Merge pull request #603 from pallene-lang/stack-trace-optimizations

Pallene Traceback Optimizations and Improvements

spec/traceback/anon_lua/anon_lua.pln

@@ -0,0 +1,12 @@
+-- Copyright (c) 2024, The Pallene Developers
+-- Pallene is licensed under the MIT license.
+-- Please refer to the LICENSE and AUTHORS files for details
+-- SPDX-License-Identifier: MIT
+
+local mod: module = {}
+
+function mod.call_anon_lua_fn(callback: () -> ())
+    callback()
+end
+
+return mod

spec/traceback/anon_lua/main.lua

@@ -0,0 +1,15 @@
+-- Copyright (c) 2024, The Pallene Developers
+-- Pallene is licensed under the MIT license.
+-- Please refer to the LICENSE and AUTHORS files for details
+-- SPDX-License-Identifier: MIT
+
+local anon = require "spec.traceback.anon_lua.anon_lua"
+
+local function wrapper()
+    anon.call_anon_lua_fn(function()
+        error "Error from an anonymous Lua fn!"
+    end)
+end
+
+-- luacheck: globals pallene_tracer_debug_traceback
+xpcall(wrapper, pallene_tracer_debug_traceback)

spec/traceback/depth_recursion/main.lua

@@ -3,7 +3,7 @@
 -- Please refer to the LICENSE and AUTHORS files for details
 -- SPDX-License-Identifier: MIT
 
-local pallene = require 'spec.traceback.depth_recursion.depth_recursion'
+local pallene = require "spec.traceback.depth_recursion.depth_recursion"
 
 -- luacheck: globals lua_fn
 function lua_fn(depth)

spec/traceback/module_lua/main.lua

@@ -3,8 +3,8 @@
 -- Please refer to the LICENSE and AUTHORS files for details
 -- SPDX-License-Identifier: MIT
 
-local another_module = require 'spec.traceback.module_lua.another_module'
-local pallene = require 'spec.traceback.module_lua.module_lua'
+local another_module = require "spec.traceback.module_lua.another_module"
+local pallene = require "spec.traceback.module_lua.module_lua"
 
 -- luacheck: globals lua_1
 function lua_1()

spec/traceback/module_pallene/main.lua

@@ -3,12 +3,12 @@
 -- Please refer to the LICENSE and AUTHORS files for details
 -- SPDX-License-Identifier: MIT
 
-local pallene = require 'spec.traceback.module_pallene.module_pallene'
-local pallene_alt = require 'spec.traceback.module_pallene.module_pallene_alt'
+local pallene = require "spec.traceback.module_pallene.module_pallene"
+local pallene_alt = require "spec.traceback.module_pallene.module_pallene_alt"
 
 -- luacheck: globals lua_2
 function lua_2()
-    error "There's an error in everyday life. Shame!"
+    error "There's an error in everyday life. Alas!"
 end
 
 -- luacheck: globals lua_1

spec/traceback/rect/main.lua

@@ -3,7 +3,7 @@
 -- Please refer to the LICENSE and AUTHORS files for details
 -- SPDX-License-Identifier: MIT
 
-local rect = require 'spec.traceback.rect.rect'
+local rect = require "spec.traceback.rect.rect"
 
 -- Should be local.
 -- Making it global so that it is visible in the traceback.

spec/traceback/stack_overflow/main.lua

@@ -0,0 +1,19 @@
+-- Copyright (c) 2024, The Pallene Developers
+-- Pallene is licensed under the MIT license.
+-- Please refer to the LICENSE and AUTHORS files for details
+-- SPDX-License-Identifier: MIT
+
+local so = require "spec.traceback.stack_overflow.stack_overflow"
+
+-- luacheck: globals please_dont_overflow
+function please_dont_overflow()
+    so.no_overflow(please_dont_overflow)
+end
+
+-- luacheck: globals wrapper
+function wrapper()
+    please_dont_overflow()
+end
+
+-- luacheck: globals pallene_tracer_debug_traceback
+xpcall(wrapper, pallene_tracer_debug_traceback)

spec/traceback/stack_overflow/stack_overflow.pln

@@ -0,0 +1,12 @@
+-- Copyright (c) 2024, The Pallene Developers
+-- Pallene is licensed under the MIT license.
+-- Please refer to the LICENSE and AUTHORS files for details
+-- SPDX-License-Identifier: MIT
+
+local mod: module = {}
+
+function mod.no_overflow(callback: () -> ())
+    callback()
+end
+
+return mod

