Function contracts: removing loops that do not pass the loop-freeness check for assigns clause instrumentation

Author: Remi Delmas

regression/contracts/assigns_validity_pointer_01/test.desc

@@ -8,7 +8,6 @@ SUCCESS
 // bar
 ASSERT \*foo::x > 0
 IF ¬\(\*foo::x = 3\) THEN GOTO \d
-IF ¬\(.*0.* = NULL\) THEN GOTO \d
 ASSIGN .*::tmp_if_expr := \(\*\(.*0.*\) = 5 \? true : false\)
 ASSIGN .*::tmp_if_expr\$\d := .*::tmp_if_expr \? true : false
 ASSUME .*::tmp_if_expr\$\d
@@ -23,4 +22,4 @@ Verification:
 This test checks support for a NULL pointer that is assigned to by
 a function (bar and baz). Both functions bar and baz are being replaced by
 their function contracts, while the calling function foo is being checked
-(by enforcing it's function contracts).
+(by enforcing its function contracts).

regression/contracts/function_check_02/main.c

@@ -15,10 +15,16 @@ int initialize(int *arr)
   )
 // clang-format on
 {
-  for(int i = 0; i < 10; i++)
-  {
-    arr[i] = i;
-  }
+  arr[0] = 0;
+  arr[1] = 1;
+  arr[2] = 2;
+  arr[3] = 3;
+  arr[4] = 4;
+  arr[5] = 5;
+  arr[6] = 6;
+  arr[7] = 7;
+  arr[8] = 8;
+  arr[9] = 9;
 
   return 0;
 }

regression/contracts/quantifiers-exists-ensures-enforce/main.c

@@ -7,10 +7,16 @@ int f1(int *arr)
   })
 // clang-format on
 {
-  for(int i = 0; i < 10; i++)
-  {
-    arr[i] = i;
-  }
+  arr[0] = 0;
+  arr[1] = 1;
+  arr[2] = 2;
+  arr[3] = 3;
+  arr[4] = 4;
+  arr[5] = 5;
+  arr[6] = 6;
+  arr[7] = 7;
+  arr[8] = 8;
+  arr[9] = 9;
 
   return 0;
 }
@@ -24,10 +30,16 @@ int f2(int *arr)
   })
 // clang-format on
 {
-  for(int i = 0; i < 10; i++)
-  {
-    arr[i] = 0;
-  }
+  arr[0] = 0;
+  arr[1] = 1;
+  arr[2] = 2;
+  arr[3] = 3;
+  arr[4] = 4;
+  arr[5] = 5;
+  arr[6] = 6;
+  arr[7] = 7;
+  arr[8] = 8;
+  arr[9] = 9;
 
   return 0;
 }

regression/contracts/quantifiers-exists-requires-enforce/main.c

@@ -1,7 +1,7 @@
 #include <stdbool.h>
 #include <stdlib.h>
 
-#define MAX_LEN 64
+#define MAX_LEN 10
 
 // clang-format off
 bool f1(int *arr, int len)
@@ -18,11 +18,27 @@ bool f1(int *arr, int len)
 // clang-format on
 {
   bool found_four = false;
-  for(int i = 0; i <= MAX_LEN; i++)
-  {
-    if(i < len)
-      found_four |= (arr[i] == 4);
-  }
+  if(0 < len)
+    found_four |= (arr[0] == 4);
+  if(1 < len)
+    found_four |= (arr[1] == 4);
+  if(2 < len)
+    found_four |= (arr[2] == 4);
+  if(3 < len)
+    found_four |= (arr[3] == 4);
+  if(4 < len)
+    found_four |= (arr[4] == 4);
+  if(5 < len)
+    found_four |= (arr[5] == 4);
+  if(6 < len)
+    found_four |= (arr[6] == 4);
+  if(7 < len)
+    found_four |= (arr[7] == 4);
+  if(8 < len)
+    found_four |= (arr[8] == 4);
+
+  if(9 < len)
+    found_four |= (arr[9] == 4);
 
