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folkertdevfolkertdev
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error on calls to ABIs that cannot be called
1 parent d9ca9bd commit 8a2bc53

14 files changed

+1364
-326
lines changed

‎compiler/rustc_abi/src/extern_abi.rs

Lines changed: 41 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -249,6 +249,47 @@ impl ExternAbi {
249249
_ => false,
250250
}
251251
}
252+
253+
/// Can a function with this ABI be called with a rust call expression?
254+
///
255+
/// Some ABIs cannot be called from rust, either because rust does not know how to
256+
/// generate code for the call, or because a call does not semantically make sense.
257+
pub fn can_be_called_with_call_expr(self) -> bool {
258+
match self {
259+
// Rust doesn't know how to call functions with this ABI.
260+
ExternAbi::Custom => false,
261+
262+
// This is a function for the GPU, and cannot be called by the host.
263+
ExternAbi::PtxKernel | ExternAbi::GpuKernel => false,
264+
265+
// The interrupt ABIs should only be called by the CPU.
266+
// They have complex pre- and postconditions.
267+
ExternAbi::AvrInterrupt
268+
| ExternAbi::AvrNonBlockingInterrupt
269+
| ExternAbi::Msp430Interrupt
270+
| ExternAbi::RiscvInterruptM
271+
| ExternAbi::RiscvInterruptS
272+
| ExternAbi::X86Interrupt => false,
273+
274+
ExternAbi::C { .. }
275+
| ExternAbi::System { .. }
276+
| ExternAbi::Rust
277+
| ExternAbi::RustCall
278+
| ExternAbi::RustCold
279+
| ExternAbi::Unadjusted
280+
| ExternAbi::EfiApi
281+
| ExternAbi::Aapcs { .. }
282+
| ExternAbi::CCmseNonSecureCall
283+
| ExternAbi::CCmseNonSecureEntry
284+
| ExternAbi::Cdecl { .. }
285+
| ExternAbi::Stdcall { .. }
286+
| ExternAbi::Fastcall { .. }
287+
| ExternAbi::Thiscall { .. }
288+
| ExternAbi::Vectorcall { .. }
289+
| ExternAbi::SysV64 { .. }
290+
| ExternAbi::Win64 { .. } => true,
291+
}
292+
}
252293
}
253294

254295
pub fn all_names() -> Vec<&'static str> {

‎compiler/rustc_hir_typeck/messages.ftl

Lines changed: 3 additions & 3 deletions
Original file line numberDiff line numberDiff line change
@@ -1,6 +1,6 @@
1-
hir_typeck_abi_custom_call =
2-
functions with the `"custom"` ABI cannot be called
3-
.note = an `extern "custom"` function can only be called from within inline assembly
1+
hir_typeck_abi_cannot_be_called =
2+
functions with the `"{$abi}"` ABI cannot be called
3+
.note = an `extern "{$abi}"` function can only be called using inline assembly
44
55
hir_typeck_add_missing_parentheses_in_range = you must surround the range in parentheses to call its `{$func_name}` function
66

‎compiler/rustc_hir_typeck/src/callee.rs

Lines changed: 6 additions & 9 deletions
Original file line numberDiff line numberDiff line change
@@ -1,6 +1,5 @@
11
use std::iter;
22

3-
use rustc_abi::ExternAbi;
43
use rustc_ast::util::parser::ExprPrecedence;
54
use rustc_errors::{Applicability, Diag, ErrorGuaranteed, StashKey};
65
use rustc_hir::def::{self, CtorKind, Namespace, Res};
@@ -84,7 +83,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
8483
while result.is_none() && autoderef.next().is_some() {
8584
result = self.try_overloaded_call_step(call_expr, callee_expr, arg_exprs, &autoderef);
8685
}
87-
self.check_call_custom_abi(autoderef.final_ty(false), call_expr.span);
86+
self.check_call_abi(autoderef.final_ty(false), call_expr.span);
8887
self.register_predicates(autoderef.into_obligations());
8988

9089
let output = match result {
@@ -137,19 +136,17 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
137136
output
138137
}
139138

140-
/// Functions of type `extern "custom" fn(/* ... */)` cannot be called using `ExprKind::Call`.
141-
///
142-
/// These functions have a calling convention that is unknown to rust, hence it cannot generate
143-
/// code for the call. The only way to execute such a function is via inline assembly.
144-
fn check_call_custom_abi(&self, callee_ty: Ty<'tcx>, span: Span) {
139+
fn check_call_abi(&self, callee_ty: Ty<'tcx>, span: Span) {
145140
let abi = match callee_ty.kind() {
146141
ty::FnDef(def_id, _) => self.tcx.fn_sig(def_id).skip_binder().skip_binder().abi,
147142
ty::FnPtr(_, header) => header.abi,
148143
_ => return,
149144
};
150145

151-
if let ExternAbi::Custom = abi {
152-
self.tcx.dcx().emit_err(errors::AbiCustomCall { span });
146+
// Some ABIs cannot be called from rust, either because rust does not know how to generate
147+
// code for the call, or because a call does not semantically make sense.
148+
if !abi.can_be_called_with_call_expr() {
149+
self.tcx.dcx().emit_err(crate::errors::AbiCannotBeCalled { span, abi: abi.as_str() });
153150
}
154151
}
155152

‎compiler/rustc_hir_typeck/src/errors.rs

Lines changed: 4 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -1165,8 +1165,10 @@ pub(crate) struct NakedFunctionsMustNakedAsm {
11651165
}
11661166

