Improved flow analysis in general and especially for "for" loops. Added more

tests.

test/misc/Makefile

@@ -157,6 +157,11 @@ $(WORKDIR)/flow-do-01.$1.$2.prg: flow-do-01.c $(ISEQUAL) | $(WORKDIR)
 	$(CC65) -t sim$2 -$1 -o $$@ $$< $(NULLOUT) 2>$(WORKDIR)/flow-do-01.$1.$2.out
 	$(ISEQUAL) $(WORKDIR)/flow-do-01.$1.$2.out flow-do-01.ref
 
+$(WORKDIR)/flow-for-01.$1.$2.prg: flow-for-01.c $(ISEQUAL) | $(WORKDIR)
+	$(if $(QUIET),echo misc/flow-for-01.$1.$2.prg)
+	$(CC65) -t sim$2 -$1 -o $$@ $$< $(NULLOUT) 2>$(WORKDIR)/flow-for-01.$1.$2.out
+	$(ISEQUAL) $(WORKDIR)/flow-for-01.$1.$2.out flow-for-01.ref
+
 $(WORKDIR)/flow-if-01.$1.$2.prg: flow-if-01.c $(ISEQUAL) | $(WORKDIR)
 	$(if $(QUIET),echo misc/flow-if-01.$1.$2.prg)
 	$(CC65) -t sim$2 -$1 -o $$@ $$< $(NULLOUT) 2>$(WORKDIR)/flow-if-01.$1.$2.out

test/misc/flow-for-01.c

@@ -0,0 +1,90 @@
+int a;
+
+static int f1(void)
+{
+    for (;;) {
+        ++a;
+    }
+    /* Unreachable */
+    a = 2;
+    return a;
+}
+
+static int f2(void)
+{
+    for (;1;) {
+        ++a;
+    }
+    /* Unreachable */
+    a = 2;
+    return a;							 
+}
+
+static int f3(void)
+{
+    for (;;) {
+        ++a;
+        if (a == 5) break;
+    }
+    /* Reachable */
+    a = 2;
+    return a;
+}
+
+static int f4(void)
+{
+    for (;;) {
+        ++a;
+        return a;
+    }
+    /* Unreachable */
+    a = 2;
+}
+
+static int f5(void)
+{
+    for (;0;) {
+        /* Unreachable */
+        ++a;
+        return a;
+    }
+    /* Reachable */
+    a = 2;
+    return 0;
+}
+
+static int f6(void)
+{
+    for (;;) {
+        ++a;
+        if (a == 4) goto L;
+        return a;
+    }
+    /* Reachable via L */
+L:  a = 2;
+}
+
+static int f7(void)
+{
+    for (;0;) {
+        /* Unreachable but no warning */
+    }
+    a = 2;
+    return a;
+}
+
+static int f8(void)
+{
+    for (;a;) {
+        return a;
+    }
+    /* Reachable */
+    a = 2;
+    return a;
+}
+
+int main(void)
+{
+    return f1() + f2() + f3() + f4() + f5() + f6() + f7() + f8();
+}
+

test/misc/flow-for-01.ref

@@ -0,0 +1,4 @@
+flow-for-01.c:9: Warning: Unreachable code
+flow-for-01.c:19: Warning: Unreachable code
+flow-for-01.c:41: Warning: Unreachable code
+flow-for-01.c:48: Warning: Unreachable code

test/misc/flow-while-01.c

@@ -63,8 +63,18 @@ static int f6(void)
     return a;
 }
 
-int main(void)
+static int f7(void)
 {
-    return f1() + f2() + f3() + f4() + f5() + f6();
+    while (a) {
+        return a;
+    }
+    /* Reachable */
+    a = 2;
+    return a;
+}
+
+int main(void)
+{
+    return f1() + f2() + f3() + f4() + f5() + f6() + f7();
 }
 

test/misc/flow-while-02.c

@@ -22,7 +22,7 @@ static int f2(void)
         /* Unreachable */
         break;
     }
-    /* Unreachable but no warning */
+    /* Unreachable */
     a = 2;
     return a;
 }

test/misc/flow-while-02.ref

@@ -1,6 +1,7 @@
 flow-while-02.c:8: Warning: Unreachable code
 flow-while-02.c:12: Warning: Unreachable code
 flow-while-02.c:23: Warning: Unreachable code
+flow-while-02.c:26: Warning: Unreachable code
 flow-while-02.c:38: Warning: Unreachable code
 flow-while-02.c:50: Warning: Unreachable code
 flow-while-02.c:66: Warning: Unreachable code