From a83c35692fa5fc65ec9860599501f1a5a5e98214 Mon Sep 17 00:00:00 2001
From: Vadim Petrochenkov <vadim.petrochenkov@gmail.com>
Date: Mon, 19 Aug 2019 23:44:57 +0300
Subject: [PATCH] expand: Do not do questionable span adjustment before eagerly
 expanding an expression

Maybe it made sense when it was introduced, but now it's doing something incorrect.
---
 src/libsyntax/ext/base.rs                    |  5 +----
 src/test/ui/hygiene/eager-from-opaque.rs     |  4 +++-
 src/test/ui/hygiene/eager-from-opaque.stderr | 11 -----------
 3 files changed, 4 insertions(+), 16 deletions(-)
 delete mode 100644 src/test/ui/hygiene/eager-from-opaque.stderr

diff --git a/src/libsyntax/ext/base.rs b/src/libsyntax/ext/base.rs
index b0a4a6af9839c..376df4062b116 100644
--- a/src/libsyntax/ext/base.rs
+++ b/src/libsyntax/ext/base.rs
@@ -908,12 +908,9 @@ impl<'a> ExtCtxt<'a> {
 /// compilation on error, merely emits a non-fatal error and returns `None`.
 pub fn expr_to_spanned_string<'a>(
     cx: &'a mut ExtCtxt<'_>,
-    mut expr: P<ast::Expr>,
+    expr: P<ast::Expr>,
     err_msg: &str,
 ) -> Result<(Symbol, ast::StrStyle, Span), Option<DiagnosticBuilder<'a>>> {
-    // Update `expr.span`'s ctxt now in case expr is an `include!` macro invocation.
-    expr.span = expr.span.apply_mark(cx.current_expansion.id);
-
     // Perform eager expansion on the expression.
     // We want to be able to handle e.g., `concat!("foo", "bar")`.
     let expr = cx.expander().fully_expand_fragment(AstFragment::Expr(expr)).make_expr();
diff --git a/src/test/ui/hygiene/eager-from-opaque.rs b/src/test/ui/hygiene/eager-from-opaque.rs
index 57925d626b9d1..6f3215dd697f3 100644
--- a/src/test/ui/hygiene/eager-from-opaque.rs
+++ b/src/test/ui/hygiene/eager-from-opaque.rs
@@ -1,6 +1,8 @@
 // Opaque macro can eagerly expand its input without breaking its resolution.
 // Regression test for issue #63685.
 
+// check-pass
+
 macro_rules! foo {
     () => {
         "foo"
@@ -9,7 +11,7 @@ macro_rules! foo {
 
 macro_rules! bar {
     () => {
-        foo!() //~ ERROR cannot find macro `foo!` in this scope
+        foo!()
     };
 }
 
diff --git a/src/test/ui/hygiene/eager-from-opaque.stderr b/src/test/ui/hygiene/eager-from-opaque.stderr
deleted file mode 100644
index f696e6caff7ca..0000000000000
--- a/src/test/ui/hygiene/eager-from-opaque.stderr
+++ /dev/null
@@ -1,11 +0,0 @@
-error: cannot find macro `foo!` in this scope
-  --> $DIR/eager-from-opaque.rs:12:9
-   |
-LL |         foo!()
-   |         ^^^
-...
-LL |     format_args!(bar!());
-   |                  ------ in this macro invocation
-
-error: aborting due to previous error
-