guppy/platform/
platform_spec.rs

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1// Copyright (c) The cargo-guppy Contributors
2// SPDX-License-Identifier: MIT OR Apache-2.0
3
4#[allow(unused_imports)]
5use crate::platform::EnabledTernary;
6use crate::{errors::TargetSpecError, platform::Platform};
7use std::sync::Arc;
8
9/// A specifier for a single platform, or for a range of platforms.
10///
11/// Some uses of `guppy` care about a single platform, and others care about queries against the
12/// intersection of all hypothetical platforms, or against a union of any of them. `PlatformSpec`
13/// handles the
14///
15/// `PlatformSpec` does not currently support expressions, but it might in the future, using an
16/// [SMT solver](https://en.wikipedia.org/wiki/Satisfiability_modulo_theories).
17#[derive(Clone, Debug)]
18#[non_exhaustive]
19pub enum PlatformSpec {
20    /// The intersection of all platforms.
21    ///
22    /// Dependency queries performed against this variant will return [`EnabledTernary::Enabled`] if
23    /// and only if a dependency is not platform-dependent. They can never return
24    /// [`EnabledTernary::Unknown`].
25    ///
26    /// This variant does not currently understand expressions that always evaluate to true
27    /// (tautologies), like `cfg(any(unix, not(unix)))` or `cfg(all())`. In the future, an SMT
28    /// solver would be able to handle such expressions.
29    Always,
30
31    /// An individual platform.
32    ///
33    /// Dependency queries performed against this variant will return [`EnabledTernary::Enabled`] if
34    /// and only if a dependency is enabled on this platform. They may also return
35    /// [`EnabledTernary::Unknown`] if a platform is not enabled.
36    Platform(Arc<Platform>),
37
38    /// The union of all platforms.
39    ///
40    /// Dependency queries performed against this variant will return [`EnabledTernary::Enabled`] if
41    /// a dependency is enabled on any platform.
42    ///
43    /// This variant does not currently understand expressions that always evaluate to false
44    /// (contradictions), like `cfg(all(unix, not(unix)))` or `cfg(any())`. In the future, an SMT
45    /// solver would be able to handle such expressions.
46    Any,
47}
48
49impl PlatformSpec {
50    /// Previous name for [`Self::build_target`], renamed to clarify what
51    /// `current` means.
52    ///
53    /// This method is deprecated and will be removed in a future version.
54    #[deprecated(
55        since = "0.17.13",
56        note = "this method has been renamed to `build_target`"
57    )]
58    #[inline]
59    pub fn current() -> Result<Self, TargetSpecError> {
60        Self::build_target()
61    }
62
63    /// Returns a `PlatformSpec` corresponding to the target platform, as
64    /// determined at build time.
65    ///
66    /// Returns an error if the build target was unknown to the version of
67    /// `target-spec` in use.
68    pub fn build_target() -> Result<Self, TargetSpecError> {
69        Ok(PlatformSpec::Platform(Arc::new(Platform::build_target()?)))
70    }
71}
72
73impl<T: Into<Arc<Platform>>> From<T> for PlatformSpec {
74    #[inline]
75    fn from(platform: T) -> Self {
76        PlatformSpec::Platform(platform.into())
77    }
78}
guppy/platform/platform_spec.rs

guppy/platform/
platform_spec.rs
