diff mbox series

[v1,09/13] perf symbol: Add abi::__cxa_demangle C++ demangling support

Message ID 20230311065753.3012826-10-irogers@google.com
State New
Headers
Series Perf tool build improvements |

Commit Message

Ian Rogers March 11, 2023, 6:57 a.m. UTC 
  Refactor C++ demangling out of symbol-elf into its own files similar
to other languages. Add abi::__cxa_demangle support. As the other
demanglers are not shippable with distributions, this brings back C++
demangling in a common case. It isn't perfect as the support for
optionally demangling arguments and modifiers isn't present.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/Makefile.config       | 29 +++++++++---------
 tools/perf/util/Build            |  1 +
 tools/perf/util/demangle-cxx.cpp | 50 ++++++++++++++++++++++++++++++++
 tools/perf/util/demangle-cxx.h   | 16 ++++++++++
 tools/perf/util/symbol-elf.c     | 37 +++++------------------
 5 files changed, 88 insertions(+), 45 deletions(-)
 create mode 100644 tools/perf/util/demangle-cxx.cpp
 create mode 100644 tools/perf/util/demangle-cxx.h

Comments

James Clark March 30, 2023, 2:08 p.m. UTC | #1 
On 11/03/2023 06:57, Ian Rogers wrote:
> Refactor C++ demangling out of symbol-elf into its own files similar
> to other languages. Add abi::__cxa_demangle support. As the other
> demanglers are not shippable with distributions, this brings back C++
> demangling in a common case. It isn't perfect as the support for
> optionally demangling arguments and modifiers isn't present.
> 
> Signed-off-by: Ian Rogers <irogers@google.com>
> ---
>  tools/perf/Makefile.config       | 29 +++++++++---------
>  tools/perf/util/Build            |  1 +
>  tools/perf/util/demangle-cxx.cpp | 50 ++++++++++++++++++++++++++++++++
>  tools/perf/util/demangle-cxx.h   | 16 ++++++++++
>  tools/perf/util/symbol-elf.c     | 37 +++++------------------
>  5 files changed, 88 insertions(+), 45 deletions(-)
>  create mode 100644 tools/perf/util/demangle-cxx.cpp
>  create mode 100644 tools/perf/util/demangle-cxx.h
> 
> diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
> index 5756498248e0..fdeca45cf15f 100644
> --- a/tools/perf/Makefile.config
> +++ b/tools/perf/Makefile.config
> @@ -906,6 +906,7 @@ ifdef BUILD_NONDISTRO
>    endif
>  
>    CFLAGS += -DHAVE_LIBBFD_SUPPORT
> +  CXXFLAGS += -DHAVE_LIBBFD_SUPPORT
>    ifeq ($(feature-libbfd-buildid), 1)
>      CFLAGS += -DHAVE_LIBBFD_BUILDID_SUPPORT
>    else
> @@ -913,26 +914,24 @@ ifdef BUILD_NONDISTRO
>    endif
>  endif
>  
> -ifdef NO_DEMANGLE
> -  CFLAGS += -DNO_DEMANGLE
> -else
> +ifndef NO_DEMANGLE
> +  $(call feature_check,cxa-demangle)
> +  ifeq ($(feature-cxa-demangle), 1)
> +    EXTLIBS += -lstdc++

Hi Ian,

I think cross compilation for arm on x86 isn't working after this change
(at least on Ubuntu).

Even with all of the arm64 libstdc++ stuff installed, you can only link
to it using g++, but the perf build tries to link to it using gcc. Not
sure it's some quirk with the search paths on Ubuntu or something else:

  $ aarch64-linux-gnu-gcc -lstdc++

   /usr/lib/gcc-cross/aarch64-linux-gnu/12/../../../../aarch64-linux-
gnu/bin/ld: cannot find -lstdc++: No such file or directory
  collect2: error: ld returned 1 exit status

g++ gets further:

  $ aarch64-linux-gnu-g++ -lstdc++

  ...
  (.text+0x20): undefined reference to `main'
collect2: error: ld returned 1 exit status

At the end of the perf build it looks like something similar is
happening (with all the non interesting bits deleted):

   $ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- -C tools/perf
NO_BPF_SKEL=1 V=1

  aarch64-linux-gnu-gcc ... -o perf

/usr/lib/gcc-cross/aarch64-linux-gnu/12/../../../../aarch64-linux-gnu/bin/ld:
cannot find -lstdc++: No such file or directory

If I build with NO_DEMANGLE=1 then the build works, but I think it would
at be best to autodetect rather than have to do this. Or maybe even link
at the end with g++ if we're going to use libstdc++?

