From 66ddce49d92ddaab94dba269ca5661367dc9f925 Mon Sep 17 00:00:00 2001
From: Seth LaForge <seth@ridemission.com>
Date: Wed, 2 Dec 2015 20:40:56 -0800
Subject: [PATCH] Add DW_TAG_GNU_call_site* for better tail-call debug
 descriptions.

This comes up for functions which have tail-calls optimized.
Describe location list for DW_AT_GNU_call_site_* to match readelf.
Add test elf file to demonstrate that we match readelf for DW_AT_GNU_call_site_*. C source is:
  extern int f2(int a, char b);
  extern char var;
  int f1(void) { return f2(666, var); }
---
 elftools/dwarf/descriptions.py                |   4 ++++
 elftools/dwarf/enums.py                       |   2 ++
 test/testfiles_for_readelf/gcc_tailcall.o.elf | Bin 0 -> 2920 bytes
 3 files changed, 6 insertions(+)
 create mode 100644 test/testfiles_for_readelf/gcc_tailcall.o.elf

diff --git a/elftools/dwarf/descriptions.py b/elftools/dwarf/descriptions.py
index 9c56d67..abe9252 100644
--- a/elftools/dwarf/descriptions.py
+++ b/elftools/dwarf/descriptions.py
@@ -489,6 +489,10 @@ _EXTRA_INFO_DESCRIPTION_MAP = defaultdict(
     DW_AT_data_location=_location_list_extra,
     DW_AT_stride=_location_list_extra,
     DW_AT_import=_import_extra,
+    DW_AT_GNU_call_site_value=_location_list_extra,
+    DW_AT_GNU_call_site_data_value=_location_list_extra,
+    DW_AT_GNU_call_site_target=_location_list_extra,
+    DW_AT_GNU_call_site_target_clobbered=_location_list_extra,
 )
 
 # 8 in a line, for easier counting
diff --git a/elftools/dwarf/enums.py b/elftools/dwarf/enums.py
index d576dff..9140f91 100644
--- a/elftools/dwarf/enums.py
+++ b/elftools/dwarf/enums.py
@@ -79,6 +79,8 @@ ENUM_DW_TAG = dict(
     DW_TAG_rvalue_reference_type    = 0x42,
 
     DW_TAG_lo_user                  = 0x4080,
+    DW_TAG_GNU_call_site            = 0x4109,
+    DW_TAG_GNU_call_site_parameter  = 0x410a,
     DW_TAG_hi_user                  = 0xffff,
 
     _default_                       = Pass,
diff --git a/test/testfiles_for_readelf/gcc_tailcall.o.elf b/test/testfiles_for_readelf/gcc_tailcall.o.elf
new file mode 100644
index 0000000000000000000000000000000000000000..0d7766d01a4483af1fd13815efad522dc72afb8d
GIT binary patch
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literal 0
HcmV?d00001

-- 
2.30.2