From 47685d82b07b7f42d3edfc01a83c1f2107712d17 Mon Sep 17 00:00:00 2001
From: FellippeHeitor <fellippeheitor@gmail.com>
Date: Wed, 21 Nov 2018 00:47:46 -0200
Subject: [PATCH] Implements unused variables indicator

An arrow to the left of the line where a variable was defined will be shown after compilation to indicate that variable hasn't been used throughout the program.
---
 source/ide/ide_methods.bas | 57 ++++++++++++++++++++++++-
 source/qb64.bas            | 85 +++++++++++++++++++++++++++++++++++++-
 2 files changed, 138 insertions(+), 4 deletions(-)

diff --git a/source/ide/ide_methods.bas b/source/ide/ide_methods.bas
index 6fe6ddec5..c74fe6dbe 100644
--- a/source/ide/ide_methods.bas
+++ b/source/ide/ide_methods.bas
@@ -1255,8 +1255,17 @@ FUNCTION ide2 (ignore)
                     QuickNavHover = -1
                     LOCATE 2, 4
                     COLOR 15, 3
-                    PRINT " " + CHR$(17) + " back to line "; str2$(QuickNavHistory(QuickNavTotal)); " ";
+                    popup$ = " " + CHR$(17) + " back to line " + str2$(QuickNavHistory(QuickNavTotal)) + " "
+                    PRINT popup$;
+
+                    'shadow
+                    COLOR 2, 0
+                    FOR x2 = 6 TO 4 + LEN(popup$)
+                        LOCATE 3, x2: PRINT CHR$(SCREEN(3, x2));
+                    NEXT
+
                     PCOPY 3, 0
+
                     IF mB THEN
                         ideselect = 0
                         idecy = QuickNavHistory(QuickNavTotal)
@@ -1269,6 +1278,7 @@ FUNCTION ide2 (ignore)
                         QuickNavHover = 0
                         GOSUB UpdateTitleOfMainWindow
                         GOSUB DrawQuickNav
+                        ideshowtext
                         PCOPY 3, 0
                     END IF
                 END IF
@@ -1277,11 +1287,44 @@ FUNCTION ide2 (ignore)
                     QuickNavHover = 0
                     GOSUB UpdateTitleOfMainWindow
                     GOSUB DrawQuickNav
+                    ideshowtext
                     PCOPY 3, 0
                 END IF
             END IF
         END IF
 
+        IF mX > 0 AND mY > 0 THEN
+            IF showingUnusedVariableWarning = 0 THEN
+                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))
+                    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$(26) + unusedVariableWarning$
+
+                    'shadow
+                    COLOR 2, 0
+                    FOR x2 = mX + 2 TO mX + LEN(unusedVariableWarning$) + 1
+                        LOCATE mY + 1, x2: PRINT CHR$(SCREEN(mY + 1, x2));
+                    NEXT
+
+                    PCOPY 3, 0
+                    showingUnusedVariableWarning = -1
+                END IF
+            ELSE
+                IF unusedVariableWarningX <> mX OR unusedVariableWarningY <> mY THEN
+                    ideshowtext
+                    PCOPY 3, 0
+                    showingUnusedVariableWarning = 0
+                END IF
+            END IF
+        END IF
+
         IF _WINDOWHASFOCUS THEN
             LOCATE , , 1
             _PALETTECOLOR 5, IDEBracketHighlightColor, 0
@@ -8498,6 +8541,14 @@ SUB ideshowtext
         END IF
 
         IF l <= iden THEN
+            IF idecompiling = 0 AND INSTR(usedVariableList$, CHR$(1) + MKL$(l) + CHR$(2)) > 0 THEN
+                LOCATE y + 3, 1
+                prevBG% = _BACKGROUNDCOLOR
+                COLOR 13, 1
+                PRINT CHR$(26); 'indicate there's an unused variable defined on this line
+                COLOR , prevBG%
+            END IF
+
             a$ = idegetline(l)
             link_idecx = 0
             rgb_idecx = 0
@@ -8878,7 +8929,9 @@ SUB ideshowtext
     FOR b = 1 TO IdeBmkN
         y = IdeBmk(b).y
         IF y >= idesy AND y <= idesy + (idewy - 9) THEN
-            LOCATE 3 + y - idesy, 1: PRINT CHR$(197);
+            IF INSTR(usedVariableList$, CHR$(1) + MKL$(y) + CHR$(2)) = 0 THEN
+                LOCATE 3 + y - idesy, 1: PRINT CHR$(197);
+            END IF
         END IF
     NEXT
 