Thanks
James

> +    CFLAGS += -DHAVE_CXA_DEMANGLE_SUPPORT
> +    CXXFLAGS += -DHAVE_CXA_DEMANGLE_SUPPORT
> +  endif
>    ifdef BUILD_NONDISTRO
>      ifeq ($(filter -liberty,$(EXTLIBS)),)
> -      ifdef HAVE_CPLUS_DEMANGLE_SUPPORT
> +      $(call feature_check,cplus-demangle)
> +      ifeq ($(feature-cplus-demangle), 1)
>          EXTLIBS += -liberty
> -      else
> -        $(call feature_check,cplus-demangle)
> -        ifeq ($(feature-cplus-demangle), 1)
> -          EXTLIBS += -liberty
> -        endif
>        endif
>      endif
> -  endif
> -
> -  ifneq ($(filter -liberty,$(EXTLIBS)),)
> -    CFLAGS += -DHAVE_CPLUS_DEMANGLE_SUPPORT
> -  else
> -    CFLAGS += -DNO_DEMANGLE
> +    ifneq ($(filter -liberty,$(EXTLIBS)),)
> +      CFLAGS += -DHAVE_CPLUS_DEMANGLE_SUPPORT
> +      CXXFLAGS += -DHAVE_CPLUS_DEMANGLE_SUPPORT
> +    endif
>    endif
>  endif
>  
> diff --git a/tools/perf/util/Build b/tools/perf/util/Build
> index 918b501f9bd8..8607575183a9 100644
> --- a/tools/perf/util/Build
> +++ b/tools/perf/util/Build
> @@ -211,6 +211,7 @@ perf-$(CONFIG_ZSTD) += zstd.o
>  
>  perf-$(CONFIG_LIBCAP) += cap.o
>  
> +perf-y += demangle-cxx.o
>  perf-y += demangle-ocaml.o
>  perf-y += demangle-java.o
>  perf-y += demangle-rust.o
> diff --git a/tools/perf/util/demangle-cxx.cpp b/tools/perf/util/demangle-cxx.cpp
> new file mode 100644
> index 000000000000..8708bcafd370
> --- /dev/null
> +++ b/tools/perf/util/demangle-cxx.cpp
> @@ -0,0 +1,50 @@
> +// SPDX-License-Identifier: GPL-2.0
> +#include "demangle-cxx.h"
> +#include <stdlib.h>
> +#include <string.h>
> +#include <linux/compiler.h>
> +
> +#ifdef HAVE_LIBBFD_SUPPORT
> +#define PACKAGE 'perf'
> +#include <bfd.h>
> +#endif
> +
> +#ifdef HAVE_CXA_DEMANGLE_SUPPORT
> +#include <cxxabi.h>
> +#endif
> +
> +#if defined(HAVE_LIBBFD_SUPPORT) || defined(HAVE_CPLUS_DEMANGLE_SUPPORT)
> +#ifndef DMGL_PARAMS
> +#define DMGL_PARAMS     (1 << 0)  /* Include function args */
> +#define DMGL_ANSI       (1 << 1)  /* Include const, volatile, etc */
> +#endif
> +#endif
> +
> +/*
> + * Demangle C++ function signature
> + *
> + * Note: caller is responsible for freeing demangled string
> + */
> +extern "C"
> +char *cxx_demangle_sym(const char *str, bool params __maybe_unused,
> +                       bool modifiers __maybe_unused)
> +{
> +#ifdef HAVE_LIBBFD_SUPPORT
> +        int flags = (params ? DMGL_PARAMS : 0) | (modifiers ? DMGL_ANSI : 0);
> +
> +        return bfd_demangle(NULL, str, flags);
> +#elif defined(HAVE_CPLUS_DEMANGLE_SUPPORT)
> +        int flags = (params ? DMGL_PARAMS : 0) | (modifiers ? DMGL_ANSI : 0);
> +
> +        return cplus_demangle(str, flags);
> +#elif defined(HAVE_CXA_DEMANGLE_SUPPORT)
> +        size_t len = strlen(str);
> +        char *output = (char*)malloc(len);
> +        int status;
> +
> +        output = abi::__cxa_demangle(str, output, &len, &status);
> +        return output;
> +#else
> +        return NULL;
> +#endif
> +}
> diff --git a/tools/perf/util/demangle-cxx.h b/tools/perf/util/demangle-cxx.h
> new file mode 100644
> index 000000000000..26b5b66c0b4e
> --- /dev/null
> +++ b/tools/perf/util/demangle-cxx.h
> @@ -0,0 +1,16 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#ifndef __PERF_DEMANGLE_CXX
> +#define __PERF_DEMANGLE_CXX 1
> +
> +#ifdef __cplusplus
> +extern "C" {
> +#endif
> +
> +char *cxx_demangle_sym(const char *str, bool params, bool modifiers);
> +
> +#ifdef __cplusplus
> +}
> +#endif
> +
> +
> +#endif /* __PERF_DEMANGLE_CXX */
> diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
> index 41882ae8452e..c0a2de42c51b 100644
> --- a/tools/perf/util/symbol-elf.c
> +++ b/tools/perf/util/symbol-elf.c
> @@ -12,6 +12,7 @@
>  #include "maps.h"
>  #include "symbol.h"
>  #include "symsrc.h"
> +#include "demangle-cxx.h"
>  #include "demangle-ocaml.h"
>  #include "demangle-java.h"
>  #include "demangle-rust.h"
> @@ -25,6 +26,11 @@
>  #include <symbol/kallsyms.h>
>  #include <internal/lib.h>
>  
> +#ifdef HAVE_LIBBFD_SUPPORT
> +#define PACKAGE 'perf'
> +#include <bfd.h>
> +#endif
> +
>  #ifndef EM_AARCH64
>  #define EM_AARCH64	183  /* ARM 64 bit */
>  #endif
> @@ -45,34 +51,6 @@
>  
>  typedef Elf64_Nhdr GElf_Nhdr;
>  
> -#ifndef DMGL_PARAMS
> -#define DMGL_NO_OPTS     0              /* For readability... */
> -#define DMGL_PARAMS      (1 << 0)       /* Include function args */
> -#define DMGL_ANSI        (1 << 1)       /* Include const, volatile, etc */
> -#endif
> -
> -#ifdef HAVE_LIBBFD_SUPPORT
> -#define PACKAGE 'perf'
> -#include <bfd.h>
> -#else
> -#ifdef HAVE_CPLUS_DEMANGLE_SUPPORT
> -extern char *cplus_demangle(const char *, int);
> -
> -static inline char *bfd_demangle(void __maybe_unused *v, const char *c, int i)
> -{
> -	return cplus_demangle(c, i);
> -}
> -#else
> -#ifdef NO_DEMANGLE
> -static inline char *bfd_demangle(void __maybe_unused *v,
> -				 const char __maybe_unused *c,
> -				 int __maybe_unused i)
> -{
> -	return NULL;
> -}
> -#endif
> -#endif
> -#endif
>  
>  #ifndef HAVE_ELF_GETPHDRNUM_SUPPORT
>  static int elf_getphdrnum(Elf *elf, size_t *dst)
> @@ -295,7 +273,6 @@ static bool want_demangle(bool is_kernel_sym)
>  
>  static char *demangle_sym(struct dso *dso, int kmodule, const char *elf_name)
>  {
> -	int demangle_flags = verbose > 0 ? (DMGL_PARAMS | DMGL_ANSI) : DMGL_NO_OPTS;
>  	char *demangled = NULL;
>  
>  	/*
> @@ -306,7 +283,7 @@ static char *demangle_sym(struct dso *dso, int kmodule, const char *elf_name)
>  	if (!want_demangle(dso->kernel || kmodule))
>  	    return demangled;
>  
> -	demangled = bfd_demangle(NULL, elf_name, demangle_flags);
> +	demangled = cxx_demangle_sym(elf_name, verbose > 0, verbose > 0);
>  	if (demangled == NULL) {
>  		demangled = ocaml_demangle_sym(elf_name);
>  		if (demangled == NULL) {
Ian Rogers March 30, 2023, 4:50 p.m. UTC | #2 
On Thu, Mar 30, 2023 at 7:08 AM James Clark <james.clark@arm.com> wrote:
>
>
>
> On 11/03/2023 06:57, Ian Rogers wrote:
> > Refactor C++ demangling out of symbol-elf into its own files similar
> > to other languages. Add abi::__cxa_demangle support. As the other
> > demanglers are not shippable with distributions, this brings back C++
> > demangling in a common case. It isn't perfect as the support for
> > optionally demangling arguments and modifiers isn't present.
> >
> > Signed-off-by: Ian Rogers <irogers@google.com>
> > ---
> >  tools/perf/Makefile.config       | 29 +++++++++---------
> >  tools/perf/util/Build            |  1 +
> >  tools/perf/util/demangle-cxx.cpp | 50 ++++++++++++++++++++++++++++++++
> >  tools/perf/util/demangle-cxx.h   | 16 ++++++++++
> >  tools/perf/util/symbol-elf.c     | 37 +++++------------------
> >  5 files changed, 88 insertions(+), 45 deletions(-)
> >  create mode 100644 tools/perf/util/demangle-cxx.cpp
> >  create mode 100644 tools/perf/util/demangle-cxx.h
> >
> > diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
> > index 5756498248e0..fdeca45cf15f 100644
> > --- a/tools/perf/Makefile.config
> > +++ b/tools/perf/Makefile.config
> > @@ -906,6 +906,7 @@ ifdef BUILD_NONDISTRO
> >    endif
> >
> >    CFLAGS += -DHAVE_LIBBFD_SUPPORT
> > +  CXXFLAGS += -DHAVE_LIBBFD_SUPPORT
> >    ifeq ($(feature-libbfd-buildid), 1)
> >      CFLAGS += -DHAVE_LIBBFD_BUILDID_SUPPORT
> >    else
> > @@ -913,26 +914,24 @@ ifdef BUILD_NONDISTRO
> >    endif
> >  endif
> >
> > -ifdef NO_DEMANGLE
> > -  CFLAGS += -DNO_DEMANGLE
> > -else
> > +ifndef NO_DEMANGLE
> > +  $(call feature_check,cxa-demangle)
> > +  ifeq ($(feature-cxa-demangle), 1)
> > +    EXTLIBS += -lstdc++
>
> Hi Ian,
>
> I think cross compilation for arm on x86 isn't working after this change
> (at least on Ubuntu).
>
> Even with all of the arm64 libstdc++ stuff installed, you can only link
> to it using g++, but the perf build tries to link to it using gcc. Not
> sure it's some quirk with the search paths on Ubuntu or something else:
>
>   $ aarch64-linux-gnu-gcc -lstdc++
>
>    /usr/lib/gcc-cross/aarch64-linux-gnu/12/../../../../aarch64-linux-
> gnu/bin/ld: cannot find -lstdc++: No such file or directory
>   collect2: error: ld returned 1 exit status
>
> g++ gets further:
>
>   $ aarch64-linux-gnu-g++ -lstdc++
>
>   ...
>   (.text+0x20): undefined reference to `main'
> collect2: error: ld returned 1 exit status
>
> At the end of the perf build it looks like something similar is
> happening (with all the non interesting bits deleted):
>
>    $ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- -C tools/perf
> NO_BPF_SKEL=1 V=1
>
>   aarch64-linux-gnu-gcc ... -o perf
>
> /usr/lib/gcc-cross/aarch64-linux-gnu/12/../../../../aarch64-linux-gnu/bin/ld:
> cannot find -lstdc++: No such file or directory
>
> If I build with NO_DEMANGLE=1 then the build works, but I think it would
> at be best to autodetect rather than have to do this. Or maybe even link
> at the end with g++ if we're going to use libstdc++?

