From d97bde059a21211de92344233738ede496df3e32 Mon Sep 17 00:00:00 2001
From: Jubilee Young <workingjubilee@gmail.com>
Date: Tue, 11 Feb 2025 17:22:27 -0800
Subject: [PATCH 1/2] Revert "Stabilize `extended_varargs_abi_support`"
This reverts commit 685f189b4307435b83d625fea397ef36dff4e955.
---
compiler/rustc_feature/src/accepted.rs | 3 --
compiler/rustc_feature/src/unstable.rs | 3 ++
compiler/rustc_hir_analysis/messages.ftl | 2 +-
compiler/rustc_hir_analysis/src/errors.rs | 3 +-
compiler/rustc_hir_analysis/src/lib.rs | 31 ++++++++++-
library/std/src/lib.rs | 1 +
.../extended-varargs-abi-support.md | 10 ++++
...ature-gate-extended_varargs_abi_support.rs | 19 +++++++
...e-gate-extended_varargs_abi_support.stderr | 52 +++++++++++++++++++
tests/ui/c-variadic/variadic-ffi-1.stderr | 2 +-
tests/ui/c-variadic/variadic-ffi-2-arm.rs | 1 +
tests/ui/c-variadic/variadic-ffi-2.rs | 1 +
tests/ui/c-variadic/variadic-ffi-2.stderr | 2 +-
.../cmse-nonsecure-call/generics.rs | 2 +-
.../cmse-nonsecure-call/generics.stderr | 2 +-
tests/ui/error-codes/E0045.stderr | 2 +-
16 files changed, 124 insertions(+), 12 deletions(-)
create mode 100644 src/doc/unstable-book/src/language-features/extended-varargs-abi-support.md
create mode 100644 tests/ui/c-variadic/feature-gate-extended_varargs_abi_support.rs
create mode 100644 tests/ui/c-variadic/feature-gate-extended_varargs_abi_support.stderr
diff --git a/compiler/rustc_feature/src/accepted.rs b/compiler/rustc_feature/src/accepted.rs
index 822cf4982b56a..76ca0d618d555 100644
--- a/compiler/rustc_feature/src/accepted.rs
+++ b/compiler/rustc_feature/src/accepted.rs
@@ -197,9 +197,6 @@ declare_features! (
(accepted, expr_fragment_specifier_2024, "1.83.0", Some(123742)),
/// Allows arbitrary expressions in key-value attributes at parse time.
(accepted, extended_key_value_attributes, "1.54.0", Some(78835)),
- /// Allows using `efiapi`, `aapcs`, `sysv64` and `win64` as calling
- /// convention for functions with varargs.
- (accepted, extended_varargs_abi_support, "1.85.0", Some(100189)),
/// Allows resolving absolute paths as paths from other crates.
(accepted, extern_absolute_paths, "1.30.0", Some(44660)),
/// Allows `extern crate foo as bar;`. This puts `bar` into extern prelude.
diff --git a/compiler/rustc_feature/src/unstable.rs b/compiler/rustc_feature/src/unstable.rs
index a4c5e4800eb4a..ee22d8990fa46 100644
--- a/compiler/rustc_feature/src/unstable.rs
+++ b/compiler/rustc_feature/src/unstable.rs
@@ -487,6 +487,9 @@ declare_features! (
(unstable, exhaustive_patterns, "1.13.0", Some(51085)),
/// Allows explicit tail calls via `become` expression.
(incomplete, explicit_tail_calls, "1.72.0", Some(112788)),
+ /// Allows using `efiapi`, `sysv64` and `win64` as calling convention
+ /// for functions with varargs.
+ (unstable, extended_varargs_abi_support, "1.65.0", Some(100189)),
/// Allows defining `extern type`s.
