Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Ensure all tests in the workspace are run and that const extern fn is always enabled #4151

Merged
merged 3 commits into from
Nov 26, 2024
Merged

Ensure all tests in the workspace are run and that const extern fn is always enabled #4151

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
f553033
tests: Ensure all tests in the workspace are run
tgross35 Nov 26, 2024
e18ee8c
fix: Ensure that `const extern fn` is always enabled
tgross35 Nov 26, 2024
e6d7b51
cleanup: Remove the `const-extern-fn` feature
tgross35 Nov 26, 2024
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
6 changes: 1 addition & 5 deletions Cargo.toml
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -135,14 +135,10 @@ cargo-args = ["-Zbuild-std=core"]
rustc-std-workspace-core = { version = "1.0.0", optional = true }

[features]
default = ["const-extern-fn", "std"]
default = ["std"]
std = []
rustc-dep-of-std = ["rustc-std-workspace-core"]
extra_traits = []

# `const-extern-function` is deprecated and no longer does anything
# FIXME(1.0): remove this completely
const-extern-fn = []

[workspace]
members = ["libc-test"]
5 changes: 5 additions & 0 deletions build.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -13,6 +13,8 @@ const ALLOWED_CFGS: &'static [&'static str] = &[
"freebsd13",
"freebsd14",
"freebsd15",
// FIXME(ctest): this config shouldn't be needed but ctest can't parse `const extern fn`
"libc_const_extern_fn",
"libc_deny_warnings",
"libc_ctest",
];
Expand Down Expand Up @@ -74,6 +76,9 @@ fn main() {
set_cfg("libc_deny_warnings");
}

// Set unconditionally when ctest is not being invoked.
set_cfg("libc_const_extern_fn");

// check-cfg is a nightly cargo/rustc feature to warn when unknown cfgs are used across the
// codebase. libc can configure it if the appropriate environment variable is passed. Since
// rust-lang/rust enforces it, this is useful when using a custom libc fork there.
Expand Down
11 changes: 5 additions & 6 deletions ci/run.sh
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -84,16 +84,15 @@ cmd="cargo test --target $target ${LIBC_CI_ZBUILD_STD+"-Zbuild-std"}"

# Run tests in the `libc` crate
case "$target" in
# Only run `libc-test`
# FIXME(android): unit tests fail to start on Android
# FIXME(s390x): unit tests fail to locate glibc
*android*) ;;
*s390x*) ;;
*) $cmd
*android*) cmd="$cmd --manifest-path libc-test/Cargo.toml" ;;
*s390x*) cmd="$cmd --manifest-path libc-test/Cargo.toml" ;;
# For all other platforms, test everything in the workspace
*) cmd="$cmd --workspace"
esac

# Everything else is in `libc-test`
cmd="$cmd --manifest-path libc-test/Cargo.toml"

if [ "$target" = "s390x-unknown-linux-gnu" ]; then
# FIXME: s390x-unknown-linux-gnu often fails to test due to timeout,
# so we retry this N times.
Expand Down
1 change: 0 additions & 1 deletion ci/verify-build.sh
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -62,7 +62,6 @@ test_target() {

# Test with expected combinations of features
$cmd
$cmd --features const-extern-fn
$cmd --features extra_traits

# Test again without default features, i.e. without "std"
Expand Down
45 changes: 18 additions & 27 deletions src/macros.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -167,40 +167,31 @@ macro_rules! e {
)*);
}