Hi James,

sorry for the problems you are having, I'll see if I can get a repo. I
did add a feature test with this change in the same set:
https://lore.kernel.org/lkml/20230311065753.3012826-9-irogers@google.com/
So it should be feature testing and only enabling when
HAVE_CXA_DEMANGLE_SUPPORT is present. Obviously something is up, so
I'll have a think about it.

Thanks,
Ian

> Thanks
> James
>
> > +    CFLAGS += -DHAVE_CXA_DEMANGLE_SUPPORT
> > +    CXXFLAGS += -DHAVE_CXA_DEMANGLE_SUPPORT
> > +  endif
> >    ifdef BUILD_NONDISTRO
> >      ifeq ($(filter -liberty,$(EXTLIBS)),)
> > -      ifdef HAVE_CPLUS_DEMANGLE_SUPPORT
> > +      $(call feature_check,cplus-demangle)
> > +      ifeq ($(feature-cplus-demangle), 1)
> >          EXTLIBS += -liberty
> > -      else
> > -        $(call feature_check,cplus-demangle)
> > -        ifeq ($(feature-cplus-demangle), 1)
> > -          EXTLIBS += -liberty
> > -        endif
> >        endif
> >      endif
> > -  endif
> > -
> > -  ifneq ($(filter -liberty,$(EXTLIBS)),)
> > -    CFLAGS += -DHAVE_CPLUS_DEMANGLE_SUPPORT
> > -  else
> > -    CFLAGS += -DNO_DEMANGLE
> > +    ifneq ($(filter -liberty,$(EXTLIBS)),)
> > +      CFLAGS += -DHAVE_CPLUS_DEMANGLE_SUPPORT
> > +      CXXFLAGS += -DHAVE_CPLUS_DEMANGLE_SUPPORT
> > +    endif
> >    endif
> >  endif
> >
> > diff --git a/tools/perf/util/Build b/tools/perf/util/Build
> > index 918b501f9bd8..8607575183a9 100644
> > --- a/tools/perf/util/Build
> > +++ b/tools/perf/util/Build
> > @@ -211,6 +211,7 @@ perf-$(CONFIG_ZSTD) += zstd.o
> >
> >  perf-$(CONFIG_LIBCAP) += cap.o
> >
> > +perf-y += demangle-cxx.o
> >  perf-y += demangle-ocaml.o
> >  perf-y += demangle-java.o
> >  perf-y += demangle-rust.o
> > diff --git a/tools/perf/util/demangle-cxx.cpp b/tools/perf/util/demangle-cxx.cpp
> > new file mode 100644
> > index 000000000000..8708bcafd370
> > --- /dev/null
> > +++ b/tools/perf/util/demangle-cxx.cpp
> > @@ -0,0 +1,50 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +#include "demangle-cxx.h"
> > +#include <stdlib.h>
> > +#include <string.h>
> > +#include <linux/compiler.h>
> > +
> > +#ifdef HAVE_LIBBFD_SUPPORT
> > +#define PACKAGE 'perf'
> > +#include <bfd.h>
> > +#endif
> > +
> > +#ifdef HAVE_CXA_DEMANGLE_SUPPORT
> > +#include <cxxabi.h>
> > +#endif
> > +
> > +#if defined(HAVE_LIBBFD_SUPPORT) || defined(HAVE_CPLUS_DEMANGLE_SUPPORT)
> > +#ifndef DMGL_PARAMS
> > +#define DMGL_PARAMS     (1 << 0)  /* Include function args */
> > +#define DMGL_ANSI       (1 << 1)  /* Include const, volatile, etc */
> > +#endif
> > +#endif
> > +
> > +/*
> > + * Demangle C++ function signature
> > + *
> > + * Note: caller is responsible for freeing demangled string
> > + */
> > +extern "C"
> > +char *cxx_demangle_sym(const char *str, bool params __maybe_unused,
> > +                       bool modifiers __maybe_unused)
> > +{
> > +#ifdef HAVE_LIBBFD_SUPPORT
> > +        int flags = (params ? DMGL_PARAMS : 0) | (modifiers ? DMGL_ANSI : 0);
> > +
> > +        return bfd_demangle(NULL, str, flags);
> > +#elif defined(HAVE_CPLUS_DEMANGLE_SUPPORT)
> > +        int flags = (params ? DMGL_PARAMS : 0) | (modifiers ? DMGL_ANSI : 0);
> > +
> > +        return cplus_demangle(str, flags);
> > +#elif defined(HAVE_CXA_DEMANGLE_SUPPORT)
> > +        size_t len = strlen(str);
> > +        char *output = (char*)malloc(len);
> > +        int status;
> > +
> > +        output = abi::__cxa_demangle(str, output, &len, &status);
> > +        return output;
> > +#else
> > +        return NULL;
> > +#endif
> > +}
> > diff --git a/tools/perf/util/demangle-cxx.h b/tools/perf/util/demangle-cxx.h
> > new file mode 100644
> > index 000000000000..26b5b66c0b4e
> > --- /dev/null
> > +++ b/tools/perf/util/demangle-cxx.h
> > @@ -0,0 +1,16 @@
> > +/* SPDX-License-Identifier: GPL-2.0 */
> > +#ifndef __PERF_DEMANGLE_CXX
> > +#define __PERF_DEMANGLE_CXX 1
> > +
> > +#ifdef __cplusplus
> > +extern "C" {
> > +#endif
> > +
> > +char *cxx_demangle_sym(const char *str, bool params, bool modifiers);
> > +
> > +#ifdef __cplusplus
> > +}
> > +#endif
> > +
> > +
> > +#endif /* __PERF_DEMANGLE_CXX */
> > diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
> > index 41882ae8452e..c0a2de42c51b 100644
> > --- a/tools/perf/util/symbol-elf.c
> > +++ b/tools/perf/util/symbol-elf.c
> > @@ -12,6 +12,7 @@
> >  #include "maps.h"
> >  #include "symbol.h"
> >  #include "symsrc.h"
> > +#include "demangle-cxx.h"
> >  #include "demangle-ocaml.h"
> >  #include "demangle-java.h"
> >  #include "demangle-rust.h"
> > @@ -25,6 +26,11 @@
> >  #include <symbol/kallsyms.h>
> >  #include <internal/lib.h>
> >
> > +#ifdef HAVE_LIBBFD_SUPPORT
> > +#define PACKAGE 'perf'
> > +#include <bfd.h>
> > +#endif
> > +
> >  #ifndef EM_AARCH64
> >  #define EM_AARCH64   183  /* ARM 64 bit */
> >  #endif
> > @@ -45,34 +51,6 @@
> >
> >  typedef Elf64_Nhdr GElf_Nhdr;
> >
> > -#ifndef DMGL_PARAMS
> > -#define DMGL_NO_OPTS     0              /* For readability... */
> > -#define DMGL_PARAMS      (1 << 0)       /* Include function args */
> > -#define DMGL_ANSI        (1 << 1)       /* Include const, volatile, etc */
> > -#endif
> > -
> > -#ifdef HAVE_LIBBFD_SUPPORT
> > -#define PACKAGE 'perf'