(unstable, extern_types, "1.23.0", Some(43467)),
/// Allow using 128-bit (quad precision) floating point numbers.
diff --git a/compiler/rustc_hir_analysis/messages.ftl b/compiler/rustc_hir_analysis/messages.ftl
index 258267c5ca929..be731547b31b6 100644
--- a/compiler/rustc_hir_analysis/messages.ftl
+++ b/compiler/rustc_hir_analysis/messages.ftl
@@ -602,7 +602,7 @@ hir_analysis_value_of_associated_struct_already_specified =
.label = re-bound here
.previous_bound_label = `{$item_name}` bound here first
-hir_analysis_variadic_function_compatible_convention = C-variadic function must have a compatible calling convention, like `C`, `cdecl`, `system`, `aapcs`, `win64`, `sysv64` or `efiapi`
+hir_analysis_variadic_function_compatible_convention = C-variadic function must have a compatible calling convention, like {$conventions}
.label = C-variadic function must have a compatible calling convention
hir_analysis_variances_of = {$variances}
diff --git a/compiler/rustc_hir_analysis/src/errors.rs b/compiler/rustc_hir_analysis/src/errors.rs
index 12750543f4bf7..e1e6b677c0061 100644
--- a/compiler/rustc_hir_analysis/src/errors.rs
+++ b/compiler/rustc_hir_analysis/src/errors.rs
@@ -646,10 +646,11 @@ pub(crate) struct MainFunctionGenericParameters {
#[derive(Diagnostic)]
#[diag(hir_analysis_variadic_function_compatible_convention, code = E0045)]
-pub(crate) struct VariadicFunctionCompatibleConvention {
+pub(crate) struct VariadicFunctionCompatibleConvention<'a> {
#[primary_span]
#[label]
pub span: Span,
+ pub conventions: &'a str,
}
#[derive(Diagnostic)]
diff --git a/compiler/rustc_hir_analysis/src/lib.rs b/compiler/rustc_hir_analysis/src/lib.rs
index 3af4318544e96..323b912ca18ad 100644
--- a/compiler/rustc_hir_analysis/src/lib.rs
+++ b/compiler/rustc_hir_analysis/src/lib.rs
@@ -100,6 +100,8 @@ use rustc_middle::middle;
use rustc_middle::mir::interpret::GlobalId;
use rustc_middle::query::Providers;
use rustc_middle::ty::{self, Const, Ty, TyCtxt};
+use rustc_session::parse::feature_err;
+use rustc_span::symbol::sym;
use rustc_span::{ErrorGuaranteed, Span};
use rustc_trait_selection::traits;
@@ -114,9 +116,34 @@ fn require_c_abi_if_c_variadic(
abi: ExternAbi,
span: Span,
) {
- if decl.c_variadic && !abi.supports_varargs() {
- tcx.dcx().emit_err(errors::VariadicFunctionCompatibleConvention { span });
+ const CONVENTIONS_UNSTABLE: &str =
+ "`C`, `cdecl`, `system`, `aapcs`, `win64`, `sysv64` or `efiapi`";
+ const CONVENTIONS_STABLE: &str = "`C` or `cdecl`";
+ const UNSTABLE_EXPLAIN: &str =
+ "using calling conventions other than `C` or `cdecl` for varargs functions is unstable";
+
+ if !decl.c_variadic || matches!(abi, ExternAbi::C { .. } | ExternAbi::Cdecl { .. }) {
+ return;
}
+
+ let extended_abi_support = tcx.features().extended_varargs_abi_support();
+ let conventions = match (extended_abi_support, abi.supports_varargs()) {
+ // User enabled additional ABI support for varargs and function ABI matches those ones.
+ (true, true) => return,
+
+ // Using this ABI would be ok, if the feature for additional ABI support was enabled.
+ // Return CONVENTIONS_STABLE, because we want the other error to look the same.
