bjoernager/rust
bjoernager/rust
1
Fork 0
Code Activity

Explicitly reject const C-variadic functions

Browse source 
Trying to use C-variadics in a const function would previously fail with
an error like "destructor of `VaListImpl<'_>` cannot be evaluated at
compile-time".

Add an explicit check for const C-variadics to provide a clearer error:
"functions cannot be both `const` and C-variadic".
This commit is contained in:
Nicholas Bishop 2023-10-29 17:28:56 -04:00
parent 8508e65895
commit f91b5ceaf2
5 changed files with 120 additions and 22 deletions
Download patch file Download diff file Expand all files Collapse all files

4
compiler/rustc_ast_passes/messages.ftl
View file

@ -42,6 +42,10 @@ ast_passes_const_and_async = functions cannot be both `const` and `async`
.async = `async` because of this .async = `async` because of this
.label = {""} .label = {""}
ast_passes_const_and_c_variadic = functions cannot be both `const` and C-variadic
.const = `const` because of this
.variadic = C-variadic because of this
ast_passes_const_without_body = ast_passes_const_without_body =
free constant item without body free constant item without body
.suggestion = provide a definition for the constant .suggestion = provide a definition for the constant

19
compiler/rustc_ast_passes/src/ast_validation.rs
View file

@ -482,8 +482,11 @@ impl<'a> AstValidator<'a> {
} }
} }
/// Reject C-variadic type unless the function is foreign, /// Reject invalid C-variadic types.
/// or free and `unsafe extern "C"` semantically. ///
/// C-variadics must be:
/// - Non-const
/// - Either foreign, or free and `unsafe extern "C"` semantically
fn check_c_variadic_type(&self, fk: FnKind<'a>) { fn check_c_variadic_type(&self, fk: FnKind<'a>) {
let variadic_spans: Vec<_> = fk let variadic_spans: Vec<_> = fk
.decl() .decl()
@ -497,6 +500,18 @@ impl<'a> AstValidator<'a> {
return; return;
} }
if let Some(header) = fk.header() {
if let Const::Yes(const_span) = header.constness {
let mut spans = variadic_spans.clone();
spans.push(const_span);
self.err_handler().emit_err(errors::ConstAndCVariadic {
spans,
const_span,
variadic_spans: variadic_spans.clone(),
});
}
}
match (fk.ctxt(), fk.header()) { match (fk.ctxt(), fk.header()) {
(Some(FnCtxt::Foreign), _) => return, (Some(FnCtxt::Foreign), _) => return,
(Some(FnCtxt::Free), Some(header)) => match header.ext { (Some(FnCtxt::Free), Some(header)) => match header.ext {

11
compiler/rustc_ast_passes/src/errors.rs
View file

@ -583,6 +583,17 @@ pub struct ConstAndAsync {
pub span: Span, pub span: Span,
} }
#[derive(Diagnostic)]
#[diag(ast_passes_const_and_c_variadic)]
pub struct ConstAndCVariadic {
#[primary_span]
pub spans: Vec<Span>,
#[label(ast_passes_const)]
pub const_span: Span,
#[label(ast_passes_variadic)]
pub variadic_spans: Vec<Span>,
}
#[derive(Diagnostic)] #[derive(Diagnostic)]
#[diag(ast_passes_pattern_in_foreign, code = "E0130")] #[diag(ast_passes_pattern_in_foreign, code = "E0130")]
pub struct PatternInForeign { pub struct PatternInForeign {

