Add more utilities for scalars and add range tests in CfimOfJson

3 files changed, 186 insertions, 43 deletions

diff --git a/rust-tests/src/main.rs b/rust-tests/src/main.rs
index f87fa40f..e85acf8c 100644
--- a/rust-tests/src/main.rs
+++ b/rust-tests/src/main.rs
@@ -1,11 +1,21 @@
 /// The following code generates the limits for the scalar types
 
 fn main() {
-    let ints = &[
+    let ints_lower = [
         "isize", "i8", "i16", "i32", "i64", "i128", "usize", "u8", "u16", "u32", "u64", "u128",
     ];
-    // Generate the code to print the limits
-    for s in ints {
+
+    let ints_upper = [
+        "Isize", "I8", "I16", "I32", "I64", "I128", "Usize", "U8", "U16", "U32", "U64", "U128",
+    ];
+
+    let mut ints_pairs = vec![];
+    for i in 0..ints_lower.len() {
+        ints_pairs.push((&ints_lower[i], &ints_upper[i]));
+    }
+
+    // Generate the code to print the scalar ranges
+    for s in &ints_lower {
         println!(
             "println!(\"let {}_min = Z.of_string \\\"{{}}\\\"\", {}::MIN);",
             s, s
@@ -17,7 +27,8 @@ fn main() {
     }
     println!("\n");
 
-    // Generate the OCaml definitions - this code is generated (comes from the above)
+    // Generate the OCaml definitions for the ranges - this code is
+    // generated (comes from the above)
     println!("let isize_min = Z.of_string \"{}\"", isize::MIN);
     println!("let isize_max = Z.of_string \"{}\"", isize::MAX);
     println!("let i8_min = Z.of_string \"{}\"", i8::MIN);
@@ -42,4 +53,17 @@ fn main() {
     println!("let u64_max = Z.of_string \"{}\"", u64::MAX);
     println!("let u128_min = Z.of_string \"{}\"", u128::MIN);
     println!("let u128_max = Z.of_string \"{}\"", u128::MAX);
+    println!("\n");
+
+    // Generate the check_int_in_range body
+    for (lo, up) in &ints_pairs {
+        println!("| {} -> Z.leq {}_min i && Z.leq i {}_max", up, lo, lo);
+    }
+    println!("\n");
+
+    // Generate the scalar_value_get_value_range body
+    for s in &ints_upper {
+        println!("| {} i -> i", s);
+    }
+    println!("\n");
 }
diff --git a/src/CfimOfJson.ml b/src/CfimOfJson.ml
index cc7b5603..0b9caebc 100644
--- a/src/CfimOfJson.ml
+++ b/src/CfimOfJson.ml
@@ -12,6 +12,7 @@ open Yojson.Basic
 open Identifiers
 open Types
 open OfJsonBasic
+open Scalars
 
 let name_of_json (js : json) : (name, string) result =
   combine_error_msgs js "name_of_json" (list_of_json string_of_json js)
@@ -190,46 +191,54 @@ let big_int_of_json (js : json) : (big_int, string) result =
     | `String is -> Ok (Z.of_string is)
     | _ -> Error "")
 
+(** Deserialize a [scalar_value] from JSON and **check the ranges** *)
 let scalar_value_of_json (js : json) : (scalar_value, string) result =
-  combine_error_msgs js "scalar_value_of_json"
-    (match js with
-    | `Assoc [ ("Isize", bi) ] ->
-        let* bi = big_int_of_json bi in
-        Ok (Isize bi)
-    | `Assoc [ ("I8", bi) ] ->
-        let* bi = big_int_of_json bi in
-        Ok (I8 bi)
-    | `Assoc [ ("I16", bi) ] ->
-        let* bi = big_int_of_json bi in
-        Ok (I16 bi)
-    | `Assoc [ ("I32", bi) ] ->
-        let* bi = big_int_of_json bi in
-        Ok (I32 bi)
-    | `Assoc [ ("I64", bi) ] ->
-        let* bi = big_int_of_json bi in
-        Ok (I64 bi)
-    | `Assoc [ ("I128", bi) ] ->
-        let* bi = big_int_of_json bi in
-        Ok (I128 bi)
-    | `Assoc [ ("Usize", bi) ] ->
-        let* bi = big_int_of_json bi in
-        Ok (Usize bi)
-    | `Assoc [ ("U8", bi) ] ->
-        let* bi = big_int_of_json bi in
-        Ok (U8 bi)
-    | `Assoc [ ("U16", bi) ] ->
-        let* bi = big_int_of_json bi in
-        Ok (U16 bi)
-    | `Assoc [ ("U32", bi) ] ->
-        let* bi = big_int_of_json bi in
-        Ok (U32 bi)
-    | `Assoc [ ("U64", bi) ] ->
-        let* bi = big_int_of_json bi in
-        Ok (U64 bi)
-    | `Assoc [ ("U128", bi) ] ->
-        let* bi = big_int_of_json bi in
-        Ok (U128 bi)
-    | _ -> Error "")
+  let res =
+    combine_error_msgs js "scalar_value_of_json"
+      (match js with
+      | `Assoc [ ("Isize", bi) ] ->
+          let* bi = big_int_of_json bi in
+          Ok (Isize bi)
+      | `Assoc [ ("I8", bi) ] ->
+          let* bi = big_int_of_json bi in
+          Ok (I8 bi)
+      | `Assoc [ ("I16", bi) ] ->
+          let* bi = big_int_of_json bi in
+          Ok (I16 bi)
+      | `Assoc [ ("I32", bi) ] ->
+          let* bi = big_int_of_json bi in
+          Ok (I32 bi)
+      | `Assoc [ ("I64", bi) ] ->
+          let* bi = big_int_of_json bi in
+          Ok (I64 bi)
+      | `Assoc [ ("I128", bi) ] ->
+          let* bi = big_int_of_json bi in
+          Ok (I128 bi)
+      | `Assoc [ ("Usize", bi) ] ->
+          let* bi = big_int_of_json bi in
+          Ok (Usize bi)
+      | `Assoc [ ("U8", bi) ] ->
+          let* bi = big_int_of_json bi in
+          Ok (U8 bi)
+      | `Assoc [ ("U16", bi) ] ->
+          let* bi = big_int_of_json bi in
+          Ok (U16 bi)
+      | `Assoc [ ("U32", bi) ] ->
+          let* bi = big_int_of_json bi in
+          Ok (U32 bi)
+      | `Assoc [ ("U64", bi) ] ->
+          let* bi = big_int_of_json bi in
+          Ok (U64 bi)
+      | `Assoc [ ("U128", bi) ] ->
+          let* bi = big_int_of_json bi in
+          Ok (U128 bi)
+      | _ -> Error "")
+  in
+  match res with
+  | Error _ -> res
+  | Ok sv ->
+      assert (check_scalar_value_in_range sv);
+      res
 
