Update tests for extern block linting

Author: Mark-Simulacrum

compiler/rustc_error_codes/src/error_codes/E0044.md

@@ -3,13 +3,13 @@ You cannot use type or const parameters on foreign items.
 Example of erroneous code:
 
 ```compile_fail,E0044
-extern { fn some_func<T>(x: T); }
+extern "C" { fn some_func<T>(x: T); }
 ```
 
 To fix this, replace the generic parameter with the specializations that you
 need:
 
 ```
-extern { fn some_func_i32(x: i32); }
-extern { fn some_func_i64(x: i64); }
+extern "C" { fn some_func_i32(x: i32); }
+extern "C" { fn some_func_i64(x: i64); }
 ```

compiler/rustc_error_codes/src/error_codes/E0130.md

@@ -3,7 +3,7 @@ A pattern was declared as an argument in a foreign function declaration.
 Erroneous code example:
 
 ```compile_fail,E0130
-extern {
+extern "C" {
     fn foo((a, b): (u32, u32)); // error: patterns aren't allowed in foreign
                                 //        function declarations
 }
@@ -17,15 +17,15 @@ struct SomeStruct {
     b: u32,
 }
 
-extern {
+extern "C" {
     fn foo(s: SomeStruct); // ok!
 }
 ```
 
 Or:
 
 ```
-extern {
+extern "C" {
     fn foo(a: (u32, u32)); // ok!
 }
 ```

compiler/rustc_error_codes/src/error_codes/E0454.md

@@ -3,13 +3,13 @@ A link name was given with an empty name.
 Erroneous code example:
 
 ```compile_fail,E0454
-#[link(name = "")] extern {}
+#[link(name = "")] extern "C" {}
 // error: `#[link(name = "")]` given with empty name
 ```
 
 The rust compiler cannot link to an external library if you don't give it its
 name. Example:
 
 ```no_run
-#[link(name = "some_lib")] extern {} // ok!
+#[link(name = "some_lib")] extern "C" {} // ok!
 ```

compiler/rustc_error_codes/src/error_codes/E0455.md

@@ -4,15 +4,15 @@ as frameworks are specific to that operating system.
 Erroneous code example:
 
 ```ignore (should-compile_fail-but-cannot-doctest-conditionally-without-macos)
-#[link(name = "FooCoreServices", kind = "framework")] extern {}
+#[link(name = "FooCoreServices", kind = "framework")] extern "C" {}
 // OS used to compile is Linux for example
 ```
 
 To solve this error you can use conditional compilation:
 
 ```
 #[cfg_attr(target="macos", link(name = "FooCoreServices", kind = "framework"))]
-extern {}
+extern "C" {}
 ```
 
 Learn more in the [Conditional Compilation][conditional-compilation] section

compiler/rustc_error_codes/src/error_codes/E0458.md

@@ -3,7 +3,7 @@ An unknown "kind" was specified for a link attribute.
 Erroneous code example:
 
 ```compile_fail,E0458
-#[link(kind = "wonderful_unicorn")] extern {}
+#[link(kind = "wonderful_unicorn")] extern "C" {}
 // error: unknown kind: `wonderful_unicorn`
 ```
 

compiler/rustc_error_codes/src/error_codes/E0459.md

@@ -3,13 +3,13 @@ A link was used without a name parameter.
 Erroneous code example:
 
 ```compile_fail,E0459
-#[link(kind = "dylib")] extern {}
+#[link(kind = "dylib")] extern "C" {}
 // error: `#[link(...)]` specified without `name = "foo"`
 ```
 
 Please add the name parameter to allow the rust compiler to find the library
 you want. Example:
 
 ```no_run
-#[link(kind = "dylib", name = "some_lib")] extern {} // ok!
+#[link(kind = "dylib", name = "some_lib")] extern "C" {} // ok!
 ```

compiler/rustc_error_codes/src/error_codes/E0617.md

@@ -3,7 +3,7 @@ Attempted to pass an invalid type of variable into a variadic function.
 Erroneous code example:
 
 ```compile_fail,E0617
-extern {
+extern "C" {
     fn printf(c: *const i8, ...);
 }
 
@@ -21,7 +21,7 @@ to import from `std::os::raw`).
 In this case, `c_double` has the same size as `f64` so we can use it directly:
 
 ```no_run
-# extern {
+# extern "C" {
 #     fn printf(c: *const i8, ...);
 # }
 unsafe {

