Implement the basis of a function call

1 files changed, 91 insertions, 45 deletions

diff --git a/src/program.c b/src/program.c
index efb9407..88f94a4 100644
--- a/src/program.c
+++ b/src/program.c
@@ -38,6 +38,7 @@ void tsl_program_deinit(TslProgram *self) {
         ++bytecode_writer;
     }
     tsl_buffer_deinit(&self->function_bytecode_list);
+    GC_deinit(); /* TODO: Remove this */
 }
 
 static int program_output_temp(char *data, int size, void *userdata) {
@@ -70,7 +71,8 @@ static TslProgramResult tsl_string_ref_get_item_at_index(const TslStringView *se
     return TSL_PROGRAM_RESULT_OK;
 }
 
-static TslProgramResult tsl_value_create_from_stack_value(TslProgram *self, TslStackValue *src, TslValue *dst) {
+static TslProgramResult tsl_value_create_from_stack_value(TslProgram *self, TslValue *dst) {
+    TslStackValue *src = tsl_buffer_pop(&self->stack_values, sizeof(TslStackValue));
     tsl_value_clear(dst);
     switch(src->type) {
         case TSL_STACK_VALUE_TYPE_NUMBER: {
@@ -136,10 +138,8 @@ static TslProgramResult tsl_value_create_from_stack_value(TslProgram *self, TslS
             break;
         }
         case TSL_STACK_VALUE_TYPE_LIST: {
-            TslStackValue *items_begin = tsl_buffer_pop(&self->stack_values, sizeof(TslStackValue) * src->data.integer);
-            TslStackValue *items_end = items_begin + src->data.integer;
-            TslStackValue *item = items_end - 1;
             TslValue *list_item;
+            int i = src->data.integer - 1;
             dst->data.list = GC_MALLOC(sizeof(TslList));
             return_if_error(dst->data.list);
 
@@ -148,44 +148,40 @@ static TslProgramResult tsl_value_create_from_stack_value(TslProgram *self, TslS
             dst->data.list->size = sizeof(TslValue) * src->data.integer;
             list_item = tsl_list_end(dst->data.list) - sizeof(TslValue);
 
-            while(item != items_begin - 1) {
-                return_if_error(tsl_value_create_from_stack_value(self, item, list_item));
+            while(i >= 0) {
+                return_if_error(tsl_value_create_from_stack_value(self, list_item));
                 --list_item;
-                --item;
+                --i;
             }
 
             dst->type = TSL_TYPE_LIST;
             break;
         }
         case TSL_STACK_VALUE_TYPE_MAP: {
-            TslStackValue *items_begin = tsl_buffer_pop(&self->stack_values, sizeof(TslStackValue) * src->data.integer);
-            TslStackValue *items_end = items_begin + src->data.integer;
-            TslStackValue *item = items_end - 1;
+            int i = src->data.integer - 1;
 
             dst->data.map = GC_MALLOC(sizeof(TslHashMap));
             return_if_error(dst->data.map);
             tsl_hash_map_init(dst->data.map);
 
             assert(src->data.integer % 2 == 0);
-            while(item != items_begin - 1) {
+            while(i >= 0) {
                 TslValue map_key;
                 TslValue map_value;
-                return_if_error(tsl_value_create_from_stack_value(self, item, &map_value));
-                return_if_error(tsl_value_create_from_stack_value(self, item - 1, &map_key));
+                return_if_error(tsl_value_create_from_stack_value(self, &map_value));
+                return_if_error(tsl_value_create_from_stack_value(self, &map_key));
                 return_if_error(tsl_hash_map_insert(dst->data.map, &map_key, &map_value));
-                item -= 2;
+                i -= 2;
             }
 
             dst->type = TSL_TYPE_MAP;
             break;
         }
         case TSL_STACK_VALUE_TYPE_INDEX: {
-            TslStackValue *args = tsl_buffer_pop(&self->stack_values, sizeof(TslStackValue) * 2);
             TslValue var;
             TslValue key;
-
-            return_if_error(tsl_value_create_from_stack_value(self, args + 1, &key));
-            return_if_error(tsl_value_create_from_stack_value(self, args, &var));
+            return_if_error(tsl_value_create_from_stack_value(self, &key));
+            return_if_error(tsl_value_create_from_stack_value(self, &var));
 
             if(var.type == TSL_TYPE_LIST) {
                 TslValue *list_item;
@@ -236,13 +232,12 @@ static TslProgramResult tsl_value_create_from_stack_value(TslProgram *self, TslS
 }
 
 static TslProgramResult tsl_program_perform_operation(TslProgram *self, TslNumber(*operation_func)(TslNumber lhs, TslNumber rhs)) {
-    TslStackValue *args = tsl_buffer_pop(&self->stack_values, sizeof(TslStackValue) * 2);
     TslValue lhs_value;
     TslValue rhs_value;
     TslStackValue stack_value;
 
-    return_if_error(tsl_value_create_from_stack_value(self, args + 1, &rhs_value));
-    return_if_error(tsl_value_create_from_stack_value(self, args, &lhs_value));
+    return_if_error(tsl_value_create_from_stack_value(self, &rhs_value));
+    return_if_error(tsl_value_create_from_stack_value(self, &lhs_value));
 
     if(lhs_value.type != TSL_TYPE_NUMBER) {
         fprintf(stderr, "Error: Unable to perform operation '+' between a TODO and a TODO\n");
@@ -270,21 +265,12 @@ static TslNumber number_operation_div(TslNumber lhs, TslNumber rhs) {
     return lhs / rhs;
 }
 
-TslProgramResult tsl_program_run(TslProgram *self) {
+static TslProgramResult tsl_program_run_function(TslProgram *self, int function_index) {
     TslProgramResult result = TSL_PROGRAM_RESULT_OK;
-    TslBytecode *file_scope_bytecode = tsl_buffer_begin(&self->function_bytecode_list);
-    char *instruction = tsl_buffer_begin(&file_scope_bytecode->buffer);
-    char *instruction_end = tsl_buffer_end(&file_scope_bytecode->buffer);
-
-    self->variables = GC_MALLOC_UNCOLLECTABLE(sizeof(TslHashMap));
-    if(!self->variables) {
-        fprintf(stderr, "Error: Failed to allocate root object\n");
-        return TSL_PROGRAM_RESULT_ERR;
-    }
-    tsl_hash_map_init(self->variables);
-    tsl_buffer_init(&self->stack_values);
-
-    printf("###########################\n");
+    TslBytecode *function_bytecode = (TslBytecode*)tsl_buffer_begin(&self->function_bytecode_list) + function_index;
+    char *instruction = tsl_buffer_begin(&function_bytecode->buffer);
+    char *instruction_end = tsl_buffer_end(&function_bytecode->buffer);
+    size_t prev_stack_value_size = self->stack_values.size;
 
     /* TODO: Verify if these don't cause unaligned memory access on non-x86 platforms */
     while(instruction != instruction_end) {
@@ -348,7 +334,6 @@ TslProgramResult tsl_program_run(TslProgram *self) {
                 break;
             }
             case TSL_OPCODE_SETV: {
-                TslStackValue *stack_value = tsl_buffer_pop(&self->stack_values, sizeof(TslStackValue));
                 TslValue map_key;
                 TslValue *map_value;
                 map_key.type = TSL_TYPE_STRING_REF;
@@ -357,7 +342,7 @@ TslProgramResult tsl_program_run(TslProgram *self) {
                 map_value = tsl_hash_map_get_or_create(self->variables, &map_key);
                 cleanup_if_error(map_value);
 