   // clang-format off
   return (len > 0 ==> found_four);

regression/contracts/quantifiers-forall-ensures-enforce/main.c

@@ -1,6 +1,6 @@
 #include <stdlib.h>
 
-#define MAX_LEN 16
+#define MAX_LEN 10
 
 // clang-format off
 int f1(int *arr, int len)
@@ -12,11 +12,27 @@ int f1(int *arr, int len)
   })
 // clang-format on
 {
-  for(int i = 0; i < MAX_LEN; i++)
-  {
-    if(i < len)
-      arr[i] = 0;
-  }
+  if(0 < len)
+    arr[0] = 0;
+  if(1 < len)
+    arr[1] = 0;
+  if(2 < len)
+    arr[2] = 0;
+  if(3 < len)
+    arr[3] = 0;
+  if(4 < len)
+    arr[4] = 0;
+  if(5 < len)
+    arr[5] = 0;
+  if(6 < len)
+    arr[6] = 0;
+  if(7 < len)
+    arr[7] = 0;
+  if(8 < len)
+    arr[8] = 0;
+  if(9 < len)
+    arr[9] = 0;
+
   return 0;
 }
 

regression/contracts/quantifiers-forall-ensures-enforce/test.desc

@@ -4,10 +4,11 @@ main.c
 ^EXIT=0$
 ^SIGNAL=0$
 ^\[postcondition.\d+\] file main.c line \d+ Check ensures clause: SUCCESS$
-^\[f1.\d+\] line \d+ Check that arr\[\(.*\)i\] is assignable: SUCCESS$
+^\[f1.\d+\] line \d+ Check that arr\[\(.*\)\d\] is assignable: SUCCESS$
 ^VERIFICATION SUCCESSFUL$
 --
 ^warning: ignoring
+^\[f1.\d+\] line \d+ Check that arr\[\(.*\)\d\] is assignable: FAILURE$
 --
 The purpose of this test is to ensure that we can safely use __CPROVER_forall
 within positive contexts (enforced ENSURES clauses).

regression/contracts/quantifiers-forall-requires-enforce/main.c

@@ -12,8 +12,16 @@ bool f1(int *arr)
 // clang-format on
 {
   bool is_identity = true;
-  for(int i = 0; i < 10; ++i)
-    is_identity &= (arr[i] == i);
+  is_identity &= (arr[0] == 0);
+  is_identity &= (arr[1] == 1);
+  is_identity &= (arr[2] == 2);
+  is_identity &= (arr[3] == 3);
+  is_identity &= (arr[4] == 4);
+  is_identity &= (arr[5] == 5);
+  is_identity &= (arr[6] == 6);
+  is_identity &= (arr[7] == 7);
+  is_identity &= (arr[8] == 8);
+  is_identity &= (arr[9] == 9);
   return is_identity;
 }
 

regression/contracts/quantifiers-nested-01/main.c

@@ -11,10 +11,16 @@ int f1(int *arr)
   })
 // clang-format on
 {
-  for(int i = 0; i < 10; i++)
-  {
-    arr[i] = i;
-  }
+  arr[0] = 0;
+  arr[1] = 1;
+  arr[2] = 2;
+  arr[3] = 3;
+  arr[4] = 4;
+  arr[5] = 5;
+  arr[6] = 6;
+  arr[7] = 7;
+  arr[8] = 8;
+  arr[9] = 9;
 
   return 0;
 }

regression/contracts/quantifiers-nested-03/main.c

@@ -10,10 +10,16 @@ __CPROVER_assigns(__CPROVER_POINTER_OBJECT(arr))
   )
 // clang-format on
 {
-  for(int i = 0; i < 10; i++)
-  {
-    arr[i] = i;
-  }
+  arr[0] = 0;
+  arr[1] = 1;
+  arr[2] = 2;
+  arr[3] = 3;
+  arr[4] = 4;
+  arr[5] = 5;
+  arr[6] = 6;
+  arr[7] = 7;
+  arr[8] = 8;
+  arr[9] = 9;
 
   return 0;
 }