diff --git a/source/qb64.bas b/source/qb64.bas
index 353a4276e..fd8277f30 100644
--- a/source/qb64.bas
+++ b/source/qb64.bas
@@ -111,6 +111,8 @@ IF OS_BITS = 32 THEN _TITLE "QB64 x32" ELSE _TITLE "QB64 x64"
 DIM SHARED ConsoleMode, No_C_Compile_Mode, Cloud, NoIDEMode
 DIM SHARED CMDLineFile AS STRING
 
+DIM SHARED totalUnusedVariables AS LONG, usedVariableList$, bypassNextVariable AS _BYTE
+DIM SHARED warning$(100), totalWarnings AS LONG
 DIM SHARED ExeIconSet AS LONG
 DIM SHARED VersionInfoSet AS _BYTE
 
@@ -1429,7 +1431,9 @@ subfunc = ""
 SelectCaseCounter = 0
 ExecCounter = 0
 UserDefineCount = 6
-
+usedVariableList$ = ""
+totalUnusedVariables = 0
+totalWarnings = 0
 
 ''create a type for storing memory blocks
 ''UDT
@@ -7280,6 +7284,7 @@ DO
             'create variable
             IF LEN(s$) THEN typ$ = s$ ELSE typ$ = t$
             IF optionexplicit THEN a$ = "Variable '" + n$ + "' (" + symbol2fulltypename$(typ$) + ") not defined": GOTO errmes
+            bypassNextVariable = -1
             retval = dim2(n$, typ$, method, "")
             IF Error_Happened THEN GOTO errmes
             'note: variable created!
@@ -14725,6 +14730,11 @@ FUNCTION dim2 (varname$, typ2$, method, elements$)
     Give_Error "Unknown type": EXIT FUNCTION
     dim2exitfunc:
 
+    IF bypassNextVariable = 0 THEN
+        manageVariableList cvarname$, n$, 0
+    END IF
+    bypassNextVariable = 0
+
     IF dimsfarray THEN
         ids(idn).sfid = glinkid
         ids(idn).sfarg = glinkarg
@@ -15116,6 +15126,7 @@ FUNCTION evaluate$ (a2$, typ AS LONG)
                                     END IF 'varname
                                 NEXT
                             END IF 'subfuncn
+                            bypassNextVariable = -1
                             ignore = dim2(l$, dtyp$, method, fakee$)
                             IF Error_Happened THEN EXIT FUNCTION
                             dimstatic = olddimstatic
@@ -15310,6 +15321,7 @@ FUNCTION evaluate$ (a2$, typ AS LONG)
 
                     IF Debug THEN PRINT #9, "CREATING VARIABLE:" + x$
                     IF optionexplicit THEN Give_Error "Variable '" + x$ + "' (" + symbol2fulltypename$(typ$) + ") not defined": EXIT FUNCTION
+                    bypassNextVariable = -1
                     retval = dim2(x$, typ$, 1, "")
                     IF Error_Happened THEN EXIT FUNCTION
 
@@ -17736,6 +17748,32 @@ FUNCTION findid& (n2$)
 
     id = ids(i)
 
+    t = id.t
+    IF t = 0 THEN
+        t = id.arraytype
+        IF t AND ISUDT THEN
+            manageVariableList "", scope$ + "ARRAY_UDT_" + RTRIM$(id.n), 2
+        ELSE
+            n$ = id2fulltypename$
+            IF LEFT$(n$, 1) = "_" THEN
+                manageVariableList "", scope$ + "ARRAY" + n$ + "_" + RTRIM$(id.n), 2
+            ELSE
+                manageVariableList "", scope$ + "ARRAY_" + n$ + "_" + RTRIM$(id.n), 2
+            END IF
+        END IF
+    ELSE
+        IF t AND ISUDT THEN
+            manageVariableList "", scope$ + "UDT_" + RTRIM$(id.n), 2
+        ELSE
+            n$ = id2fulltypename$
+            IF LEFT$(n$, 1) = "_" THEN
+                manageVariableList "", scope$ + MID$(n$, 2) + "_" + RTRIM$(id.n), 2
+            ELSE
+                manageVariableList "", scope$ + n$ + "_" + RTRIM$(id.n), 2
+            END IF
+        END IF
+    END IF
+
     currentid = i
     EXIT FUNCTION
 