15
tests/ui/parser/variadic-ffi-semantic-restrictions.rs
View file

@ -32,6 +32,18 @@ extern "C" fn f3_3(..., x: isize) {}
//~^ ERROR only foreign or `unsafe extern "C"` functions may be C-variadic //~^ ERROR only foreign or `unsafe extern "C"` functions may be C-variadic
//~| ERROR `...` must be the last argument of a C-variadic function //~| ERROR `...` must be the last argument of a C-variadic function
const unsafe extern "C" fn f4_1(x: isize, ...) {}
//~^ ERROR functions cannot be both `const` and C-variadic
const extern "C" fn f4_2(x: isize, ...) {}
//~^ ERROR functions cannot be both `const` and C-variadic
//~| ERROR only foreign or `unsafe extern "C"` functions may be C-variadic
const extern "C" fn f4_3(..., x: isize, ...) {}
//~^ ERROR functions cannot be both `const` and C-variadic
//~| ERROR only foreign or `unsafe extern "C"` functions may be C-variadic
//~| ERROR `...` must be the last argument of a C-variadic function
extern "C" { extern "C" {
fn e_f1(...); fn e_f1(...);
//~^ ERROR C-variadic function must be declared with at least one named argument //~^ ERROR C-variadic function must be declared with at least one named argument
@ -53,6 +65,9 @@ impl X {
fn i_f4(..., x: isize, ...) {} fn i_f4(..., x: isize, ...) {}
//~^ ERROR only foreign or `unsafe extern "C"` functions may be C-variadic //~^ ERROR only foreign or `unsafe extern "C"` functions may be C-variadic
//~| ERROR `...` must be the last argument of a C-variadic function //~| ERROR `...` must be the last argument of a C-variadic function
const fn i_f5(x: isize, ...) {}
//~^ ERROR only foreign or `unsafe extern "C"` functions may be C-variadic
//~| ERROR functions cannot be both `const` and C-variadic
} }
trait T { trait T {

