Merge pull request #1077 from owen-jones-diffblue/feature/parseInt#613

Feature/parse int#613

Author: smowton

regression/strings-smoke-tests/java_parseint/test.desc

@@ -3,6 +3,5 @@ test_parseint.class
 --refine-strings
 ^EXIT=10$
 ^SIGNAL=0$
-^\[.*assertion.1\].* line 7.* SUCCESS$
-^\[.*assertion.2\].* line 8.* FAILURE$
---
+^\[.*assertion.1\].* line 8.* SUCCESS$
+^\[.*assertion.2\].* line 9.* FAILURE$

regression/strings-smoke-tests/java_parseint/test_parseint.class

@@ -1,10 +1,12 @@
 public class test_parseint
 {
-   public static void main(String[] argv)
-   {
-      String twelve = new String("12");
-      int parsed = Integer.parseInt(twelve);
-      assert(parsed == 12);
-      assert(parsed != 12);
-   }
+    public static void main(String[] args)
+    {
+        if (args.length == 1) {
+            String twelve = new String("12");
+            int parsed1 = Integer.parseInt(twelve);
+            assert(parsed1 == 12);
+            assert(parsed1 != 12);
+        }
+    }
 }

regression/strings-smoke-tests/java_parseint/test_parseint.java

@@ -0,0 +1,12 @@
+KNOWNBUG
+test_parseint.class
+--refine-strings
+^EXIT=10$
+^SIGNAL=0$
+^\[.*assertion.1\].* line 9.* SUCCESS$
+^\[.*assertion.2\].* line 10.* FAILURE$
+^\[.*assertion.3\].* line 17.* SUCCESS$
+^\[.*assertion.4\].* line 18.* FAILURE$
+--
+--
+Issue #664 is about turning these tests on

regression/strings-smoke-tests/java_parseint_knownbug/test.desc

@@ -0,0 +1,21 @@
+public class test_parseint
+{
+    public static void main(String[] args)
+    {
+        if (args.length == 2) {
+            // 2^31-1, max value of Integer
+            String max_int = new String("2147483647");
+            int parsed2 = Integer.parseInt(max_int);
+            assert(parsed2 == 2147483647);
+            assert(parsed2 != 2147483647);
+        }
+        else if (args.length == 3) {
+            // -2^31, min value of Integer, and longest string we could have without
+            // leading zeroes
+            String min_int = new String("-2147483648");
+            int parsed3 = Integer.parseInt(min_int);
+            assert(parsed3 == -2147483648);
+            assert(parsed3 != -2147483648);
+        }
+    }
+}

regression/strings-smoke-tests/java_parseint_knownbug/test_parseint.class

@@ -0,0 +1,16 @@
+CORE
+test_parseint_with_radix.class
+--refine-strings
+^EXIT=10$
+^SIGNAL=0$
+^\[.*assertion.1\].* line 8.* SUCCESS$
+^\[.*assertion.2\].* line 9.* FAILURE$
+^\[.*assertion.3\].* line 14.* SUCCESS$
+^\[.*assertion.4\].* line 15.* FAILURE$
+^\[.*assertion.5\].* line 20.* SUCCESS$
+^\[.*assertion.6\].* line 21.* FAILURE$
+^\[.*assertion.7\].* line 26.* SUCCESS$
+^\[.*assertion.8\].* line 27.* FAILURE$
+^\[.*assertion.9\].* line 32.* SUCCESS$
+^\[.*assertion.10\].* line 33.* FAILURE$
+--

regression/strings-smoke-tests/java_parseint_knownbug/test_parseint.java

@@ -0,0 +1,36 @@
+public class test_parseint_with_radix
+{
+    public static void main(String[] args)
+    {
+        if (args.length == 1) {
+            String str1 = new String("F");
+            int parsed1 = Integer.parseInt(str1, 16);
+            assert(parsed1 == 15);
+            assert(parsed1 != 15);
+        }
+        else if (args.length == 2) {
+            String str2 = new String("123");
+            int parsed2 = Integer.parseInt(str2, 10);
+            assert(parsed2 == 123);
+            assert(parsed2 != 123);
+        }
+        else if (args.length == 3) {
+            String str3 = new String("77");
+            int parsed3 = Integer.parseInt(str3, 8);
+            assert(parsed3 == 63);
+            assert(parsed3 != 63);
+        }
+        else if (args.length == 4) {
+            String str4 = new String("-101");
+            int parsed4 = Integer.parseInt(str4, 2);
+            assert(parsed4 == -5);
+            assert(parsed4 != -5);
+        }
+        else if (args.length == 5) {
+            String str5 = new String("00aB");
+            int parsed5 = Integer.parseInt(str5, 16);
+            assert(parsed5 == 171);
+            assert(parsed5 != 171);
+        }
+    }
+}

