1+ OutFile("Loops.exe");
2+ ShowInstDetails("show");
3+ XPStyle("on");
4+ RequestExecutionLevel("admin");
5+
6+ section Loops()
7+ {
8+ DetailPrint("For Loop 1");
9+ for ($i = 0, $j = 10; $i < 5 || $j > 0; $i++, $j--)
10+ {
11+ DetailPrint("$i = ".$i." and $j = ".$j);
12+ }
13+
14+ DetailPrint("For Loop 2");
15+ for ($i = 0, $j = 10; $i < 5 && $j > 0; $i++, $j--)
16+ {
17+ DetailPrint("$i = ".$i." and $j = ".$j);
18+ }
19+
20+ /* Currently even though the code below is not assembled, $k will
21+ * still get declared and if $k is not used elsewhere in the script,
22+ * $k will be wasting run-time memory. To fix, the assembler will need
23+ * to remove $k from the variables list if it is not already used
24+ * prior to its use here.
25+ */
26+ DetailPrint("For Loop 3 (never gets assembled)");
27+ for ($k = 0; true && false; $k++)
28+ {
29+ DetailPrint("$k = ".$k);
30+ }
31+
32+ DetailPrint("For Loop 4");
33+ $m = 5;
34+ for (; $m >= 0;)
35+ {
36+ DetailPrint("$m = ".$m);
37+ if (true)
38+ $m--;
39+ }
40+
41+ DetailPrint("For Loop 5 (same as Loop 4)");
42+ $m = 5;
43+ for (;;)
44+ {
45+ DetailPrint("$m = ".$m);
46+ if ($m > 0)
47+ {
48+ $m--;
49+ continue;
50+ }
51+ break;
52+ }
53+
54+ DetailPrint("While Loop 1");
55+ $i = 0;
56+ while ($i < 9)
57+ {
58+ DetailPrint("$i = ".$i);
59+ $i++;
60+ }
61+
62+ /* Currently this IS assembled even though it will never execute.
63+ * Further optimisations could be done here if there are no
64+ * assignments or function calls on the left hand side of the && (as
65+ * is the case). That however would require a walk of its parse tree
66+ * or new code to propogate down the parse tree that there are
67+ * assignments or method calls within the tree.
68+ */
69+ DetailPrint("While Loop 2");
70+ while ($i < 9 && false)
71+ {
72+ DetailPrint("$i = ".$i);
73+ $i++;
74+ }
75+
76+ DetailPrint("Do While Loop 1");
77+ $i = 0;
78+ do
79+ {
80+ DetailPrint("$i = ".$i);
81+ $i++;
82+ }
83+ while ($i < 5);
84+
85+ /* Because this only executes once we end up with an unused go-to
86+ * label at the top. We cannot simply remove it because of
87+ * while(false), as there may well be a 'continue' statement inside
88+ * that wants to use the label. Because the assembler writes the
89+ * output in a single pass, it is not possible to back-track and
90+ * remove the label at a later date. Instead, and because the makensis
91+ * compiler issues a "label not used" message, we are forced to
92+ * reference the label with StrCmp "" "" 0 [label]. The zero-jump will
93+ * always be taken of course.
94+ */
95+ DetailPrint("Do While Loop 2");
96+ $i = 0;
97+ do
98+ {
99+ DetailPrint("This appears once only");
100+ }
101+ while (false);
102+ }
0 commit comments