From 218caa410aa38c29984be31a5229b9fa717560ee Mon Sep 17 00:00:00 2001
From: Daniel Baumann <daniel.baumann@progress-linux.org>
Date: Wed, 17 Apr 2024 14:19:13 +0200
Subject: Merging upstream version 1.68.2+dfsg1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
---
 .../auxiliary/invalid-span-helper-lib.rs           | 11 ++++++++++
 .../auxiliary/invalid-span-helper-mod.rs           | 14 +++++++++++++
 .../issue-85197-invalid-span/auxiliary/respan.rs   | 19 +++++++++++++++++
 .../issue-85197-invalid-span/invalid_span_main.rs  | 24 ++++++++++++++++++++++
 4 files changed, 68 insertions(+)
 create mode 100644 tests/incremental/issue-85197-invalid-span/auxiliary/invalid-span-helper-lib.rs
 create mode 100644 tests/incremental/issue-85197-invalid-span/auxiliary/invalid-span-helper-mod.rs
 create mode 100644 tests/incremental/issue-85197-invalid-span/auxiliary/respan.rs
 create mode 100644 tests/incremental/issue-85197-invalid-span/invalid_span_main.rs

(limited to 'tests/incremental/issue-85197-invalid-span')

diff --git a/tests/incremental/issue-85197-invalid-span/auxiliary/invalid-span-helper-lib.rs b/tests/incremental/issue-85197-invalid-span/auxiliary/invalid-span-helper-lib.rs
new file mode 100644
index 000000000..2453af5b6
--- /dev/null
+++ b/tests/incremental/issue-85197-invalid-span/auxiliary/invalid-span-helper-lib.rs
@@ -0,0 +1,11 @@
+// revisions: rpass1 rpass2
+
+extern crate respan;
+
+#[macro_use]
+#[path = "invalid-span-helper-mod.rs"]
+mod invalid_span_helper_mod;
+
+// Invoke a macro from a different file - this
+// allows us to get tokens with spans from different files
+helper!(1);
diff --git a/tests/incremental/issue-85197-invalid-span/auxiliary/invalid-span-helper-mod.rs b/tests/incremental/issue-85197-invalid-span/auxiliary/invalid-span-helper-mod.rs
new file mode 100644
index 000000000..747174b1e
--- /dev/null
+++ b/tests/incremental/issue-85197-invalid-span/auxiliary/invalid-span-helper-mod.rs
@@ -0,0 +1,14 @@
+#[macro_export]
+macro_rules! helper {
+    // Use `:tt` instead of `:ident` so that we don't get a `None`-delimited group
+    ($first:tt) => {
+        pub fn foo<T>() {
+            // The span of `$first` comes from another file,
+            // so the expression `1 + $first` ends up with an
+            // 'invalid' span that starts and ends in different files.
+            // We use the `respan!` macro to give all tokens the same
+            // `SyntaxContext`, so that the parser will try to merge the spans.
+            respan::respan!(let a = 1 + $first;);
+        }
+    }
+}
diff --git a/tests/incremental/issue-85197-invalid-span/auxiliary/respan.rs b/tests/incremental/issue-85197-invalid-span/auxiliary/respan.rs
new file mode 100644
index 000000000..5088eab62
--- /dev/null
+++ b/tests/incremental/issue-85197-invalid-span/auxiliary/respan.rs
@@ -0,0 +1,19 @@
+// force-host
+// no-prefer-dynamic
+
+#![crate_type = "proc-macro"]
+
+extern crate proc_macro;
+use proc_macro::TokenStream;
+
+
+/// Copies the resolution information (the `SyntaxContext`) of the first
+/// token to all other tokens in the stream. Does not recurse into groups.
+#[proc_macro]
+pub fn respan(input: TokenStream) -> TokenStream {
+    let first_span = input.clone().into_iter().next().unwrap().span();
+    input.into_iter().map(|mut tree| {
+        tree.set_span(tree.span().resolved_at(first_span));
+        tree
+    }).collect()
+}
diff --git a/tests/incremental/issue-85197-invalid-span/invalid_span_main.rs b/tests/incremental/issue-85197-invalid-span/invalid_span_main.rs
new file mode 100644
index 000000000..f358460b3
--- /dev/null
+++ b/tests/incremental/issue-85197-invalid-span/invalid_span_main.rs
@@ -0,0 +1,24 @@
+// revisions: rpass1 rpass2
+// aux-build:respan.rs
+// aux-build:invalid-span-helper-lib.rs
+
+// This issue has several different parts. The high level idea is:
+// 1. We create an 'invalid' span with the help of the `respan` proc-macro,
+// The compiler attempts to prevent the creation of invalid spans by
+// refusing to join spans with different `SyntaxContext`s. We work around
+// this by applying the same `SyntaxContext` to the span of every token,
+// using `Span::resolved_at`
+// 2. We using this invalid span in the body of a function, causing it to get
+// encoded into the `optimized_mir`
+// 3. We call the function from a different crate - since the function is generic,
+// monomorphization runs, causing `optimized_mir` to get called.
+// 4. We re-run compilation using our populated incremental cache, but without
+// making any changes. When we recompile the crate containing our generic function
+// (`invalid_span_helper_lib`), we load the span from the incremental cache, and
+// write it into the crate metadata.
+
+extern crate invalid_span_helper_lib;
+
+fn main() {
+    invalid_span_helper_lib::foo::<u8>();
+}
-- 
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