent style for links)

r? `@ghost`
`@rustbot` modify labels: rollup

4 files changed, 72 insertions, 11 deletions

diff --git a/library/std/src/fs.rs b/library/std/src/fs.rs
index 9017ba79714..b1102b440e0 100644
--- a/library/std/src/fs.rs
+++ b/library/std/src/fs.rs
@@ -37,7 +37,7 @@ use crate::time::SystemTime;
 ///
 /// # Examples
 ///
-/// Creates a new file and write bytes to it (you can also use [`write()`]):
+/// Creates a new file and write bytes to it (you can also use [`write`]):
 ///
 /// ```no_run
 /// use std::fs::File;
@@ -2018,7 +2018,7 @@ pub fn rename<P: AsRef<Path>, Q: AsRef<Path>>(from: P, to: Q) -> io::Result<()>
 /// the length of the `to` file as reported by `metadata`.
 ///
 /// If you want to copy the contents of one file to another and you’re
-/// working with [`File`]s, see the [`io::copy()`] function.
+/// working with [`File`]s, see the [`io::copy`](io::copy()) function.
 ///
 /// # Platform-specific behavior
 ///
diff --git a/library/std/src/sys/pal/mod.rs b/library/std/src/sys/pal/mod.rs
index 7c87deed371..8c75ac65299 100644
--- a/library/std/src/sys/pal/mod.rs
+++ b/library/std/src/sys/pal/mod.rs
@@ -37,12 +37,12 @@ cfg_if::cfg_if! {
     } else if #[cfg(target_os = "hermit")] {
         mod hermit;
         pub use self::hermit::*;
-    } else if #[cfg(target_os = "wasi")] {
-        mod wasi;
-        pub use self::wasi::*;
     } else if #[cfg(all(target_os = "wasi", target_env = "p2"))] {
         mod wasip2;
         pub use self::wasip2::*;
+    } else if #[cfg(target_os = "wasi")] {
+        mod wasi;
+        pub use self::wasi::*;
     } else if #[cfg(target_family = "wasm")] {
         mod wasm;
         pub use self::wasm::*;
diff --git a/library/std/src/sys/pal/wasip2/cabi_realloc.rs b/library/std/src/sys/pal/wasip2/cabi_realloc.rs
new file mode 100644
index 00000000000..820063173d6
--- /dev/null
+++ b/library/std/src/sys/pal/wasip2/cabi_realloc.rs
@@ -0,0 +1,65 @@
+//! This module contains a canonical definition of the `cabi_realloc` function
+//! for the component model.
+//!
+//! The component model's canonical ABI for representing datatypes in memory
+//! makes use of this function when transferring lists and strings, for example.
+//! This function behaves like C's `realloc` but also takes alignment into
+//! account.
+//!
+//! Components are notably not required to export this function, but nearly
+//! all components end up doing so currently. This definition in the standard
+//! library removes the need for all compilations to define this themselves.
+//!
+//! More information about the canonical ABI can be found at
+//! <https://github.com/WebAssembly/component-model/blob/main/design/mvp/CanonicalABI.md>
+//!
+//! Note that the name of this function is not standardized in the canonical ABI
+//! at this time. Instead it's a convention of the "componentization process"
+//! where a core wasm module is converted to a component to use this name.
+//! Additionally this is not the only possible definition of this function, so
+//! this is defined as a "weak" symbol. This means that other definitions are
+//! allowed to overwrite it if they are present in a compilation.
+
+use crate::alloc::{self, Layout};
+use crate::ptr;
+
+#[used]
+static FORCE_CODEGEN_OF_CABI_REALLOC: unsafe extern "C" fn(
+    *mut u8,
+    usize,
+    usize,
+    usize,
+) -> *mut u8 = cabi_realloc;
+
+#[linkage = "weak"]
+#[no_mangle]
+pub unsafe extern "C" fn cabi_realloc(
+    old_ptr: *mut u8,
+    old_len: usize,
+    align: usize,
+    new_len: usize,
+) -> *mut u8 {
+    let layout;
+    let ptr = if old_len == 0 {
+        if new_len == 0 {
+            return ptr::without_provenance_mut(align);
+        }
+        layout = Layout::from_size_align_unchecked(new_len, align);
+        alloc::alloc(layout)
+    } else {
+        debug_assert_ne!(new_len, 0, "non-zero old_len requires non-zero new_len!");
+        layout = Layout::from_size_align_unchecked(old_len, align);
+        alloc::realloc(old_ptr, layout, new_len)
+    };
+    if ptr.is_null() {
+        // Print a nice message in debug mode, but in release mode don't
+        // pull in so many dependencies related to printing so just emit an
+        // `unreachable` instruction.
+        if cfg!(debug_assertions) {
+            alloc::handle_alloc_error(layout);
+        } else {
+            super::abort_internal();
+        }
+    }
+    return ptr;
+}
diff --git a/library/std/src/sys/pal/wasip2/mod.rs b/library/std/src/sys/pal/wasip2/mod.rs
index d1d444d7b79..94aa458d2f9 100644
--- a/library/std/src/sys/pal/wasip2/mod.rs
+++ b/library/std/src/sys/pal/wasip2/mod.rs
@@ -10,8 +10,6 @@
 pub mod alloc;
 #[path = "../wasi/args.rs"]
 pub mod args;
-#[path = "../unix/cmath.rs"]
-pub mod cmath;
 #[path = "../wasi/env.rs"]
 pub mod env;
 #[path = "../wasi/fd.rs"]
@@ -28,10 +26,6 @@ pub mod io;
 pub mod net;
 #[path = "../wasi/os.rs"]
 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"]
@@ -72,3 +66,5 @@ pub use helpers::decode_error_kind;
 use helpers::err2io;
 pub use helpers::hashmap_random_keys;
 pub use helpers::is_interrupted;
+
+mod cabi_realloc;