Struct Global 

pub struct Global {
    pub name: String,
    pub ty: Option<usize>,
    pub decl: Option<Place>,
    pub external: bool,
}

One variable the unit defines at file scope.

Not the same problem as a local, and that is the whole reason this is here and a local is not. A file-scope variable is at one address for the whole of the program, so its location is the address of its own symbol and the linker fills it in, the same way it fills in a function’s. A local’s location is wherever the code happens to be keeping it at the program counter the debugger stopped at, which is a list rather than an expression, and that is the rest of tamnd/rucc#9.

Fields

name: String

Its name, as the C program spelled it, which is what the relocation asks the linker for.

ty: Option<usize>

Which of the unit’s types it is, and None when this compiler cannot yet say.

A variable with nothing here still gets an entry, which is the one place the rule for a function is turned around. A DW_TAG_variable with no DW_AT_type does not say void, because nothing in C is a variable of type void, so a reader takes it as a variable whose type was not recorded. The name and the address are worth having on their own: they are what lets a debugger resolve the name at all, and a program that knows what it is looking at can cast.

decl: Option<Place>

Where it was declared, and nothing when that is not known.

external: bool

Whether anything outside this unit can see it, which is the opposite of static.

Trait Implementations

impl Clone for Global

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Global

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

Formats the value using the given formatter.

impl Default for Global

fn default() -> Self

Returns the “default value” for a type.

impl Eq for Global

impl PartialEq for Global

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for Global