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

AngheloAlf · web-flow · commit fe8e7029f620 · 2025-09-22T17:24:29.000-06:00
diff --git a/Cargo.lock b/Cargo.lock
diff --git a/objdiff-core/Cargo.toml b/objdiff-core/Cargo.toml
@@ -41,7 +41,8 @@ any-arch = [
     "dep:regex",
     "dep:similar",
     "dep:syn",
-    "dep:encoding_rs"
+    "dep:encoding_rs",
+    "demangler",
 ]
 bindings = [
     "dep:prost",
@@ -88,38 +89,37 @@ std = [
 ]
 mips = [
     "any-arch",
-    "dep:cpp_demangle",
-    "dep:cwdemangle",
     "dep:rabbitizer",
 ]
 ppc = [
     "any-arch",
-    "dep:cwdemangle",
     "dep:cwextab",
     "dep:powerpc",
     "dep:rlwinmdec",
 ]
 x86 = [
     "any-arch",
-    "dep:cpp_demangle",
     "dep:iced-x86",
-    "dep:msvc-demangler",
 ]
 arm = [
     "any-arch",
     "dep:arm-attr",
-    "dep:cpp_demangle",
     "dep:unarm",
 ]
 arm64 = [
     "any-arch",
-    "dep:cpp_demangle",
     "dep:yaxpeax-arch",
     "dep:yaxpeax-arm",
 ]
 superh = [
     "any-arch",
 ]
+demangler = [
+    "dep:cpp_demangle",
+    "dep:cwdemangle",
+    "dep:gnuv2_demangle",
+    "dep:msvc-demangler",
+]
 
 [package.metadata.docs.rs]
 features = ["all"]
@@ -150,7 +150,6 @@ gimli = { git = "https://github.com/gimli-rs/gimli", rev = "7335f00e7c39fd501511
 typed-arena = { version = "2.0", default-features = false, optional = true }
 
 # ppc
-cwdemangle = { version = "1.0", optional = true }
 cwextab = { version = "1.1", optional = true }
 powerpc = { version = "0.4", optional = true }
 rlwinmdec = { version = "1.1", optional = true }
@@ -159,9 +158,7 @@ rlwinmdec = { version = "1.1", optional = true }
 rabbitizer = { version = "2.0.0-alpha.4", default-features = false, features = ["all_extensions"], optional = true }
 
 # x86
-cpp_demangle = { version = "0.4", default-features = false, features = ["alloc"], optional = true }
 iced-x86 = { version = "1.21", default-features = false, features = ["decoder", "intel", "gas", "masm", "nasm", "exhaustive_enums", "no_std"], optional = true }
-msvc-demangler = { version = "0.11", optional = true }
 
 # arm
 unarm = { version = "1.9", optional = true }
@@ -179,6 +176,12 @@ tempfile = { version = "3.20", optional = true }
 time = { version = "0.3", optional = true }
 encoding_rs = { version = "0.8.35", optional = true }
 
+# demangler
+cpp_demangle = { version = "0.4", optional = true, default-features = false, features = ["alloc"] }
+cwdemangle = { version = "1.0", optional = true }
+gnuv2_demangle = { version = "0.1.0", optional = true }
+msvc-demangler = { version = "0.11", optional = true }
+
 [target.'cfg(windows)'.dependencies]
 winapi = { version = "0.3", optional = true, features = ["winbase"] }
 
