Allow "C-unwind" fn to have C variadics

workingjubilee · workingjubilee · commit 26dccadb476a · 2024-06-22T15:14:14.000-07:00
diff --git a/compiler/rustc_ast_passes/src/ast_validation.rs b/compiler/rustc_ast_passes/src/ast_validation.rs
@@ -637,6 +637,7 @@ impl<'a> AstValidator<'a> {
             (Some(FnCtxt::Foreign), _) => return,
             (Some(FnCtxt::Free), Some(header)) => match header.ext {
                 Extern::Explicit(StrLit { symbol_unescaped: sym::C, .. }, _)
+                | Extern::Explicit(StrLit { symbol_unescaped: sym::C_dash_unwind, .. }, _)
                 | Extern::Implicit(_)
                     if matches!(header.safety, Safety::Unsafe(_)) =>
                 {
diff --git a/compiler/rustc_span/src/symbol.rs b/compiler/rustc_span/src/symbol.rs
@@ -167,6 +167,7 @@ symbols! {
         Break,
         C,
         CStr,
+        C_dash_unwind: "C-unwind",
         CallOnceFuture,
         CallRefFuture,
         Capture,
diff --git a/tests/ui/abi/variadic-ffi.rs b/tests/ui/abi/variadic-ffi.rs
@@ -14,6 +14,10 @@ pub unsafe extern "C" fn test_valist_forward(n: u64, mut ap: ...) -> f64 {
     rust_valist_interesting_average(n, ap.as_va_list())
 }
 
+pub unsafe extern "C-unwind" fn c_unwind_can_forward(n: u64, mut ap: ...) -> f64 {
+    rust_valist_interesting_average(n, ap.as_va_list())
+}
+
 pub unsafe extern "C" fn test_va_copy(_: u64, mut ap: ...) {
     let mut ap2 = ap.clone();
     assert_eq!(rust_valist_interesting_average(2, ap2.as_va_list()) as i64, 30);
@@ -72,6 +76,10 @@ pub fn main() {
         assert_eq!(test_valist_forward(2, 10i64, 10f64, 20i64, 20f64) as i64, 30);
     }
 
+    unsafe {
+        assert_eq!(c_unwind_can_forward(2, 10i64, 10f64, 20i64, 20f64) as i64, 30);
+    }
+
     unsafe {
         test_va_copy(4, 10i64, 10f64, 20i64, 20f64, 30i64, 30f64, 40i64, 40f64);
     }

Original file line number	Diff line number	Diff line change
`@@ -637,6 +637,7 @@ impl<'a> AstValidator<'a> {`
`637`	`637`	`(Some(FnCtxt::Foreign), _) => return,`
`638`	`638`	`(Some(FnCtxt::Free), Some(header)) => match header.ext {`
`639`	`639`	`Extern::Explicit(StrLit { symbol_unescaped: sym::C, .. }, _)`
	`640`	`+ \| Extern::Explicit(StrLit { symbol_unescaped: sym::C_dash_unwind, .. }, _)`
`640`	`641`	`\| Extern::Implicit(_)`
`641`	`642`	`if matches!(header.safety, Safety::Unsafe(_)) =>`
`642`	`643`	`{`
Original file line number	Diff line number	Diff line change
`@@ -14,6 +14,10 @@ pub unsafe extern "C" fn test_valist_forward(n: u64, mut ap: ...) -> f64 {`
`14`	`14`	`rust_valist_interesting_average(n, ap.as_va_list())`
`15`	`15`	`}`
`16`	`16`
	`17`	`+pub unsafe extern "C-unwind" fn c_unwind_can_forward(n: u64, mut ap: ...) -> f64 {`
	`18`	`+ rust_valist_interesting_average(n, ap.as_va_list())`
	`19`	`+}`
	`20`	`+`
`17`	`21`	`pub unsafe extern "C" fn test_va_copy(_: u64, mut ap: ...) {`
`18`	`22`	`let mut ap2 = ap.clone();`
`19`	`23`	`assert_eq!(rust_valist_interesting_average(2, ap2.as_va_list()) as i64, 30);`
`@@ -72,6 +76,10 @@ pub fn main() {`
`72`	`76`	`assert_eq!(test_valist_forward(2, 10i64, 10f64, 20i64, 20f64) as i64, 30);`
`73`	`77`	`}`
`74`	`78`
	`79`	`+ unsafe {`
	`80`	`+ assert_eq!(c_unwind_can_forward(2, 10i64, 10f64, 20i64, 20f64) as i64, 30);`
	`81`	`+ }`
	`82`	`+`
`75`	`83`	`unsafe {`
`76`	`84`	`test_va_copy(4, 10i64, 10f64, 20i64, 20f64, 30i64, 30f64, 40i64, 40f64);`
`77`	`85`	`}`