> > -#include <bfd.h>
> > -#else
> > -#ifdef HAVE_CPLUS_DEMANGLE_SUPPORT
> > -extern char *cplus_demangle(const char *, int);
> > -
> > -static inline char *bfd_demangle(void __maybe_unused *v, const char *c, int i)
> > -{
> > -     return cplus_demangle(c, i);
> > -}
> > -#else
> > -#ifdef NO_DEMANGLE
> > -static inline char *bfd_demangle(void __maybe_unused *v,
> > -                              const char __maybe_unused *c,
> > -                              int __maybe_unused i)
> > -{
> > -     return NULL;
> > -}
> > -#endif
> > -#endif
> > -#endif
> >
> >  #ifndef HAVE_ELF_GETPHDRNUM_SUPPORT
> >  static int elf_getphdrnum(Elf *elf, size_t *dst)
> > @@ -295,7 +273,6 @@ static bool want_demangle(bool is_kernel_sym)
> >
> >  static char *demangle_sym(struct dso *dso, int kmodule, const char *elf_name)
> >  {
> > -     int demangle_flags = verbose > 0 ? (DMGL_PARAMS | DMGL_ANSI) : DMGL_NO_OPTS;
> >       char *demangled = NULL;
> >
> >       /*
> > @@ -306,7 +283,7 @@ static char *demangle_sym(struct dso *dso, int kmodule, const char *elf_name)
> >       if (!want_demangle(dso->kernel || kmodule))
> >           return demangled;
> >
> > -     demangled = bfd_demangle(NULL, elf_name, demangle_flags);
> > +     demangled = cxx_demangle_sym(elf_name, verbose > 0, verbose > 0);
> >       if (demangled == NULL) {
> >               demangled = ocaml_demangle_sym(elf_name);
> >               if (demangled == NULL) {
Ian Rogers March 30, 2023, 7:03 p.m. UTC | #3 
On Thu, Mar 30, 2023 at 9:50 AM Ian Rogers <irogers@google.com> wrote:
>
> On Thu, Mar 30, 2023 at 7:08 AM James Clark <james.clark@arm.com> wrote:
> >
> >
> >
> > On 11/03/2023 06:57, Ian Rogers wrote:
> > > Refactor C++ demangling out of symbol-elf into its own files similar
> > > to other languages. Add abi::__cxa_demangle support. As the other
> > > demanglers are not shippable with distributions, this brings back C++
> > > demangling in a common case. It isn't perfect as the support for
> > > optionally demangling arguments and modifiers isn't present.
> > >
> > > Signed-off-by: Ian Rogers <irogers@google.com>
> > > ---
> > >  tools/perf/Makefile.config       | 29 +++++++++---------
> > >  tools/perf/util/Build            |  1 +
> > >  tools/perf/util/demangle-cxx.cpp | 50 ++++++++++++++++++++++++++++++++
> > >  tools/perf/util/demangle-cxx.h   | 16 ++++++++++
> > >  tools/perf/util/symbol-elf.c     | 37 +++++------------------
> > >  5 files changed, 88 insertions(+), 45 deletions(-)
> > >  create mode 100644 tools/perf/util/demangle-cxx.cpp
> > >  create mode 100644 tools/perf/util/demangle-cxx.h
> > >
> > > diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
> > > index 5756498248e0..fdeca45cf15f 100644
> > > --- a/tools/perf/Makefile.config
> > > +++ b/tools/perf/Makefile.config
> > > @@ -906,6 +906,7 @@ ifdef BUILD_NONDISTRO
> > >    endif
> > >
> > >    CFLAGS += -DHAVE_LIBBFD_SUPPORT
> > > +  CXXFLAGS += -DHAVE_LIBBFD_SUPPORT
> > >    ifeq ($(feature-libbfd-buildid), 1)
> > >      CFLAGS += -DHAVE_LIBBFD_BUILDID_SUPPORT
> > >    else
> > > @@ -913,26 +914,24 @@ ifdef BUILD_NONDISTRO
> > >    endif
> > >  endif
> > >
> > > -ifdef NO_DEMANGLE
> > > -  CFLAGS += -DNO_DEMANGLE
> > > -else
> > > +ifndef NO_DEMANGLE
> > > +  $(call feature_check,cxa-demangle)
> > > +  ifeq ($(feature-cxa-demangle), 1)
> > > +    EXTLIBS += -lstdc++
> >
> > Hi Ian,
> >
> > I think cross compilation for arm on x86 isn't working after this change
> > (at least on Ubuntu).
> >
> > Even with all of the arm64 libstdc++ stuff installed, you can only link
> > to it using g++, but the perf build tries to link to it using gcc. Not
> > sure it's some quirk with the search paths on Ubuntu or something else:
> >
> >   $ aarch64-linux-gnu-gcc -lstdc++
> >
> >    /usr/lib/gcc-cross/aarch64-linux-gnu/12/../../../../aarch64-linux-
> > gnu/bin/ld: cannot find -lstdc++: No such file or directory
> >   collect2: error: ld returned 1 exit status
> >
> > g++ gets further:
> >
> >   $ aarch64-linux-gnu-g++ -lstdc++
> >
> >   ...
> >   (.text+0x20): undefined reference to `main'
> > collect2: error: ld returned 1 exit status
> >
> > At the end of the perf build it looks like something similar is
> > happening (with all the non interesting bits deleted):
> >
> >    $ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- -C tools/perf
> > NO_BPF_SKEL=1 V=1
> >
> >   aarch64-linux-gnu-gcc ... -o perf
> >
> > /usr/lib/gcc-cross/aarch64-linux-gnu/12/../../../../aarch64-linux-gnu/bin/ld:
> > cannot find -lstdc++: No such file or directory
> >
> > If I build with NO_DEMANGLE=1 then the build works, but I think it would
> > at be best to autodetect rather than have to do this. Or maybe even link
> > at the end with g++ if we're going to use libstdc++?
>
> Hi James,
>
> sorry for the problems you are having, I'll see if I can get a repo. I
> did add a feature test with this change in the same set:
> https://lore.kernel.org/lkml/20230311065753.3012826-9-irogers@google.com/
> So it should be feature testing and only enabling when
> HAVE_CXA_DEMANGLE_SUPPORT is present. Obviously something is up, so
> I'll have a think about it.
>
> Thanks,
> Ian

