Enum Compress 

pub enum Compress {
    None,
    Zlib,
    ZlibGnu,
    Zstd,
}

How the debug sections are compressed, which is what -gz asks.

Debug information is much larger than the code it describes and almost never read, so an ELF section holding it may be stored compressed: the section keeps its name, gains the SHF_COMPRESSED flag and starts with a header saying what it decompresses to, and every reader that understands the flag unpacks it on the way in. A distribution that ships debug symbols for everything it builds saves more from this than from anything else it passes.

This compiler writes no debug sections at all yet, so every answer here produces the same bytes, and an object built with -gz=zstd is identical to one built without the flag. It is recorded rather than dropped for the reason section 4.1 gives for the rest of the family: the answer has to be sitting in the options on the day rucc-debug has something to compress, and a build that asked for it and got silence would have no way of noticing the difference.

Variants

None

-gz=none, and what a command line that says nothing gets. gcc’s default is the same.

Zlib

-gz and -gz=zlib. The ELF way, with the SHF_COMPRESSED flag and an Elf64_Chdr in front of the data. Bare -gz means this one, which is worth knowing because the manual describes the flag without saying so.

ZlibGnu

-gz=zlib-gnu. The older way, where the section is renamed from .debug_info to .zdebug_info and carries ZLIB and a length instead of a real header. Kept because binutils still reads it and some build systems still ask for it by name.

Zstd

-gz=zstd. The same arrangement as Zlib with a different algorithm in the header, which packs debug information smaller and unpacks it faster.

Implementations

impl Compress

pub const fn as_str(self) -> &'static str

The spelling this is asked for by, without the -gz= in front of it.

Trait Implementations

impl Clone for Compress

fn clone(&self) -> Compress

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for Compress

impl Debug for Compress

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

Formats the value using the given formatter.

impl Default for Compress

fn default() -> Compress

Returns the “default value” for a type.

impl Display for Compress

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

Formats the value using the given formatter.

impl Eq for Compress

impl FromStr for Compress

fn from_str(s: &str) -> Result<Self, ()>

Parses the part after -gz=. Bare -gz is not this function’s business because there is nothing after the flag to hand it.

type Err = ()

The associated error which can be returned from parsing.

impl Hash for Compress

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 Compress

fn cmp(&self, other: &Compress) -> 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.

fn clamp_to<R>(self, range: R) -> Self

where Self: Sized, R: ClampBounds<Self>,

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

Restrict a value to a certain range.

impl PartialEq for Compress

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

Equality operator ==.

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

Inequality operator !=.

impl PartialOrd for Compress

fn partial_cmp(&self, other: &Compress) -> 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 StructuralPartialEq for Compress