regression/strings-smoke-tests/java_parseint_with_radix/test.desc

@@ -0,0 +1,12 @@
+KNOWNBUG
+test_parseint_with_radix.class
+--refine-strings
+^EXIT=10$
+^SIGNAL=0$
+^\[.*assertion.1\].* line 9.* SUCCESS$
+^\[.*assertion.2\].* line 10.* FAILURE$
+^\[.*assertion.3\].* line 16.* SUCCESS$
+^\[.*assertion.4\].* line 17.* FAILURE$
+--
+--
+Issue #664 is about turning these tests on

regression/strings-smoke-tests/java_parseint_with_radix/test_parseint_with_radix.class

@@ -0,0 +1,20 @@
+public class test_parseint_with_radix
+{
+    public static void main(String[] args)
+    {
+        if (args.length == 1) {
+            // 2^31-1, max value of Integer
+            String str1 = new String("7FFFFFFF");
+            int parsed1 = Integer.parseInt(str1, 16);
+            assert(parsed1 == 2147483647);
+            assert(parsed1 != 2147483647);
+        }
+        else if (args.length == 2) {
+            // -2^31, min value of Integer, and longest string we could have
+            String str2 = new String("-100000000000000000000000000000000");
+            int parsed2 = Integer.parseInt(str2, 2);
+            assert(parsed2 == -2147483648);
+            assert(parsed2 != -2147483648);
+        }
+   }
+}

regression/strings-smoke-tests/java_parseint_with_radix/test_parseint_with_radix.java

@@ -1954,6 +1954,9 @@ void java_string_library_preprocesst::initialize_conversion_table()
   cprover_equivalent_to_java_function
     ["java::java.lang.Integer.parseInt:(Ljava/lang/String;)I"]=
       ID_cprover_string_parse_int_func;
+  cprover_equivalent_to_java_function
+    ["java::java.lang.Integer.parseInt:(Ljava/lang/String;I)I"]=
+      ID_cprover_string_parse_int_func;
   cprover_equivalent_to_java_string_returning_function
     ["java::java.lang.Integer.toHexString:(I)Ljava/lang/String;"]=
       ID_cprover_string_of_int_hex_func;

regression/strings-smoke-tests/java_parseint_with_radix_knownbug/test.desc

@@ -294,7 +294,7 @@ class string_constraint_generatort
 
   exprt add_axioms_for_parse_int(const function_application_exprt &f);
   exprt add_axioms_for_correct_number_format(
-    const string_exprt &str, std::size_t max_size=10);
+    const string_exprt &str, const exprt &radix, std::size_t max_size=10);
   exprt add_axioms_for_to_char_array(const function_application_exprt &f);
   exprt add_axioms_for_compare_to(const function_application_exprt &f);
 
@@ -328,4 +328,8 @@ class string_constraint_generatort
   bool is_constant_string(const string_exprt &expr) const;
 };
 
+exprt is_digit_with_radix(exprt chr, exprt radix);
+exprt get_numeric_value_from_character(
+  const exprt &chr, const typet &char_type, const typet &type);
+
 #endif

regression/strings-smoke-tests/java_parseint_with_radix_knownbug/test_parseint_with_radix.class

@@ -357,11 +357,14 @@ string_exprt string_constraint_generatort::add_axioms_for_value_of(
 }
 
 /// Add axioms making the return value true if the given string is a correct
-/// number.
-/// \param f: function application with one string expression
-/// \return an boolean expression
+/// number in the given radix
+/// \param str: string expression
+/// \param radix: the radix
+/// \param max_size: maximum number of characters
+/// \return a boolean expression saying whether the string does represent a
+///   number with the given radix
 exprt string_constraint_generatort::add_axioms_for_correct_number_format(
-  const string_exprt &str, std::size_t max_size)
+  const string_exprt &str, const exprt &radix, std::size_t max_size)
 {
   symbol_exprt correct=fresh_boolean("correct_number_format");
   const refined_string_typet &ref_type=to_refined_string_type(str.type());
@@ -375,16 +378,14 @@ exprt string_constraint_generatort::add_axioms_for_correct_number_format(
   exprt chr=str[0];
   equal_exprt starts_with_minus(chr, minus_char);
   equal_exprt starts_with_plus(chr, plus_char);
-  and_exprt starts_with_digit(
-    binary_relation_exprt(chr, ID_ge, zero_char),
-    binary_relation_exprt(chr, ID_le, nine_char));
+  exprt starts_with_digit=is_digit_with_radix(chr, radix);
 
   // TODO: we should have implications in the other direction for correct
   // correct => |str| > 0
   exprt non_empty=str.axiom_for_is_longer_than(from_integer(1, index_type));
   axioms.push_back(implies_exprt(correct, non_empty));
 
-  // correct => (str[0] = '+' or '-' || '0' <= str[0] <= '9')
+  // correct => (str[0] = '+' or '-' || is_digit_with_radix(str[0], radix))
   or_exprt correct_first(
     or_exprt(starts_with_minus, starts_with_plus), starts_with_digit);
   axioms.push_back(implies_exprt(correct, correct_first));
@@ -399,11 +400,9 @@ exprt string_constraint_generatort::add_axioms_for_correct_number_format(
   axioms.push_back(
     implies_exprt(correct, str.axiom_for_is_shorter_than(max_size)));
 
-  // forall 1 <= qvar < |str| . correct => '0'<= str[qvar] <= '9'
+  // forall 1 <= qvar < |str| . correct => is_digit_with_radix(str[qvar], radix)
   symbol_exprt qvar=fresh_univ_index("number_format", index_type);
-  and_exprt is_digit(
-    binary_relation_exprt(str[qvar], ID_ge, zero_char),
-    binary_relation_exprt(str[qvar], ID_le, nine_char));
+  exprt is_digit=is_digit_with_radix(str[qvar], radix);
   string_constraintt all_digits(
     qvar, from_integer(1, index_type), str.length(), correct, is_digit);
   axioms.push_back(all_digits);
@@ -412,58 +411,66 @@ exprt string_constraint_generatort::add_axioms_for_correct_number_format(
 }
 
 /// add axioms corresponding to the Integer.parseInt java function
-/// \param f: function application with one string expression
+/// \param f: a function application with either one string expression or one
+///   string expression and an expression for the radix
 /// \return an integer expression
 exprt string_constraint_generatort::add_axioms_for_parse_int(
   const function_application_exprt &f)
 {
-  string_exprt str=get_string_expr(args(f, 1)[0]);
+  PRECONDITION(f.arguments().size()==1 || f.arguments().size()==2);
+  string_exprt str=get_string_expr(f.arguments()[0]);
+  const exprt radix=
+    f.arguments().size()==1?from_integer(10, f.type()):f.arguments()[1];
+
   const typet &type=f.type();
   symbol_exprt i=fresh_symbol("parsed_int", type);
   const refined_string_typet &ref_type=to_refined_string_type(str.type());
   const typet &char_type=ref_type.get_char_type();
-  exprt zero_char=constant_char('0', char_type);
   exprt minus_char=constant_char('-', char_type);
   exprt plus_char=constant_char('+', char_type);
   assert(type.id()==ID_signedbv);
-  exprt ten=from_integer(10, type);
 
   exprt chr=str[0];
   exprt starts_with_minus=equal_exprt(chr, minus_char);
   exprt starts_with_plus=equal_exprt(chr, plus_char);
-  exprt starts_with_digit=binary_relation_exprt(chr, ID_ge, zero_char);
+  exprt starts_with_digit=
+    not_exprt(or_exprt(starts_with_minus, starts_with_plus));
 
-  // TODO: we should throw an exception when this does not hold:
-  exprt correct=add_axioms_for_correct_number_format(str);
+  /// TODO: we should throw an exception when this does not hold:
+  exprt correct=add_axioms_for_correct_number_format(str, radix);
   axioms.push_back(correct);
 
+  /// TODO(OJones): size should depend on the radix
+  /// TODO(OJones): we should deal with overflow properly
   for(unsigned size=1; size<=10; size++)
   {
     exprt sum=from_integer(0, type);
-    exprt first_value=typecast_exprt(minus_exprt(chr, zero_char), type);
+    exprt first_value=get_numeric_value_from_character(chr, char_type, type);
+    equal_exprt premise=str.axiom_for_has_length(size);
 
     for(unsigned j=1; j<size; j++)
     {
-      mult_exprt ten_sum(sum, ten);
+      mult_exprt radix_sum(sum, radix);
       if(j>=9)
       {
         // We have to be careful about overflows
-        div_exprt div(sum, ten);
-        equal_exprt no_overflow(div, sum);
+        div_exprt div(sum, radix);
+        implies_exprt no_overflow(premise, (equal_exprt(div, sum)));
         axioms.push_back(no_overflow);
       }
 
       sum=plus_exprt_with_overflow_check(
-        ten_sum,
-        typecast_exprt(minus_exprt(str[j], zero_char), type));
+        radix_sum,
+        get_numeric_value_from_character(str[j], char_type, type));
 