Sorry to say I couldn't repro on Debian:

$ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- -C tools/perf
NO_LIBELF=1 NO_LIBTRACEEVENT=1
make: Entering directory '/home/irogers/kernel.org/tools/perf'
 BUILD:   Doing 'make -j16' parallel build
Warning: Kernel ABI header at 'tools/include/uapi/linux/in.h' differs
from latest version at 'include/uapi/linux/in.h'
diff -u tools/include/uapi/linux/in.h include/uapi/linux/in.h
Warning: Kernel ABI header at
'tools/arch/x86/include/asm/cpufeatures.h' differs from latest version
at 'arch/x86/include/asm/cpufeatures.h'
diff -u tools/arch/x86/include/asm/cpufeatures.h
arch/x86/include/asm/cpufeatures.h
Warning: Kernel ABI header at
'tools/arch/arm64/include/uapi/asm/perf_regs.h' differs from latest
version at 'arch/arm64/include/uapi/asm/perf_regs.h'
diff -u tools/arch/arm64/include/uapi/asm/perf_regs.h
arch/arm64/include/uapi/asm/perf_regs.h
Warning: Kernel ABI header at 'tools/include/linux/coresight-pmu.h'
differs from latest version at 'include/linux/coresight-pmu.h'
diff -u tools/include/linux/coresight-pmu.h include/linux/coresight-pmu.h
Makefile.config:588: No sys/sdt.h found, no SDT events are defined,
please install systemtap-sdt-devel or systemtap-sdt-dev
Makefile.config:679: Disabling post unwind, no support found.
Makefile.config:747: No libcrypto.h found, disables jitted code
injection, please install openssl-devel or libssl-dev
Makefile.config:759: slang not found, disables TUI support. Please
install slang-devel, libslang-devor libslang2-dev
Makefile.config:806: Missing perl devel files. Disabling perl
scripting support, please install perl-ExtUtils-Embed/libperl-dev
Makefile.config:846: No 'Python.h' was found: disables Python support
- please install python-devel/python-dev
Makefile.config:951: No liblzma found, disables xz kernel module
decompression, please install xz-devel/liblzma-dev
Makefile.config:964: No libzstd found, disables trace compression,
please install libzstd-dev[el] and/or set LIBZSTD_DIR
Makefile.config:975: No libcap found, disables capability support,
please install libcap-devel/libcap-dev
Makefile.config:988: No numa.h found, disables 'perf bench numa mem'
benchmark, please install numactl-devel/libnuma-devel/libnuma-dev
Makefile.config:1047: No libbabeltrace found, disables 'perf data' CTF
format support, please install
libbabeltrace-dev[el]/libbabeltrace-ctf-dev
Makefile.config:1138: libpfm4 not found, disables libpfm4 support.
Please install libpfm4-dev

Auto-detecting system features:
...                                   dwarf: [ OFF ]
...                      dwarf_getlocations: [ OFF ]
...                                   glibc: [ on  ]
...                                  libbfd: [ OFF ]
...                          libbfd-buildid: [ OFF ]
...                                  libcap: [ OFF ]
...                                  libelf: [ OFF ]
...                                 libnuma: [ OFF ]
...                  numa_num_possible_cpus: [ OFF ]
...                                 libperl: [ OFF ]
...                               libpython: [ OFF ]
...                               libcrypto: [ OFF ]
...                               libunwind: [ OFF ]
...                      libdw-dwarf-unwind: [ OFF ]
...                                    zlib: [ OFF ]
...                                    lzma: [ OFF ]
...                               get_cpuid: [ OFF ]
...                                     bpf: [ on  ]
...                                  libaio: [ on  ]
...                                 libzstd: [ OFF ]

 INSTALL libsubcmd_headers
 INSTALL libsymbol_headers
 INSTALL libapi_headers
 INSTALL libperf_headers
 FLEX    util/parse-events-flex.c
 FLEX    util/pmu-flex.c
 CC      util/pmu-bison.o
 FLEX    util/expr-flex.c
 CC      util/expr-bison.o
 CXX     util/demangle-cxx.o
 CC      util/demangle-ocaml.o
 CC      util/demangle-java.o
 CC      util/demangle-rust.o
 CC      util/perf-hooks.o
 CC      util/parse-events.o
 CC      util/parse-events-flex.o
 CC      util/pmu.o
 CC      util/pmu-flex.o
 CC      util/expr-flex.o
 CC      util/expr.o
 LD      util/perf-in.o
 LD      perf-in.o
 LINK    perf
make: Leaving directory '.../tools/perf'

