From bf12aa49e71d6e444c34d7adb87647f36b7dde1a Mon Sep 17 00:00:00 2001
From: Michael Baikov <manpacket@gmail.com>
Date: Thu, 21 Mar 2024 16:13:46 -0400
Subject: [PATCH] Don't emit an error about failing to produce a file with a
 specific name

If user never gave an explicit name
---
 compiler/rustc_codegen_ssa/src/back/write.rs  |  2 +-
 compiler/rustc_session/src/config.rs          |  5 ++++
 .../issues/no-explicit-path-issue-122509.rs   | 23 +++++++++++++++++++
 3 files changed, 29 insertions(+), 1 deletion(-)
 create mode 100644 tests/ui/issues/no-explicit-path-issue-122509.rs

diff --git a/compiler/rustc_codegen_ssa/src/back/write.rs b/compiler/rustc_codegen_ssa/src/back/write.rs
index 4eda4c2f08c..b7bcaac3b18 100644
--- a/compiler/rustc_codegen_ssa/src/back/write.rs
+++ b/compiler/rustc_codegen_ssa/src/back/write.rs
@@ -592,7 +592,7 @@ fn produce_final_output_artifacts(
                 .unwrap()
                 .to_owned();
 
-            if crate_output.outputs.contains_key(&output_type) {
+            if crate_output.outputs.contains_explicit_name(&output_type) {
                 // 2) Multiple codegen units, with `--emit foo=some_name`. We have
                 //    no good solution for this case, so warn the user.
                 sess.dcx().emit_warn(errors::IgnoringEmitPath { extension });
diff --git a/compiler/rustc_session/src/config.rs b/compiler/rustc_session/src/config.rs
index e6eb1a3e83c..e4d2af95c57 100644
--- a/compiler/rustc_session/src/config.rs
+++ b/compiler/rustc_session/src/config.rs
@@ -557,6 +557,11 @@ pub fn contains_key(&self, key: &OutputType) -> bool {
         self.0.contains_key(key)
     }
 
+    /// Returns `true` if user specified a name and not just produced type
+    pub fn contains_explicit_name(&self, key: &OutputType) -> bool {
+        self.0.get(key).map_or(false, |f| f.is_some())
+    }
+
     pub fn iter(&self) -> BTreeMapIter<'_, OutputType, Option<OutFileName>> {
         self.0.iter()
     }
diff --git a/tests/ui/issues/no-explicit-path-issue-122509.rs b/tests/ui/issues/no-explicit-path-issue-122509.rs
new file mode 100644
index 00000000000..4e8eefde5da
--- /dev/null
+++ b/tests/ui/issues/no-explicit-path-issue-122509.rs
@@ -0,0 +1,23 @@
+//@ build-pass
+//@ compile-flags: -C codegen-units=2 --emit asm
+
+fn one() -> usize {
+    1
+}
+
+pub mod a {
+    pub fn two() -> usize {
+        ::one() + ::one()
+    }
+}
+
+pub mod b {
+    pub fn three() -> usize {
+        ::one() + ::a::two()
+    }
+}
+
+fn main() {
+    a::two();
+    b::three();
+}