compiler/rustc_error_codes/src/error_codes/E0724.md

@@ -18,7 +18,7 @@ the function inside of an `extern` block.
 ```
 #![feature(ffi_returns_twice)]
 
-extern {
+extern "C" {
    #[ffi_returns_twice] // ok!
    pub fn foo();
 }

compiler/rustc_llvm/src/lib.rs

@@ -38,7 +38,7 @@ pub fn initialize_available_targets() {
         ($cfg:meta, $($method:ident),*) => { {
             #[cfg($cfg)]
             fn init() {
-                extern {
+                extern "C" {
                     $(fn $method();)*
                 }
                 unsafe {

library/core/src/sync/atomic.rs

@@ -809,7 +809,7 @@ impl AtomicBool {
     /// ```ignore (extern-declaration)
     /// # fn main() {
     /// use std::sync::atomic::AtomicBool;
-    /// extern {
+    /// extern "C" {
     ///     fn my_atomic_op(arg: *mut bool);
     /// }
     ///
@@ -2068,7 +2068,7 @@ macro_rules! atomic_int {
             /// # fn main() {
             #[doc = concat!($extra_feature, "use std::sync::atomic::", stringify!($atomic_type), ";")]
             ///
-            /// extern {
+            /// extern "C" {
             #[doc = concat!("    fn my_atomic_op(arg: *mut ", stringify!($int_type), ");")]
             /// }
             ///

library/std/src/ffi/c_str.rs

@@ -86,7 +86,7 @@ use crate::sys;
 /// use std::ffi::CString;
 /// use std::os::raw::c_char;
 ///
-/// extern {
+/// extern "C" {
 ///     fn my_printer(s: *const c_char);
 /// }
 ///
@@ -144,7 +144,7 @@ pub struct CString {
 /// use std::ffi::CStr;
 /// use std::os::raw::c_char;
 ///
-/// extern { fn my_string() -> *const c_char; }
+/// extern "C" { fn my_string() -> *const c_char; }
 ///
 /// unsafe {
 ///     let slice = CStr::from_ptr(my_string());
@@ -159,7 +159,7 @@ pub struct CString {
 /// use std::os::raw::c_char;
 ///
 /// fn work(data: &CStr) {
-///     extern { fn work_with(data: *const c_char); }
+///     extern "C" { fn work_with(data: *const c_char); }
 ///
 ///     unsafe { work_with(data.as_ptr()) }
 /// }
@@ -174,7 +174,7 @@ pub struct CString {
 /// use std::ffi::CStr;
 /// use std::os::raw::c_char;
 ///
-/// extern { fn my_string() -> *const c_char; }
+/// extern "C" { fn my_string() -> *const c_char; }
 ///
 /// fn my_string_safe() -> String {
 ///     unsafe {
@@ -359,7 +359,7 @@ impl CString {
     /// use std::ffi::CString;
     /// use std::os::raw::c_char;
     ///
-    /// extern { fn puts(s: *const c_char); }
+    /// extern "C" { fn puts(s: *const c_char); }
     ///
     /// let to_print = CString::new("Hello!").expect("CString::new failed");
     /// unsafe {
@@ -465,7 +465,7 @@ impl CString {
     /// use std::ffi::CString;
     /// use std::os::raw::c_char;
     ///
-    /// extern {
+    /// extern "C" {
     ///     fn some_extern_function(s: *mut c_char);
     /// }
     ///
@@ -1147,7 +1147,7 @@ impl CStr {
     /// use std::ffi::CStr;
     /// use std::os::raw::c_char;
     ///
-    /// extern {
+    /// extern "C" {
     ///     fn my_string() -> *const c_char;
     /// }
     ///

src/doc/unstable-book/src/language-features/link-args.md

@@ -15,7 +15,7 @@ usage would be:
 #![feature(link_args)]
 
 #[link_args = "-foo -bar -baz"]
-extern {}
+extern "C" {}
 # fn main() {}
 ```
 

src/test/codegen/call-llvm-intrinsics.rs

@@ -13,7 +13,7 @@ impl Drop for A {
     }
 }
 
-extern {
+extern "C" {
     #[link_name = "llvm.sqrt.f32"]
     fn sqrt(x: f32) -> f32;
 }

src/test/codegen/dealloc-no-unwind.rs

@@ -8,7 +8,7 @@ struct A;
 
 impl Drop for A {
     fn drop(&mut self) {
-        extern { fn foo(); }
+        extern "C" { fn foo(); }
         unsafe { foo(); }
     }
 }

src/test/codegen/debug-column.rs

@@ -18,7 +18,7 @@ fn main() {
     }
 }
 
-extern {
+extern "C" {
     fn giraffe();
     fn turtle();
 }

src/test/codegen/ffi-const.rs

@@ -4,7 +4,7 @@
 
 pub fn bar() { unsafe { foo() } }
 
-extern {
+extern "C" {
     // CHECK-LABEL: declare void @foo()
     // CHECK-SAME: [[ATTRS:#[0-9]+]]
     // CHECK-DAG: attributes [[ATTRS]] = { {{.*}}readnone{{.*}} }

src/test/codegen/ffi-out-of-bounds-loads.rs

@@ -11,7 +11,7 @@ struct S {
     f3: i32,
 }
 
-extern {
+extern "C" {
     fn foo(s: S);
 }
 

src/test/codegen/ffi-pure.rs

@@ -4,7 +4,7 @@
 
 pub fn bar() { unsafe { foo() } }
 
-extern {
+extern "C" {
     // CHECK-LABEL: declare void @foo()
     // CHECK-SAME: [[ATTRS:#[0-9]+]]
     // CHECK-DAG: attributes [[ATTRS]] = { {{.*}}readonly{{.*}} }

src/test/codegen/ffi-returns-twice.rs

@@ -4,7 +4,7 @@
 
 pub fn bar() { unsafe { foo() } }
 
-extern {
+extern "C" {
     // CHECK-LABEL: declare void @foo()
     // CHECK-SAME: [[ATTRS:#[0-9]+]]
     // CHECK-DAG: attributes [[ATTRS]] = { {{.*}}returns_twice{{.*}} }

src/test/codegen/riscv-abi/call-llvm-intrinsics.rs

@@ -13,7 +13,7 @@ impl Drop for A {
     }
 }
 
-extern {
+extern "C" {
     #[link_name = "llvm.sqrt.f32"]
     fn sqrt(x: f32) -> f32;
 }

src/test/codegen/unwind-extern-imports.rs

@@ -4,7 +4,7 @@
 #![crate_type = "lib"]
 #![feature(unwind_attributes)]
 
-extern {
+extern "C" {
 // CHECK: Function Attrs:{{.*}}nounwind
 // CHECK-NEXT: declare void @extern_fn
     fn extern_fn();