Auto merge of #125031 - Oneirical:dynamic-libs, r=jieyouxu

Migrate `run-make/issue-11908` to new `rmake.rs` format
Part of #121876 and the associated [Google Summer of Code project](https://blog.rust-lang.org/2024/05/01/gsoc-2024-selected-projects.html).
Set as draft, because I have a few concerns:
- [x] I am not sure if `target().contains("darwin")` is a good way of checking that the target is on OSX.
- [x] I find it strange that the `dylib` part of the test adapts to different target platforms, but not the `rlib` part. Is `rlib` named the same on all platforms?

Author: bors

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

@@ -40,12 +40,17 @@ pub fn target() -> String {
 
 /// Check if target is windows-like.
 pubfnis_windows() -> bool{
-env::var_os("IS_WINDOWS").is_some()
+target().contains("windows")
 }
 
 /// Check if target uses msvc.
 pubfnis_msvc() -> bool{
- env::var_os("IS_MSVC").is_some()
+target().contains("msvc")
+}
+
+/// Check if target uses macOS.
+pubfnis_darwin() -> bool{
+target().contains("darwin")
 }
 
 /// Construct a path to a static library under `$TMPDIR` given the library name. This will return a
@@ -82,9 +87,47 @@ pub fn static_lib_name(name: &str) -> String {
 // endif
 // endif
 // ```
-assert!(!name.contains(char::is_whitespace),"name cannot contain whitespace");
+assert!(!name.contains(char::is_whitespace),"static library name cannot contain whitespace");
+
+ifis_msvc(){format!("{name}.lib")}else{format!("lib{name}.a")}
+}
+
+/// Construct a path to a dynamic library under `$TMPDIR` given the library name. This will return a
+/// path with `$TMPDIR` joined with platform-and-compiler-specific library name.
+pubfndynamic_lib(name:&str) -> PathBuf{
+tmp_dir().join(dynamic_lib_name(name))
+}
+
+/// Construct the dynamic library name based on the platform.
+pubfndynamic_lib_name(name:&str) -> String{
+// See tools.mk (irrelevant lines omitted):
+//
+// ```makefile
+// ifeq ($(UNAME),Darwin)
+// DYLIB = $(TMPDIR)/lib$(1).dylib
+// else
+// ifdef IS_WINDOWS
+// DYLIB = $(TMPDIR)/$(1).dll
+// else
+// DYLIB = $(TMPDIR)/lib$(1).so
+// endif
+// endif
+// ```
+assert!(!name.contains(char::is_whitespace),"dynamic library name cannot contain whitespace");
+
+ifis_darwin(){
+format!("lib{name}.dylib")
+}elseifis_windows(){
+format!("{name}.dll")
+}else{
+format!("lib{name}.so")
+}
+}
 
-iftarget().contains("msvc"){format!("{name}.lib")}else{format!("lib{name}.a")}
+/// Construct a path to a rust library (rlib) under `$TMPDIR` given the library name. This will return a
+/// path with `$TMPDIR` joined with the library name.
+pubfnrust_lib(name:&str) -> PathBuf{
+tmp_dir().join(format!("lib{name}.rlib"))
 }
 
 /// Construct the binary name based on platform.

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

@@ -91,7 +91,7 @@ impl Rustc {
 self
 }
 
-/// Specify path to the output file.
+/// Specify path to the output file. Equivalent to `-o`` in rustc.
 pubfnoutput<P:AsRef<Path>>(&mutself,path:P) -> &mutSelf{
 self.cmd.arg("-o");
 self.cmd.arg(path.as_ref());
@@ -150,13 +150,7 @@ impl Rustc {
 self
 }
 
-/// Enables link time optimizations in rustc. Equivalent to `-Clto``.
-pubfnlto(&mutself) -> &mutSelf{
-self.cmd.arg("-Clto");
-self
-}
-
-/// Add a directory to the library search path.
+/// Add a directory to the library search path. Equivalent to `-L`` in rustc.
 pubfnlibrary_search_path<P:AsRef<Path>>(&mutself,path:P) -> &mutSelf{
 self.cmd.arg("-L");
 self.cmd.arg(path.as_ref());

src/tools/tidy/src/allowed_run_make_makefiles.txt

@@ -94,7 +94,6 @@ run-make/invalid-staticlib/Makefile
 run-make/issue-107094/Makefile
 run-make/issue-10971-temps-dir/Makefile
 run-make/issue-109934-lto-debuginfo/Makefile
-run-make/issue-11908/Makefile
 run-make/issue-14698/Makefile
 run-make/issue-15460/Makefile
 run-make/issue-18943/Makefile

tests/run-make/issue-11908/Makefile

@@ -9,15 +9,15 @@
 
 //@ ignore-cross-compile
 
-use run_make_support::{cc, extra_c_flags, run, rustc, static_lib, tmp_dir};
+use run_make_support::{cc, extra_c_flags, run, rustc, static_lib};
 
 fnmain(){
 let libbar_path = static_lib("bar");
 rustc().input("foo.rs").crate_type("rlib").run();
 rustc()
 .input("bar.rs")
 .crate_type("staticlib")
-.lto()
+.arg("-Clto")
 .library_search_path(".")
 .output(&libbar_path)
 .run();

tests/run-make/reachable-extern-fn-available-lto/rmake.rs

@@ -0,0 +1,28 @@
+// A path which contains the same rlib or dylib in two locations
+// should not cause an assertion panic in the compiler.
+// This test tries to replicate the linked issue and checks
+// if the bugged error makes a resurgence.
+
+// See https://github.com/rust-lang/rust/issues/11908
+
+//@ ignore-cross-compile
+
+use run_make_support::{dynamic_lib, rust_lib, rustc, tmp_dir};
+use std::fs;
+
+fnmain(){
+let tmp_dir_other = tmp_dir().join("other");
+
+ fs::create_dir(&tmp_dir_other);
+rustc().input("foo.rs").crate_type("dylib").arg("-Cprefer-dynamic").run();
+ fs::rename(dynamic_lib("foo"),&tmp_dir_other);
+rustc().input("foo.rs").crate_type("dylib").arg("-Cprefer-dynamic").run();
+rustc().input("bar.rs").library_search_path(&tmp_dir_other).run();
+ fs::remove_dir_all(tmp_dir());
+
+ fs::create_dir_all(&tmp_dir_other);
+rustc().input("foo.rs").crate_type("rlib").run();
+ fs::rename(rust_lib("foo"),&tmp_dir_other);
+rustc().input("foo.rs").crate_type("rlib").run();
+rustc().input("bar.rs").library_search_path(tmp_dir_other).run();
+}