[cfe-dev] Demangled function name in FunctionPass?

John McCall rjmccall at apple.com
Mon Jul 12 10:20:19 PDT 2010

On Jul 12, 2010, at 9:06 AM, Bjorn Reese wrote:

> On 2010-07-10 19:32, Chris Lattner wrote:
>> On Jul 10, 2010, at 8:47 AM, Bjorn Reese wrote:
>>> If I use the "Hello World Pass" example from "Writing an LLVM Pass",
>>> then the C++ function names (from Function::getName) are mangled.
>>> Is it possible to get the demangled function name instead?
>> You should be able to demangle it yourself.  libstdc++ provides the __cxa_demangle function that will do this for you:
>> http://idlebox.net/2008/0901-stacktrace-demangled/cxa_demangle.htt
>> LLVM doesn't provide any direct capabilities to do this.
> Is there any way to detect that the function names have been mangled
> by the C++ ABI rules (or that we are optimizing C++ code)?

Every mangling under the Itanium C++ ABI starts with _Z.

Of course it's still possible to declare a C function called, say,
  int _ZN3foo3barEi(int x);
which would then have the same mangling as the C++ function
  namespace foo { int bar(int x); }
That these collide is okay under the standard because names starting with
underscores are reserved for future use, so programs using them do so at
their own risk.


More information about the cfe-dev mailing list