Auto merge of rust-lang#125872 - fmease:rollup-ei6igof, r=fmease

Rollup of 4 pull requests

Successful merges:

 - rust-lang#124294 (Unroll first iteration of checked_ilog loop)
 - rust-lang#125773 (Migrate run make cdylib)
 - rust-lang#125808 (Migrate `run-make/c-link-to-rust-dylib` to `rmake.rs`)
 - rust-lang#125822 (Refactor `--print=check-cfg` test)

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

Author: bors

library/core/src/num/uint_macros.rs

@@ -1148,9 +1148,12 @@ macro_rules! uint_impl {
         pub const fn checked_ilog(self, base: Self) -> Option<u32> {
             if self <= 0 || base <= 1 {
                 None
+            } else if self < base {
+                Some(0)
             } else {
-                let mut n = 0;
-                let mut r = 1;
+                // Since base >= self, n >= 1
+                let mut n = 1;
+                let mut r = base;
 
                 // Optimization for 128 bit wide integers.
                 if Self::BITS == 128 {

src/tools/run-make-support/src/cc.rs

@@ -80,6 +80,13 @@ impl Cc {
         self
     }
 
+    /// Specify path of the output binary.
+    pub fn output<P: AsRef<Path>>(&mut self, path: P) -> &mut Self {
+        self.cmd.arg("-o");
+        self.cmd.arg(path.as_ref());
+        self
+    }
+
     /// Get the [`Output`][::std::process::Output] of the finished process.
     pub fn command_output(&mut self) -> ::std::process::Output {
         self.cmd.output().expect("failed to get output of finished process")

src/tools/run-make-support/src/lib.rs

@@ -123,12 +123,23 @@ pub fn dynamic_lib_name(name: &str) -> String {
     // ```
     assert!(!name.contains(char::is_whitespace), "dynamic library name cannot contain whitespace");
 
+    let extension = dynamic_lib_extension();
     if is_darwin() {
-        format!("lib{name}.dylib")
+        format!("lib{name}.{extension}")
     } else if is_windows() {
-        format!("{name}.dll")
+        format!("{name}.{extension}")
     } else {
-        format!("lib{name}.so")
+        format!("lib{name}.{extension}")
+    }
+}
+
+pub fn dynamic_lib_extension() -> &'static str {
+    if is_darwin() {
+        "dylib"
+    } else if is_windows() {
+        "dll"
+    } else {
+        "so"
     }
 }
 
@@ -249,16 +260,13 @@ pub fn recursive_diff(dir1: impl AsRef<Path>, dir2: impl AsRef<Path>) {
     }
 
     let dir2 = dir2.as_ref();
-    for entry in fs::read_dir(dir1).unwrap() {
-        let entry = entry.unwrap();
-        let entry_name = entry.file_name();
-        let path = entry.path();
-
-        if path.is_dir() {
-            recursive_diff(&path, &dir2.join(entry_name));
+    read_dir(dir1, |entry_path| {
+        let entry_name = entry_path.file_name().unwrap();
+        if entry_path.is_dir() {
+            recursive_diff(&entry_path, &dir2.join(entry_name));
         } else {
             let path2 = dir2.join(entry_name);
-            let file1 = read_file(&path);
+            let file1 = read_file(&entry_path);
             let file2 = read_file(&path2);
 
             // We don't use `assert_eq!` because they are `Vec<u8>`, so not great for display.
@@ -267,10 +275,16 @@ pub fn recursive_diff(dir1: impl AsRef<Path>, dir2: impl AsRef<Path>) {
             assert!(
                 file1 == file2,
                 "`{}` and `{}` have different content",
-                path.display(),
+                entry_path.display(),
                 path2.display(),
             );
         }
+    });
+}
+
+pub fn read_dir<F: Fn(&Path)>(dir: impl AsRef<Path>, callback: F) {
+    for entry in fs::read_dir(dir).unwrap() {
+        callback(&entry.unwrap().path());
     }
 }
 