-      mult_exprt first(first_value, ten);
+      mult_exprt first(first_value, radix);
       if(j>=9)
       {
         // We have to be careful about overflows
-        div_exprt div_first(first, ten);
+        div_exprt div_first(first, radix);
         implies_exprt no_overflow_first(
-          starts_with_digit, equal_exprt(div_first, first_value));
+          and_exprt(starts_with_digit, premise),
+          equal_exprt(div_first, first_value));
         axioms.push_back(no_overflow_first);
       }
       first_value=first;
@@ -474,7 +481,6 @@ exprt string_constraint_generatort::add_axioms_for_parse_int(
     // a2 : starts_with_plus => i=sum
     // a3 : starts_with_minus => i=-sum
 
-    equal_exprt premise=str.axiom_for_has_length(size);
     implies_exprt a1(
       and_exprt(premise, starts_with_digit),
       equal_exprt(i, plus_exprt(sum, first_value)));
@@ -490,3 +496,70 @@ exprt string_constraint_generatort::add_axioms_for_parse_int(
   }
   return i;
 }
+
+/// Check if a character is a digit with respect to the given radix, e.g. if the
+/// radix is 10 then check if the character is in the range 0-9.
+/// \param chr: the character
+/// \param radix:  the radix
+/// \return an expression for the condition
+exprt is_digit_with_radix(exprt chr, exprt radix)
+{
+  const typet &char_type=chr.type();
+  exprt zero_char=from_integer('0', char_type);
+  exprt nine_char=from_integer('9', char_type);
+  exprt a_char=from_integer('a', char_type);
+  exprt A_char=from_integer('A', char_type);
+
+  and_exprt is_digit_when_radix_le_10(
+    binary_relation_exprt(chr, ID_ge, zero_char),
+    binary_relation_exprt(
+      chr, ID_lt, plus_exprt(zero_char, typecast_exprt(radix, char_type))));
+
+  minus_exprt radix_minus_ten(
+    typecast_exprt(radix, char_type), from_integer(10, char_type));
+
+  or_exprt is_digit_when_radix_gt_10(
+    and_exprt(
+      binary_relation_exprt(chr, ID_ge, zero_char),
+      binary_relation_exprt(chr, ID_le, nine_char)),
+    and_exprt(
+      binary_relation_exprt(chr, ID_ge, a_char),
+      binary_relation_exprt(chr, ID_lt, plus_exprt(a_char, radix_minus_ten))),
+    and_exprt(
+      binary_relation_exprt(chr, ID_ge, A_char),
+      binary_relation_exprt(chr, ID_lt, plus_exprt(A_char, radix_minus_ten))));
+
+  return if_exprt(
+    binary_relation_exprt(radix, ID_le, from_integer(10, radix.type())),
+    is_digit_when_radix_le_10,
+    is_digit_when_radix_gt_10);
+}
+
+/// Get the numeric value of a character, assuming that the radix is large
+/// enough
+/// \param chr: the character to get the numeric value of
+/// \param char_type: the type to use for characters
+/// \param type: the type to use for the return value
+/// \return an integer expression of the given type with the numeric value of
+///   the char
+exprt get_numeric_value_from_character(
+  const exprt &chr, const typet &char_type, const typet &type)
+{
+  constant_exprt zero_char=from_integer('0', char_type);
+  constant_exprt a_char=from_integer('a', char_type);
+  constant_exprt A_char=from_integer('A', char_type);
+  constant_exprt ten_int=from_integer(10, char_type);
+
+  binary_relation_exprt upper_case(chr, ID_ge, A_char);
+  binary_relation_exprt lower_case(chr, ID_ge, a_char);
+
+  return typecast_exprt(
+    if_exprt(
+      lower_case,
+      plus_exprt(minus_exprt(chr, a_char), ten_int),
+      if_exprt(
+        upper_case,
+        plus_exprt(minus_exprt(chr, A_char), ten_int),
+        minus_exprt(chr, zero_char))),
+    type);
+}