From 738fe6924dc27784ded377c83f7b3888db37221e Mon Sep 17 00:00:00 2001
From: FellippeHeitor <fellippeheitor@gmail.com>
Date: Mon, 31 Dec 2018 21:00:16 -0200
Subject: [PATCH] Improved detection of unused variables.

---
 source/ide/ide_methods.bas | 14 ++++++++------
 source/qb64.bas            | 29 +++++++++++++++--------------
 2 files changed, 23 insertions(+), 20 deletions(-)

diff --git a/source/ide/ide_methods.bas b/source/ide/ide_methods.bas
index c74fe6dbe..724b6f40d 100644
--- a/source/ide/ide_methods.bas
+++ b/source/ide/ide_methods.bas
@@ -1298,14 +1298,16 @@ FUNCTION ide2 (ignore)
                 IF mX = 1 AND SCREEN(mY, mX) = 26 THEN
                     unusedVariableWarningX = mX
                     unusedVariableWarningY = mY
-                    findItem = INSTR(usedVariableList$, CHR$(1) + MKL$((mY - 3) + idesy) + CHR$(2))
-                    unusedVariableName$ = MID$(usedVariableList$, findItem + 6, INSTR(findItem, usedVariableList$, CHR$(10)) - findItem - 6)
-                    findItem = INSTR(unusedVariableName$, CHR$(3))
+                    findItem = INSTR(usedVariableList$, CHR$(1) + MKL$((mY - 3) + idesy) + CHR$(2) + CHR$(3))
+                    unusedVariableName$ = MID$(usedVariableList$, findItem + 6, INSTR(findItem, usedVariableList$, CHR$(5)) - findItem - 6)
+                    findItem = MID$(usedVariableList$, findItem + 6 + LEN(unusedVariableName$) INSTR(findItem, usedVariableList$, CHR$(3))
                     unusedVariableName$ = LEFT$(unusedVariableName$, findItem - 1) + " (" + MID$(unusedVariableName$, findItem + 1) + ") "
                     unusedVariableWarning$ = LEFT$(" Variable hasn't yet been used: " + unusedVariableName$, idewx - 2)
                     LOCATE mY, mX
                     COLOR 0, 3
-                    PRINT CHR$(26) + unusedVariableWarning$
+                    PRINT CHR$(26) + LEFT$(unusedVariableWarning$, 32);
+                    COLOR 15
+                    PRINT MID$(unusedVariableWarning$, 33);
 
                     'shadow
                     COLOR 2, 0
@@ -8541,7 +8543,7 @@ SUB ideshowtext
         END IF
 
         IF l <= iden THEN
-            IF idecompiling = 0 AND INSTR(usedVariableList$, CHR$(1) + MKL$(l) + CHR$(2)) > 0 THEN
+            IF idecompiling = 0 AND INSTR(usedVariableList$, CHR$(1) + MKL$(l) + CHR$(2) + CHR$(4)) > 0 THEN
                 LOCATE y + 3, 1
                 prevBG% = _BACKGROUNDCOLOR
                 COLOR 13, 1
@@ -8929,7 +8931,7 @@ SUB ideshowtext
     FOR b = 1 TO IdeBmkN
         y = IdeBmk(b).y
         IF y >= idesy AND y <= idesy + (idewy - 9) THEN
-            IF INSTR(usedVariableList$, CHR$(1) + MKL$(y) + CHR$(2)) = 0 THEN
+            IF INSTR(usedVariableList$, CHR$(1) + MKL$(y) + CHR$(2) + CHR$(4)) = 0 THEN
                 LOCATE 3 + y - idesy, 1: PRINT CHR$(197);
             END IF
         END IF
diff --git a/source/qb64.bas b/source/qb64.bas
index fd8277f30..8c21c2cf3 100644
--- a/source/qb64.bas
+++ b/source/qb64.bas
@@ -11631,7 +11631,10 @@ OPEN compilelog$ FOR OUTPUT AS #1: CLOSE #1 'Clear log
 
 
 
-
+OPEN "unusedVariableList.txt" FOR OUTPUT AS #1: CLOSE #1
+OPEN "unusedVariableList.txt" FOR BINARY AS #1
+PUT #1, 1, usedVariableList$
+CLOSE #1
 
 
 
@@ -24849,22 +24852,20 @@ SUB manageVariableList (name$, __cname$, action AS _BYTE)
 
     SELECT CASE action
         CASE 0 'add
-            usedVariableList$ = usedVariableList$ + CHR$(1) + MKL$(linenumber) + CHR$(2)
-            usedVariableList$ = usedVariableList$ + name$ + CHR$(3) + cname$ + CHR$(10)
-            totalUnusedVariables = totalUnusedVariables + 1
-            'usedVariableList$ = usedVariableList$ + "Adding " + cname$ + " at line" + STR$(linenumber) + CHR$(10)
+            s$ = CHR$(4) + MKI$(LEN(cname$)) + cname$ + CHR$(5)
+            IF INSTR(usedVariableList$, s$) = 0 THEN
+                ASC(s$, 1) = 3
+                usedVariableList$ = usedVariableList$ + CHR$(1) + MKL$(linenumber) + CHR$(2)
+                usedVariableList$ = usedVariableList$ + s$ + name$ + CHR$(10)
+                totalUnusedVariables = totalUnusedVariables + 1
+                'usedVariableList$ = usedVariableList$ + "Adding " + cname$ + " at line" + STR$(linenumber) + CHR$(10)
+            END IF
         CASE ELSE 'find and remove
-            s$ = CHR$(3) + cname$ + CHR$(10)
+            s$ = CHR$(3) + cname$ + CHR$(5)
             findItem = INSTR(usedVariableList$, s$)
             IF findItem THEN
-                FOR i = findItem TO 1 STEP -1
-                    IF ASC(usedVariableList$, i) = 1 THEN
-                        findItem = INSTR(findItem, usedVariableList$, CHR$(10))
-                        usedVariableList$ = LEFT$(usedVariableList$, i - 1) + MID$(usedVariableList$, findItem + 1)
-                        totalUnusedVariables = totalUnusedVariables - 1
-                        EXIT FOR
-                    END IF
-                NEXT
+                ASC(usedVariableList$, findItem) = 4
+                totalUnusedVariables = totalUnusedVariables - 1
             END IF
             'usedVariableList$ = usedVariableList$ + STR$(action) + " Searching " + cname$ + " at line" + STR$(linenumber) + CHR$(10)
     END SELECT