src/tools/tidy/src/allowed_run_make_makefiles.txt

@@ -6,15 +6,13 @@ run-make/bare-outfile/Makefile
 run-make/branch-protection-check-IBT/Makefile
 run-make/c-dynamic-dylib/Makefile
 run-make/c-dynamic-rlib/Makefile
-run-make/c-link-to-rust-dylib/Makefile
 run-make/c-static-dylib/Makefile
 run-make/c-static-rlib/Makefile
 run-make/c-unwind-abi-catch-lib-panic/Makefile
 run-make/c-unwind-abi-catch-panic/Makefile
 run-make/cat-and-grep-sanity-check/Makefile
 run-make/cdylib-dylib-linkage/Makefile
 run-make/cdylib-fewer-symbols/Makefile
-run-make/cdylib/Makefile
 run-make/codegen-options-parsing/Makefile
 run-make/comment-section/Makefile
 run-make/compiler-lookup-paths-2/Makefile

tests/codegen/checked_ilog.rs

@@ -0,0 +1,20 @@
+//@ compile-flags: -O
+
+#![crate_type = "lib"]
+
+// Ensure that when val < base, we do not divide or multiply.
+
+// CHECK-LABEL: @checked_ilog
+// CHECK-SAME: (i16 noundef %val, i16 noundef %base)
+#[no_mangle]
+pub fn checked_ilog(val: u16, base: u16) -> Option<u32> {
+    // CHECK-NOT: udiv
+    // CHECK-NOT: mul
+    // CHECK: %[[IS_LESS:.+]] = icmp ult i16 %val, %base
+    // CHECK-NEXT: br i1 %[[IS_LESS]], label %[[TRUE:.+]], label %[[FALSE:.+]]
+    // CHECK: [[TRUE]]:
+    // CHECK-NOT: udiv
+    // CHECK-NOT: mul
+    // CHECK: ret { i32, i32 }
+    val.checked_ilog(base)
+}

tests/run-make/c-link-to-rust-dylib/Makefile

@@ -0,0 +1,41 @@
+// This test checks that C linking with Rust does not encounter any errors, with dynamic libraries.
+// See <https://github.com/rust-lang/rust/issues/10434>.
+
+//@ ignore-cross-compile
+
+use std::fs::remove_file;
+
+use run_make_support::{
+    dynamic_lib_extension, is_msvc, read_dir, run, run_fail, rustc, tmp_dir, Cc,
+};
+
+fn main() {
+    rustc().input("foo.rs").run();
+
+    if is_msvc() {
+        Cc::new().input("bar.c").arg(tmp_dir().join("foo.dll.lib")).out_exe("bar").run();
+    } else {
+        Cc::new()
+            .input("bar.c")
+            .arg("-lfoo")
+            .output(tmp_dir().join("bar"))
+            .library_search_path(tmp_dir())
+            .run();
+    }
+
+    run("bar");
+
+    let expected_extension = dynamic_lib_extension();
+    read_dir(tmp_dir(), |path| {
+        if path.is_file()
+            && path.extension().is_some_and(|ext| ext == expected_extension)
+            && path
+                .file_name()
+                .and_then(|name| name.to_str())
+                .is_some_and(|name| name.starts_with("lib"))
+        {
+            remove_file(path).unwrap();
+        }
+    });
+    run_fail("bar");
+}

tests/run-make/c-link-to-rust-dylib/rmake.rs

@@ -0,0 +1,36 @@
+// This test tries to check that basic cdylib libraries can be compiled and linked successfully
+// with C code, that the cdylib itself can depend on another rlib, and that the library can be built
+// with LTO.
+//
+// - `bar.rs` is a rlib
+// - `foo.rs` is a cdylib that relies on an extern crate `bar` and defines two `extern "C"`
+//   functions:
+//     - `foo()` which calls `bar::bar()`.
+//     - `bar()` which implements basic addition.
+
+//@ ignore-cross-compile
+
+use std::fs::remove_file;
+
+use run_make_support::{cc, dynamic_lib, is_msvc, run, rustc, tmp_dir};
+
+fn main() {
+    rustc().input("bar.rs").run();
+    rustc().input("foo.rs").run();
+
+    if is_msvc() {
+        cc().input("foo.c").arg(tmp_dir().join("foo.dll.lib")).out_exe("foo").run();
+    } else {
+        cc().input("foo.c")
+            .arg("-lfoo")
+            .output(tmp_dir().join("foo"))
+            .library_search_path(tmp_dir())
+            .run();
+    }
+
+    run("foo");
+    remove_file(dynamic_lib("foo")).unwrap();
+
+    rustc().input("foo.rs").arg("-Clto").run();
+    run("foo");
+}