spec/traceback_spec.lua

@@ -57,7 +57,7 @@ end)
 
 it("Multi-module Pallene", function()
     assert_test("module_pallene", [[
-Runtime error: spec/traceback/module_pallene/main.lua:11: There's an error in everyday life. Shame!
+Runtime error: spec/traceback/module_pallene/main.lua:11: There's an error in everyday life. Alas!
 Stack traceback:
     C: in function 'error'
     spec/traceback/module_pallene/main.lua:11: in function 'lua_2'
@@ -94,3 +94,46 @@ Stack traceback:
 ]])
 end)
 
+it("Stack overflow", function()
+    assert_test("stack_overflow", [[
+Runtime error: C stack overflow
+Stack traceback:
+    spec/traceback/stack_overflow/stack_overflow.pln:8: in function 'no_overflow'
+    spec/traceback/stack_overflow/main.lua:10: in function 'please_dont_overflow'
+    spec/traceback/stack_overflow/stack_overflow.pln:8: in function 'no_overflow'
+    spec/traceback/stack_overflow/main.lua:10: in function 'please_dont_overflow'
+    spec/traceback/stack_overflow/stack_overflow.pln:8: in function 'no_overflow'
+    spec/traceback/stack_overflow/main.lua:10: in function 'please_dont_overflow'
+    spec/traceback/stack_overflow/stack_overflow.pln:8: in function 'no_overflow'
+    spec/traceback/stack_overflow/main.lua:10: in function 'please_dont_overflow'
+    spec/traceback/stack_overflow/stack_overflow.pln:8: in function 'no_overflow'
+    spec/traceback/stack_overflow/main.lua:10: in function 'please_dont_overflow'
+
+    ... (Skipped 379 frames) ...
+
+    spec/traceback/stack_overflow/stack_overflow.pln:8: in function 'no_overflow'
+    spec/traceback/stack_overflow/main.lua:10: in function 'please_dont_overflow'
+    spec/traceback/stack_overflow/stack_overflow.pln:8: in function 'no_overflow'
+    spec/traceback/stack_overflow/main.lua:10: in function 'please_dont_overflow'
+    spec/traceback/stack_overflow/stack_overflow.pln:8: in function 'no_overflow'
+    spec/traceback/stack_overflow/main.lua:10: in function 'please_dont_overflow'
+    spec/traceback/stack_overflow/main.lua:15: in function 'wrapper'
+    C: in function 'xpcall'
+    spec/traceback/stack_overflow/main.lua:19: in <main>
+    C: in function '<?>'
+]])
+end)
+
+it("Anonymous lua functions", function()
+    assert_test("anon_lua", [[
+Runtime error: spec/traceback/anon_lua/main.lua:10: Error from an anonymous Lua fn!
+Stack traceback:
+    C: in function 'error'
+    spec/traceback/anon_lua/main.lua:10: in function '<?>'
+    spec/traceback/anon_lua/anon_lua.pln:8: in function 'call_anon_lua_fn'
+    spec/traceback/anon_lua/main.lua:9: in function '<?>'
+    C: in function 'xpcall'
+    spec/traceback/anon_lua/main.lua:15: in <main>
+    C: in function '<?>'
+]])
+end)

src/pallene/coder.lua

@@ -461,7 +461,9 @@ function Coder:pallene_entry_point_definition(f_id)
     local void_frameexit = ""
     if self.flags.use_traceback then
         table.insert(prologue, util.render([[
-            PALLENE_C_FRAMEENTER(L, "$name");
+            /**/
+            pt_cont_t *cont = pvalue(&K->uv[0].uv);
+            PALLENE_C_FRAMEENTER(cont, "$name");
             /**/
         ]], {
             name = func.name
@@ -470,7 +472,7 @@ function Coder:pallene_entry_point_definition(f_id)
         setline = string.format("PALLENE_SETLINE(%d);", func.loc and func.loc.line or 0)
 
         if #func.typ.ret_types == 0 then
-            void_frameexit = "PALLENE_FRAMEEXIT(L);"
+            void_frameexit = "PALLENE_FRAMEEXIT(cont);"
         end
     end
 