diff --git a/objdiff-core/config-schema.json b/objdiff-core/config-schema.json
@@ -25,6 +25,37 @@
         }
       ]
     },
+    {
+      "id": "demangler",
+      "type": "choice",
+      "default": "auto",
+      "name": "Demangler",
+      "description": "Which demangler should be used to demangle each symbol.",
+      "items": [
+        {
+          "value": "auto",
+          "name": "Auto",
+          "description": "Try to automatically guess the mangling format."
+        },
+        {
+          "value": "codewarrior",
+          "name": "CodeWarrior"
+        },
+        {
+          "value": "msvc",
+          "name": "MSVC"
+        },
+        {
+          "value": "itanium",
+          "name": "Itanium"
+        },
+        {
+          "value": "gnu_legacy",
+          "name": "GNU g++ (Legacy)",
+          "description": "Use the old GNU mangling ABI. Used up to g++ 2.9.x"
+        }
+      ]
+    },
     {
       "id": "analyzeDataFlow",
       "type": "boolean",
@@ -259,6 +290,7 @@
       "name": "General",
       "properties": [
         "functionRelocDiffs",
+        "demangler",
         "spaceBetweenArgs",
         "combineDataSections",
         "combineTextSections"
diff --git a/objdiff-core/src/arch/arm.rs b/objdiff-core/src/arch/arm.rs
@@ -1,9 +1,4 @@
-use alloc::{
-    collections::BTreeMap,
-    format,
-    string::{String, ToString},
-    vec::Vec,
-};
+use alloc::{collections::BTreeMap, format, string::ToString, vec::Vec};
 
 use anyhow::{Result, bail};
 use arm_attr::{BuildAttrs, enums::CpuArch, tag::Tag};
@@ -409,12 +404,6 @@ impl Arch for ArchArm {
         }
     }
 
-    fn demangle(&self, name: &str) -> Option<String> {
-        cpp_demangle::Symbol::new(name)
-            .ok()
-            .and_then(|s| s.demangle(&cpp_demangle::DemangleOptions::default()).ok())
-    }
-
     fn reloc_name(&self, flags: RelocationFlags) -> Option<&'static str> {
         match flags {
             RelocationFlags::Elf(r_type) => match r_type {
diff --git a/objdiff-core/src/arch/arm64.rs b/objdiff-core/src/arch/arm64.rs
@@ -1,8 +1,4 @@
-use alloc::{
-    format,
-    string::{String, ToString},
-    vec::Vec,
-};
+use alloc::{format, string::ToString, vec::Vec};
 use core::cmp::Ordering;
 
 use anyhow::Result;
@@ -108,12 +104,6 @@ impl Arch for ArchArm64 {
         Ok(())
     }
 
-    fn demangle(&self, name: &str) -> Option<String> {
-        cpp_demangle::Symbol::new(name)
-            .ok()
-            .and_then(|s| s.demangle(&cpp_demangle::DemangleOptions::default()).ok())
-    }
-
     fn reloc_name(&self, flags: RelocationFlags) -> Option<&'static str> {
         match flags {
             RelocationFlags::Elf(r_type) => match r_type {
diff --git a/objdiff-core/src/arch/mips.rs b/objdiff-core/src/arch/mips.rs
@@ -1,6 +1,6 @@
 use alloc::{
     collections::{BTreeMap, BTreeSet},
-    string::{String, ToString},
+    string::ToString,
     vec::Vec,
 };
 
@@ -304,13 +304,6 @@ impl Arch for ArchMips {
         }
     }
 
-    fn demangle(&self, name: &str) -> Option<String> {
-        cpp_demangle::Symbol::new(name)
-            .ok()
-            .and_then(|s| s.demangle(&cpp_demangle::DemangleOptions::default()).ok())
-            .or_else(|| cwdemangle::demangle(name, &cwdemangle::DemangleOptions::default()))
-    }
-
     fn reloc_name(&self, flags: RelocationFlags) -> Option<&'static str> {
         match flags {
             RelocationFlags::Elf(r_type) => match r_type {
diff --git a/objdiff-core/src/arch/mod.rs b/objdiff-core/src/arch/mod.rs
@@ -371,8 +371,6 @@ pub trait Arch: Any + Debug + Send + Sync {
         Ok(None)
     }
 