// This is a pretty horrible hack to allow us to conditionally mark
// some functions as 'const', without requiring users of this macro
// to care about the "const-extern-fn" feature.
// This is a pretty horrible hack to allow us to conditionally mark some functions as 'const',
// without requiring users of this macro to care "libc_const_extern_fn".
//
// When 'const-extern-fn' is enabled, we emit the captured 'const' keyword
// in the expanded function.
// When 'libc_const_extern_fn' is enabled, we emit the captured 'const' keyword in the expanded
// function.
//
// When 'const-extern-fn' is disabled, we always emit a plain 'pub unsafe extern fn'.
// When 'libc_const_extern_fn' is disabled, we always emit a plain 'pub unsafe extern fn'.
// Note that the expression matched by the macro is exactly the same - this allows
// users of this macro to work whether or not 'const-extern-fn' is enabled
// users of this macro to work whether or not 'libc_const_extern_fn' is enabled
//
// Unfortunately, we need to duplicate most of this macro between the 'cfg_if' blocks.
// This is because 'const unsafe extern fn' won't even parse on older compilers,
// so we need to avoid emitting it at all of 'const-extern-fn'.
// so we need to avoid emitting it at all of 'libc_const_extern_fn'.
//
// Specifically, moving the 'cfg_if' into the macro body will *not* work.
// Doing so would cause the '#[cfg(feature = "const-extern-fn")]' to be emitted
// into user code. The 'cfg' gate will not stop Rust from trying to parse the
// 'pub const unsafe extern fn', so users would get a compiler error even when
// the 'const-extern-fn' feature is disabled
//
// Note that users of this macro need to place 'const' in a weird position
// (after the closing ')' for the arguments, but before the return type).
// This was the only way I could satisfy the following two requirements:
// 1. Avoid ambiguity errors from 'macro_rules!' (which happen when writing '$foo:ident fn'
// 2. Allow users of this macro to mix 'pub fn foo' and 'pub const fn bar' within the same
// 'f!' block
// Specifically, moving the 'cfg_if' into the macro body will *not* work. Doing so would cause the
// '#[cfg(libc_const_extern_fn)]' to be emitted into user code. The 'cfg' gate will not stop Rust
// from trying to parse the 'pub const unsafe extern fn', so users would get a compiler error even
// when the 'libc_const_extern_fn' feature is disabled.
Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

as i mentioned in the backport PR, this is no longer a feature. i'm noticing now that this is also an inconsistent use of quotes vs ticks below

Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Thanks for noticing, but I'm not worried about it - this comment is preexisting and will hopefully go away in the near future once ctest gets fixed.


// FIXME(ctest): ctest can't handle `const extern` functions, we should be able to remove this
// cfg completely.
// FIXME(ctest): ctest can't handle `$(,)?` so we use `$(,)*` which isn't quite correct.
cfg_if! {
if #[cfg(feature = "const-extern-fn")] {
Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

consider removing the feature from the default features (in this commit, so it is backported) and also updating the comment in src/macros.rs in this commit (so it no longer mentions this feature, also so it is backported).

Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Reasonable 👍 changed, thanks for taking a look.

/// Define an `unsafe` function that is const as long as `const-extern-fn` is enabled.
if #[cfg(libc_const_extern_fn)] {
/// Define an `unsafe` function that is const as long as `libc_const_extern_fn` is enabled.
macro_rules! f {
($(
$(#[$attr:meta])*
Expand All @@ -214,7 +205,7 @@ cfg_if! {
)*)
}

/// Define a safe function that is const as long as `const-extern-fn` is enabled.
/// Define a safe function that is const as long as `libc_const_extern_fn` is enabled.
macro_rules! safe_f {
($(
$(#[$attr:meta])*
Expand All @@ -228,7 +219,7 @@ cfg_if! {
)*)
}

/// A nonpublic function that is const as long as `const-extern-fn` is enabled.
/// A nonpublic function that is const as long as `libc_const_extern_fn` is enabled.
macro_rules! const_fn {
($(
$(#[$attr:meta])*
Expand All @@ -242,7 +233,7 @@ cfg_if! {
)*)
}
} else {
/// Define an `unsafe` function that is const as long as `const-extern-fn` is enabled.
/// Define an `unsafe` function that is const as long as `libc_const_extern_fn` is enabled.
macro_rules! f {
($(
$(#[$attr:meta])*
Expand All @@ -256,7 +247,7 @@ cfg_if! {
)*)
}

/// Define a safe function that is const as long as `const-extern-fn` is enabled.
/// Define a safe function that is const as long as `libc_const_extern_fn` is enabled.
macro_rules! safe_f {
($(
$(#[$attr:meta])*
Expand All @@ -270,7 +261,7 @@ cfg_if! {
)*)
}

/// A nonpublic function that is const as long as `const-extern-fn` is enabled.
/// A nonpublic function that is const as long as `libc_const_extern_fn` is enabled.
macro_rules! const_fn {
($(
$(#[$attr:meta])*
Expand Down