[Tarantool-patches] [PATCH luajit] luajit-gdb: support full-range 64-bit lightud

[Maxim Kokryashkin via Tarantool-patches <tarantool-patches@dev.tarantool.org>]

Following up the introduction of full-range 64-bit lightuserdata
support in commit 2cacfa8 ("Add support for full-range 64 bit
lightuserdata."), this patch modifies the corresponding dumper
behavior for LJ_64 platforms in the luajit-gdb extension.

Resolves tarantool/tarantool#6481
---
Branch: https://github.com/tarantool/luajit/tree/fckxorg/gh-6481-luajit-gdb-light-ud
Issue: https://github.com/tarantool/tarantool/issues/6481
 src/luajit-gdb.py | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/src/luajit-gdb.py b/src/luajit-gdb.py
index 6480d014..2993f2c1 100644
--- a/src/luajit-gdb.py
+++ b/src/luajit-gdb.py
@@ -166,6 +166,9 @@ LJ_GCVMASK = ((1 << 47) - 1)
 LJ_TISNUM = None
 PADDING = None
 
+LJ_LIGHTUD_BITS_SEG = 8
+LJ_LIGHTUD_BITS_LO = 47 - LJ_LIGHTUD_BITS_SEG
+
 # }}}
 
 def itype(o):
@@ -315,6 +318,12 @@ def frames(L):
             break
         framelink = frame_prev(framelink)
 
+def lightudseg(u):
+  return (u >> LJ_LIGHTUD_BITS_LO) & ((1 << LJ_LIGHTUD_BITS_SEG) - 1)
+
+def lightudlo(u):
+  return u & ((1 << LJ_LIGHTUD_BITS_LO) - 1)
+
 # Dumpers {{{
 
 def dump_lj_tnil(tv):
@@ -327,7 +336,14 @@ def dump_lj_ttrue(tv):
     return 'true'
 
 def dump_lj_tlightud(tv):
-    return 'light userdata @ {}'.format(strx64(gcval(tv['gcr'])))
+    if LJ_64:
+        u = int(tv['u64'])
+        seg = lightudseg(u)
+        segmap = mref('uint32_t *', G(L(None))['gc']['lightudseg'])
+        addr = (int(segmap[seg]) << 32) | lightudlo(u)
+    else:
+        addr = gcval(tv['gcr'])
+    return 'light userdata @ {}'.format(strx64(addr))
 
 def dump_lj_tstr(tv):
     return 'string {body} @ {address}'.format(
-- 
2.36.1