93
tests/ui/parser/variadic-ffi-semantic-restrictions.stderr
View file

@ -76,119 +76,172 @@ error: only foreign or `unsafe extern "C"` functions may be C-variadic
LL | extern "C" fn f3_3(..., x: isize) {} LL | extern "C" fn f3_3(..., x: isize) {}
| ^^^ | ^^^
error: functions cannot be both `const` and C-variadic
--> $DIR/variadic-ffi-semantic-restrictions.rs:35:1
|
LL | const unsafe extern "C" fn f4_1(x: isize, ...) {}
| ^^^^^ `const` because of this ^^^ C-variadic because of this
error: functions cannot be both `const` and C-variadic
--> $DIR/variadic-ffi-semantic-restrictions.rs:38:1
|
LL | const extern "C" fn f4_2(x: isize, ...) {}
| ^^^^^ `const` because of this ^^^ C-variadic because of this
error: only foreign or `unsafe extern "C"` functions may be C-variadic
--> $DIR/variadic-ffi-semantic-restrictions.rs:38:36
|
LL | const extern "C" fn f4_2(x: isize, ...) {}
| ^^^
error: `...` must be the last argument of a C-variadic function
--> $DIR/variadic-ffi-semantic-restrictions.rs:42:26
|
LL | const extern "C" fn f4_3(..., x: isize, ...) {}
| ^^^
error: functions cannot be both `const` and C-variadic
--> $DIR/variadic-ffi-semantic-restrictions.rs:42:1
|
LL | const extern "C" fn f4_3(..., x: isize, ...) {}
| ^^^^^ ^^^ ^^^ C-variadic because of this
| | |
| | C-variadic because of this
| `const` because of this
error: only foreign or `unsafe extern "C"` functions may be C-variadic
--> $DIR/variadic-ffi-semantic-restrictions.rs:42:26
|
LL | const extern "C" fn f4_3(..., x: isize, ...) {}
| ^^^ ^^^
error: C-variadic function must be declared with at least one named argument error: C-variadic function must be declared with at least one named argument
--> $DIR/variadic-ffi-semantic-restrictions.rs:36:13 --> $DIR/variadic-ffi-semantic-restrictions.rs:48:13
| |
LL | fn e_f1(...); LL | fn e_f1(...);
| ^^^ | ^^^
error: `...` must be the last argument of a C-variadic function error: `...` must be the last argument of a C-variadic function
--> $DIR/variadic-ffi-semantic-restrictions.rs:38:13 --> $DIR/variadic-ffi-semantic-restrictions.rs:50:13
| |
LL | fn e_f2(..., x: isize); LL | fn e_f2(..., x: isize);
| ^^^ | ^^^
error: only foreign or `unsafe extern "C"` functions may be C-variadic error: only foreign or `unsafe extern "C"` functions may be C-variadic
--> $DIR/variadic-ffi-semantic-restrictions.rs:45:23 --> $DIR/variadic-ffi-semantic-restrictions.rs:57:23
| |
LL | fn i_f1(x: isize, ...) {} LL | fn i_f1(x: isize, ...) {}
| ^^^ | ^^^
error: C-variadic function must be declared with at least one named argument error: C-variadic function must be declared with at least one named argument
--> $DIR/variadic-ffi-semantic-restrictions.rs:47:13 --> $DIR/variadic-ffi-semantic-restrictions.rs:59:13
| |
LL | fn i_f2(...) {} LL | fn i_f2(...) {}
| ^^^ | ^^^
error: only foreign or `unsafe extern "C"` functions may be C-variadic error: only foreign or `unsafe extern "C"` functions may be C-variadic
--> $DIR/variadic-ffi-semantic-restrictions.rs:47:13 --> $DIR/variadic-ffi-semantic-restrictions.rs:59:13
| |
LL | fn i_f2(...) {} LL | fn i_f2(...) {}
| ^^^ | ^^^
error: `...` must be the last argument of a C-variadic function error: `...` must be the last argument of a C-variadic function
--> $DIR/variadic-ffi-semantic-restrictions.rs:50:13 --> $DIR/variadic-ffi-semantic-restrictions.rs:62:13
| |
LL | fn i_f3(..., x: isize, ...) {} LL | fn i_f3(..., x: isize, ...) {}
| ^^^ | ^^^
error: only foreign or `unsafe extern "C"` functions may be C-variadic error: only foreign or `unsafe extern "C"` functions may be C-variadic
--> $DIR/variadic-ffi-semantic-restrictions.rs:50:13 --> $DIR/variadic-ffi-semantic-restrictions.rs:62:13
| |
LL | fn i_f3(..., x: isize, ...) {} LL | fn i_f3(..., x: isize, ...) {}
| ^^^ ^^^ | ^^^ ^^^
error: `...` must be the last argument of a C-variadic function error: `...` must be the last argument of a C-variadic function
--> $DIR/variadic-ffi-semantic-restrictions.rs:53:13 --> $DIR/variadic-ffi-semantic-restrictions.rs:65:13
| |
