From fec6ad0f5f47c1bea6f4ecc06c1b28c1e3461cd6 Mon Sep 17 00:00:00 2001
From: Sainan <sainan@calamity.inc>
Date: Thu, 23 Jan 2025 05:46:31 +0100
Subject: [PATCH] Add $assert

---
 src/lbaselib.cpp         |  2 +-
 src/lparser.cpp          | 53 +++++++++++++++++++++++-----------------
 testes/pluto/basic.pluto |  5 ++++
 3 files changed, 37 insertions(+), 23 deletions(-)

diff --git a/src/lbaselib.cpp b/src/lbaselib.cpp
index 5ce87fe69..a550341f4 100644
--- a/src/lbaselib.cpp
+++ b/src/lbaselib.cpp
@@ -499,7 +499,7 @@ static int luaB_dofile (lua_State *L) {
 }
 
 
-static int luaB_assert (lua_State *L) {
+int luaB_assert (lua_State *L) {
   if (l_likely(lua_toboolean(L, 1)))  /* condition is true? */
     return lua_gettop(L);  /* return all arguments */
   else {  /* error */
diff --git a/src/lparser.cpp b/src/lparser.cpp
index 0b3d6abe6..4b55f4fe1 100644
--- a/src/lparser.cpp
+++ b/src/lparser.cpp
@@ -2675,6 +2675,13 @@ static void safe_navigation (LexState *ls, expdesc *v) {
 static void top_to_expdesc (LexState *ls, expdesc *v) {
   lua_State *L = ls->L;
   switch (lua_type(L, -1)) {
+    case LUA_TNONE:
+    case LUA_TNIL:
+      init_exp(v, VNIL, 0);
+      break;
+    case LUA_TBOOLEAN:
+      init_exp(v, lua_istrue(L, -1) ? VTRUE : VFALSE, 0);
+      break;
     case LUA_TNUMBER: {
       if (lua_isinteger(L, -1)) {
         init_exp(v, VKINT, 0);
@@ -2777,26 +2784,37 @@ int luaB_utonumber (lua_State *L);
 int luaB_tostring (lua_State *L);
 int luaB_utostring (lua_State *L);
 int luaB_type (lua_State *L);
+int luaB_assert (lua_State *L);
 
 static void const_expr (LexState *ls, expdesc *v) {
   switch (ls->t.token) {
     case TK_NAME: {
-      const Pluto::ConstexprLibrary* lib = nullptr;
-      for (const auto& library : Pluto::all_preloaded) {
-        if (strcmp(library->name, getstr(ls->t.seminfo.ts)) == 0) {
-          lib = library;
-          break;
-        }
-      }
-      if (lib == nullptr) {
-        for (const auto& library : Pluto::all_constexpr) {
+      if (!check_constexpr_call(ls, v, "tonumber", luaB_tonumber)
+          && !check_constexpr_call(ls, v, "utonumber", luaB_utonumber)
+          && !check_constexpr_call(ls, v, "tostring", luaB_tostring)
+          && !check_constexpr_call(ls, v, "utostring", luaB_utostring)
+          && !check_constexpr_call(ls, v, "type", luaB_type)
+          && !check_constexpr_call(ls, v, "assert", luaB_assert)
+        )
+      {
+        const Pluto::ConstexprLibrary* lib = nullptr;
+        for (const auto& library : Pluto::all_preloaded) {
           if (strcmp(library->name, getstr(ls->t.seminfo.ts)) == 0) {
             lib = library;
             break;
           }
         }
-      }
-      if (lib != nullptr) {
+        if (lib == nullptr) {
+          for (const auto& library : Pluto::all_constexpr) {
+            if (strcmp(library->name, getstr(ls->t.seminfo.ts)) == 0) {
+              lib = library;
+              break;
+            }
+          }
+          if (lib == nullptr) {
+            throwerr(ls, luaO_fmt(ls->L, "%s is not available in constant expression", getstr(ls->t.seminfo.ts)), "unrecognized name.");
+          }
+        }
         luaX_next(ls); /* skip TK_NAME */
         checknext(ls, '.');
         check(ls, TK_NAME);
@@ -2815,15 +2833,6 @@ static void const_expr (LexState *ls, expdesc *v) {
           constexpr_call(ls, v, f);
         }
       }
-      else if (!check_constexpr_call(ls, v, "tonumber", luaB_tonumber)
-          && !check_constexpr_call(ls, v, "utonumber", luaB_utonumber)
-          && !check_constexpr_call(ls, v, "tostring", luaB_tostring)
-          && !check_constexpr_call(ls, v, "utostring", luaB_utostring)
-          && !check_constexpr_call(ls, v, "type", luaB_type)
-        )
-      {
-        throwerr(ls, luaO_fmt(ls->L, "%s is not available in constant expression", getstr(ls->t.seminfo.ts)), "unrecognized name.");
-      }
       return;
     }
     default: {
@@ -4669,8 +4678,8 @@ static void constexprstat (LexState *ls, int line) {
     constexprdefinestat(ls, line);
   }
   else {
-    const char *token = luaX_token2str(ls, ls->t);
-    throwerr(ls, luaO_fmt(ls->L, "unexpected symbol near %s", token), "unexpected symbol.");
+    expdesc v;
+    const_expr(ls, &v);
   }
 }
 
diff --git a/testes/pluto/basic.pluto b/testes/pluto/basic.pluto
index 862d6da86..b998f4021 100644
--- a/testes/pluto/basic.pluto
+++ b/testes/pluto/basic.pluto
@@ -3416,6 +3416,11 @@ do
         $end
     end
     assert(elseif_test() == "branch 2")
+
+    $assert(true)
+    $define COND = true
+    $assert(COND)
+    assert(not load[[$assert(false)]])
 end
 
 print "Testing preprocessor."