From e316d53fa73509a6c647b355273b1c5be1ed5ecb Mon Sep 17 00:00:00 2001
From: Thakee Nathees <thakeenathees@gmail.com>
Date: Tue, 14 Jun 2022 17:22:32 +0530
Subject: [PATCH] fiber ret updated before loading native modules

---
 src/core/vm.c       |  7 +++++++
 src/libs/std_math.c | 14 ++++++++++++++
 2 files changed, 21 insertions(+)

diff --git a/src/core/vm.c b/src/core/vm.c
index f0b3be1..8b8eeaa 100644
--- a/src/core/vm.c
+++ b/src/core/vm.c
@@ -370,7 +370,14 @@ static Module* _importDL(PKVM* vm, String* resolved, String* name) {
     return NULL;
   }
 
+  // Since the DL library can use stack via slots api, we need to update
+  // ret and then restore it back. We're using offset instead of a pointer
+  // because the stack might be reallocated if it grows.
+  uintptr_t ret_offset = vm->fiber->ret - vm->fiber->stack;
+  vm->fiber->ret = vm->fiber->sp;
   PkHandle* pkhandle = vm->config.import_dl_fn(vm, handle);
+  vm->fiber->ret = vm->fiber->stack + ret_offset;
+
   if (pkhandle == NULL) {
     VM_SET_ERROR(vm, stringFormat(vm, "Error loading module at \"@\"",
       resolved));
diff --git a/src/libs/std_math.c b/src/libs/std_math.c
index eaf550c..5b8bc8f 100644
--- a/src/libs/std_math.c
+++ b/src/libs/std_math.c
@@ -169,6 +169,19 @@ DEF(stdMathArcTangent,
   pkSetSlotNumber(vm, 0, atan(num));
 }
 
+DEF(stdMathArcTan2,
+  "math.atan2(y:Number, x:Number) -> Number",
+  "These functions calculate the principal value of the arc tangent "
+  "of y / x, using the signs of the two arguments to determine the "
+  "quadrant of the result") {
+
+  double y, x;
+  if (!pkValidateSlotNumber(vm, 1, &y)) return;
+  if (!pkValidateSlotNumber(vm, 2, &x)) return;
+
+  pkSetSlotNumber(vm, 0, atan2(y, x));
+}
+
 DEF(stdMathLog10,
   "math.log10(value:Number) -> Number",
   "Return the logarithm to base 10 of argument [value]") {
@@ -226,6 +239,7 @@ void registerModuleMath(PKVM* vm) {
   REGISTER_FN(math, "asin",   stdMathArcSine,    1);
   REGISTER_FN(math, "acos",   stdMathArcCosine,  1);
   REGISTER_FN(math, "atan",   stdMathArcTangent, 1);
+  REGISTER_FN(math, "atan2",  stdMathArcTan2,    2);
   REGISTER_FN(math, "log10",  stdMathLog10,      1);
   REGISTER_FN(math, "round",  stdMathRound,      1);
   REGISTER_FN(math, "rand",   stdMathRand,       0);