From 71c1f42d85ee1819741786255dc8876047398e8e Mon Sep 17 00:00:00 2001
From: Paul Zander <negril.nx+gentoo@gmail.com>
Date: Sun, 12 Jan 2025 19:22:48 +0100
Subject: [PATCH] properly demangle typenames

C++ class names are mangled. How these are mangled is implementation specific.
Using string offsets is naive and caused at minimum testfailures.

For gcc and clang you can use cxxabi.h to get demangled name.
This initial patch uses this for linux only, so the gentoo build suceeeds.

Signed-off-by: Paul Zander <negril.nx+gentoo@gmail.com>

diff --git a/OndselSolver/ASMTItem.cpp b/OndselSolver/ASMTItem.cpp
index a18e7c9..9d5383a 100644
--- a/OndselSolver/ASMTItem.cpp
+++ b/OndselSolver/ASMTItem.cpp
@@ -12,6 +12,7 @@
 #include "ASMTAssembly.h"
 #include "Constant.h"
 #include <algorithm>
+#include "Demangle.h"
 
 using namespace MbD;
 
@@ -41,9 +42,7 @@ void MbD::ASMTItem::noop()
 
 std::string MbD::ASMTItem::classname()
 {
-	std::string str = typeid(*this).name();
-	auto answer = str.substr(11, str.size() - 11);
-	return answer;
+	return demangle(typeid(*this).name());
 }
 
 void MbD::ASMTItem::setName(const std::string& str)
diff --git a/OndselSolver/ASMTJoint.cpp b/OndselSolver/ASMTJoint.cpp
index 40edd52..bb710e3 100644
--- a/OndselSolver/ASMTJoint.cpp
+++ b/OndselSolver/ASMTJoint.cpp
@@ -9,6 +9,7 @@
 
 #include "ASMTJoint.h"
 #include "Joint.h"
+#include "Demangle.h"
 
 using namespace MbD;
 
@@ -47,9 +48,7 @@ void MbD::ASMTJoint::storeOnLevel(std::ofstream& os, size_t level)
 
 void MbD::ASMTJoint::storeOnTimeSeries(std::ofstream& os)
 {
-	std::string label = typeid(*this).name();
-	label = label.substr(15, label.size() - 15);
-	os << label << "Series\t" << fullName("") << std::endl;
+	os << demangle(typeid(*this).name()) << "Series\t" << fullName("") << std::endl;
 	ASMTItemIJ::storeOnTimeSeries(os);
 }
 
diff --git a/OndselSolver/Array.h b/OndselSolver/Array.h
index 636e9a5..e270795 100644
--- a/OndselSolver/Array.h
+++ b/OndselSolver/Array.h
@@ -16,6 +16,7 @@
 #include "Numeric.h"
 #include <limits>
 
+#include "Demangle.h"
 //#include "Symbolic.h"
 
 namespace MbD {
@@ -51,10 +52,7 @@ namespace MbD {
 		void atitimes(size_t i, double factor);
 
 		virtual std::ostream& printOn(std::ostream& s) const {
-			std::string str = typeid(*this).name();
-			auto classname = str.substr(11, str.size() - 11);
-			s << classname << std::endl;
-			return s;
+			return s << demangle(typeid(*this).name()) << std::endl;
 		}
 		friend std::ostream& operator<<(std::ostream& s, const Array& array)
 		{
diff --git a/OndselSolver/Demangle.h b/OndselSolver/Demangle.h
new file mode 100644
index 0000000..810936d
--- /dev/null
+++ b/OndselSolver/Demangle.h
@@ -0,0 +1,39 @@
+#ifndef DEMANGLE_H
+#define DEMANGLE_H 1
+#include <string>
+
+#ifdef _WIN32
+#include <typeinfo>
+namespace {
+std::string demangle(const char* mangled_name) noexcept {
+  return mangled_name;
+}
+}
+#else // __linux__
+#include <cxxabi.h>
+namespace {
+std::string demangle(const char* mangled_name) noexcept {
+  int error = 0;
+  char *demang_name = abi::__cxa_demangle(mangled_name, 0, 0, &error);
+
+  switch (error) {
+  case 0:
+    break;
+  case -1:
+    return "memory allocation failed";
+  case -2:
+    return "not a valid mangled name";
+  case -3:
+    return "invalid arguments";
+  default:
+    return "__cxa_demangle failed";
+  }
+
+  std::string name(demang_name);
+  free(demang_name);
+
+  return name.substr(name.find_last_of("::") + 1);
+}
+}
+#endif // __linux__
+#endif
diff --git a/OndselSolver/Item.cpp b/OndselSolver/Item.cpp
index 4435d5d..120cd3c 100644
--- a/OndselSolver/Item.cpp
+++ b/OndselSolver/Item.cpp
@@ -15,6 +15,7 @@
 #include "Item.h"
 #include "System.h"
 #include "Symbolic.h"
+#include "Demangle.h"
 
 using namespace MbD;
 
@@ -44,10 +45,7 @@ void Item::initialize()
 
 std::ostream& Item::printOn(std::ostream& s) const
 {
-	std::string str = typeid(*this).name();
-	auto classname = str.substr(11, str.size() - 11);
-	s << classname << std::endl;
-	return s;
+	return s << demangle(typeid(*this).name()) << std::endl;
 }
 
 void Item::initializeLocally()
diff --git a/OndselSolver/Symbolic.cpp b/OndselSolver/Symbolic.cpp
index 75bcbb6..4961964 100644
--- a/OndselSolver/Symbolic.cpp
+++ b/OndselSolver/Symbolic.cpp
@@ -15,6 +15,7 @@
 #include "Product.h"
 #include "Sum.h"
 #include "Power.h"
+#include "Demangle.h"
 
 using namespace MbD;
 
@@ -160,10 +161,7 @@ bool Symbolic::isConstant()
 
 std::ostream& Symbolic::printOn(std::ostream& s) const
 {
-	std::string str = typeid(*this).name();
-	auto classname = str.substr(11, str.size() - 11);
-	s << classname;
-	return s;
+	return s << demangle(typeid(*this).name());
 }
 
 std::shared_ptr<std::vector<Symsptr>> Symbolic::getTerms()
diff --git a/OndselSolver/CMakeLists.txt b/OndselSolver/CMakeLists.txt
index 6836e72..30d5bf4 100644
--- a/OndselSolver/CMakeLists.txt
+++ b/OndselSolver/CMakeLists.txt
@@ -426,6 +426,7 @@ set(ONDSELSOLVER_HEADERS
         CREATE.h
         CylindricalJoint.h
         CylSphJoint.h
+        Demangle.h
         DiagonalMatrix.h
         DifferenceOperator.h
         DifferentiatedGeneralSpline.h
-- 
2.48.0