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-rw-r--r--src/doc/rustc-dev-guide/src/the-parser.md5
1 files changed, 5 insertions, 0 deletions
diff --git a/src/doc/rustc-dev-guide/src/the-parser.md b/src/doc/rustc-dev-guide/src/the-parser.md
index c84ac4ea2e1..c0f2a071b53 100644
--- a/src/doc/rustc-dev-guide/src/the-parser.md
+++ b/src/doc/rustc-dev-guide/src/the-parser.md
@@ -38,6 +38,11 @@ To minimise the amount of copying that is done, both the `StringReader` and
 `Parser` have lifetimes which bind them to the parent `ParseSess`. This contains
 all the information needed while parsing, as well as the `SourceMap` itself.
 
+Note that while parsing, we may encounter macro definitions or invocations. We
+set these aside to be expanded (see [this chapter](./macro-expansion.md)).
+Expansion may itself require parsing the output of the macro, which may reveal
+more macros to be expanded, and so on.
+
 ## More on Lexical Analysis
 
 Code for lexical analysis is split between two crates: