Merge pull request #70 from koltenpearson/c_binding_api

revamped c bindings

c_bindings/pocketpy_c.cpp

@@ -0,0 +1,544 @@
+#include "pocketpy.h"
+#include "pocketpy_c.h"
+
+using namespace pkpy;
+
+#define PKPY_STACK_SIZE 32
+
+#define SAFEGUARD_OPEN try { \
+
+#define SAFEGUARD_CLOSE \
+    } catch(std::exception& e) { \
+        std::cerr << "ERROR: a std::exception " \
+        << "this probably means pocketpy itself has a bug!\n" \
+        << e.what() << "\n"; \
+        exit(2); \
+    } catch(...) { \
+        std::cerr << "ERROR: a unknown exception was thrown " \
+        << "this probably means pocketpy itself has a bug!\n"; \
+        exit(2); \
+    }
+
+
+#define ERRHANDLER_OPEN SAFEGUARD_OPEN \
+    try { \
+    if (vm->c_data->size() > 0 && vm->c_data->top() == nullptr) \
+        return false; \
+
+#define ERRHANDLER_CLOSE \
+    } catch( Exception e ) { \
+        vm->c_data->push(py_var(vm, e)); \
+        vm->c_data->push(NULL); \
+        return false; \
+    } \
+    SAFEGUARD_CLOSE \
+
+
+
+class CVM : public VM {
+    public :
+
+    ValueStackImpl<PKPY_STACK_SIZE>* c_data;
+    CVM(bool enable_os=true) : VM(enable_os) {
+        c_data = new ValueStackImpl<PKPY_STACK_SIZE>();
+    }
+
+    ~CVM() {
+        c_data->clear();
+        delete c_data;
+    }
+};
+
+
+//for now I will unpack a tuple automatically, we may not want to handle
+//it this way, not sure
+//it is more lua like, but maybe not python like
+static void unpack_return(CVM* vm, PyObject* ret) {
+    if (is_type(ret, vm->tp_tuple)) {
+        Tuple& t = py_cast<Tuple&>(vm, ret);
+        for (int i = 0; i < t.size(); i++) 
+            vm->c_data->push(t[i]);
+    } else if (ret == vm->None) {
+        //do nothing here
+        //having to pop the stack after every call that returns none is annoying
+        //lua does not do this
+        //
+        //so for now we will not push none on the stack when it is the sole thing returned
+        //if this becomes a problem we can change it
+        //
+        //you can still check if it returned none by comparing stack size before
+        //and after if you have to
+    } else 
+        vm->c_data->push(ret);
+
+}
+
+
+bool pkpy_clear_error(pkpy_vm* vm_handle, char** message) {
+    CVM* vm = (CVM*) vm_handle;
+    SAFEGUARD_OPEN
+
+        if (vm->c_data->size() == 0 || vm->c_data->top() != nullptr) 
+            return false;
+
+        vm->c_data->pop();
+        Exception& e = py_cast<Exception&>(vm, vm->c_data->top());
+        if (message != nullptr) 
+            *message = e.summary().c_str_dup();
+        else
+            std::cerr << "ERROR: " << e.summary() << "\n";
+
+        vm->c_data->clear();
+        vm->callstack.clear();
+        vm->s_data.clear(); 
+        return true;
+
+    SAFEGUARD_CLOSE
+}
+
+void gc_marker_ex(CVM* vm) {
+    for(PyObject* obj: *vm->c_data) if(obj!=nullptr) OBJ_MARK(obj);
+}
+
+
+static void noop_output_handler(VM* vm, const Str& str) {
+    (void) vm;
+    (void) str;
+}
+
+pkpy_vm* pkpy_vm_create(bool use_stdio, bool enable_os) {
+
+    CVM* vm = new CVM(enable_os);
+    vm->c_data = new ValueStackImpl<PKPY_STACK_SIZE>();
+    vm->_gc_marker_ex = (void (*)(VM*)) gc_marker_ex;
+
+    if (!use_stdio) {
+        vm->_stdout = noop_output_handler;
+        vm->_stderr = noop_output_handler;
+    }
+
+    return (pkpy_vm*) vm;
+}
+
+bool pkpy_vm_run(pkpy_vm* vm_handle, const char* source) {
+    CVM* vm = (CVM*) vm_handle;
+    ERRHANDLER_OPEN
+
+    CodeObject_ code = vm->compile(source, "<c-bound>", EXEC_MODE);
+    PyObject* result = vm->_exec(code, vm->_main);
+
+    //unpack_return(w, result);
+    //NOTE: it seems like vm->_exec should return whatever the last command it
+    //ran returned but instead it seems to pretty much always return None
+    //so I guess uncomment this line if that every changes
+
+    return true;
+    ERRHANDLER_CLOSE
+}
+
+void pkpy_vm_destroy(pkpy_vm* vm_handle) {
+    CVM* vm = (CVM*) vm_handle;
+    delete vm;
+}
+
+static void propagate_if_errored(CVM* vm, ValueStackImpl<PKPY_STACK_SIZE>* stored_stack) {
+    try {
+        if (vm->c_data->size() == 0 || vm->c_data->top() != nullptr) 
+            return;
+
+        vm->c_data->pop();
+        Exception& e = py_cast<Exception&>(vm, vm->c_data->top());
+        vm->c_data->pop();
+
+        vm->c_data = stored_stack;
+
+        throw e;
+    } catch(Exception& e) {
+        throw;
+    } catch(...) {
+        std::cerr << "ERROR: a non pocketpy exeception was thrown " 
+            << "this probably means pocketpy itself has a bug!\n"; 
+        exit(2); 
+    }
+}
+
+PyObject* c_function_wrapper(VM* vm, ArgsView args) {
+    LuaStyleFuncC f = py_cast<NativeFunc&>(vm, args[-2])._lua_f;
+    CVM* cvm = (CVM*) vm;
+
+    //setup c stack
+    ValueStackImpl<PKPY_STACK_SIZE> local_stack;
+
+    for (int i = 0; i < args.size(); i++)
+        local_stack.push(args[i]);
+    
+    ValueStackImpl<PKPY_STACK_SIZE>* stored_stack = cvm->c_data;
+    cvm->c_data = &local_stack;
+
+    int retc = f(cvm);
+
+    propagate_if_errored(cvm, stored_stack);
+    cvm->c_data = stored_stack;
+
+    PyObject* ret = cvm->None;
+
+    if (retc == 1) 
+        ret = local_stack.top();
+    else if (retc > 1) {
+        Tuple t(retc);
+
+        for (int i = 0; i < retc; i++)  {
+            int stack_index = (local_stack.size() - retc) + i;
+            t[i] = local_stack.begin()[stack_index];
+        }
+
+        ret = py_var(cvm, t);
+    }
+
+    return ret;
+}
+
+bool pkpy_push_function(pkpy_vm* vm_handle, pkpy_function f) {
+    CVM* vm = (CVM*) vm_handle;
+    ERRHANDLER_OPEN
+
+    //TODO right now we just treat all c bound functions a varargs functions
+    //do we want to change that?
+    NativeFunc nf = NativeFunc(c_function_wrapper, -1, 0);
+    nf._lua_f = (LuaStyleFuncC) f;
+
+    vm->c_data->push(py_var(vm, nf));
+
+    return true;
+    ERRHANDLER_CLOSE
+}
+
+bool pkpy_push_int(pkpy_vm* vm_handle, int value) {
+    CVM* vm = (CVM*) vm_handle;
+    ERRHANDLER_OPEN
+
+    vm->c_data->push(py_var(vm, value));
+
+    return true;
+    ERRHANDLER_CLOSE
+}
+
+bool pkpy_push_float(pkpy_vm* vm_handle, double value) {
+    CVM* vm = (CVM*) vm_handle;
+    ERRHANDLER_OPEN
+    vm->c_data->push(py_var(vm, value));
+
+    return true;
+    ERRHANDLER_CLOSE
+}
+
+bool pkpy_push_bool(pkpy_vm* vm_handle, bool value) {
+    CVM* vm = (CVM*) vm_handle;
+    ERRHANDLER_OPEN
+    vm->c_data->push(py_var(vm, value));
+
+    return true;
+    ERRHANDLER_CLOSE
+}
+
+bool pkpy_push_string(pkpy_vm* vm_handle, const char* value) {
+    CVM* vm = (CVM*) vm_handle;
+    ERRHANDLER_OPEN
+    vm->c_data->push(py_var(vm, value));
+
+    return true;
+    ERRHANDLER_CLOSE
+}
+
+bool pkpy_push_stringn(pkpy_vm* vm_handle, const char* value, int length) {
+    CVM* vm = (CVM*) vm_handle;
+    ERRHANDLER_OPEN
+
+    Str s = Str(value, length);
+    vm->c_data->push(py_var(vm, s));
+
+    return true;
+    ERRHANDLER_CLOSE
+}
+
+bool pkpy_push_voidp(pkpy_vm* vm_handle, void* value) {
+    CVM* vm = (CVM*) vm_handle;
+    ERRHANDLER_OPEN
+    vm->c_data->push(py_var(vm, value));
+
+    return true;
+    ERRHANDLER_CLOSE
+}
+
+bool pkpy_push_none(pkpy_vm* vm_handle) {
+    CVM* vm = (CVM*) vm_handle;
+    ERRHANDLER_OPEN
+    vm->c_data->push(vm->None);
+
+    return true;
+    ERRHANDLER_CLOSE
+}
+
+
+
+bool pkpy_set_global(pkpy_vm* vm_handle, const char* name) {
+    CVM* vm = (CVM*) vm_handle;
+    ERRHANDLER_OPEN
+
+    vm->_main->attr().set(name, vm->c_data->top());
+
+    vm->c_data->pop();
+
+    return true;
+    ERRHANDLER_CLOSE
+}
+
+//get global will also get bulitins
+bool pkpy_get_global(pkpy_vm* vm_handle, const char* name) {
+    CVM* vm = (CVM*) vm_handle;
+    ERRHANDLER_OPEN
+
+    PyObject* o = vm->_main->attr().try_get(name);
+    if (o == nullptr) {
+        o = vm->builtins->attr().try_get(name);
+        if (o == nullptr)
+            vm->NameError("could not find requested global");
+    }
+
+    vm->c_data->push(o);
+
+    return true;
+    ERRHANDLER_CLOSE
+}
+
+
+bool pkpy_call(pkpy_vm* vm_handle, int argc) {
+    CVM* vm = (CVM*) vm_handle;
+    ERRHANDLER_OPEN
+
+    int callable_index = vm->c_data->size() - argc  - 1;
+
+    PyObject* callable = vm->c_data->begin()[callable_index];
+
+    vm->s_data.push(callable);
+    vm->s_data.push(PY_NULL);
+
+    for (int i = 0; i < argc; i++) 
+        vm->s_data.push(vm->c_data->begin()[callable_index + i + 1]);
+
+    PyObject* o = vm->vectorcall(argc);
+
+    vm->c_data->shrink(argc + 1);
+
+    unpack_return(vm, o);
+
+    return true;
+    ERRHANDLER_CLOSE
+}
+
+bool pkpy_call_method(pkpy_vm* vm_handle, const char* name, int argc) {
+    CVM* vm = (CVM*) vm_handle;
+    ERRHANDLER_OPEN
+
+    int self_index = vm->c_data->size() - argc  - 1;
+    PyObject* self = vm->c_data->begin()[self_index];
+
+    PyObject* callable = vm->get_unbound_method(self, name, &self);
+
+    vm->s_data.push(callable);
+    vm->s_data.push(self);
+
+    for (int i = 0; i < argc; i++) 
+        vm->s_data.push(vm->c_data->begin()[self_index + i + 1]);
+
+    PyObject* o = vm->vectorcall(argc);
+
+    vm->c_data->shrink(argc + 1);
+
+    unpack_return(vm, o);
+
+    return true;
+    ERRHANDLER_CLOSE
+}
+
+
+
+static int lua_to_cstack_index(int index, int size) {
+    if (index < 0)
+        index = size + index;
+    return index;
+}
+
+bool pkpy_to_int(pkpy_vm* vm_handle, int index, int* ret) {
+    CVM* vm = (CVM*) vm_handle;
+    ERRHANDLER_OPEN
+
+    index = lua_to_cstack_index(index, vm->c_data->size());
+
+    PyObject* o = vm->c_data->begin()[index];
+    if (ret != nullptr)
+        *ret = py_cast<int>(vm, o);
+
+    return true;
+    ERRHANDLER_CLOSE
+}
+
+bool pkpy_to_float(pkpy_vm* vm_handle, int index, double* ret) {
+    CVM* vm = (CVM*) vm_handle;
+    ERRHANDLER_OPEN
+
+    index = lua_to_cstack_index(index, vm->c_data->size());
+
+    PyObject* o = vm->c_data->begin()[index];
+    if (ret != nullptr)
+        *ret = py_cast<double>(vm, o);
+
+    return true;
+    ERRHANDLER_CLOSE
+}
+
+bool pkpy_to_bool(pkpy_vm* vm_handle, int index, bool* ret) {
+    CVM* vm = (CVM*) vm_handle;
+    ERRHANDLER_OPEN
+
+    index = lua_to_cstack_index(index, vm->c_data->size());
+
+    PyObject* o = vm->c_data->begin()[index];
+    if (ret != nullptr)
+        *ret = py_cast<bool>(vm, o);
+
+    return true;
+    ERRHANDLER_CLOSE
+}
+
+bool pkpy_to_voidp(pkpy_vm* vm_handle, int index, void** ret) {
+    CVM* vm = (CVM*) vm_handle;
+    ERRHANDLER_OPEN
+
+    index = lua_to_cstack_index(index, vm->c_data->size());
+
+    PyObject* o = vm->c_data->begin()[index];
+    if (ret != nullptr) 
+        *ret = py_cast<void*>(vm, o);
+
+    return true;
+    ERRHANDLER_CLOSE
+}
+
+bool pkpy_to_string(pkpy_vm* vm_handle, int index, char** ret) {
+    CVM* vm = (CVM*) vm_handle;
+    ERRHANDLER_OPEN
+
+    index = lua_to_cstack_index(index, vm->c_data->size());
+
+    PyObject* o = vm->c_data->begin()[index];
+    if (ret != nullptr) {
+        Str& s = py_cast<Str&>(vm, o);
+        *ret = s.c_str_dup();
+    }
+
+    return true;
+    ERRHANDLER_CLOSE
+}
+
+bool pkpy_to_stringn(pkpy_vm* vm_handle, int index, const char** ret, int* size) {
+    CVM* vm = (CVM*) vm_handle;
+    ERRHANDLER_OPEN
+
+    index = lua_to_cstack_index(index, vm->c_data->size());
+
+    PyObject* o = vm->c_data->begin()[index];
+    if (ret != nullptr) {
+        std::string_view sv = py_cast<Str&>(vm, o).sv();
+        *ret = sv.data();
+        *size = sv.size();
+    }
+
+    return true;
+    ERRHANDLER_CLOSE
+}
+
+
+bool pkpy_is_int(pkpy_vm* vm_handle, int index) {
+    CVM* vm = (CVM*) vm_handle;
+    index = lua_to_cstack_index(index, vm->c_data->size());
+    PyObject* o = vm->c_data->begin()[index];
+
+    return is_type(o, vm->tp_int);
+}
+bool pkpy_is_float(pkpy_vm* vm_handle, int index) {
+    CVM* vm = (CVM*) vm_handle;
+    index = lua_to_cstack_index(index, vm->c_data->size());
+    PyObject* o = vm->c_data->begin()[index];
+
+    return is_type(o, vm->tp_float);
+}
+bool pkpy_is_bool(pkpy_vm* vm_handle, int index) {
+    CVM* vm = (CVM*) vm_handle;
+    index = lua_to_cstack_index(index, vm->c_data->size());
+    PyObject* o = vm->c_data->begin()[index];
+
+    return is_type(o, vm->tp_bool);
+}
+bool pkpy_is_string(pkpy_vm* vm_handle, int index) {
+    CVM* vm = (CVM*) vm_handle;
+    index = lua_to_cstack_index(index, vm->c_data->size());
+    PyObject* o = vm->c_data->begin()[index];
+
+    return is_type(o, vm->tp_str);
+}
+bool pkpy_is_voidp(pkpy_vm* vm_handle, int index) {
+    CVM* vm = (CVM*) vm_handle;
+    index = lua_to_cstack_index(index, vm->c_data->size());
+    PyObject* o = vm->c_data->begin()[index];
+
+    return is_type(o, VoidP::_type(vm));
+}
+
+bool pkpy_is_none(pkpy_vm* vm_handle, int index) {
+    CVM* vm = (CVM*) vm_handle;
+    index = lua_to_cstack_index(index, vm->c_data->size());
+    PyObject* o = vm->c_data->begin()[index];
+
+    return o == vm->None;
+}
+
+bool pkpy_check_global(pkpy_vm* vm_handle, const char* name) {
+    CVM* vm = (CVM*) vm_handle;
+    SAFEGUARD_OPEN
+    PyObject* o = vm->_main->attr().try_get(name);
+    if (o == nullptr) {
+        o = vm->builtins->attr().try_get(name);
+        if (o == nullptr)
+            return false;
+    }
+    return true;
+
+    SAFEGUARD_CLOSE
+}
+
+bool pkpy_check_error(pkpy_vm* vm_handle) {
+    CVM* vm = (CVM*) vm_handle;
+    SAFEGUARD_OPEN
+    if (vm->c_data->size() > 0 && vm->c_data->top() == nullptr) 
+        return true; 
+    return false;
+    SAFEGUARD_CLOSE
+}
+
+
+bool pkpy_check_stack(pkpy_vm* vm_handle, int free) {
+    CVM* vm = (CVM*) vm_handle;
+    return free + vm->c_data->size() <= PKPY_STACK_SIZE;
+}
+
+int pkpy_stack_size(pkpy_vm* vm_handle) {
+    CVM* vm = (CVM*) vm_handle;
+    return vm->c_data->size();
+}
+
+bool pkpy_pop(pkpy_vm* vm_handle, int n) {
+    CVM* vm = (CVM*) vm_handle;
+    vm->c_data->shrink(n);
+    return true;
+}

c_bindings/pocketpy_c.h

@@ -0,0 +1,104 @@
+#ifndef POCKETPY_C_H 
+#define POCKETPY_C_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stdbool.h>
+#include <stdint.h>
+
+typedef struct pkpy_vm_handle pkpy_vm;
+
+//we we take a lot of inspiration from the lua api for these bindings
+//the key difference being most methods return a bool, 
+//true if it succeeded false if it did not
+
+//if a method returns false call the pkpy_clear_error method to check the error and clear it
+//if pkpy_clear_error returns false it means that no error was set, and it takes no action
+//if pkpy_clear_error returns true it means there was an error and it was cleared, 
+//it will provide a string summary of the error in the message parameter (if it is not NULL)
+//if null is passed in as message, and it will just print the message to stderr
+bool pkpy_clear_error(pkpy_vm*, char** message);
+//NOTE you are responsible for freeing message 
+
+pkpy_vm* pkpy_vm_create(bool use_stdio, bool enable_os);
+bool pkpy_vm_run(pkpy_vm*, const char* source);
+void pkpy_vm_destroy(pkpy_vm*);
+
+typedef int (*pkpy_function)(pkpy_vm*); 
+
+bool pkpy_pop(pkpy_vm*, int n);
+
+bool pkpy_push_function(pkpy_vm*, pkpy_function);
+bool pkpy_push_int(pkpy_vm*, int);
+bool pkpy_push_float(pkpy_vm*, double);
+bool pkpy_push_bool(pkpy_vm*, bool);
+bool pkpy_push_string(pkpy_vm*, const char*);
+bool pkpy_push_stringn(pkpy_vm*, const char*, int length);
+bool pkpy_push_voidp(pkpy_vm*, void*);
+bool pkpy_push_none(pkpy_vm*);
+
+bool pkpy_set_global(pkpy_vm*, const char* name);
+bool pkpy_get_global(pkpy_vm*, const char* name);
+
+//first push callable you want to call
+//then push the arguments to send
+//argc is the number of arguments that was pushed (not counting the callable)
+bool pkpy_call(pkpy_vm*, int argc);
+
+//first push the object the method belongs to (self)
+//then push the the argments
+//argc is the number of arguments that was pushed (not counting the callable or self)
+//name is the name of the method to call on the object
+bool pkpy_call_method(pkpy_vm*, const char* name, int argc);
+
+
+//we will break with the lua api here
+//lua uses 1 as the index to the first pushed element for all of these functions
+//but we will start counting at zero to match python
+//we will allow negative numbers to count backwards from the top
+bool pkpy_to_int(pkpy_vm*, int index, int* ret);
+bool pkpy_to_float(pkpy_vm*, int index, double* ret);
+bool pkpy_to_bool(pkpy_vm*, int index, bool* ret);
+bool pkpy_to_voidp(pkpy_vm*, int index, void** ret);
+
+//this method provides a strong reference, you are responsible for freeing the
+//string when you are done with it
+bool pkpy_to_string(pkpy_vm*, int index, char** ret);
+
+//this method provides a weak reference, it is only valid until the
+//next api call
+//it is not null terminated
+bool pkpy_to_stringn(pkpy_vm*, int index, const char** ret, int* size);
+
+
+//these do not follow the same error semantics as above, their return values
+//just say whether the check succeeded or not, or else return the value asked for
+
+bool pkpy_is_int(pkpy_vm*, int index);
+bool pkpy_is_float(pkpy_vm*, int index);
+bool pkpy_is_bool(pkpy_vm*, int index);
+bool pkpy_is_string(pkpy_vm*, int index);
+bool pkpy_is_voidp(pkpy_vm*, int index);
+bool pkpy_is_none(pkpy_vm*, int index);
+
+
+//will return true if global exists
+bool pkpy_check_global(pkpy_vm*, const char* name);
+
+//will return true if the vm is currently in an error state
+bool pkpy_check_error(pkpy_vm*);
+
+//will return true if at least free empty slots remain on the stack
+bool pkpy_check_stack(pkpy_vm*, int free);
+
+//returns the number of elements on the stack
+int pkpy_stack_size(pkpy_vm*);
+
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif

c_bindings/test.c

@@ -0,0 +1,300 @@
+#include "pocketpy_c.h"
+#include <stdio.h>
+#include <stdlib.h>
+
+//tests the c bindings for pocketpy
+
+void check_impl(pkpy_vm* vm, bool result, int lineno) {
+    if (!result) {
+        printf("ERROR: failed where it should have succeed at line %i\n", lineno);
+        char* message;
+        if (!pkpy_clear_error(vm, &message)) {
+            printf("clear error reported everything was fine\n");
+            exit(1);
+        }
+
+        printf("%s\n", message);
+        free(message);
+        exit(1);
+    }
+}
+
+void fail_impl(pkpy_vm* vm, bool result, int lineno) {
+    if (result) {
+        printf("ERROR: succeeded where it should have failed line %i\n", lineno);
+        exit(1);
+    } else {
+        char* message;
+        if (pkpy_clear_error(vm, &message)) {
+            printf("actually errored!\n");
+            free(message);
+            exit(1);
+        }
+    }
+}
+
+void error_impl(pkpy_vm* vm, bool result, int lineno) {
+    if (result) {
+        printf("ERROR: succeeded where it should have failed line %i\n", lineno);
+        exit(1);
+    } else {
+        char* message;
+        if (!pkpy_clear_error(vm, &message)) 
+            printf("clear error reported everything was fine\n");
+        else {
+            printf("successfully errored with this message: \n");
+            printf("%s\n", message);
+            free(message);
+        }
+    }
+}
+
+
+#define check(r) check_impl(vm, (r), __LINE__)
+#define fail(r) fail_impl(vm, (r), __LINE__)
+#define error(r) error_impl(vm, (r), __LINE__)
+
+int test_binding(pkpy_vm* vm) {
+    pkpy_push_int(vm, 12);
+    return 1;
+}
+
+int test_multiple_return(pkpy_vm* vm) {
+    pkpy_push_int(vm, 12);
+    pkpy_push_int(vm, 13);
+    return 2;
+}
+
+int test_return_none(pkpy_vm* vm) {
+    return 0;
+}
+
+int test_error_propagate(pkpy_vm* vm) {
+    pkpy_get_global(vm, "does not exist");
+    return 1;
+}
+
+
+pkpy_vm* vm;
+
+void cleanup(void) {
+    pkpy_vm_destroy(vm);
+}
+
+int main(int argc, char** argv) {
+
+    vm = pkpy_vm_create(true, true);
+    atexit(cleanup);
+
+    //test run
+    check(pkpy_vm_run(vm, "print('hello world!')"));
+
+    error(pkpy_get_global(vm, "nonexistatn"));
+
+    printf("\ntesting int methods\n");
+    int r_int;
+    check(pkpy_push_int(vm, 11));
+    check(pkpy_set_global(vm, "eleven"));
+    check(pkpy_vm_run(vm, "print(eleven)"));
+    check(pkpy_get_global(vm, "eleven"));
+    check(pkpy_is_int(vm, -1));
+    check(pkpy_to_int(vm, -1, &r_int));
+    printf("%i\n", r_int);
+    fail(pkpy_is_float(vm, -1));
+    fail(pkpy_is_bool(vm, -1));
+    fail(pkpy_is_string(vm, -1));
+    fail(pkpy_is_none(vm, -1));
+    fail(pkpy_is_voidp(vm, -1));
+
+    printf("\ntesting float methods\n");
+    double r_float;
+    check(pkpy_push_float(vm, 11.11));
+    check(pkpy_set_global(vm, "elevenf"));
+    check(pkpy_vm_run(vm, "print(elevenf)"));
+    check(pkpy_get_global(vm, "elevenf"));
+    check(pkpy_is_float(vm, -1));
+    check(pkpy_to_float(vm, -1, &r_float));
+    printf("%f\n", r_float);
+    fail(pkpy_is_int(vm, -1));
+    fail(pkpy_is_bool(vm, -1));
+    fail(pkpy_is_string(vm, -1));
+    fail(pkpy_is_none(vm, -1));
+    fail(pkpy_is_voidp(vm, -1));
+
+    printf("\ntesting bool methods\n");
+    bool r_bool;
+    check(pkpy_push_bool(vm, false));
+    check(pkpy_set_global(vm, "false_test"));
+    check(pkpy_vm_run(vm, "print(false_test)"));
+    check(pkpy_get_global(vm, "false_test"));
+    check(pkpy_is_bool(vm, -1));
+    check(pkpy_to_bool(vm, -1, &r_bool));
+    printf("%i\n", r_bool);
+    fail(pkpy_is_int(vm, -1));
+    fail(pkpy_is_float(vm, -1));
+    fail(pkpy_is_string(vm, -1));
+    fail(pkpy_is_none(vm, -1));
+    fail(pkpy_is_voidp(vm, -1));
+
+    printf("\ntesting string methods\n");
+    char* r_string;
+    check(pkpy_push_string(vm, "hello!"));
+    check(pkpy_set_global(vm, "hello1"));
+    check(pkpy_vm_run(vm, "print(hello1)"));
+    check(pkpy_push_stringn(vm, "hello!", 5));
+    check(pkpy_is_string(vm, -1));
+    check(pkpy_to_string(vm, -1, &r_string));
+    printf("%s\n", r_string);
+    free(r_string);
+    const char* r_stringn;
+    int r_size;
+    check(pkpy_to_stringn(vm, -1, &r_stringn, &r_size));
+    printf("%.*s\n", r_size, r_stringn);
+    fail(pkpy_is_int(vm, -1));
+    fail(pkpy_is_float(vm, -1));
+    fail(pkpy_is_bool(vm, -1));
+    fail(pkpy_is_none(vm, -1));
+    fail(pkpy_is_voidp(vm, -1));
+
+    printf("\ntesting None methods\n");
+    check(pkpy_push_none(vm));
+    check(pkpy_set_global(vm, "none"));
+    check(pkpy_vm_run(vm, "print(none)"));
+    check(pkpy_get_global(vm, "none"));
+    check(pkpy_is_none(vm, -1));
+    fail(pkpy_is_int(vm, -1));
+    fail(pkpy_is_float(vm, -1));
+    fail(pkpy_is_bool(vm, -1));
+    fail(pkpy_is_string(vm, -1));
+    fail(pkpy_is_voidp(vm, -1));
+
+    printf("\ntesting voidp methods\n");
+    void* vp = (void*) 123;
+    check(pkpy_push_voidp(vm, vp));
+    check(pkpy_set_global(vm, "vp"));
+    check(pkpy_vm_run(vm, "print(vp)"));
+    check(pkpy_get_global(vm, "vp"));
+    check(pkpy_is_voidp(vm, -1));
+    vp = NULL;
+    check(pkpy_to_voidp(vm, -1, &vp));
+    printf("%i\n", (int) (intptr_t) vp);
+    fail(pkpy_is_int(vm, -1));
+    fail(pkpy_is_float(vm, -1));
+    fail(pkpy_is_bool(vm, -1));
+    fail(pkpy_is_string(vm, -1));
+    fail(pkpy_is_none(vm, -1));
+
+
+    printf("\ntesting sizing and indexing\n");
+    int stack_size = pkpy_stack_size(vm);
+    printf("stack size %i\n", stack_size);
+    check(pkpy_check_stack(vm, 10));
+    check(pkpy_check_stack(vm, 26));
+    fail(pkpy_check_stack(vm, 27));
+    check(pkpy_is_int(vm, 0));
+    check(pkpy_is_float(vm, 1));
+    check(pkpy_is_bool(vm, 2));
+    check(pkpy_is_string(vm, 3));
+    check(pkpy_is_none(vm, 4));
+    check(pkpy_is_voidp(vm, 5));
+    check(pkpy_is_int(vm, -6));
+    check(pkpy_is_float(vm, -5));
+    check(pkpy_is_bool(vm, -4));
+    check(pkpy_is_string(vm, -3));
+    check(pkpy_is_none(vm, -2));
+    check(pkpy_is_voidp(vm, -1));
+    
+    printf("\ntesting error catching\n");
+    error(pkpy_vm_run(vm, "let's make sure syntax errors get caught"));
+    check(pkpy_stack_size(vm) == 0); //stack should be cleared after error is resolved
+
+    printf("\ntesting calls\n");
+
+    check(pkpy_vm_run(vm, "def x(x, y) : return x - y"));
+    check(pkpy_vm_run(vm, "def vararg_x(*x) : return sum(x)"));
+    check(pkpy_vm_run(vm, "def keyword_x(x=1, y=1) : return x+y"));
+    check(pkpy_vm_run(vm, "def retmany_x() : return 1, 2, 3"));
+
+    check(pkpy_get_global(vm, "x"));
+    check(pkpy_push_int(vm, 2));
+    check(pkpy_push_int(vm, 3));
+    check(pkpy_call(vm, 2));
+    check(pkpy_to_int(vm, -1, &r_int));
+    printf("x : %i\n", r_int);
+
+    check(pkpy_get_global(vm, "vararg_x"));
+    check(pkpy_push_int(vm, 1));
+    check(pkpy_push_int(vm, 2));
+    check(pkpy_push_int(vm, 3));
+    check(pkpy_push_int(vm, 4));
+    check(pkpy_push_int(vm, 5));
+    check(pkpy_push_int(vm, 6));
+    check(pkpy_call(vm, 6));
+    check(pkpy_to_int(vm, -1, &r_int));
+    printf("vararg_x : %i\n", r_int);
+
+    check(pkpy_get_global(vm, "keyword_x"));
+    check(pkpy_push_int(vm, 3));
+    check(pkpy_call(vm, 1));
+    check(pkpy_to_int(vm, -1, &r_int));
+    printf("keyword_x : %i\n", r_int);
+
+    check(pkpy_get_global(vm, "keyword_x"));
+    check(pkpy_call(vm, 0));
+    check(pkpy_to_int(vm, -1, &r_int));
+    printf("keyword_x : %i\n", r_int);
+
+    check(pkpy_stack_size(vm) == 4);
+
+    check(pkpy_get_global(vm, "retmany_x"));
+    check(pkpy_call(vm, 0));
+    check(pkpy_stack_size(vm) == 7);
+    check(pkpy_to_int(vm, -3, &r_int));
+    printf("retmany_x : %i\n", r_int);
+    check(pkpy_to_int(vm, -2, &r_int));
+    printf("retmany_x : %i\n", r_int);
+    check(pkpy_to_int(vm, -1, &r_int));
+    printf("retmany_x : %i\n", r_int);
+
+    check(pkpy_get_global(vm, "x"));
+    error(pkpy_call(vm, 0));
+
+    check(pkpy_vm_run(vm, "l = []"));
+
+    check(pkpy_get_global(vm, "l"));
+    check(pkpy_push_string(vm, "hello"));
+    check(pkpy_call_method(vm, "append", 1));
+    check(pkpy_vm_run(vm, "print(l)"));
+
+
+    printf("\ntesting pushing functions\n");
+
+    check(pkpy_push_function(vm, test_binding));
+    check(pkpy_set_global(vm, "test_binding"));
+    check(pkpy_vm_run(vm, "print(test_binding())"));
+
+    check(pkpy_push_function(vm, test_multiple_return));
+    check(pkpy_set_global(vm, "test_multiple_return"));
+
+    //uncomment if _exec changes
+    //check(pkpy_vm_run(vm, "test_multiple_return()"));
+    //check(pkpy_stack_size(vm) == 2);
+
+    check(pkpy_push_function(vm, test_error_propagate));
+    check(pkpy_set_global(vm, "test_error_propagate"));
+    error(pkpy_vm_run(vm, "test_error_propagate()"));
+
+    check(pkpy_get_global(vm, "test_multiple_return"));
+    check(pkpy_call(vm, 0));
+    check(pkpy_stack_size(vm) == 2);
+
+    check(pkpy_pop(vm, 2));
+    check(pkpy_stack_size(vm) == 0);
+
+    check(pkpy_check_global(vm, "test_error_propagate"));
+    fail(pkpy_check_global(vm, "nonexistant"));
+    pkpy_vm_run(vm, "test_error_propagate()");
+    check(pkpy_check_error(vm));
+
+    return 0;
+}

c_bindings/test_answers.txt

@@ -0,0 +1,51 @@
+hello world!
+successfully errored with this message: 
+NameError: name 'could not find requested global' is not defined
+
+testing int methods
+11
+11
+
+testing float methods
+11.11
+11.110000
+
+testing bool methods
+False
+0
+
+testing string methods
+hello!
+hello
+hello
+
+testing None methods
+None
+
+testing voidp methods
+<void* at 0x7b>
+123
+
+testing sizing and indexing
+stack size 6
+
+testing error catching
+successfully errored with this message: 
+  File "<c-bound>", line 1
+    let's make sure syntax errors get caught
+SyntaxError: EOL while scanning string literal
+
+testing calls
+x : -1
+vararg_x : 21
+keyword_x : 4
+keyword_x : 2
+retmany_x : 1
+retmany_x : 2
+retmany_x : 3
+successfully errored with this message: 
+TypeError: expected 2 positional arguments, but got 0 (x)
+['hello']
+
+testing pushing functions
+12

run_c_binding_test.sh

@@ -0,0 +1,26 @@
+python3 preprocess.py
+
+if [ ! -f "pocketpy_c.o" ] 
+then
+    echo "compiling c++ lib"
+    clang++ -c -o pocketpy_c.o c_bindings/pocketpy_c.cpp -Wfatal-errors --std=c++17 -O2 -Wall -Wno-sign-compare -Wno-unused-variable -fno-rtti -stdlib=libc++ -I src/ -fsanitize=address -g
+else
+    echo "DETECTED PREVIOUS COMPILATION USING IT"
+fi
+
+echo "compiling c executable" 
+clang -c -o test.o c_bindings/test.c -Wfatal-errors -O2 -Wall -Wno-sign-compare -Wno-unused-variable -I src/ -fsanitize=address -g
+echo "linking"
+clang++ -o c_binding_test test.o pocketpy_c.o -stdlib=libc++ -fsanitize=address -g
+echo "running, leaksanitizer is finding a false postive leak in the CVM constructor"
+echo "ignore that but pay attention to anything else"
+./c_binding_test > binding_test_scratch
+echo "checking results (they should be identical)"
+diff -q -s  binding_test_scratch c_bindings/test_answers.txt
+
+echo "cleaning up"
+rm pocketpy_c.o
+rm test.o
+rm binding_test_scratch
+rm c_binding_test
+