[Tarantool-patches] [PATCH luajit v3 2/2] memprof: update memprof parser

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

This commit introduces demangling of C symbols to memprof parser.

As symbol table format has changed, parser needed to be updated too.
Now the parser supports new symbol table entries, containing data
about symbols from shared objects, that were loaded at the moment of
data collection. Also, now the parser supports symtab events in the
event stream and extends the symtab corresponding to them.

Closes tarantool/tarantool#5813
---
 .../misclib-memprof-lapi.test.lua             |  4 +--
 tools/memprof.lua                             |  6 ++++
 tools/memprof/parse.lua                       | 17 ++++++++-
 tools/memprof/process.lua                     |  7 ++++
 tools/utils/symtab.lua                        | 35 +++++++++++++++----
 5 files changed, 60 insertions(+), 9 deletions(-)

diff --git a/test/tarantool-tests/misclib-memprof-lapi.test.lua b/test/tarantool-tests/misclib-memprof-lapi.test.lua
index 06d96b3b..bdb77549 100644
--- a/test/tarantool-tests/misclib-memprof-lapi.test.lua
+++ b/test/tarantool-tests/misclib-memprof-lapi.test.lua
@@ -61,10 +61,10 @@ local function fill_ev_type(events, symbols, event_type)
         name = "INTERNAL",
         num = event.num,
     }
-    elseif symbols[addr] then
+    elseif symbols.SYMTAB_LFUNC[addr] then
       ev_type[event.loc.line] = {
         name = string.format(
-          "%s:%d", symbols[addr].source, symbols[addr].linedefined
+          "%s:%d", symbols.SYMTAB_LFUNC[addr].source, symbols.SYMTAB_LFUNC[addr].linedefined
         ),
         num = event.num,
       }
diff --git a/tools/memprof.lua b/tools/memprof.lua
index 18b44fdd..8fbc6a3c 100644
--- a/tools/memprof.lua
+++ b/tools/memprof.lua
@@ -101,6 +101,12 @@ local function dump(inputfile)
   local reader = bufread.new(inputfile)
   local symbols = symtab.parse(reader)
   local events = memprof.parse(reader, symbols)
+
+  -- TODO move this for to process.lua
+  for addr, event in pairs(events.symtab) do
+    symtab.add_cfunc(symbols, addr, event.name)
+  end
+
   if not leak_only then
     view.profile_info(events, symbols)
   end
diff --git a/tools/memprof/parse.lua b/tools/memprof/parse.lua
index 12e2758f..61a95d0f 100644
--- a/tools/memprof/parse.lua
+++ b/tools/memprof/parse.lua
@@ -11,10 +11,11 @@ local lshift = bit.lshift
 local string_format = string.format
 
 local LJM_MAGIC = "ljm"
-local LJM_CURRENT_VERSION = 1
+local LJM_CURRENT_VERSION = 2
 
 local LJM_EPILOGUE_HEADER = 0x80
 
+local AEVENT_SYMTAB = 0
 local AEVENT_ALLOC = 1
 local AEVENT_FREE = 2
 local AEVENT_REALLOC = 3
@@ -36,6 +37,7 @@ local function new_event(loc)
     free = 0,
     alloc = 0,
     primary = {},
+    name = nil
   }
 end
 
@@ -77,6 +79,17 @@ local function parse_location(reader, asource)
   error("Unknown asource "..asource)
 end
 
+local function parse_symtab(reader, asource, events, heap)
+  local id = reader:read_uleb128()
+  local name = reader:read_string()
+
+  if not events[id] then
+    events[id] = new_event(0)
+  end
+
+  events[id].name = name
+end
+
 local function parse_alloc(reader, asource, events, heap)
   local id, loc = parse_location(reader, asource)
 
@@ -134,6 +147,7 @@ local function parse_free(reader, asource, events, heap)
 end
 
 local parsers = {
+  [AEVENT_SYMTAB] = {evname = "symtab", parse = parse_symtab},
   [AEVENT_ALLOC] = {evname = "alloc", parse = parse_alloc},
   [AEVENT_FREE] = {evname = "free", parse = parse_free},
   [AEVENT_REALLOC] = {evname = "realloc", parse = parse_realloc},
@@ -174,6 +188,7 @@ function M.parse(reader)
     realloc = {},
     free = {},
     heap = {},
+    symtab = {}
   }
 
   local magic = reader:read_octets(3)
diff --git a/tools/memprof/process.lua b/tools/memprof/process.lua
index 0bcb965b..25a70878 100644
--- a/tools/memprof/process.lua
+++ b/tools/memprof/process.lua
@@ -56,4 +56,11 @@ function M.form_heap_delta(events, symbols)
   return dheap
 end
 
+function M.enrich_symtab(events, symbols)
+  for event, addr in pairs(events.symtab) do
+    print(event.name)
+    symtab.add_cfunc(symtab, addr, event.name)
+  end
+end
+
 return M
diff --git a/tools/utils/symtab.lua b/tools/utils/symtab.lua
index 3ed1dd13..79f656ac 100644
--- a/tools/utils/symtab.lua
+++ b/tools/utils/symtab.lua
@@ -10,11 +10,12 @@ local band = bit.band
 local string_format = string.format
 
 local LJS_MAGIC = "ljs"
-local LJS_CURRENT_VERSION = 1
+local LJS_CURRENT_VERSION = 2
 local LJS_EPILOGUE_HEADER = 0x80
 local LJS_SYMTYPE_MASK = 0x03
 
 local SYMTAB_LFUNC = 0
+local SYMTAB_CFUNC = 1
 
 local M = {}
 
@@ -24,18 +25,33 @@ local function parse_sym_lfunc(reader, symtab)
   local sym_chunk = reader:read_string()
   local sym_line = reader:read_uleb128()
 
-  symtab[sym_addr] = {
+  symtab.SYMTAB_LFUNC[sym_addr] = {
     source = sym_chunk,
     linedefined = sym_line,
   }
 end
 
+-- Parse a single entry in a symtab: .so library
+local function parse_sym_cfunc(reader, symtab)
+  local addr = reader:read_uleb128()
+  local name = reader:read_string()
+
+  symtab.SYMTAB_CFUNC[addr] = {
+    name = name
+  }
+end
+
 local parsers = {
   [SYMTAB_LFUNC] = parse_sym_lfunc,
+  [SYMTAB_CFUNC] = parse_sym_cfunc
 }
 
 function M.parse(reader)
-  local symtab = {}
+  local symtab = {
+    SYMTAB_LFUNC = {},
+    SYMTAB_CFUNC = {}
+  }
+
   local magic = reader:read_octets(3)
   local version = reader:read_octets(1)
 
@@ -69,7 +85,6 @@ function M.parse(reader)
       parsers[sym_type](reader, symtab)
     end
   end
-
   return symtab
 end
 
@@ -80,11 +95,19 @@ function M.demangle(symtab, loc)
     return "INTERNAL"
   end
 
-  if symtab[addr] then
-    return string_format("%s:%d", symtab[addr].source, loc.line)
+  if symtab.SYMTAB_LFUNC[addr] then
+    return string_format("%s:%d", symtab.SYMTAB_LFUNC[addr].source, loc.line)
+  end
+
+  if symtab.SYMTAB_CFUNC[addr] then
+    return string_format("%s:%#x", symtab.SYMTAB_CFUNC[addr].name, addr)
   end
 
   return string_format("CFUNC %#x", addr)
 end
 
+function M.add_cfunc(symtab, addr, name)
+  symtab.SYMTAB_CFUNC[addr] = {name = name}
+end
+
 return M
-- 
2.33.0