Add devel/scan-vtables (Linux-only, squashed)

Author: lethosor

devel/scan-vtables.lua

@@ -0,0 +1,60 @@
+memscan = require('memscan')
+
+local df_ranges = {}
+for i,mem in ipairs(dfhack.internal.getMemRanges()) do
+    if mem.read and (
+        string.match(mem.name,'/dwarfort%.exe$')
+        or string.match(mem.name,'/dwarfort$')
+        or string.match(mem.name,'/Dwarf_Fortress$')
+        or string.match(mem.name,'Dwarf Fortress%.exe')
+        or string.match(mem.name,'/libg_src_lib.so$')
+    )
+    then
+        table.insert(df_ranges, mem)
+    end
+end
+
+function is_df_addr(a)
+    for _, mem in ipairs(df_ranges) do
+        if a >= mem.start_addr and a < mem.end_addr then
+            return true
+        end
+    end
+    return false
+end
+
+for _, range in ipairs(df_ranges) do
+    if (not range.read) or range.write or range.execute or range.name:match('g_src') then
+        goto next_range
+    end
+
+    local area = memscan.MemoryArea.new(range.start_addr, range.end_addr)
+    for i = 1, area.uintptr_t.count - 1 do
+        local vtable = area.uintptr_t:idx2addr(i)
+        local typeinfo = area.uintptr_t[i - 1]
+        if is_df_addr(typeinfo + 8) then
+            local typestring = df.reinterpret_cast('uintptr_t', typeinfo + 8)[0]
+            if is_df_addr(typestring) then
+                local vlen = 0
+                while is_df_addr(vtable + (8*vlen)) and is_df_addr(df.reinterpret_cast('uintptr_t', vtable + (8*vlen))[0]) do
+                    vlen = vlen + 1
+                    break -- for now, any vtable with one valid function pointer is valid enough
+                end
+                if vlen > 0 then
+                    local ok, name = pcall(function()
+                        return memscan.read_c_string(df.reinterpret_cast('char', typestring))--:gsub('^%d+', '')
+                    end)
+                    if not ok then
+                    else
+                        local demangled_name = dfhack.internal.cxxDemangle('_Z' .. name)
+                        if demangled_name and not demangled_name:match('[<>]') and not demangled_name:match('^std::') then
+                            print(("<vtable-address name='%s' value='0x%x'/>"):format(demangled_name, vtable))
+                        end
+                    end
+                end
+            end
+        end
+
+    end
+    ::next_range::
+end