Rollup merge of #124073 - saethlin:rust-get-test-int, r=wesleywiser

matthiaskrgr · web-flow · commit abbe0d0e478e · 2024-04-17T18:01:41.000+02:00
Remove libc from rust_get_test_int uses

`rust_test_helpers.c` has a few unfortunate signatures which have made some of our UI tests _technically_ need the `libc` crate. This is my attempt to evict the need of `libc` for `rust_get_test_int`.

I've deleted `tests/ui/abi/foreign/foreign-no-abi.rs` because the test was originally written to check that `native mod` will compile without an ABI specifier. `native mod` was removed years before 1.0 and the test hasn't checked for anything for a long time.
diff --git a/tests/ui/abi/anon-extern-mod.rs b/tests/ui/abi/anon-extern-mod.rs
@@ -1,13 +1,9 @@
 //@ run-pass
 //@ pretty-expanded FIXME #23616
 
-#![feature(rustc_private)]
-
-extern crate libc;
-
 #[link(name = "rust_test_helpers", kind = "static")]
 extern "C" {
-    fn rust_get_test_int() -> libc::intptr_t;
+    fn rust_get_test_int() -> isize;
 }
 
 pub fn main() {
diff --git a/tests/ui/abi/c-stack-as-value.rs b/tests/ui/abi/c-stack-as-value.rs
@@ -1,14 +1,10 @@
 //@ run-pass
 //@ pretty-expanded FIXME #23616
 
-#![feature(rustc_private)]
-
 mod rustrt {
-    extern crate libc;
-
     #[link(name = "rust_test_helpers", kind = "static")]
     extern "C" {
-        pub fn rust_get_test_int() -> libc::intptr_t;
+        pub fn rust_get_test_int() -> isize;
     }
 }
 
diff --git a/tests/ui/abi/cross-crate/auxiliary/anon-extern-mod-cross-crate-1.rs b/tests/ui/abi/cross-crate/auxiliary/anon-extern-mod-cross-crate-1.rs
@@ -1,9 +1,6 @@
 #![crate_name = "anonexternmod"]
-#![feature(rustc_private)]
-
-extern crate libc;
 
 #[link(name = "rust_test_helpers", kind = "static")]
 extern "C" {
-    pub fn rust_get_test_int() -> libc::intptr_t;
+    pub fn rust_get_test_int() -> isize;
 }
diff --git a/tests/ui/abi/foreign/auxiliary/foreign_lib.rs b/tests/ui/abi/foreign/auxiliary/foreign_lib.rs
@@ -1,28 +1,28 @@
 #![crate_name = "foreign_lib"]
-#![feature(rustc_private)]
 
 pub mod rustrt {
-    extern crate libc;
-
     #[link(name = "rust_test_helpers", kind = "static")]
     extern "C" {
-        pub fn rust_get_test_int() -> libc::intptr_t;
+        pub fn rust_get_test_int() -> isize;
     }
 }
 
 pub mod rustrt2 {
-    extern crate libc;
-
     extern "C" {
-        pub fn rust_get_test_int() -> libc::intptr_t;
+        pub fn rust_get_test_int() -> isize;
     }
 }
 
 pub mod rustrt3 {
-    // Different type, but same ABI (on all supported platforms).
-    // Ensures that we don't ICE or trigger LLVM asserts when
-    // importing the same symbol under different types.
-    // See https://github.com/rust-lang/rust/issues/32740.
+    // The point of this test is to ensure that we don't ICE or trigger LLVM asserts when importing
+    // the same symbol with different types. This is not really possible to test portably; there is
+    // no different signature we can come up with that is different to LLVM but which for sure has
+    // the same behavior on all platforms. The signed-ness of integers is ignored by LLVM as well
+    // as pointee types. So the only ways to make our signatures differ are to use
+    // differently-sized integers which is definitely an ABI mismatch, or to rely on pointers and
+    // isize/usize having the same ABI, which is wrong on CHERI and probably other niche platforms.
+    // If this test causes you trouble, please file an issue.
+    // See https://github.com/rust-lang/rust/issues/32740 for the bug that prompted this test.
     extern "C" {
         pub fn rust_get_test_int() -> *const u8;
     }
@@ -32,6 +32,6 @@ pub fn local_uses() {
     unsafe {
         let x = rustrt::rust_get_test_int();
         assert_eq!(x, rustrt2::rust_get_test_int());
-        assert_eq!(x as *const _, rustrt3::rust_get_test_int());
+        assert_eq!(x as *const u8, rustrt3::rust_get_test_int());
     }
 }
diff --git a/tests/ui/abi/foreign/foreign-dupe.rs b/tests/ui/abi/foreign/foreign-dupe.rs
@@ -4,13 +4,12 @@
 // Check that we can still call duplicated extern (imported) functions
 // which were declared in another crate. See issues #32740 and #32783.
 