11671167
#[derive(Diagnostic)]
1168-
#[diag(hir_typeck_abi_custom_call)]
1169-
pub(crate) struct AbiCustomCall {
1168+
#[diag(hir_typeck_abi_cannot_be_called)]
1169+
pub(crate) struct AbiCannotBeCalled {
11701170
#[primary_span]
1171+
#[note]
11711172
pub span: Span,
1173+
pub abi: &'static str,
11721174
}

‎compiler/rustc_hir_typeck/src/expr.rs

Lines changed: 8 additions & 7 deletions
Original file line numberDiff line numberDiff line change
@@ -5,7 +5,7 @@
55
//!
66
//! See [`rustc_hir_analysis::check`] for more context on type checking in general.
77
8-
use rustc_abi::{ExternAbi, FIRST_VARIANT, FieldIdx};
8+
use rustc_abi::{FIRST_VARIANT, FieldIdx};
99
use rustc_ast::util::parser::ExprPrecedence;
1010
use rustc_data_structures::fx::{FxHashMap, FxHashSet};
1111
use rustc_data_structures::stack::ensure_sufficient_stack;
@@ -1651,12 +1651,13 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
16511651
Some(method.def_id),
16521652
);
16531653

1654-
// Functions of type `extern "custom" fn(/* ... */)` cannot be called using
1655-
// `ExprKind::MethodCall`. These functions have a calling convention that is
1656-
// unknown to rust, hence it cannot generate code for the call. The only way
1657-
// to execute such a function is via inline assembly.
1658-
if let ExternAbi::Custom = method.sig.abi {
1659-
self.tcx.dcx().emit_err(crate::errors::AbiCustomCall { span: expr.span });
1654+
// Some ABIs cannot be called from rust, either because rust does not know how to generate
1655+
// code for the call, or because a call does not semantically make sense.
1656+
if !method.sig.abi.can_be_called_with_call_expr() {
1657+
self.tcx.dcx().emit_err(crate::errors::AbiCannotBeCalled {
1658+
span: expr.span,
1659+
abi: method.sig.abi.as_str(),
1660+
});
16601661
}
16611662

16621663
method.sig.output()

‎tests/ui/abi/bad-custom.stderr

Lines changed: 42 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -248,42 +248,84 @@ LL | extern "custom" fn negate(a: i64) -> i64 {
248248
error: functions with the `"custom"` ABI cannot be called
249249
--> $DIR/bad-custom.rs:75:14
250250
|
251+
LL | unsafe { f(x) }
252+
| ^^^^
253+
|
254+
note: an `extern "custom"` function can only be called using inline assembly
255+
--> $DIR/bad-custom.rs:75:14
256+
|
251257
LL | unsafe { f(x) }
252258
| ^^^^
253259

254260
error: functions with the `"custom"` ABI cannot be called
255261
--> $DIR/bad-custom.rs:80:14
256262
|
263+
LL | unsafe { f(x) }
264+
| ^^^^
265+
|
266+
note: an `extern "custom"` function can only be called using inline assembly
267+
--> $DIR/bad-custom.rs:80:14
268+
|
257269
LL | unsafe { f(x) }
258270
| ^^^^
259271

260272
error: functions with the `"custom"` ABI cannot be called
261273
--> $DIR/bad-custom.rs:87:14
262274
|
275+
LL | unsafe { f(x) }
276+
| ^^^^
277+
|
278+
note: an `extern "custom"` function can only be called using inline assembly
279+
--> $DIR/bad-custom.rs:87:14
280+
|
263281
LL | unsafe { f(x) }
264282
| ^^^^
265283

266284
error: functions with the `"custom"` ABI cannot be called
267285
--> $DIR/bad-custom.rs:109:20
268286
|
287+
LL | assert_eq!(double(21), 42);
288+
| ^^^^^^^^^^
289+
|
290+
note: an `extern "custom"` function can only be called using inline assembly
291+
--> $DIR/bad-custom.rs:109:20
292+
|
269293
LL | assert_eq!(double(21), 42);
270294
| ^^^^^^^^^^
271295

272296
error: functions with the `"custom"` ABI cannot be called
273297
--> $DIR/bad-custom.rs:112:29
274298
|
299+
LL | assert_eq!(unsafe { increment(41) }, 42);
300+
| ^^^^^^^^^^^^^
301+
|
302+
note: an `extern "custom"` function can only be called using inline assembly
303+
--> $DIR/bad-custom.rs:112:29
304+
|
275305
LL | assert_eq!(unsafe { increment(41) }, 42);
276306
| ^^^^^^^^^^^^^
277307

278308
error: functions with the `"custom"` ABI cannot be called
279309
--> $DIR/bad-custom.rs:115:17
280310
|
311+
LL | assert!(Thing(41).is_even());
312+
| ^^^^^^^^^^^^^^^^^^^
313+
|
314+
note: an `extern "custom"` function can only be called using inline assembly
315+
--> $DIR/bad-custom.rs:115:17
316+
|
281317
LL | assert!(Thing(41).is_even());
282318
| ^^^^^^^^^^^^^^^^^^^
283319

284320
error: functions with the `"custom"` ABI cannot be called
285321
--> $DIR/bad-custom.rs:118:20
286322
|
323+
LL | assert_eq!(Thing::bitwise_not(42), !42);
324+
| ^^^^^^^^^^^^^^^^^^^^^^
325+
|
326+
note: an `extern "custom"` function can only be called using inline assembly
327+
--> $DIR/bad-custom.rs:118:20
328+
|
287329
LL | assert_eq!(Thing::bitwise_not(42), !42);
288330
| ^^^^^^^^^^^^^^^^^^^^^^
289331

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