Module rustc_resolve::macros

source ·
Expand description

A bunch of methods and structures more or less related to resolving macros and interface provided by Resolver to macro expander.


Binding produced by a macro_rules item. Not modularized, can shadow previous macro_rules bindings, etc.


The scope introduced by a macro_rules! macro. This starts at the macro’s definition and ends at the end of the macro’s parent module (named or unnamed), or even further if it escapes with #[macro_use]. Some macro invocations need to introduce macro_rules scopes too because they can potentially expand into macro definitions.


Macro namespace is separated into two sub-namespaces, one for bang macros and one for attribute-like macros (attributes, derives). We ignore resolutions from one sub-namespace when searching names in scope for another.

Type Definitions

macro_rules! scopes are always kept by reference and inside a cell. The reason is that we update scopes with value MacroRulesScope::Invocation(invoc_id) in-place after invoc_id gets expanded. This helps to avoid uncontrollable growth of macro_rules! scope chains, which usually grow linearly with the number of macro invocations in a module (including derives) and hurt performance.
Res 🔒