Enum Unsupported 

pub enum Unsupported {
    Format {
        target: String,
        format: &'static str,
    },
    MsvcAbi {
        target: String,
    },
    Machine {
        target: String,
    },
    StaticStub {
        target: String,
    },
}

A target, or a combination of a target and a mode, that has no line here.

Four variants and they are different kinds of answer. A format is not supported yet and will be. The MSVC ABI is waiting on something that is not code. A static glibc link is not a thing this scheme can produce at all. The distinction matters to somebody reading the message, because only some of them are worth waiting for.

Variants

Format

The target’s object format is neither ELF nor PE, and the linker for it wants a different line rather than a different spelling of this one.

Fields

target: String

The target that was asked for.

format: &'static str

Its object format, in the spelling --print-config uses.

MsvcAbi

A Windows target in Microsoft’s ABI rather than mingw-w64’s.

Refused for two reasons and the second one is the one that matters. lld-link takes a different command line rather than a different set of flags: /MACHINE:, /SUBSYSTEM:, /DEFAULTLIB: and a response file, which is its own work. And the import libraries a program in that ABI links against come from the Windows SDK and the universal CRT, which spec/cross-compile/08-sysroots.md section 8.6 says cannot be redistributed, so there is nothing to produce on this side and a user has to point at an installed one themselves.

Fields

target: String

The target that was asked for.

Machine

A PE target whose architecture has no machine type among the ones a PE linker writes.

Unreachable through the target table, which has three mingw-w64 rows and an ARM64EC one that the MSVC ABI refuses first. It is a variant rather than a panic because the table is data and a row added to it should produce a sentence rather than a crash.

Fields

target: String

The target that was asked for.

StaticStub

A static link against a libc that is a stub.

spec/cross-compile/09-libc-stubs.md section 9.1 is the reason: a stub carries the names a library exports and none of the code behind them, which is everything a dynamic link needs and nothing a static one does. glibc’s own libc.a is several megabytes of objects that cannot be synthesized from a description of an interface, so this combination is refused here rather than failing later with several thousand undefined symbols.

Every crate::link::Libc::Stub target, which is glibc and also bionic, the BSDs and illumos. musl is the exception rather than the rule here, because musl is the one whose libc we build from source.

Fields

target: String

The target that was asked for.

Trait Implementations

impl Clone for Unsupported

fn clone(&self) -> Unsupported

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Unsupported

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Display for Unsupported

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Eq for Unsupported

impl Error for Unsupported

fn source(&self) -> Option<&(dyn Error + 'static)>

Returns the lower-level source of this error, if any.

fn description(&self) -> &str

👎Deprecated since 1.42.0:

use the Display impl or to_string()

fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0:

replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, request: &mut Request<'a>)

🔬This is a nightly-only experimental API. (error_generic_member_access)

Provides type-based access to context intended for error reports.

impl PartialEq for Unsupported

fn eq(&self, other: &Unsupported) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for Unsupported