Add warning for unused arrays

Author: boriel

src/api/optimize.py

@@ -284,6 +284,21 @@ def visit_LET(self, node):
         else:
             yield (yield self.generic_visit(node))
 
+    def visit_LETARRAY(self, node):
+        lvalue = node.args[0].entry
+        if self.O_LEVEL > 1 and not lvalue.accessed:
+            warning_not_used(lvalue.lineno, lvalue.name, fname=lvalue.filename)
+            block = symbols.BLOCK(*[
+                symbols.CALL(x.entry, x.args, x.lineno, lvalue.filename) for x in self.filter_inorder(
+                    node.children[1],
+                    lambda x: isinstance(x, symbols.FUNCCALL),
+                    lambda x: not isinstance(x, symbols.FUNCTION)
+                )
+            ])
+            yield block
+        else:
+            yield (yield self.generic_visit(node))
+
     def visit_LETSUBSTR(self, node):
         if self.O_LEVEL > 1 and not node.children[0].accessed:
             errmsg.warning_not_used(node.children[0].lineno, node.children[0].name)

tests/functional/opt2_global_array2.asm

@@ -0,0 +1,64 @@
+	org 32768
+__START_PROGRAM:
+	di
+	push ix
+	push iy
+	exx
+	push hl
+	exx
+	ld hl, 0
+	add hl, sp
+	ld (__CALL_BACK__), hl
+	ei
+	jp __MAIN_PROGRAM__
+__CALL_BACK__:
+	DEFW 0
+ZXBASIC_USER_DATA:
+	; Defines USER DATA Length in bytes
+ZXBASIC_USER_DATA_LEN EQU ZXBASIC_USER_DATA_END - ZXBASIC_USER_DATA
+	.__LABEL__.ZXBASIC_USER_DATA_LEN EQU ZXBASIC_USER_DATA_LEN
+	.__LABEL__.ZXBASIC_USER_DATA EQU ZXBASIC_USER_DATA
+_myArray2:
+	DEFW __LABEL0
+_myArray2.__DATA__.__PTR__:
+	DEFW _myArray2.__DATA__
+_myArray2.__DATA__:
+	DEFB 00h
+	DEFB 00h
+	DEFB 00h
+	DEFB 00h
+	DEFB 00h
+	DEFB 00h
+__LABEL0:
+	DEFW 0000h
+	DEFB 01h
+ZXBASIC_USER_DATA_END:
+__MAIN_PROGRAM__:
+	call _Init
+	ld hl, 0
+	ld b, h
+	ld c, l
+__END_PROGRAM:
+	di
+	ld hl, (__CALL_BACK__)
+	ld sp, hl
+	exx
+	pop hl
+	pop iy
+	pop ix
+	exx
+	ei
+	ret
+_Init:
+	push ix
+	ld ix, 0
+	add ix, sp
+	ld hl, 0
+	push hl
+	inc sp
+_Init__leave:
+	ld sp, ix
+	pop ix
+	ret
+	;; --- end of user code ---
+	END

tests/functional/opt2_global_array2.bas

@@ -0,0 +1,10 @@
+DIM myArray(1 to 6) as ubyte
+DIM myArray2(1 to 6) as Ubyte
+
+
+SUB Init()
+    DIM i as ubyte
+    myArray(i) = 2 * myArray2(i)
+END SUB
+
+Init()

tests/functional/test_errmsg.txt

@@ -200,6 +200,8 @@ dim_at_init_err.bas:4: error: Syntax Error. Unexpected token 'AT' <AT>
 bad_pragma.bas:2: warning: Ignoring unknown pragma 'BAD_PRAGMA'
 bad_pragma.bas:4: warning: Ignoring unknown pragma 'BAD_PRAGMA'
 bad_pragma.bas:6: warning: Ignoring unknown pragma 'BAD_PRAGMA'
+>>> process_file('opt2_global_array2.bas')
+opt2_global_array2.bas:1: warning: Variable 'myArray' is never used
 
 # Test warning silencing
 >>> process_file('mcleod3.bas', ['-S', '-q', '-O --expect-warnings=2'])