Thanks,
Ian

> > Thanks
> > James
> >
> > > +    CFLAGS += -DHAVE_CXA_DEMANGLE_SUPPORT
> > > +    CXXFLAGS += -DHAVE_CXA_DEMANGLE_SUPPORT
> > > +  endif
> > >    ifdef BUILD_NONDISTRO
> > >      ifeq ($(filter -liberty,$(EXTLIBS)),)
> > > -      ifdef HAVE_CPLUS_DEMANGLE_SUPPORT
> > > +      $(call feature_check,cplus-demangle)
> > > +      ifeq ($(feature-cplus-demangle), 1)
> > >          EXTLIBS += -liberty
> > > -      else
> > > -        $(call feature_check,cplus-demangle)
> > > -        ifeq ($(feature-cplus-demangle), 1)
> > > -          EXTLIBS += -liberty
> > > -        endif
> > >        endif
> > >      endif
> > > -  endif
> > > -
> > > -  ifneq ($(filter -liberty,$(EXTLIBS)),)
> > > -    CFLAGS += -DHAVE_CPLUS_DEMANGLE_SUPPORT
> > > -  else
> > > -    CFLAGS += -DNO_DEMANGLE
> > > +    ifneq ($(filter -liberty,$(EXTLIBS)),)
> > > +      CFLAGS += -DHAVE_CPLUS_DEMANGLE_SUPPORT
> > > +      CXXFLAGS += -DHAVE_CPLUS_DEMANGLE_SUPPORT
> > > +    endif
> > >    endif
> > >  endif
> > >
> > > diff --git a/tools/perf/util/Build b/tools/perf/util/Build
> > > index 918b501f9bd8..8607575183a9 100644
> > > --- a/tools/perf/util/Build
> > > +++ b/tools/perf/util/Build
> > > @@ -211,6 +211,7 @@ perf-$(CONFIG_ZSTD) += zstd.o
> > >
> > >  perf-$(CONFIG_LIBCAP) += cap.o
> > >
> > > +perf-y += demangle-cxx.o
> > >  perf-y += demangle-ocaml.o
> > >  perf-y += demangle-java.o
> > >  perf-y += demangle-rust.o
> > > diff --git a/tools/perf/util/demangle-cxx.cpp b/tools/perf/util/demangle-cxx.cpp
> > > new file mode 100644
> > > index 000000000000..8708bcafd370
> > > --- /dev/null
> > > +++ b/tools/perf/util/demangle-cxx.cpp
> > > @@ -0,0 +1,50 @@
> > > +// SPDX-License-Identifier: GPL-2.0
> > > +#include "demangle-cxx.h"
> > > +#include <stdlib.h>
> > > +#include <string.h>
> > > +#include <linux/compiler.h>
> > > +
> > > +#ifdef HAVE_LIBBFD_SUPPORT
> > > +#define PACKAGE 'perf'
> > > +#include <bfd.h>
> > > +#endif
> > > +
> > > +#ifdef HAVE_CXA_DEMANGLE_SUPPORT
> > > +#include <cxxabi.h>
> > > +#endif
> > > +
> > > +#if defined(HAVE_LIBBFD_SUPPORT) || defined(HAVE_CPLUS_DEMANGLE_SUPPORT)
> > > +#ifndef DMGL_PARAMS
> > > +#define DMGL_PARAMS     (1 << 0)  /* Include function args */
> > > +#define DMGL_ANSI       (1 << 1)  /* Include const, volatile, etc */
> > > +#endif
> > > +#endif
> > > +
> > > +/*
> > > + * Demangle C++ function signature
> > > + *
> > > + * Note: caller is responsible for freeing demangled string
> > > + */
> > > +extern "C"
> > > +char *cxx_demangle_sym(const char *str, bool params __maybe_unused,
> > > +                       bool modifiers __maybe_unused)
> > > +{
> > > +#ifdef HAVE_LIBBFD_SUPPORT
> > > +        int flags = (params ? DMGL_PARAMS : 0) | (modifiers ? DMGL_ANSI : 0);
> > > +
> > > +        return bfd_demangle(NULL, str, flags);
> > > +#elif defined(HAVE_CPLUS_DEMANGLE_SUPPORT)
> > > +        int flags = (params ? DMGL_PARAMS : 0) | (modifiers ? DMGL_ANSI : 0);
> > > +
> > > +        return cplus_demangle(str, flags);
> > > +#elif defined(HAVE_CXA_DEMANGLE_SUPPORT)
> > > +        size_t len = strlen(str);
> > > +        char *output = (char*)malloc(len);
> > > +        int status;
> > > +
> > > +        output = abi::__cxa_demangle(str, output, &len, &status);
> > > +        return output;
> > > +#else
> > > +        return NULL;
> > > +#endif
> > > +}
> > > diff --git a/tools/perf/util/demangle-cxx.h b/tools/perf/util/demangle-cxx.h
> > > new file mode 100644
> > > index 000000000000..26b5b66c0b4e
> > > --- /dev/null
> > > +++ b/tools/perf/util/demangle-cxx.h
> > > @@ -0,0 +1,16 @@
> > > +/* SPDX-License-Identifier: GPL-2.0 */
> > > +#ifndef __PERF_DEMANGLE_CXX
> > > +#define __PERF_DEMANGLE_CXX 1
> > > +
> > > +#ifdef __cplusplus
> > > +extern "C" {
> > > +#endif
> > > +
> > > +char *cxx_demangle_sym(const char *str, bool params, bool modifiers);
> > > +
> > > +#ifdef __cplusplus
> > > +}
> > > +#endif
> > > +
> > > +
> > > +#endif /* __PERF_DEMANGLE_CXX */
> > > diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
> > > index 41882ae8452e..c0a2de42c51b 100644
> > > --- a/tools/perf/util/symbol-elf.c
> > > +++ b/tools/perf/util/symbol-elf.c
> > > @@ -12,6 +12,7 @@
> > >  #include "maps.h"
> > >  #include "symbol.h"
> > >  #include "symsrc.h"
> > > +#include "demangle-cxx.h"
> > >  #include "demangle-ocaml.h"
> > >  #include "demangle-java.h"
> > >  #include "demangle-rust.h"
> > > @@ -25,6 +26,11 @@
> > >  #include <symbol/kallsyms.h>
> > >  #include <internal/lib.h>
> > >
> > > +#ifdef HAVE_LIBBFD_SUPPORT
> > > +#define PACKAGE 'perf'
> > > +#include <bfd.h>
> > > +#endif
> > > +
> > >  #ifndef EM_AARCH64
> > >  #define EM_AARCH64   183  /* ARM 64 bit */
> > >  #endif
> > > @@ -45,34 +51,6 @@
> > >
> > >  typedef Elf64_Nhdr GElf_Nhdr;
> > >
> > > -#ifndef DMGL_PARAMS
> > > -#define DMGL_NO_OPTS     0              /* For readability... */
> > > -#define DMGL_PARAMS      (1 << 0)       /* Include function args */
> > > -#define DMGL_ANSI        (1 << 1)       /* Include const, volatile, etc */
> > > -#endif
> > > -
> > > -#ifdef HAVE_LIBBFD_SUPPORT
> > > -#define PACKAGE 'perf'
> > > -#include <bfd.h>
> > > -#else
> > > -#ifdef HAVE_CPLUS_DEMANGLE_SUPPORT
> > > -extern char *cplus_demangle(const char *, int);
> > > -