-    fn demangle(&self, _name: &str) -> Option<String> { None }
-
     fn reloc_name(&self, _flags: RelocationFlags) -> Option<&'static str> { None }
 
     fn data_reloc_size(&self, flags: RelocationFlags) -> usize;
diff --git a/objdiff-core/src/arch/ppc/mod.rs b/objdiff-core/src/arch/ppc/mod.rs
@@ -308,18 +308,6 @@ impl Arch for ArchPpc {
         }
     }
 
-    fn demangle(&self, mut name: &str) -> Option<String> {
-        if name.starts_with('?') {
-            msvc_demangler::demangle(name, msvc_demangler::DemangleFlags::llvm()).ok()
-        } else {
-            name = name.trim_start_matches('.');
-            cpp_demangle::Symbol::new(name)
-                .ok()
-                .and_then(|s| s.demangle(&cpp_demangle::DemangleOptions::default()).ok())
-                .or_else(|| cwdemangle::demangle(name, &cwdemangle::DemangleOptions::default()))
-        }
-    }
-
     fn reloc_name(&self, flags: RelocationFlags) -> Option<&'static str> {
         match flags {
             RelocationFlags::Elf(r_type) => match r_type {
diff --git a/objdiff-core/src/arch/superh/mod.rs b/objdiff-core/src/arch/superh/mod.rs
@@ -1,4 +1,4 @@
-use alloc::{collections::BTreeMap, format, string::String, vec, vec::Vec};
+use alloc::{collections::BTreeMap, format, vec, vec::Vec};
 
 use anyhow::Result;
 use object::elf;
@@ -132,12 +132,6 @@ impl Arch for ArchSuperH {
         Ok(())
     }
 
-    fn demangle(&self, name: &str) -> Option<String> {
-        cpp_demangle::Symbol::new(name)
-            .ok()
-            .and_then(|s| s.demangle(&cpp_demangle::DemangleOptions::default()).ok())
-    }
-
     fn reloc_name(&self, flags: RelocationFlags) -> Option<&'static str> {
         match flags {
             RelocationFlags::Elf(r_type) => match r_type {
diff --git a/objdiff-core/src/arch/x86.rs b/objdiff-core/src/arch/x86.rs
@@ -1,4 +1,4 @@
-use alloc::{boxed::Box, format, string::String, vec::Vec};
+use alloc::{boxed::Box, format, vec::Vec};
 use core::cmp::Ordering;
 
 use anyhow::{Context, Result, anyhow, bail};
@@ -300,16 +300,6 @@ impl Arch for ArchX86 {
         Ok(Some(RelocationOverride { target: RelocationOverrideTarget::Keep, addend }))
     }
 
-    fn demangle(&self, name: &str) -> Option<String> {
-        if name.starts_with('?') {
-            msvc_demangler::demangle(name, msvc_demangler::DemangleFlags::llvm()).ok()
-        } else {
-            cpp_demangle::Symbol::new(name)
-                .ok()
-                .and_then(|s| s.demangle(&cpp_demangle::DemangleOptions::default()).ok())
-        }
-    }
-
     fn reloc_name(&self, flags: RelocationFlags) -> Option<&'static str> {
         match self.arch {
             Architecture::X86 => match flags {
diff --git a/objdiff-core/src/diff/demangler.rs b/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 }
+}
diff --git a/objdiff-core/src/diff/mod.rs b/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"));
diff --git a/objdiff-core/src/obj/read.rs b/objdiff-core/src/obj/read.rs
diff --git a/objdiff-gui/src/views/demangle.rs b/objdiff-gui/src/views/demangle.rs

Original file line number	Diff line number	Diff line change
`@@ -371,8 +371,6 @@ pub trait Arch: Any + Debug + Send + Sync {`
`371`	`371`	`Ok(None)`
`372`	`372`	`}`
`373`	`373`
`374`		`- fn demangle(&self, _name: &str) -> Option<String> { None }`
`375`		`-`
`376`	`374`	`fn reloc_name(&self, _flags: RelocationFlags) -> Option<&'static str> { None }`
`377`	`375`
`378`	`376`	`fn data_reloc_size(&self, flags: RelocationFlags) -> usize;`