From e3c3efe5abb2025fdc8a4937b22e76fbd8093dd5 Mon Sep 17 00:00:00 2001
From: Guillaume Gomez <guillaume1.gomez@gmail.com>
Date: Sat, 10 Oct 2020 15:31:14 +0200
Subject: [PATCH 1/2] Filter out imports added by the compiler

---
 src/librustdoc/clean/mod.rs | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/src/librustdoc/clean/mod.rs b/src/librustdoc/clean/mod.rs
index 501891da573a6..4bbf5edeaf348 100644
--- a/src/librustdoc/clean/mod.rs
+++ b/src/librustdoc/clean/mod.rs
@@ -24,9 +24,9 @@ use rustc_middle::ty::fold::TypeFolder;
 use rustc_middle::ty::subst::{InternalSubsts, Subst};
 use rustc_middle::ty::{self, AdtKind, Lift, Ty, TyCtxt};
 use rustc_mir::const_eval::{is_const_fn, is_min_const_fn, is_unstable_const_fn};
-use rustc_span::hygiene::MacroKind;
+use rustc_span::hygiene::{AstPass, MacroKind};
 use rustc_span::symbol::{kw, sym, Ident, Symbol};
-use rustc_span::{self, Pos};
+use rustc_span::{self, ExpnKind, Pos};
 use rustc_typeck::hir_ty_to_ty;
 
 use std::collections::hash_map::Entry;
@@ -2232,6 +2232,13 @@ impl Clean<Vec<Item>> for doctree::ExternCrate<'_> {
 
 impl Clean<Vec<Item>> for doctree::Import<'_> {
     fn clean(&self, cx: &DocContext<'_>) -> Vec<Item> {
+        // We need this comparison because some imports (for std types for example)
+        // are "inserted" as well but directly by the compiler and they should not be
+        // taken into account.
+        if self.span.ctxt().outer_expn_data().kind == ExpnKind::AstPass(AstPass::StdImports) {
+            return Vec::new();
+        }
+
         // We consider inlining the documentation of `pub use` statements, but we
         // forcefully don't inline if this is not public or if the
         // #[doc(no_inline)] attribute is present.

From 0faaa499ccc9fb4835251845cf457bae385f07f5 Mon Sep 17 00:00:00 2001
From: Guillaume Gomez <guillaume1.gomez@gmail.com>
Date: Sat, 10 Oct 2020 15:34:18 +0200
Subject: [PATCH 2/2] Add test for compiler reexports removal

---
 src/test/rustdoc/no-compiler-reexport.rs | 7 +++++++
 1 file changed, 7 insertions(+)
 create mode 100644 src/test/rustdoc/no-compiler-reexport.rs

diff --git a/src/test/rustdoc/no-compiler-reexport.rs b/src/test/rustdoc/no-compiler-reexport.rs
new file mode 100644
index 0000000000000..6d50325fed550
--- /dev/null
+++ b/src/test/rustdoc/no-compiler-reexport.rs
@@ -0,0 +1,7 @@
+// compile-flags: --no-defaults
+
+#![crate_name = "foo"]
+
+// @has 'foo/index.html' '//code' 'extern crate std;'
+// @!has 'foo/index.html' '//code' 'use std::prelude::v1::*;'
+pub struct Foo;