Merge pull request #443 from boriel/bugfix/byref_str

Bugfix/byref str

Author: boriel

src/api/check.py

@@ -420,7 +420,7 @@ def is_block_accessed(block):
 def is_temporary_value(node) -> bool:
     """ Returns if the AST node value is a variable or a temporary copy in the heap.
     """
-    return node.token not in ('STRING', 'VAR') and node.t[0] not in ('_', '#')
+    return node.token not in ('PARAMDECL', 'STRING', 'VAR') and node.t[0] not in ('_', '#')
 
 
 def common_type(a, b):

src/arch/zx48k/backend/__pload.py

@@ -51,12 +51,12 @@ def _paddr(ins):
 
 def _pload(offset, size):
     """ Generic parameter loading.
-    Emits output code for setting IX at the right location.
+    Emits output code for loading at (IX + offset).
     size = Number of bytes to load:
-        1 => 8 bit value
-        2 => 16 bit value / string
-        4 => 32 bit value / f16 value
-        5 => 40 bit value
+        1 => 8 bit value   # A register
+        2 => 16 bit value / string  # HL register
+        4 => 32 bit value / f16 value  # DE (HI), HL (LO) register
+        5 => 40 bit value / float value  # A (exp) BC (HI), DE (LO) mantissa (as ZX Spectrum ROM)
     """
     output = []
 

src/arch/zx48k/translator.py

@@ -323,6 +323,9 @@ def visit_LETARRAY(self, node):
                 raise InternalError("Invalid scope {} for variable '{}'".format(scope, arr.entry.name))
 
     def visit_LETSUBSTR(self, node):
+        """ LET X$(a TO b) = Y$
+        """
+        # load Y$
         yield node.children[3]
 
         if check.is_temporary_value(node.children[3]):
@@ -332,11 +335,30 @@ def visit_LETSUBSTR(self, node):
             self.ic_param(gl.PTR_TYPE, node.children[3].t)
             self.ic_param(TYPE.ubyte, 0)
 
+        # Load a
         yield node.children[1]
         self.ic_param(gl.PTR_TYPE, node.children[1].t)
+        # Load b
         yield node.children[2]
         self.ic_param(gl.PTR_TYPE, node.children[2].t)
-        self.ic_fparam(gl.PTR_TYPE, node.children[0].t)
+        # Load x$
+        str_var = node.children[0]
+        scope = str_var.scope
+
+        if scope == SCOPE.global_:
+            self.ic_fparam(gl.PTR_TYPE, str_var.t)
+        elif scope == SCOPE.local:
+            self.ic_pload(gl.PTR_TYPE, str_var.t, -str_var.offset)
+            self.ic_fparam(gl.PTR_TYPE, f"{str_var.t}")
+        elif scope == SCOPE.parameter:
+            self.ic_pload(gl.PTR_TYPE, str_var.t, str_var.offset)
+            if str_var.byref:
+                self.ic_fparam(gl.PTR_TYPE, f"*{str_var.t}")
+            else:
+                self.ic_fparam(gl.PTR_TYPE, f"{str_var.t}")
+        else:
+            raise InternalError("Invalid scope {} for variable '{}'".format(scope, node.name))
+
         self.ic_call('__LETSUBSTR', 0)
         backend.REQUIRES.add('letsubstr.asm')
 

tests/api/test_check.py

@@ -0,0 +1,28 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+import unittest
+
+from src.api import check
+from src import symbols
+
+
+class TestCheck(unittest.TestCase):
+    """ Tests api.check
+    """
+    def test_is_temporary_value_const_string(self):
+        node = symbols.STRING("Hello world", 1)
+        self.assertFalse(check.is_temporary_value(node))
+
+    def test_is_temporary_value_var(self):
+        node = symbols.VAR("a", 1)
+        self.assertFalse(check.is_temporary_value(node))
+
+    def test_is_temporary_value_param(self):
+        node = symbols.PARAMDECL("a", 1)
+        self.assertFalse(check.is_temporary_value(node))
+
+    def test_is_temporary_value_expr(self):
+        child = symbols.VAR("a", 1)
+        node = symbols.BINARY('PLUS', child, child, 1)
+        self.assertTrue(check.is_temporary_value(node))