From 3ce416e2ffee12dc84a44fc0a0387f32e697ec06 Mon Sep 17 00:00:00 2001
From: Jeff Charles <jeff.charles@shopify.com>
Date: Mon, 31 Aug 2026 16:55:18 -0400
Subject: [PATCH] Update `cpp_demangle`

---
 Cargo.lock | 13 +++++++++++--
 Cargo.toml |  2 +-
 src/lib.rs | 35 +++++++++++++++++++++++++++++++++--
 3 files changed, 45 insertions(+), 5 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index f887b6d..d7ef47b 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -118,6 +118,15 @@ dependencies = [
  "cfg-if",
 ]
 
+[[package]]
+name = "cpp_demangle"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0667304c32ea56cb4cd6d2d7c0cfe9a2f8041229db8c033af7f8d69492429def"
+dependencies = [
+ "cfg-if",
+]
+
 [[package]]
 name = "cpufeatures"
 version = "0.2.16"
@@ -1087,7 +1096,7 @@ dependencies = [
 name = "wasmprof"
 version = "0.12.0"
 dependencies = [
- "cpp_demangle",
+ "cpp_demangle 0.5.1",
  "libc",
  "nix",
  "rustc-demangle",
@@ -1157,7 +1166,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9fd1d43cfaa1a0859d2f4fccc15e7e571e2a88b357e81bc88ba6c501b83d925d"
 dependencies = [
  "anyhow",
- "cpp_demangle",
+ "cpp_demangle 0.4.4",
  "cranelift-bitset",
  "cranelift-entity",
  "gimli",
diff --git a/Cargo.toml b/Cargo.toml
index 76c2faf..e631771 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -9,7 +9,7 @@ keywords = ["wasm", "wasmtime", "profiler"]
 categories = ["wasm", "development-tools::profiling"]
 
 [dependencies]
-cpp_demangle = "0.4.1"
+cpp_demangle = "0.5.1"
 libc = "0.2.142"
 nix = { version = "0.31", default-features = false, features = ["signal"] }
 rustc-demangle = "0.1.23"
diff --git a/src/lib.rs b/src/lib.rs
index 78e64ee..e7ce847 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -156,9 +156,40 @@ impl<'a, T> ProfilerBuilder<'a, T> {
 fn unmangle_name(name: &str) -> String {
     if let Ok(demangled) = rustc_demangle::try_demangle(name) {
         demangled.to_string()
-    } else if let Ok(demangled) = cpp_demangle::Symbol::new(name) {
-        demangled.to_string()
+    } else if let Ok(cpp_symbol) = cpp_demangle::Symbol::new(name) {
+        cpp_symbol.demangle().unwrap_or_else(|_| name.to_string())
     } else {
         name.to_string()
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::unmangle_name;
+
+    #[test]
+    fn unmangles_rust_symbols() {
+        assert_eq!(unmangle_name("_ZN4testE"), "test");
+    }
+
+    #[test]
+    fn unmangles_cpp_symbols() {
+        assert_eq!(
+            unmangle_name("_ZN5space3fooEibc"),
+            "space::foo(int, bool, char)"
+        );
+    }
+
+    #[test]
+    fn preserves_unmangled_symbols() {
+        assert_eq!(
+            unmangle_name("not_a_mangled_symbol"),
+            "not_a_mangled_symbol"
+        );
+    }
+
+    #[test]
+    fn preserves_symbols_that_fail_cpp_parsing() {
+        assert_eq!(unmangle_name("_Z"), "_Z");
+    }
+}