Rollup merge of #109677 - dpaoliello:rawdylib, r=michaelwoerister,wesleywiser

Stabilize raw-dylib, link_ordinal, import_name_type and -Cdlltool

This stabilizes the `raw-dylib` feature (#58713) for all architectures (i.e., `x86` as it is already stable for all other architectures).

Changes:
* Permit the use of the `raw-dylib` link kind for x86, the `link_ordinal` attribute and the `import_name_type` key for the `link` attribute.
* Mark the `raw_dylib` feature as stable.
* Stabilized the `-Zdlltool` argument as `-Cdlltool`.
* Note the path to `dlltool` if invoking it failed (we don't need to do this if `dlltool` returns an error since it prints its path in the error message).
* Adds tests for `-Cdlltool`.
* Adds tests for being unable to find the dlltool executable, and dlltool failing.
* Fixes a bug where we were checking the exit code of dlltool to see if it failed, but dlltool always returns 0 (indicating success), so instead we need to check if anything was written to `stderr`.

NOTE: As previously noted (https://github.com/rust-lang/rust/pull/104218#issuecomment-1315895618) using dlltool within rustc is temporary, but this is not the first time that Rust has added a temporary tool use and argument: https://github.com/rust-lang/rust/pull/104218#issuecomment-1318720482

Big thanks to ``````@tbu-`````` for the first version of this PR (#104218)

3 files changed, 39 insertions, 39 deletions

diff --git a/src/doc/rustc/src/codegen-options/index.md b/src/doc/rustc/src/codegen-options/index.md
index e2b859e705d..1041d502669 100644
--- a/src/doc/rustc/src/codegen-options/index.md
+++ b/src/doc/rustc/src/codegen-options/index.md
@@ -90,6 +90,14 @@ It takes one of the following values:
 For example, for gcc flavor linkers, this issues the `-nodefaultlibs` flag to
 the linker.
 
+## dlltool
+
+On `windows-gnu` targets, this flag controls which dlltool `rustc` invokes to
+generate import libraries when using the [`raw-dylib` link kind](../../reference/items/external-blocks.md#the-link-attribute).
+It takes a path to [the dlltool executable](https://sourceware.org/binutils/docs/binutils/dlltool.html).
+If this flag is not specified, a dlltool executable will be inferred based on
+the host environment and target.
+
 ## embed-bitcode
 
 This flag controls whether or not the compiler embeds LLVM bitcode into object
diff --git a/src/doc/unstable-book/src/language-features/raw-dylib.md b/src/doc/unstable-book/src/language-features/raw-dylib.md
deleted file mode 100644
index 5fd208ae757..00000000000
--- a/src/doc/unstable-book/src/language-features/raw-dylib.md
+++ /dev/null
@@ -1,34 +0,0 @@
-# `raw_dylib`
-
-The tracking issue for this feature is: [#58713]
-
-[#58713]: https://github.com/rust-lang/rust/issues/58713
-
-------------------------
-
-The `raw_dylib` feature allows you to link against the implementations of functions in an `extern`
-block without, on Windows, linking against an import library.
-
-```rust,ignore (partial-example)
-#![feature(raw_dylib)]
-
-#[link(name="library", kind="raw-dylib")]
-extern {
-    fn extern_function(x: i32);
-}
-
-fn main() {
-    unsafe {
-        extern_function(14);
-    }
-}
-```
-
-## Limitations
-
-This feature is unstable for the `x86` architecture, and stable for all other architectures.
-
-This feature is only supported on Windows.
-
-On the `x86` architecture, this feature supports only the `cdecl`, `stdcall`, `system`, `fastcall`, and
-`vectorcall` calling conventions.
diff --git a/src/tools/compiletest/src/header/needs.rs b/src/tools/compiletest/src/header/needs.rs
index 81179480ed8..4a57c61406c 100644
--- a/src/tools/compiletest/src/header/needs.rs
+++ b/src/tools/compiletest/src/header/needs.rs
@@ -116,6 +116,11 @@ pub(super) fn handle_needs(
             ignore_reason: "ignored when dlltool for x86_64 is not present",
         },
         Need {
+            name: "needs-dlltool",
+            condition: cache.dlltool,
+            ignore_reason: "ignored when dlltool for the current architecture is not present",
+        },
+        Need {
             name: "needs-git-hash",
             condition: config.git_hash,
             ignore_reason: "ignored when git hashes have been omitted for building",
@@ -183,6 +188,7 @@ pub(super) struct CachedNeedsConditions {
     rust_lld: bool,
     i686_dlltool: bool,
     x86_64_dlltool: bool,
+    dlltool: bool,
 }
 
 impl CachedNeedsConditions {
@@ -190,6 +196,17 @@ impl CachedNeedsConditions {
         let path = std::env::var_os("PATH").expect("missing PATH environment variable");
         let path = std::env::split_paths(&path).collect::<Vec<_>>();
 
+        // On Windows, dlltool.exe is used for all architectures.
+        #[cfg(windows)]
+        let dlltool = path.iter().any(|dir| dir.join("dlltool.exe").is_file());
+
+        // For non-Windows, there are architecture specific dlltool binaries.
+        #[cfg(not(windows))]
+        let i686_dlltool = path.iter().any(|dir| dir.join("i686-w64-mingw32-dlltool").is_file());
+        #[cfg(not(windows))]
+        let x86_64_dlltool =
+            path.iter().any(|dir| dir.join("x86_64-w64-mingw32-dlltool").is_file());
+
         let target = &&*config.target;
         Self {
             sanitizer_support: std::env::var_os("RUSTC_SANITIZER_SUPPORT").is_some(),
@@ -225,17 +242,26 @@ impl CachedNeedsConditions {
                 .join(if config.host.contains("windows") { "rust-lld.exe" } else { "rust-lld" })
                 .exists(),
 
-            // On Windows, dlltool.exe is used for all architectures.
             #[cfg(windows)]
-            i686_dlltool: path.iter().any(|dir| dir.join("dlltool.exe").is_file()),
+            i686_dlltool: dlltool,
             #[cfg(windows)]
-            x86_64_dlltool: path.iter().any(|dir| dir.join("dlltool.exe").is_file()),
+            x86_64_dlltool: dlltool,
+            #[cfg(windows)]
+            dlltool,
 
             // For non-Windows, there are architecture specific dlltool binaries.
             #[cfg(not(windows))]
-            i686_dlltool: path.iter().any(|dir| dir.join("i686-w64-mingw32-dlltool").is_file()),
+            i686_dlltool,
+            #[cfg(not(windows))]
+            x86_64_dlltool,
             #[cfg(not(windows))]
-            x86_64_dlltool: path.iter().any(|dir| dir.join("x86_64-w64-mingw32-dlltool").is_file()),
+            dlltool: if config.matches_arch("x86") {
+                i686_dlltool
+            } else if config.matches_arch("x86_64") {
+                x86_64_dlltool
+            } else {
+                false
+            },
         }
     }
 }