> > > -static inline char *bfd_demangle(void __maybe_unused *v, const char *c, int i)
> > > -{
> > > -     return cplus_demangle(c, i);
> > > -}
> > > -#else
> > > -#ifdef NO_DEMANGLE
> > > -static inline char *bfd_demangle(void __maybe_unused *v,
> > > -                              const char __maybe_unused *c,
> > > -                              int __maybe_unused i)
> > > -{
> > > -     return NULL;
> > > -}
> > > -#endif
> > > -#endif
> > > -#endif
> > >
> > >  #ifndef HAVE_ELF_GETPHDRNUM_SUPPORT
> > >  static int elf_getphdrnum(Elf *elf, size_t *dst)
> > > @@ -295,7 +273,6 @@ static bool want_demangle(bool is_kernel_sym)
> > >
> > >  static char *demangle_sym(struct dso *dso, int kmodule, const char *elf_name)
> > >  {
> > > -     int demangle_flags = verbose > 0 ? (DMGL_PARAMS | DMGL_ANSI) : DMGL_NO_OPTS;
> > >       char *demangled = NULL;
> > >
> > >       /*
> > > @@ -306,7 +283,7 @@ static char *demangle_sym(struct dso *dso, int kmodule, const char *elf_name)
> > >       if (!want_demangle(dso->kernel || kmodule))
> > >           return demangled;
> > >
> > > -     demangled = bfd_demangle(NULL, elf_name, demangle_flags);
> > > +     demangled = cxx_demangle_sym(elf_name, verbose > 0, verbose > 0);
> > >       if (demangled == NULL) {
> > >               demangled = ocaml_demangle_sym(elf_name);
> > >               if (demangled == NULL) {
James Clark March 31, 2023, 9:27 a.m. UTC | #4 
On 30/03/2023 20:03, Ian Rogers wrote:
> On Thu, Mar 30, 2023 at 9:50 AM Ian Rogers <irogers@google.com> wrote:
>>
>> On Thu, Mar 30, 2023 at 7:08 AM James Clark <james.clark@arm.com> wrote:
>>>
>>>
>>>
>>> On 11/03/2023 06:57, Ian Rogers wrote:
>>>> Refactor C++ demangling out of symbol-elf into its own files similar
>>>> to other languages. Add abi::__cxa_demangle support. As the other
>>>> demanglers are not shippable with distributions, this brings back C++
>>>> demangling in a common case. It isn't perfect as the support for
>>>> optionally demangling arguments and modifiers isn't present.
>>>>
>>>> Signed-off-by: Ian Rogers <irogers@google.com>
>>>> ---
>>>>  tools/perf/Makefile.config       | 29 +++++++++---------
>>>>  tools/perf/util/Build            |  1 +
>>>>  tools/perf/util/demangle-cxx.cpp | 50 ++++++++++++++++++++++++++++++++
>>>>  tools/perf/util/demangle-cxx.h   | 16 ++++++++++
>>>>  tools/perf/util/symbol-elf.c     | 37 +++++------------------
>>>>  5 files changed, 88 insertions(+), 45 deletions(-)
>>>>  create mode 100644 tools/perf/util/demangle-cxx.cpp
>>>>  create mode 100644 tools/perf/util/demangle-cxx.h
>>>>
>>>> diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
>>>> index 5756498248e0..fdeca45cf15f 100644
>>>> --- a/tools/perf/Makefile.config
>>>> +++ b/tools/perf/Makefile.config
>>>> @@ -906,6 +906,7 @@ ifdef BUILD_NONDISTRO
>>>>    endif
>>>>
>>>>    CFLAGS += -DHAVE_LIBBFD_SUPPORT
>>>> +  CXXFLAGS += -DHAVE_LIBBFD_SUPPORT
>>>>    ifeq ($(feature-libbfd-buildid), 1)
>>>>      CFLAGS += -DHAVE_LIBBFD_BUILDID_SUPPORT
>>>>    else
>>>> @@ -913,26 +914,24 @@ ifdef BUILD_NONDISTRO
>>>>    endif
>>>>  endif
>>>>
>>>> -ifdef NO_DEMANGLE
>>>> -  CFLAGS += -DNO_DEMANGLE
>>>> -else
>>>> +ifndef NO_DEMANGLE
>>>> +  $(call feature_check,cxa-demangle)
>>>> +  ifeq ($(feature-cxa-demangle), 1)
>>>> +    EXTLIBS += -lstdc++
>>>
>>> Hi Ian,
>>>
>>> I think cross compilation for arm on x86 isn't working after this change
>>> (at least on Ubuntu).
>>>
>>> Even with all of the arm64 libstdc++ stuff installed, you can only link
>>> to it using g++, but the perf build tries to link to it using gcc. Not
>>> sure it's some quirk with the search paths on Ubuntu or something else:
>>>
>>>   $ aarch64-linux-gnu-gcc -lstdc++
>>>
>>>    /usr/lib/gcc-cross/aarch64-linux-gnu/12/../../../../aarch64-linux-
>>> gnu/bin/ld: cannot find -lstdc++: No such file or directory
>>>   collect2: error: ld returned 1 exit status
>>>
>>> g++ gets further:
>>>
>>>   $ aarch64-linux-gnu-g++ -lstdc++
>>>
>>>   ...
>>>   (.text+0x20): undefined reference to `main'
>>> collect2: error: ld returned 1 exit status
>>>
>>> At the end of the perf build it looks like something similar is
>>> happening (with all the non interesting bits deleted):
>>>
>>>    $ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- -C tools/perf
>>> NO_BPF_SKEL=1 V=1
>>>
>>>   aarch64-linux-gnu-gcc ... -o perf
>>>
>>> /usr/lib/gcc-cross/aarch64-linux-gnu/12/../../../../aarch64-linux-gnu/bin/ld:
>>> cannot find -lstdc++: No such file or directory
>>>
>>> If I build with NO_DEMANGLE=1 then the build works, but I think it would
>>> at be best to autodetect rather than have to do this. Or maybe even link
>>> at the end with g++ if we're going to use libstdc++?
>>
>> Hi James,
>>
>> sorry for the problems you are having, I'll see if I can get a repo. I
>> did add a feature test with this change in the same set:
>> https://lore.kernel.org/lkml/20230311065753.3012826-9-irogers@google.com/
>> So it should be feature testing and only enabling when
>> HAVE_CXA_DEMANGLE_SUPPORT is present. Obviously something is up, so
>> I'll have a think about it.
>>
>> Thanks,
>> Ian
> 
> Sorry to say I couldn't repro on Debian:
> 
> $ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- -C tools/perf
> NO_LIBELF=1 NO_LIBTRACEEVENT=1