+ (false, true) => {
+ feature_err(&tcx.sess, sym::extended_varargs_abi_support, span, UNSTABLE_EXPLAIN)
+ .emit();
+ CONVENTIONS_STABLE
+ }
+
+ (false, false) => CONVENTIONS_STABLE,
+ (true, false) => CONVENTIONS_UNSTABLE,
+ };
+
+ tcx.dcx().emit_err(errors::VariadicFunctionCompatibleConvention { span, conventions });
}
pub fn provide(providers: &mut Providers) {
diff --git a/library/std/src/lib.rs b/library/std/src/lib.rs
index 954a4182fbd6c..378c2e18152f4 100644
--- a/library/std/src/lib.rs
+++ b/library/std/src/lib.rs
@@ -289,6 +289,7 @@
#![feature(doc_masked)]
#![feature(doc_notable_trait)]
#![feature(dropck_eyepatch)]
+#![feature(extended_varargs_abi_support)]
#![feature(f128)]
#![feature(f16)]
#![feature(formatting_options)]
diff --git a/src/doc/unstable-book/src/language-features/extended-varargs-abi-support.md b/src/doc/unstable-book/src/language-features/extended-varargs-abi-support.md
new file mode 100644
index 0000000000000..b20c30ec8f1c8
--- /dev/null
+++ b/src/doc/unstable-book/src/language-features/extended-varargs-abi-support.md
@@ -0,0 +1,10 @@
+# `extended_varargs_abi_support`
+
+The tracking issue for this feature is: [#100189]
+
+[#100189]: https://github.com/rust-lang/rust/issues/100189
+
+------------------------
+
+This feature adds the possibility of using `sysv64`, `win64` or `efiapi` calling
+conventions on functions with varargs.
diff --git a/tests/ui/c-variadic/feature-gate-extended_varargs_abi_support.rs b/tests/ui/c-variadic/feature-gate-extended_varargs_abi_support.rs
new file mode 100644
index 0000000000000..d47a8e085fd3a
--- /dev/null
+++ b/tests/ui/c-variadic/feature-gate-extended_varargs_abi_support.rs
@@ -0,0 +1,19 @@
+//@ only-x86_64
+
+fn efiapi(f: extern "efiapi" fn(usize, ...)) {
+ //~^ ERROR: C-variadic function must have a compatible calling convention, like `C` or `cdecl`
+ //~^^ ERROR: using calling conventions other than `C` or `cdecl` for varargs functions is unstable
+ f(22, 44);
+}
+fn sysv(f: extern "sysv64" fn(usize, ...)) {
+ //~^ ERROR: C-variadic function must have a compatible calling convention, like `C` or `cdecl`
+ //~^^ ERROR: using calling conventions other than `C` or `cdecl` for varargs functions is unstable
+ f(22, 44);
+}
+fn win(f: extern "win64" fn(usize, ...)) {
+ //~^ ERROR: C-variadic function must have a compatible calling convention, like `C` or `cdecl`
+ //~^^ ERROR: using calling conventions other than `C` or `cdecl` for varargs functions is unstable
+ f(22, 44);
+}
+
+fn main() {}
diff --git a/tests/ui/c-variadic/feature-gate-extended_varargs_abi_support.stderr b/tests/ui/c-variadic/feature-gate-extended_varargs_abi_support.stderr
new file mode 100644
index 0000000000000..41be378424543
--- /dev/null
+++ b/tests/ui/c-variadic/feature-gate-extended_varargs_abi_support.stderr
@@ -0,0 +1,52 @@
+error[E0658]: using calling conventions other than `C` or `cdecl` for varargs functions is unstable
+ --> $DIR/feature-gate-extended_varargs_abi_support.rs:3:14
+ |
+LL | fn efiapi(f: extern "efiapi" fn(usize, ...)) {
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+ |
+ = note: see issue #100189 <https://github.com/rust-lang/rust/issues/100189> for more information
+ = help: add `#![feature(extended_varargs_abi_support)]` to the crate attributes to enable
+ = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
+
+error[E0045]: C-variadic function must have a compatible calling convention, like `C` or `cdecl`
+ --> $DIR/feature-gate-extended_varargs_abi_support.rs:3:14
+ |
+LL | fn efiapi(f: extern "efiapi" fn(usize, ...)) {
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ C-variadic function must have a compatible calling convention
+
+error[E0658]: using calling conventions other than `C` or `cdecl` for varargs functions is unstable
+ --> $DIR/feature-gate-extended_varargs_abi_support.rs:8:12
+ |
+LL | fn sysv(f: extern "sysv64" fn(usize, ...)) {
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+ |
+ = note: see issue #100189 <https://github.com/rust-lang/rust/issues/100189> for more information
+ = help: add `#![feature(extended_varargs_abi_support)]` to the crate attributes to enable
+ = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
+
+error[E0045]: C-variadic function must have a compatible calling convention, like `C` or `cdecl`
+ --> $DIR/feature-gate-extended_varargs_abi_support.rs:8:12
+ |
+LL | fn sysv(f: extern "sysv64" fn(usize, ...)) {
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ C-variadic function must have a compatible calling convention
+
+error[E0658]: using calling conventions other than `C` or `cdecl` for varargs functions is unstable
+ --> $DIR/feature-gate-extended_varargs_abi_support.rs:13:11
+ |
+LL | fn win(f: extern "win64" fn(usize, ...)) {
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+ |
+ = note: see issue #100189 <https://github.com/rust-lang/rust/issues/100189> for more information
+ = help: add `#![feature(extended_varargs_abi_support)]` to the crate attributes to enable
+ = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
+
+error[E0045]: C-variadic function must have a compatible calling convention, like `C` or `cdecl`
+ --> $DIR/feature-gate-extended_varargs_abi_support.rs:13:11
+ |
+LL | fn win(f: extern "win64" fn(usize, ...)) {
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ C-variadic function must have a compatible calling convention
+
+error: aborting due to 6 previous errors
+
+Some errors have detailed explanations: E0045, E0658.
