Struct MacroTable 

pub struct MacroTable { /* private fields */ }

Every macro currently defined.

Implementations

impl MacroTable

pub fn new() -> MacroTable

An empty table.

pub fn lookup(&self, name: Symbol) -> Option<&MacroDef>

The definition of name, if it has one.

pub fn is_defined(&self, name: Symbol) -> bool

Whether name is defined, which is what #ifdef and defined ask.

pub fn len(&self) -> usize

How many macros are defined.

pub fn is_empty(&self) -> bool

Whether no macros are defined.

pub fn define( &mut self, def: MacroDef, interner: &Interner, ) -> Option<Diagnostic>

Adds a definition, returning a warning if it replaces a different one.

Redefining a macro to the same thing is legal and extremely common, because a header included twice through two paths does it. Redefining it to something else is a constraint violation, which GCC reports as a warning and accepts, and we match that because rejecting it would break real builds.

pub fn define_builtin(&mut self, name: Symbol, builtin: Builtin, span: Span)

Defines one of the macros whose value is a question.

span is where to say the macro came from, which is the start of <built-in>, so that a warning about redefining __FILE__ has somewhere to point.

pub fn undef(&mut self, name: Symbol) -> Option<MacroDef>

Removes a definition. Undefining a macro that is not defined is legal and silent.

pub fn sorted(&self) -> Vec<&MacroDef>

Every defined macro, sorted by symbol.

Sorted because -dM output has to be byte identical across runs and hash order is not, per spec/02-the-goal.md.

Trait Implementations

impl Debug for MacroTable

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

Formats the value using the given formatter.

impl Default for MacroTable

fn default() -> MacroTable

Returns the “default value” for a type.