LL | fn i_f4(..., x: isize, ...) {} LL | fn i_f4(..., x: isize, ...) {}
| ^^^ | ^^^
error: only foreign or `unsafe extern "C"` functions may be C-variadic error: only foreign or `unsafe extern "C"` functions may be C-variadic
--> $DIR/variadic-ffi-semantic-restrictions.rs:53:13 --> $DIR/variadic-ffi-semantic-restrictions.rs:65:13
| |
LL | fn i_f4(..., x: isize, ...) {} LL | fn i_f4(..., x: isize, ...) {}
| ^^^ ^^^ | ^^^ ^^^
error: functions cannot be both `const` and C-variadic
--> $DIR/variadic-ffi-semantic-restrictions.rs:68:5
|
LL | const fn i_f5(x: isize, ...) {}
| ^^^^^ ^^^ C-variadic because of this
| |
| `const` because of this
error: only foreign or `unsafe extern "C"` functions may be C-variadic error: only foreign or `unsafe extern "C"` functions may be C-variadic
--> $DIR/variadic-ffi-semantic-restrictions.rs:59:23 --> $DIR/variadic-ffi-semantic-restrictions.rs:68:29
|
LL | const fn i_f5(x: isize, ...) {}
| ^^^
error: only foreign or `unsafe extern "C"` functions may be C-variadic
--> $DIR/variadic-ffi-semantic-restrictions.rs:74:23
| |
LL | fn t_f1(x: isize, ...) {} LL | fn t_f1(x: isize, ...) {}
| ^^^ | ^^^
error: only foreign or `unsafe extern "C"` functions may be C-variadic error: only foreign or `unsafe extern "C"` functions may be C-variadic
--> $DIR/variadic-ffi-semantic-restrictions.rs:61:23 --> $DIR/variadic-ffi-semantic-restrictions.rs:76:23
| |
LL | fn t_f2(x: isize, ...); LL | fn t_f2(x: isize, ...);
| ^^^ | ^^^
error: C-variadic function must be declared with at least one named argument error: C-variadic function must be declared with at least one named argument
--> $DIR/variadic-ffi-semantic-restrictions.rs:63:13 --> $DIR/variadic-ffi-semantic-restrictions.rs:78:13
| |
LL | fn t_f3(...) {} LL | fn t_f3(...) {}
| ^^^ | ^^^
error: only foreign or `unsafe extern "C"` functions may be C-variadic error: only foreign or `unsafe extern "C"` functions may be C-variadic
--> $DIR/variadic-ffi-semantic-restrictions.rs:63:13 --> $DIR/variadic-ffi-semantic-restrictions.rs:78:13
| |
LL | fn t_f3(...) {} LL | fn t_f3(...) {}
| ^^^ | ^^^
error: C-variadic function must be declared with at least one named argument error: C-variadic function must be declared with at least one named argument
--> $DIR/variadic-ffi-semantic-restrictions.rs:66:13 --> $DIR/variadic-ffi-semantic-restrictions.rs:81:13
| |
LL | fn t_f4(...); LL | fn t_f4(...);
| ^^^ | ^^^
error: only foreign or `unsafe extern "C"` functions may be C-variadic error: only foreign or `unsafe extern "C"` functions may be C-variadic
--> $DIR/variadic-ffi-semantic-restrictions.rs:66:13 --> $DIR/variadic-ffi-semantic-restrictions.rs:81:13
| |
LL | fn t_f4(...); LL | fn t_f4(...);
| ^^^ | ^^^
error: `...` must be the last argument of a C-variadic function error: `...` must be the last argument of a C-variadic function
--> $DIR/variadic-ffi-semantic-restrictions.rs:69:13 --> $DIR/variadic-ffi-semantic-restrictions.rs:84:13
| |
LL | fn t_f5(..., x: isize) {} LL | fn t_f5(..., x: isize) {}
| ^^^ | ^^^
error: only foreign or `unsafe extern "C"` functions may be C-variadic error: only foreign or `unsafe extern "C"` functions may be C-variadic
--> $DIR/variadic-ffi-semantic-restrictions.rs:69:13 --> $DIR/variadic-ffi-semantic-restrictions.rs:84:13
| |
LL | fn t_f5(..., x: isize) {} LL | fn t_f5(..., x: isize) {}
| ^^^ | ^^^
error: `...` must be the last argument of a C-variadic function error: `...` must be the last argument of a C-variadic function
--> $DIR/variadic-ffi-semantic-restrictions.rs:72:13 --> $DIR/variadic-ffi-semantic-restrictions.rs:87:13
| |
LL | fn t_f6(..., x: isize); LL | fn t_f6(..., x: isize);
| ^^^ | ^^^
error: only foreign or `unsafe extern "C"` functions may be C-variadic error: only foreign or `unsafe extern "C"` functions may be C-variadic
--> $DIR/variadic-ffi-semantic-restrictions.rs:72:13 --> $DIR/variadic-ffi-semantic-restrictions.rs:87:13
| |
LL | fn t_f6(..., x: isize); LL | fn t_f6(..., x: isize);
| ^^^ | ^^^
error: aborting due to 32 previous errors error: aborting due to 40 previous errors