@@ -21255,7 +21293,6 @@ SUB setrefer (a2$, typ2 AS LONG, e2$, method AS LONG)
     getid idnumber
     IF Error_Happened THEN EXIT SUB
 
-
     'UDT?
     IF typ AND ISUDT THEN
 
@@ -21345,6 +21382,8 @@ SUB setrefer (a2$, typ2 AS LONG, e2$, method AS LONG)
 
         'print "setUDTrefer:"+r$,e$
         tlayout$ = tl$
+        IF LEFT$(r$, 1) = "*" THEN r$ = MID$(r$, 2)
+        manageVariableList "", scope$ + n$, 1
         EXIT SUB
     END IF
 
@@ -21378,6 +21417,8 @@ SUB setrefer (a2$, typ2 AS LONG, e2$, method AS LONG)
             END IF
             PRINT #12, cleanupstringprocessingcall$ + "0);"
             tlayout$ = tl$
+            IF LEFT$(r$, 1) = "*" THEN r$ = MID$(r$, 2)
+            manageVariableList "", r$, 1
             EXIT SUB
         END IF
 
@@ -21452,6 +21493,8 @@ SUB setrefer (a2$, typ2 AS LONG, e2$, method AS LONG)
             PRINT #12, cleanupstringprocessingcall$ + "0);"
             IF arrayprocessinghappened THEN arrayprocessinghappened = 0
             tlayout$ = tl$
+            IF LEFT$(r$, 1) = "*" THEN r$ = MID$(r$, 2)
+            manageVariableList "", r$, 1
             EXIT SUB
         END IF
 
@@ -21482,6 +21525,8 @@ SUB setrefer (a2$, typ2 AS LONG, e2$, method AS LONG)
             IF stringprocessinghappened THEN PRINT #12, cleanupstringprocessingcall$ + "0);": stringprocessinghappened = 0
             IF arrayprocessinghappened THEN arrayprocessinghappened = 0
             tlayout$ = tl$
+            IF LEFT$(r$, 1) = "*" THEN r$ = MID$(r$, 2)
+            manageVariableList "", r$, 1
             EXIT SUB
         END IF
 
@@ -21508,6 +21553,10 @@ SUB setrefer (a2$, typ2 AS LONG, e2$, method AS LONG)
         IF stringprocessinghappened THEN PRINT #12, cleanupstringprocessingcall$ + "0);": stringprocessinghappened = 0
         IF arrayprocessinghappened THEN arrayprocessinghappened = 0
         tlayout$ = tl$
+
+        IF LEFT$(r$, 1) = "*" THEN r$ = MID$(r$, 2)
+        manageVariableList "", r$, 1
+
         EXIT SUB
     END IF 'variable
 
@@ -24789,6 +24838,38 @@ SUB dump_udts
     CLOSE #f
 END SUB
 
+SUB manageVariableList (name$, __cname$, action AS _BYTE)
+    DIM findItem AS LONG, s$, cname$
+    cname$ = __cname$
+
+    findItem = INSTR(cname$, "[")
+    IF findItem THEN
+        cname$ = LEFT$(cname$, findItem - 1)
+    END IF
+
+    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)
+        CASE ELSE 'find and remove
+            s$ = CHR$(3) + cname$ + CHR$(10)
+            findItem = INSTR(usedVariableList$, 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
+            END IF
+            'usedVariableList$ = usedVariableList$ + STR$(action) + " Searching " + cname$ + " at line" + STR$(linenumber) + CHR$(10)
+    END SELECT
+END SUB
+
 '$INCLUDE:'utilities\strings.bas'
 
 '$INCLUDE:'subs_functions\extensions\opengl\opengl_methods.bas'