added name-mangling notes

CPP/33-name-mangling.md

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+# Name Mangling
+
+Name mangling in C++ is a technique used to resolve conflicts between identifiers that have the same name but belong to
+different scopes or have different types. This process transforms function names into unique identifiers that can be
+distinguished by the linker during the linking phase of compilation.
+
+However, it's important to note that name mangling is platform-specific. The C++ ABI (Application Binary Interface) of
+the platform you are running on defines the name mangling. There are two common C++ ABIs, which are the Itanium ABI and
+Microsoft's ABI. Depending on the platform and the compiler being used, different name mangling schemes may be applied .
+
+The C++ standard does not define a specific naming convention for mangled names, so different compilers may implement
+name mangling differently. However, mangled names typically start with \_Z followed by the mangled name of the function
+or variable, including namespace, classes, and name, with a length and the identifier 1.
+
+Here's an example of name mangling in action:
+
+```cpp
+namespace MyNamespace {
+class MyClass {
+  public:
+    void myMethod(int param);
+};
+} // namespace MyNamespace
+```
+
+The mangled name of `myMethod` might look something like `_ZN11MyNamespace7MyClass9myMethodEi`, which includes the
+namespace (`MyNamespace`), the class (`MyClass`), the method name (`myMethod`), and the parameter type (`int`).
+
+To understand the mangled names, you can use a tool like `c++filt`. `c++filt` is a command-line utility that comes with
+the GNU Binutils package and is used to demangle C++ symbols. By piping the output of `nm` (another command-line utility
+that lists symbols from object files) through `c++filt`, you can see the demangled names of the symbols.
+
+Here's how you might use `c++filt`:
+
+```bash
+nm myprogram.o | c++filt
+```
+
+This command will print out the names of all symbols in `myprogram.o`, with the mangled names replaced by their
+demangled equivalents.
+
+Output:
+
+```
+0000000000003df0 d _DYNAMIC
+0000000000003fe8 d _GLOBAL_OFFSET_TABLE_
+0000000000002000 R _IO_stdin_used
+                 w _ITM_deregisterTMCloneTable
+                 w _ITM_registerTMCloneTable
+0000000000002004 r __GNU_EH_FRAME_HDR
+0000000000004010 D __TMC_END__
+0000000000004010 B __bss_start
+                 w __cxa_finalize@GLIBC_2.2.5
+0000000000004000 D __data_start
+0000000000004008 D __dso_handle
+                 w __gmon_start__
+                 U __libc_start_main@GLIBC_2.34
+0000000000004010 D _edata
+0000000000004018 B _end
+000000000000112c T _fini
+0000000000001000 T _init
+0000000000001020 T _start
+0000000000004000 W data_start
+0000000000001119 T main
+```