feat: pop instructions

cairo/ethereum/cancun/vm/instructions/stack_instructions.cairo

@@ -1,7 +1,7 @@
 from starkware.cairo.common.math_cmp import is_le
 from starkware.cairo.common.dict import DictAccess, dict_read, dict_write
 
-from ethereum.cancun.vm.stack import push, StackDictAccess, Stack, StackStruct
+from ethereum.cancun.vm.stack import push, StackDictAccess, Stack, StackStruct, pop as stack_pop
 from ethereum.cancun.vm import Evm, EvmImpl
 from ethereum.cancun.vm.exceptions import ExceptionalHalt, StackUnderflowError
 from ethereum.cancun.vm.gas import charge_gas, GasConstants
@@ -109,6 +109,29 @@ func dup_n{range_check_ptr, evm: Evm}(item_number: Uint) -> ExceptionalHalt* {
     return ok;
 }
 
+func pop{range_check_ptr, evm: Evm}() -> ExceptionalHalt* {
+    alloc_locals;
+    // STACK
+    let stack = evm.value.stack;
+    with stack {
+        let (value, err) = stack_pop();
+        if (cast(err, felt) != 0) {
+            return err;
+        }
+    }
+
+    // GAS
+    let err = charge_gas(Uint(GasConstants.GAS_BASE));
+    if (cast(err, felt) != 0) {
+        return err;
+    }
+
+    // PROGRAM COUNTER
+    EvmImpl.set_pc_stack(Uint(evm.value.pc.value + 1), stack);
+    let ok = cast(0, ExceptionalHalt*);
+    return ok;
+}
+
 func push0{range_check_ptr, evm: Evm}() -> ExceptionalHalt* {
     return push_n{evm=evm}(Uint(0));
 }

cairo/tests/ethereum/cancun/vm/instructions/test_stack_instructions.py

@@ -8,6 +8,20 @@
 from tests.utils.evm_builder import EvmBuilder
 
 
+class TestPop:
+    @given(evm=EvmBuilder().with_stack().with_gas_left().with_code().build())
+    def test_pop(self, cairo_run, evm: Evm):
+        try:
+            cairo_result = cairo_run("pop", evm)
+        except ExceptionalHalt as cairo_error:
+            with strict_raises(type(cairo_error)):
+                stack.pop(evm)
+            return
+
+        stack.pop(evm)
+        assert evm == cairo_result
+
+
 class TestPushN:
     @pytest.mark.parametrize("num_bytes", range(33))
     @given(evm=EvmBuilder().with_stack().with_gas_left().with_code().build())