try to make synthetic tests more explicit

test/synthetic/controlflow.c

@@ -10,7 +10,7 @@ int getValue(void); // unknown int value
 // -------------------------------------
 
 void arg_in_if(int a) {
-  if (a>=100)
+  if (a==100)
     buf[a] = 0; // BUG
 }
 

test/synthetic/functions.c

@@ -2,21 +2,21 @@
 int TestData[100];
 
 
-void test_function_par1(int par) {
+void function_par_not_dependant(int par) {
-  TestData[par] = 0;
+  TestData[par] = 0; // BUG
 }
-void test_function_par2(int x, int y) {
+void function_par_dependant(int x, int y) {
-  if (x < 123)
+  if (x < 10)
-      TestData[y] = 0;
+      TestData[y] = 0; // BUG
 }
 void call(int x) {
-  test_function_par1(1000);
+  function_par_not_dependant(1000);
-  test_function_par2(x, x < 1000 ? 10 : 1000);
+  function_par_dependant(0, 1000);
 }
 
 int getLargeIndex() { return 1000; }
 void test_function_return() {
-  TestData[getLargeIndex()] = 0;
+  TestData[getLargeIndex()] = 0; // BUG
 }
 
 

test/synthetic/ub.c

@@ -1,12 +1,12 @@
-int buffer_overflow() { int x[10]; return x[100]; }
+int buffer_overflow() { int x[10]={0}; return x[100]; }
-int dead_pointer(int a) { int *p=&a; if (a) { int x; p = &x; } return *p; }
+int dead_pointer(int a) { int *p=&a; if (a) { int x=0; p = &x; } return *p; }
 int division_by_zero() { return 100 / 0; }
 int float_overflow() { float f=1E100; return f; }
 void negative_size(int sz) { if (sz < 0) { int buf[sz]; } }
 int no_return() {}
 int null_pointer() { int *p = 0; return *p; }
 int *pointer_arithmetic() { static int buf[10]; return buf + 100; }
-char pointer_overflow() { static int buf[10]; return buf; }
+char pointer_overflow() { static int buf[10]; return (int*)buf; }
 int pointer_subtraction() { char a[10]; char b[10]; return b-a; }
 int pointer_comparison() { char a[10]; char b[10]; return b<a; }
 int shift_overrun(int x) { return x << 123; }