@@ -594,27 +596,26 @@ function Coder:lua_entry_point_definition(f_id)
     ]]
 
     local frameenter = ""
-    local setline = ""
     local frameexit  = ""
     if self.flags.use_traceback then
-        frameenter = util.render([[ PALLENE_LUA_FRAMEENTER(L, $fun_name); ]], {
+        frameenter = util.render([[
+            /**/
+            pt_cont_t *cont = pvalue(&K->uv[0].uv);
+            PALLENE_LUA_FRAMEENTER(cont, $fun_name);
+            /**/
+        ]], {
             fun_name = self:lua_entry_point_name(f_id),
         })
-
-        setline = string.format("PALLENE_SETLINE(%d);", func.loc and func.loc.line or 0)
-
-        frameexit = "PALLENE_FRAMEEXIT(L);"
+        frameexit = "PALLENE_FRAMEEXIT(cont);"
     end
 
     local arity_check = util.render([[
         int nargs = lua_gettop(L);
         if (l_unlikely(nargs != $nargs)) {
-            ${setline}
             pallene_runtime_arity_error(L, $fname, $nargs, nargs);
         }
     ]], {
         nargs = C.integer(#arg_types),
-        setline = setline,
         fname = C.string(fname),
     })
 
@@ -657,9 +658,9 @@ function Coder:lua_entry_point_definition(f_id)
     return (util.render([[
         ${fun_decl}
         {
-            ${lua_fenter}
             StackValue *base = L->ci->func.p;
             ${init_global_userdata}
+            ${lua_fenter}
             /**/
             ${arity_check}
             /**/
@@ -675,8 +676,8 @@ function Coder:lua_entry_point_definition(f_id)
         }
     ]], {
         fun_decl = self:lua_entry_point_declaration(f_id),
-        lua_fenter = frameenter,
         init_global_userdata = init_global_userdata,
+        lua_fenter = frameenter,
         arity_check = arity_check,
         arg_decls = table.concat(arg_decls, "\n"),
         init_args = table.concat(init_args, "\n/**/\n"),
@@ -697,10 +698,16 @@ end
 define_union("Constant", {
     Metatable = {"typ"},
     String = {"str"},
+    DebugUserdata = {}
 })
 
 function Coder:init_upvalues()
 
+    -- If we are using tracebacks
+    if self.flags.use_traceback then
+        table.insert(self.constants, coder.Constant.DebugUserdata())
+    end
+
     -- Metatables
     for _, typ in ipairs(self.module.record_types) do
         if not typ.is_upvalue_box then
@@ -1649,7 +1656,7 @@ end
 gen_cmd["Return"] = function(self, cmd)
     local frameexit = ""
     if self.flags.use_traceback then
-        frameexit = "PALLENE_FRAMEEXIT(L);"
+        frameexit = "PALLENE_FRAMEEXIT(cont);"
     end
 
     if #cmd.srcs == 0 then
@@ -1866,6 +1873,12 @@ function Coder:generate_luaopen_function()
                 lua_pushstring(L, $str);]], {
                     str = C.string(upv.str)
                 }))
+        -- Will be used if compiling with `--use-traceback`
+        elseif tag == "coder.Constant.DebugUserdata" then
+            table.insert(init_constants, [[
+                /* Initialize Pallene Tracer. */
+                lua_pushlightuserdata(L, (void *) pallene_tracer_init(L));
+            ]]);
         else
             tagged_union.error(tag)
         end
@@ -1888,17 +1901,6 @@ function Coder:generate_luaopen_function()
         init_function = self:lua_entry_point_name(1),
     })
 
-    local init_pt = ""
-
-    if self.flags.use_traceback then
-        init_pt = [[
-            /* Initialize Pallene Tracer. */
-            pallene_tracer_init(L);
-            /**/
-        ]]
-    end
-
-
     -- NOTE: Version compatibility
     -- ---------------------------
     -- We have both a compile-time and a run-time test. The compile-time test ensures that the
@@ -1914,7 +1916,6 @@ function Coder:generate_luaopen_function()
             #error "Lua version must be exactly 5.4.6"
             #endif
 
-            ${init_pt}
             luaL_checkcoreversion(L);
 
             /**/
@@ -1939,7 +1940,6 @@ function Coder:generate_luaopen_function()
         }
     ]], {
         name = "luaopen_" .. self.modname,
-        init_pt = init_pt,
         n_upvalues = C.integer(#self.constants),
         init_constants = table.concat(init_constants, "\n"),
         init_initializers = init_initializers,