Re: [PATCH 14/17] perf, tool: Support for dwarf cfi unwinding on post processing

[Frederic Weisbecker <fweisbec@gmail.com>]

On Sun, Jul 22, 2012 at 02:14:37PM +0200, Jiri Olsa wrote:
> This brings the support for dwarf cfi unwinding on perf post
> processing. Call frame informations are retrieved and then passed
> to libunwind that requests memory and register content from the
> applications.
> 
> Adding unwind object to handle the user stack backtrace based
> on the user register values and user stack dump.
> 
> The unwind object access the libunwind via remote interface
> and provides to it all the necessary data to unwind the stack.
> 
> The unwind interface provides following function:
> 	unwind__get_entries
> 
> And callback (specified in above function) to retrieve
> the backtrace entries:
> 	typedef int (*unwind_entry_cb_t)(struct unwind_entry *entry,
> 					 void *arg);
> 
> Signed-off-by: Jiri Olsa <jolsa@redhat.com>
> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
> ---
>  tools/perf/Makefile                                |    2 +
>  tools/perf/arch/x86/Makefile                       |    3 +
>  tools/perf/arch/x86/util/unwind.c                  |  111 ++++
>  tools/perf/builtin-report.c                        |   24 +-
>  tools/perf/builtin-script.c                        |   16 +-
>  tools/perf/builtin-top.c                           |    5 +-
>  tools/perf/util/include/linux/compiler.h           |    1 +
>  tools/perf/util/map.h                              |    7 +-
>  .../perf/util/scripting-engines/trace-event-perl.c |    3 +-
>  .../util/scripting-engines/trace-event-python.c    |    3 +-
>  tools/perf/util/session.c                          |   61 ++-
>  tools/perf/util/session.h                          |    3 +-
>  tools/perf/util/trace-event-scripting.c            |    3 +-
>  tools/perf/util/trace-event.h                      |    5 +-
>  tools/perf/util/unwind.c                           |  567 ++++++++++++++++++++
>  tools/perf/util/unwind.h                           |   34 ++
>  16 files changed, 811 insertions(+), 37 deletions(-)
>  create mode 100644 tools/perf/arch/x86/util/unwind.c
>  create mode 100644 tools/perf/util/unwind.c
>  create mode 100644 tools/perf/util/unwind.h
> 
> diff --git a/tools/perf/Makefile b/tools/perf/Makefile
> index d0c3291..c18c790 100644
> --- a/tools/perf/Makefile
> +++ b/tools/perf/Makefile
> @@ -328,6 +328,7 @@ LIB_H += util/cgroup.h
>  LIB_H += $(TRACE_EVENT_DIR)event-parse.h
>  LIB_H += util/target.h
>  LIB_H += util/perf_regs.h
> +LIB_H += util/unwind.h
>  
>  LIB_OBJS += $(OUTPUT)util/abspath.o
>  LIB_OBJS += $(OUTPUT)util/alias.o
> @@ -513,6 +514,7 @@ else
>  	EXTLIBS += $(LIBUNWIND_LIBS)
>  	BASIC_CFLAGS := $(LIBUNWIND_CFLAGS) $(BASIC_CFLAGS)
>  	BASIC_LDFLAGS := $(LIBUNWIND_LDFLAGS) $(BASIC_LDFLAGS)
> +	LIB_OBJS += $(OUTPUT)util/unwind.o
>  endif
>  
>  ifdef NO_NEWT
> diff --git a/tools/perf/arch/x86/Makefile b/tools/perf/arch/x86/Makefile
> index 744e629..815841c 100644
> --- a/tools/perf/arch/x86/Makefile
> +++ b/tools/perf/arch/x86/Makefile
> @@ -2,4 +2,7 @@ ifndef NO_DWARF
>  PERF_HAVE_DWARF_REGS := 1
>  LIB_OBJS += $(OUTPUT)arch/$(ARCH)/util/dwarf-regs.o
>  endif
> +ifndef NO_LIBUNWIND
> +LIB_OBJS += $(OUTPUT)arch/$(ARCH)/util/unwind.o
> +endif
>  LIB_OBJS += $(OUTPUT)arch/$(ARCH)/util/header.o
> diff --git a/tools/perf/arch/x86/util/unwind.c b/tools/perf/arch/x86/util/unwind.c
> new file mode 100644
> index 0000000..78d956e
> --- /dev/null
> +++ b/tools/perf/arch/x86/util/unwind.c
> @@ -0,0 +1,111 @@
> +
> +#include <errno.h>
> +#include <libunwind.h>
> +#include "perf_regs.h"
> +#include "../../util/unwind.h"
> +
> +#ifdef ARCH_X86_64
> +int unwind__arch_reg_id(int regnum)

Please try to avoid __ in function names. We used that convention
before but we gave up because that's actually more painful than
anything.