+For more information about an error, try `rustc --explain E0045`.
diff --git a/tests/ui/c-variadic/variadic-ffi-1.stderr b/tests/ui/c-variadic/variadic-ffi-1.stderr
index 061eae9729e2e..dd8c7e93c4efe 100644
--- a/tests/ui/c-variadic/variadic-ffi-1.stderr
+++ b/tests/ui/c-variadic/variadic-ffi-1.stderr
@@ -1,4 +1,4 @@
-error[E0045]: C-variadic function must have a compatible calling convention, like `C`, `cdecl`, `system`, `aapcs`, `win64`, `sysv64` or `efiapi`
+error[E0045]: C-variadic function must have a compatible calling convention, like `C` or `cdecl`
--> $DIR/variadic-ffi-1.rs:9:5
|
LL | fn printf(_: *const u8, ...);
diff --git a/tests/ui/c-variadic/variadic-ffi-2-arm.rs b/tests/ui/c-variadic/variadic-ffi-2-arm.rs
index 82f9df5053c19..3b0a71007a0e6 100644
--- a/tests/ui/c-variadic/variadic-ffi-2-arm.rs
+++ b/tests/ui/c-variadic/variadic-ffi-2-arm.rs
@@ -1,5 +1,6 @@
//@ only-arm
//@ build-pass
+#![feature(extended_varargs_abi_support)]
fn aapcs(f: extern "aapcs" fn(usize, ...)) {
f(22, 44);
diff --git a/tests/ui/c-variadic/variadic-ffi-2.rs b/tests/ui/c-variadic/variadic-ffi-2.rs
index 17a1065279f4e..bafb7e2b20cc7 100644
--- a/tests/ui/c-variadic/variadic-ffi-2.rs
+++ b/tests/ui/c-variadic/variadic-ffi-2.rs
@@ -1,4 +1,5 @@
//@ ignore-arm stdcall isn't supported
+#![feature(extended_varargs_abi_support)]
#[allow(unsupported_fn_ptr_calling_conventions)]
fn baz(f: extern "stdcall" fn(usize, ...)) {
diff --git a/tests/ui/c-variadic/variadic-ffi-2.stderr b/tests/ui/c-variadic/variadic-ffi-2.stderr
index fbf273b1f1dbf..e52de93a92646 100644
--- a/tests/ui/c-variadic/variadic-ffi-2.stderr
+++ b/tests/ui/c-variadic/variadic-ffi-2.stderr
@@ -1,5 +1,5 @@
error[E0045]: C-variadic function must have a compatible calling convention, like `C`, `cdecl`, `system`, `aapcs`, `win64`, `sysv64` or `efiapi`
- --> $DIR/variadic-ffi-2.rs:4:11
+ --> $DIR/variadic-ffi-2.rs:5:11
|
LL | fn baz(f: extern "stdcall" fn(usize, ...)) {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ C-variadic function must have a compatible calling convention
diff --git a/tests/ui/cmse-nonsecure/cmse-nonsecure-call/generics.rs b/tests/ui/cmse-nonsecure/cmse-nonsecure-call/generics.rs
index da1327dace5d4..9e0ffa75c2296 100644
--- a/tests/ui/cmse-nonsecure/cmse-nonsecure-call/generics.rs
+++ b/tests/ui/cmse-nonsecure/cmse-nonsecure-call/generics.rs
@@ -39,4 +39,4 @@ type WithTransparentTraitObject =
//~^ ERROR return value of `"C-cmse-nonsecure-call"` function too large to pass via registers [E0798]
type WithVarArgs = extern "C-cmse-nonsecure-call" fn(u32, ...);
-//~^ ERROR C-variadic function must have a compatible calling convention, like `C`, `cdecl`, `system`, `aapcs`, `win64`, `sysv64` or `efiapi` [E0045]