If you have NO_LIBELF=1 it sets NO_DEMANGLE=1 automatically so it skips
the c++ linking step. If you run with V=1 you can see that it doesn't
have -lstdc++ on the last link line.

But, having said that, I went to make a full reproducer in docker but it
actually worked. Turns out that the issue was on my end. I'd used
update-alternatives for a different compiler version and looks like I
had half of one gcc and half of another g++. Completely my fault, sorry
for the noise!

James
diff mbox series

Patch

diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
index 5756498248e0..fdeca45cf15f 100644
--- a/tools/perf/Makefile.config
+++ b/tools/perf/Makefile.config
@@ -906,6 +906,7 @@  ifdef BUILD_NONDISTRO
   endif
 
   CFLAGS += -DHAVE_LIBBFD_SUPPORT
+  CXXFLAGS += -DHAVE_LIBBFD_SUPPORT
   ifeq ($(feature-libbfd-buildid), 1)
     CFLAGS += -DHAVE_LIBBFD_BUILDID_SUPPORT
   else
@@ -913,26 +914,24 @@  ifdef BUILD_NONDISTRO
   endif
 endif
 
-ifdef NO_DEMANGLE
-  CFLAGS += -DNO_DEMANGLE
-else
+ifndef NO_DEMANGLE
+  $(call feature_check,cxa-demangle)
+  ifeq ($(feature-cxa-demangle), 1)
+    EXTLIBS += -lstdc++
+    CFLAGS += -DHAVE_CXA_DEMANGLE_SUPPORT
+    CXXFLAGS += -DHAVE_CXA_DEMANGLE_SUPPORT
+  endif
   ifdef BUILD_NONDISTRO
     ifeq ($(filter -liberty,$(EXTLIBS)),)
-      ifdef HAVE_CPLUS_DEMANGLE_SUPPORT
+      $(call feature_check,cplus-demangle)
+      ifeq ($(feature-cplus-demangle), 1)
         EXTLIBS += -liberty
-      else
-        $(call feature_check,cplus-demangle)
-        ifeq ($(feature-cplus-demangle), 1)
-          EXTLIBS += -liberty
-        endif
       endif
     endif
-  endif
-
-  ifneq ($(filter -liberty,$(EXTLIBS)),)
-    CFLAGS += -DHAVE_CPLUS_DEMANGLE_SUPPORT
-  else
-    CFLAGS += -DNO_DEMANGLE
+    ifneq ($(filter -liberty,$(EXTLIBS)),)
+      CFLAGS += -DHAVE_CPLUS_DEMANGLE_SUPPORT
+      CXXFLAGS += -DHAVE_CPLUS_DEMANGLE_SUPPORT
+    endif
   endif
 endif
 
diff --git a/tools/perf/util/Build b/tools/perf/util/Build
index 918b501f9bd8..8607575183a9 100644
--- a/tools/perf/util/Build
+++ b/tools/perf/util/Build
@@ -211,6 +211,7 @@  perf-$(CONFIG_ZSTD) += zstd.o
 
 perf-$(CONFIG_LIBCAP) += cap.o
 
+perf-y += demangle-cxx.o
 perf-y += demangle-ocaml.o
 perf-y += demangle-java.o
 perf-y += demangle-rust.o
diff --git a/tools/perf/util/demangle-cxx.cpp b/tools/perf/util/demangle-cxx.cpp
new file mode 100644
index 000000000000..8708bcafd370
--- /dev/null
+++ b/tools/perf/util/demangle-cxx.cpp
@@ -0,0 +1,50 @@ 
+// SPDX-License-Identifier: GPL-2.0
+#include "demangle-cxx.h"
+#include <stdlib.h>
+#include <string.h>
+#include <linux/compiler.h>
+
+#ifdef HAVE_LIBBFD_SUPPORT
+#define PACKAGE 'perf'
+#include <bfd.h>
+#endif
+
+#ifdef HAVE_CXA_DEMANGLE_SUPPORT
+#include <cxxabi.h>
+#endif
+
+#if defined(HAVE_LIBBFD_SUPPORT) || defined(HAVE_CPLUS_DEMANGLE_SUPPORT)
+#ifndef DMGL_PARAMS
+#define DMGL_PARAMS     (1 << 0)  /* Include function args */
+#define DMGL_ANSI       (1 << 1)  /* Include const, volatile, etc */
+#endif
+#endif
+
+/*
+ * Demangle C++ function signature
+ *
+ * Note: caller is responsible for freeing demangled string
+ */
+extern "C"
+char *cxx_demangle_sym(const char *str, bool params __maybe_unused,
+                       bool modifiers __maybe_unused)
+{
+#ifdef HAVE_LIBBFD_SUPPORT
+        int flags = (params ? DMGL_PARAMS : 0) | (modifiers ? DMGL_ANSI : 0);
+
+        return bfd_demangle(NULL, str, flags);
+#elif defined(HAVE_CPLUS_DEMANGLE_SUPPORT)
+        int flags = (params ? DMGL_PARAMS : 0) | (modifiers ? DMGL_ANSI : 0);
+
+        return cplus_demangle(str, flags);
+#elif defined(HAVE_CXA_DEMANGLE_SUPPORT)
+        size_t len = strlen(str);
+        char *output = (char*)malloc(len);
+        int status;
+
+        output = abi::__cxa_demangle(str, output, &len, &status);
+        return output;
+#else
+        return NULL;
+#endif
+}
diff --git a/tools/perf/util/demangle-cxx.h b/tools/perf/util/demangle-cxx.h
new file mode 100644
index 000000000000..26b5b66c0b4e
--- /dev/null
+++ b/tools/perf/util/demangle-cxx.h
@@ -0,0 +1,16 @@ 
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __PERF_DEMANGLE_CXX
+#define __PERF_DEMANGLE_CXX 1
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+char *cxx_demangle_sym(const char *str, bool params, bool modifiers);
+
+#ifdef __cplusplus
+}
+#endif
+
+
+#endif /* __PERF_DEMANGLE_CXX */
diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
index 41882ae8452e..c0a2de42c51b 100644
--- a/tools/perf/util/symbol-elf.c
+++ b/tools/perf/util/symbol-elf.c
@@ -12,6 +12,7 @@ 
 #include "maps.h"
 #include "symbol.h"
 #include "symsrc.h"
+#include "demangle-cxx.h"
 #include "demangle-ocaml.h"
 #include "demangle-java.h"
 #include "demangle-rust.h"
@@ -25,6 +26,11 @@ 
 #include <symbol/kallsyms.h>
 #include <internal/lib.h>
 
+#ifdef HAVE_LIBBFD_SUPPORT
+#define PACKAGE 'perf'
+#include <bfd.h>
+#endif
+
 #ifndef EM_AARCH64
 #define EM_AARCH64	183  /* ARM 64 bit */
 #endif
@@ -45,34 +51,6 @@ 
 
 typedef Elf64_Nhdr GElf_Nhdr;
 
-#ifndef DMGL_PARAMS
-#define DMGL_NO_OPTS     0              /* For readability... */
-#define DMGL_PARAMS      (1 << 0)       /* Include function args */
-#define DMGL_ANSI        (1 << 1)       /* Include const, volatile, etc */
-#endif
-
-#ifdef HAVE_LIBBFD_SUPPORT
-#define PACKAGE 'perf'
-#include <bfd.h>
-#else
-#ifdef HAVE_CPLUS_DEMANGLE_SUPPORT
-extern char *cplus_demangle(const char *, int);
-
-static inline char *bfd_demangle(void __maybe_unused *v, const char *c, int i)
-{
-	return cplus_demangle(c, i);
-}
-#else
-#ifdef NO_DEMANGLE
-static inline char *bfd_demangle(void __maybe_unused *v,
-				 const char __maybe_unused *c,
-				 int __maybe_unused i)
-{
-	return NULL;
-}
-#endif
-#endif
-#endif
 
 #ifndef HAVE_ELF_GETPHDRNUM_SUPPORT
 static int elf_getphdrnum(Elf *elf, size_t *dst)
@@ -295,7 +273,6 @@  static bool want_demangle(bool is_kernel_sym)
 
 static char *demangle_sym(struct dso *dso, int kmodule, const char *elf_name)
 {
-	int demangle_flags = verbose > 0 ? (DMGL_PARAMS | DMGL_ANSI) : DMGL_NO_OPTS;
 	char *demangled = NULL;
 
 	/*
@@ -306,7 +283,7 @@  static char *demangle_sym(struct dso *dso, int kmodule, const char *elf_name)
 	if (!want_demangle(dso->kernel || kmodule))
 	    return demangled;
 
-	demangled = bfd_demangle(NULL, elf_name, demangle_flags);
+	demangled = cxx_demangle_sym(elf_name, verbose > 0, verbose > 0);
 	if (demangled == NULL) {
 		demangled = ocaml_demangle_sym(elf_name);
 		if (demangled == NULL) {