-                cleanup_if_error(tsl_value_create_from_stack_value(self, stack_value, map_value));
+                cleanup_if_error(tsl_value_create_from_stack_value(self, map_value));
                 /*printf("setv \"%.*s\"\n", (int)instruction_type4->value.size, instruction_type4->value.data);*/
                 instruction += sizeof(TslInstructionType4);
                 break;
@@ -389,22 +374,56 @@ TslProgramResult tsl_program_run(TslProgram *self) {
                 break;
             }
             case TSL_OPCODE_CALLF: {
-                /* + 1, since the first arg is the function index and the other args are the args for the function */
-                TslStackValue *args = tsl_buffer_pop(&self->stack_values, sizeof(TslStackValue) * (1 + instruction_type1->value));
-                (void)args;
+                size_t args_size = 1 + instruction_type1->value;
+                TslStackValue *args = (TslStackValue*)tsl_buffer_end(&self->stack_values) - args_size;
+                assert(self->stack_values.size >= args_size);
+
+                {
+                    /* Resolved values pushed to stack and replace them in the stack */
+                    size_t prev_stack_size = self->stack_values.size;
+                    TslStackValue *arg = (TslStackValue*)tsl_buffer_end(&self->stack_values) - 1;
+                    TslStackValue *args_begin = args - 1;
+                    while(arg != args_begin) {
+                        TslValue new_value;
+                        cleanup_if_error(tsl_value_create_from_stack_value(self, &new_value));
+                        arg->data.variable = new_value;
+                        arg->type = TSL_STACK_VALUE_TYPE_VARIABLE;
+                        --arg;
+                    }
+                    /*
+                        Reset the stack size here because @tsl_value_create_from_stack_value which is called above pops the stack (without reallocation).
+                        TODO: Modify @tsl_value_create_from_stack_value to not pop stack and instead operate with stack pointer.
+                    */
+                    self->stack_values.size = prev_stack_size;
+                }
+
+                assert(args[0].type == TSL_STACK_VALUE_TYPE_VARIABLE);
+                if(args[0].data.variable.type != TSL_TYPE_FUNCTION) {
+                    fprintf(stderr, "Error: Unable to call a non-function type\n");
+                    goto cleanup;
+                }
+
+                cleanup_if_error(tsl_program_run_function(self, args[0].data.variable.data.function));
+                tsl_buffer_pop(&self->stack_values, sizeof(TslStackValue) * args_size);
+
                 /* TODO: Implement this */
+                {
+                    /* TODO: This is only temporary. This should be replaced with push the result of the function call onto the stack */
+                    TslStackValue stack_value;
+                    stack_value.type = TSL_STACK_VALUE_TYPE_NULL;
+                    cleanup_if_error(tsl_buffer_append(&self->stack_values, &stack_value, sizeof(stack_value)));
+                }
                 /*printf("callf %d\n", instruction_type1->value);*/
                 instruction += sizeof(TslInstructionType1);
                 break;
             }
             case TSL_OPCODE_ADD: {
-                TslStackValue *args = tsl_buffer_pop(&self->stack_values, sizeof(TslStackValue) * 2);
                 TslValue lhs_value;
                 TslValue rhs_value;
                 TslStackValue stack_value;
 
-                cleanup_if_error(tsl_value_create_from_stack_value(self, args + 1, &rhs_value));
-                cleanup_if_error(tsl_value_create_from_stack_value(self, args, &lhs_value));
+                cleanup_if_error(tsl_value_create_from_stack_value(self, &rhs_value));
+                cleanup_if_error(tsl_value_create_from_stack_value(self, &lhs_value));
                 cleanup_if_error(tsl_value_add(&lhs_value, &rhs_value, &stack_value.data.variable));
 
                 stack_value.type = TSL_STACK_VALUE_TYPE_VARIABLE;
@@ -479,6 +498,13 @@ TslProgramResult tsl_program_run(TslProgram *self) {
                     }
                     command_args[arg_index] = NULL;
                 }
+
+                {
+                    /* TODO: This is only temporary. This should be replaced with push the result of the command onto the stack */
+                    TslStackValue stack_value;
+                    stack_value.type = TSL_STACK_VALUE_TYPE_NULL;
+                    cleanup_if_error(tsl_buffer_append(&self->stack_values, &stack_value, sizeof(stack_value)));
+                }
                 
                 /*printf("callc %d\n", instruction_type1->value);*/
                 instruction += sizeof(TslInstructionType1);
@@ -489,9 +515,29 @@ TslProgramResult tsl_program_run(TslProgram *self) {
 
     cleanup:
     /*
-        If self->stack_values.size is more than 0, then there are operations (for example CALLF) that pushes a value to the stack but the returned value
-        is not assigned to any variable. At the end of functions, these stack values are cleaned up even if they are not handled.
+        This a bug in the compiler. The compiler pop'ed more values that pushed to the stack.
+        It's fine if there were values that were pushed to the stack but not pop'ed. This happens for example if there is a function call
+        and the result is not assigned to a variable (in other words, the result is ignored).
+        This will automatically be cleaned up here and in loops it will be cleaned up at the end of the loop scope.
     */
+    assert(self->stack_values.size >= prev_stack_value_size);
+    self->stack_values.size = prev_stack_value_size;
+    return result;
+}
+
+TslProgramResult tsl_program_run(TslProgram *self) {
+    TslProgramResult result = TSL_PROGRAM_RESULT_OK;
+
+    self->variables = GC_MALLOC_UNCOLLECTABLE(sizeof(TslHashMap));
+    if(!self->variables) {
+        fprintf(stderr, "Error: Failed to allocate root object\n");
+        return TSL_PROGRAM_RESULT_ERR;
+    }
+    tsl_hash_map_init(self->variables);
+    tsl_buffer_init(&self->stack_values);
+
+    printf("###########################\n");
+    result = tsl_program_run_function(self, 0);
 
     tsl_buffer_deinit(&self->stack_values);
     GC_FREE(self->variables); /* Free the root object, resulting in all objects in the program being free'd */