+//~^ ERROR C-variadic function must have a compatible calling convention, like `C` or `cdecl` [E0045]
diff --git a/tests/ui/cmse-nonsecure/cmse-nonsecure-call/generics.stderr b/tests/ui/cmse-nonsecure/cmse-nonsecure-call/generics.stderr
index 0560f0eec1c02..f0d5f648f4c65 100644
--- a/tests/ui/cmse-nonsecure/cmse-nonsecure-call/generics.stderr
+++ b/tests/ui/cmse-nonsecure/cmse-nonsecure-call/generics.stderr
@@ -69,7 +69,7 @@ LL | extern "C-cmse-nonsecure-call" fn(WrapperTransparent) -> WrapperTranspa
= note: functions with the `"C-cmse-nonsecure-call"` ABI must pass their result via the available return registers
= note: the result must either be a (transparently wrapped) i64, u64 or f64, or be at most 4 bytes in size
-error[E0045]: C-variadic function must have a compatible calling convention, like `C`, `cdecl`, `system`, `aapcs`, `win64`, `sysv64` or `efiapi`
+error[E0045]: C-variadic function must have a compatible calling convention, like `C` or `cdecl`
--> $DIR/generics.rs:41:20
|
LL | type WithVarArgs = extern "C-cmse-nonsecure-call" fn(u32, ...);
diff --git a/tests/ui/error-codes/E0045.stderr b/tests/ui/error-codes/E0045.stderr
index b8ee31a40495a..25b2f2654da15 100644
--- a/tests/ui/error-codes/E0045.stderr
+++ b/tests/ui/error-codes/E0045.stderr
@@ -1,4 +1,4 @@
-error[E0045]: C-variadic function must have a compatible calling convention, like `C`, `cdecl`, `system`, `aapcs`, `win64`, `sysv64` or `efiapi`
+error[E0045]: C-variadic function must have a compatible calling convention, like `C` or `cdecl`
--> $DIR/E0045.rs:1:17
|
LL | extern "Rust" { fn foo(x: u8, ...); }
From cafa646f21ec41d6b20b5495c25456c997206dc1 Mon Sep 17 00:00:00 2001
From: Jubilee Young <workingjubilee@gmail.com>
Date: Tue, 11 Feb 2025 17:25:26 -0800
Subject: [PATCH 2/2] library: amend revert of extended_varargs_abi_support for
beta diff
And leave a comment on the unusual `cfg_attr`
Co-authored-by: waffle <waffle.lapkin@gmail.com>
---
library/std/src/lib.rs | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/library/std/src/lib.rs b/library/std/src/lib.rs
index 378c2e18152f4..aea81b4bddee0 100644
--- a/library/std/src/lib.rs
+++ b/library/std/src/lib.rs
@@ -272,6 +272,9 @@
//
// Language features:
// tidy-alphabetical-start
+
+// stabilization was reverted after it hit beta
+#![cfg_attr(not(bootstrap), feature(extended_varargs_abi_support))]
#![feature(alloc_error_handler)]
#![feature(allocator_internals)]
#![feature(allow_internal_unsafe)]
@@ -289,7 +292,6 @@
#![feature(doc_masked)]
#![feature(doc_notable_trait)]
#![feature(dropck_eyepatch)]
-#![feature(extended_varargs_abi_support)]
#![feature(f128)]
#![feature(f16)]
#![feature(formatting_options)]