-
 extern crate foreign_lib;
 
 pub fn main() {
     unsafe {
         let x = foreign_lib::rustrt::rust_get_test_int();
         assert_eq!(x, foreign_lib::rustrt2::rust_get_test_int());
-        assert_eq!(x as *const _, foreign_lib::rustrt3::rust_get_test_int());
+        assert_eq!(x as *const u8, foreign_lib::rustrt3::rust_get_test_int());
     }
 }
diff --git a/tests/ui/abi/foreign/foreign-no-abi.rs b/tests/ui/abi/foreign/foreign-no-abi.rs
diff --git a/tests/ui/attributes/item-attributes.rs b/tests/ui/attributes/item-attributes.rs
@@ -148,7 +148,7 @@ mod test_foreign_items {
             #![rustc_dummy]
 
             #[rustc_dummy]
-            fn rust_get_test_int() -> u32;
+            fn rust_get_test_int() -> isize;
         }
     }
 }
diff --git a/tests/ui/extern/issue-1251.rs b/tests/ui/extern/issue-1251.rs
@@ -2,13 +2,10 @@
 #![allow(unused_attributes)]
 #![allow(dead_code)]
 //@ pretty-expanded FIXME #23616
-#![feature(rustc_private)]
 
 mod rustrt {
-    extern crate libc;
-
     extern "C" {
-        pub fn rust_get_test_int() -> libc::intptr_t;
+        pub fn rust_get_test_int() -> isize;
     }
 }
 

Original file line number	Diff line number	Diff line change
`@@ -1,14 +1,10 @@`
`1`	`1`	`//@ run-pass`
`2`	`2`	`//@ pretty-expanded FIXME #23616`
`3`	`3`
`4`		`-#![feature(rustc_private)]`
`5`		`-`
`6`	`4`	`mod rustrt {`
`7`		`- extern crate libc;`
`8`		`-`
`9`	`5`	`#[link(name = "rust_test_helpers", kind = "static")]`
`10`	`6`	`extern "C" {`
`11`		`- pub fn rust_get_test_int() -> libc::intptr_t;`
	`7`	`+ pub fn rust_get_test_int() -> isize;`
`12`	`8`	`}`
`13`	`9`	`}`
`14`	`10`
Original file line number	Diff line number	Diff line change
`@@ -4,13 +4,12 @@`
`4`	`4`	`// Check that we can still call duplicated extern (imported) functions`
`5`	`5`	`// which were declared in another crate. See issues #32740 and #32783.`
`6`	`6`
`7`		`-`
`8`	`7`	`extern crate foreign_lib;`
`9`	`8`
`10`	`9`	`pub fn main() {`
`11`	`10`	`unsafe {`
`12`	`11`	`let x = foreign_lib::rustrt::rust_get_test_int();`
`13`	`12`	`assert_eq!(x, foreign_lib::rustrt2::rust_get_test_int());`
`14`		`- assert_eq!(x as *const _, foreign_lib::rustrt3::rust_get_test_int());`
	`13`	`+ assert_eq!(x as *const u8, foreign_lib::rustrt3::rust_get_test_int());`
`15`	`14`	`}`
`16`	`15`	`}`
Original file line number	Diff line number	Diff line change
`@@ -148,7 +148,7 @@ mod test_foreign_items {`
`148`	`148`	`#![rustc_dummy]`
`149`	`149`
`150`	`150`	`#[rustc_dummy]`
`151`		`- fn rust_get_test_int() -> u32;`
	`151`	`+ fn rust_get_test_int() -> isize;`
`152`	`152`	`}`
`153`	`153`	`}`
`154`	`154`	`}`
Original file line number	Diff line number	Diff line change
`@@ -2,13 +2,10 @@`
`2`	`2`	`#![allow(unused_attributes)]`
`3`	`3`	`#![allow(dead_code)]`
`4`	`4`	`//@ pretty-expanded FIXME #23616`
`5`		`-#![feature(rustc_private)]`
`6`	`5`
`7`	`6`	`mod rustrt {`
`8`		`- extern crate libc;`
`9`		`-`
`10`	`7`	`extern "C" {`
`11`		`- pub fn rust_get_test_int() -> libc::intptr_t;`
	`8`	`+ pub fn rust_get_test_int() -> isize;`
`12`	`9`	`}`
`13`	`10`	`}`
`14`	`11`