2009-07-20 17:14:32

by Arnaldo Carvalho de Melo

[permalink] [raw]
Subject: [PATCH 1/1 tip] perf symbol: C++ demangling

Pekka, you may be interessted in JAVA demangling, that is also supported
by bfd_demangle :-)

Thanks Clark for rescueing me from getting carried away doing DWARF
stuff for such simple stuff :-)

- Arnaldo

[acme@doppio ~]$ perf report -s comm,dso,symbol -C firefox -d /usr/lib64/xulrunner-1.9.1/libxul.so | grep :: | head
2.21% [.] nsDeque::Push(void*)
1.78% [.] GraphWalker::DoWalk(nsDeque&)
1.30% [.] GCGraphBuilder::AddNode(void*, nsCycleCollectionParticipant*)
1.27% [.] XPCWrappedNative::CallMethod(XPCCallContext&, XPCWrappedNative::CallMode)
1.18% [.] imgContainer::DrawFrameTo(gfxIImageFrame*, gfxIImageFrame*, nsRect&)
1.13% [.] nsDeque::PopFront()
1.11% [.] nsGlobalWindow::RunTimeout(nsTimeout*)
0.97% [.] nsXPConnect::Traverse(void*, nsCycleCollectionTraversalCallback&)
0.95% [.] nsJSEventListener::cycleCollection::Traverse(void*, nsCycleCollectionTraversalCallback&)
0.95% [.] nsCOMPtr_base::~nsCOMPtr_base()
[acme@doppio ~]$

Cc: Peter Zijlstra <[email protected]>
Cc: Pekka Enberg <[email protected]>
Cc: Vegard Nossum <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Fr?d?ric Weisbecker <[email protected]>
Suggested-by: Clark Williams <[email protected]>
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
---
tools/perf/Makefile | 2 +-
tools/perf/util/symbol.c | 21 +++++++++++++++++++--
2 files changed, 20 insertions(+), 3 deletions(-)

diff --git a/tools/perf/Makefile b/tools/perf/Makefile
index 7822b3d..a5e9b87 100644
--- a/tools/perf/Makefile
+++ b/tools/perf/Makefile
@@ -345,7 +345,7 @@ BUILTIN_OBJS += builtin-stat.o
BUILTIN_OBJS += builtin-top.o

PERFLIBS = $(LIB_FILE)
-EXTLIBS =
+EXTLIBS = -lbfd

#
# Platform specific tweaks
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index f40266b..98aee92 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -6,9 +6,15 @@
#include <libelf.h>
#include <gelf.h>
#include <elf.h>
+#include <bfd.h>

const char *sym_hist_filter;

+#ifndef DMGL_PARAMS
+#define DMGL_PARAMS (1 << 0) /* Include function args */
+#define DMGL_ANSI (1 << 1) /* Include const, volatile, etc */
+#endif
+
static struct symbol *symbol__new(u64 start, u64 len,
const char *name, unsigned int priv_size,
u64 obj_start, int verbose)
@@ -571,6 +577,8 @@ static int dso__load_sym(struct dso *self, int fd, const char *name,
NULL) != NULL);
elf_symtab__for_each_symbol(syms, nr_syms, index, sym) {
struct symbol *f;
+ const char *name;
+ char *demangled;
u64 obj_start;
struct section *section = NULL;
int is_label = elf_sym__is_label(&sym);
@@ -609,10 +617,19 @@ static int dso__load_sym(struct dso *self, int fd, const char *name,
goto out_elf_end;
}
}
+ /*
+ * We need to figure out if the object was created from C++ sources
+ * DWARF DW_compile_unit has this, but we don't always have access
+ * to it...
+ */
+ name = elf_sym__name(&sym, symstrs);
+ demangled = bfd_demangle(NULL, name, DMGL_PARAMS | DMGL_ANSI);
+ if (demangled != NULL)
+ name = demangled;

- f = symbol__new(sym.st_value, sym.st_size,
- elf_sym__name(&sym, symstrs),
+ f = symbol__new(sym.st_value, sym.st_size, name,
self->sym_priv_size, obj_start, verbose);
+ free(demangled);
if (!f)
goto out_elf_end;

--
1.6.2.5