Arch-independent demangling and add gnuv2_demangle for old g++ projects (#262)

objdiff-core/src/diff/demangler.rs

@@ -0,0 +1,50 @@
+use alloc::string::String;
+
+use crate::diff::Demangler;
+
+#[cfg(feature = "demangler")]
+impl Demangler {
+    pub fn demangle(&self, name: &str) -> Option<String> {
+        match self {
+            Demangler::Codewarrior => Self::demangle_codewarrior(name),
+            Demangler::Msvc => Self::demangle_msvc(name),
+            Demangler::Itanium => Self::demangle_itanium(name),
+            Demangler::GnuLegacy => Self::demangle_gnu_legacy(name),
+            Demangler::Auto => {
+                // Try to guess
+                if name.starts_with('?') {
+                    Self::demangle_msvc(name)
+                } else {
+                    Self::demangle_codewarrior(name)
+                        .or_else(|| Self::demangle_gnu_legacy(name))
+                        .or_else(|| Self::demangle_itanium(name))
+                }
+            }
+        }
+    }
+
+    fn demangle_codewarrior(name: &str) -> Option<String> {
+        cwdemangle::demangle(name, &cwdemangle::DemangleOptions::default())
+    }
+
+    fn demangle_msvc(name: &str) -> Option<String> {
+        msvc_demangler::demangle(name, msvc_demangler::DemangleFlags::llvm()).ok()
+    }
+
+    fn demangle_itanium(name: &str) -> Option<String> {
+        let name = name.trim_start_matches('.');
+        cpp_demangle::Symbol::new(name)
+            .ok()
+            .and_then(|s| s.demangle(&cpp_demangle::DemangleOptions::default()).ok())
+    }
+
+    fn demangle_gnu_legacy(name: &str) -> Option<String> {
+        let name = name.trim_start_matches('.');
+        gnuv2_demangle::demangle(name, &gnuv2_demangle::DemangleConfig::new_no_cfilt_mimics()).ok()
+    }
+}
+
+#[cfg(not(feature = "demangler"))]
+impl Demangler {
+    pub fn demangle(&self, _name: &str) -> Option<String> { None }
+}

objdiff-core/src/diff/mod.rs

@@ -22,6 +22,7 @@ use crate::{
 
 pub mod code;
 pub mod data;
+pub mod demangler;
 pub mod display;
 
 include!(concat!(env!("OUT_DIR"), "/config.gen.rs"));