Enum LibraryPath

pub enum LibraryPath {
    CargoArtifact(PathBuf),
    External(PathBuf),
}

Represents a path added to the library search path.

We need to keep track of requests to add search paths within the cargo build directory separately from paths outside of Cargo. The reason is that we want to give precedence to linking against libraries within the Cargo build directory even if a similar library exists in the system (e.g. crate A adds /usr/lib to the search path and then a later build of crate B adds target/debug/... to satisfy its request to link against the library B that it built, but B is also found in /usr/lib).

There’s some nuance here because we want to preserve relative order of paths of the same type. For example, if the build process would in declaration order emit the following linker line:

-L/usr/lib -Ltarget/debug/build/crate1/libs -L/lib -Ltarget/debug/build/crate2/libs)

we want the linker to actually receive:

-Ltarget/debug/build/crate1/libs -Ltarget/debug/build/crate2/libs) -L/usr/lib -L/lib

so that the library search paths within the crate artifacts directory come first but retain relative ordering while the system library paths come after while still retaining relative ordering among them; ordering is the order they are emitted within the build process, not lexicographic order.

WARNING: Even though this type implements PartialOrd + Ord, this is a lexicographic ordering. The linker line will require an explicit sorting algorithm. PartialOrd + Ord is derived because BuildOutput requires it but that ordering is different from the one for the linker search path, at least today. It may be worth reconsidering & perhaps it’s ok if BuildOutput doesn’t have a lexicographic ordering for the library_paths? I’m not sure the consequence of that.

Variants

CargoArtifact(PathBuf)

The path is pointing within the output folder of the crate and takes priority over external paths when passed to the linker.

External(PathBuf)

The path is pointing outside of the crate’s build location. The linker will always receive such paths after CargoArtifact.

Implementations

impl LibraryPath

fn new(p: PathBuf, script_out_dir: &Path) -> Self

pub fn into_path_buf(self) -> PathBuf

Trait Implementations

impl AsRef<PathBuf> for LibraryPath

fn as_ref(&self) -> &PathBuf

Converts this type into a shared reference of the (usually inferred) input type.

impl Clone for LibraryPath

fn clone(&self) -> LibraryPath

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for LibraryPath

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

Formats the value using the given formatter.

impl Hash for LibraryPath

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Ord for LibraryPath

fn cmp(&self, other: &LibraryPath) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl PartialEq for LibraryPath

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialOrd for LibraryPath

fn partial_cmp(&self, other: &LibraryPath) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

Tests less than (for self and other) and is used by the < operator.

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

Tests less than or equal to (for self and other) and is used by the <= operator.

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

Tests greater than (for self and other) and is used by the > operator.

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

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl Eq for LibraryPath

impl StructuralPartialEq for LibraryPath

Layout

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference's “Type Layout” chapter for details on type layout guarantees.

Size: 32 bytes

Size for each variant:

• CargoArtifact: 24 bytes
• External: 24 bytes