 let constant_value_of_json (js : json) : (constant_value, string) result =
   combine_error_msgs js "constant_value_of_json"
diff --git a/src/Scalars.ml b/src/Scalars.ml
new file mode 100644
index 00000000..29c2779f
--- /dev/null
+++ b/src/Scalars.ml
@@ -0,0 +1,110 @@
+open Types
+open Values
+
+(** The minimum/maximum values an integer type can have depending on its type *)
+
+let i8_min = Z.of_string "-128"
+
+let i8_max = Z.of_string "127"
+
+let i16_min = Z.of_string "-32768"
+
+let i16_max = Z.of_string "32767"
+
+let i32_min = Z.of_string "-2147483648"
+
+let i32_max = Z.of_string "2147483647"
+
+let i64_min = Z.of_string "-9223372036854775808"
+
+let i64_max = Z.of_string "9223372036854775807"
+
+let i128_min = Z.of_string "-170141183460469231731687303715884105728"
+
+let i128_max = Z.of_string "170141183460469231731687303715884105727"
+
+let u8_min = Z.of_string "0"
+
+let u8_max = Z.of_string "255"
+
+let u16_min = Z.of_string "0"
+
+let u16_max = Z.of_string "65535"
+
+let u32_min = Z.of_string "0"
+
+let u32_max = Z.of_string "4294967295"
+
+let u64_min = Z.of_string "0"
+
+let u64_max = Z.of_string "18446744073709551615"
+
+let u128_min = Z.of_string "0"
+
+let u128_max = Z.of_string "340282366920938463463374607431768211455"
+
+(** Being a bit conservative about isize/usize: depending on the system,
+    the values are encoded as 32-bit values or 64-bit values - we may
+    want to take that into account in the future *)
+
+let isize_min = i32_min
+
+let isize_max = i32_max
+
+let usize_min = u32_min
+
+let usize_max = u32_max
+
+(** Return the integer value in a scalar value *)
+let scalar_value_get_value (v : scalar_value) : big_int =
+  match v with
+  | Isize i -> i
+  | I8 i -> i
+  | I16 i -> i
+  | I32 i -> i
+  | I64 i -> i
+  | I128 i -> i
+  | Usize i -> i
+  | U8 i -> i
+  | U16 i -> i
+  | U32 i -> i
+  | U64 i -> i
+  | U128 i -> i
+
+(** Retrieve the [integer_type] of a scalar value *)
+let scalar_value_get_integer_type (sv : scalar_value) : integer_type =
+  match sv with
+  | Isize _ -> Types.Isize
+  | I8 _ -> Types.I8
+  | I16 _ -> Types.I16
+  | I32 _ -> Types.I32
+  | I64 _ -> Types.I64
+  | I128 _ -> Types.I128
+  | Usize _ -> Types.Usize
+  | U8 _ -> Types.U8
+  | U16 _ -> Types.U16
+  | U32 _ -> Types.U32
+  | U64 _ -> Types.U64
+  | U128 _ -> Types.U128
+
+(** Check that an integer value is in range *)
+let check_int_in_range (int_ty : integer_type) (i : big_int) : bool =
+  match int_ty with
+  | Isize -> Z.leq isize_min i && Z.leq i isize_max
+  | I8 -> Z.leq i8_min i && Z.leq i i8_max
+  | I16 -> Z.leq i16_min i && Z.leq i i16_max
+  | I32 -> Z.leq i32_min i && Z.leq i i32_max
+  | I64 -> Z.leq i64_min i && Z.leq i i64_max
+  | I128 -> Z.leq i128_min i && Z.leq i i128_max
+  | Usize -> Z.leq usize_min i && Z.leq i usize_max
+  | U8 -> Z.leq u8_min i && Z.leq i u8_max
+  | U16 -> Z.leq u16_min i && Z.leq i u16_max
+  | U32 -> Z.leq u32_min i && Z.leq i u32_max
+  | U64 -> Z.leq u64_min i && Z.leq i u64_max
+  | U128 -> Z.leq u128_min i && Z.leq i u128_max
+
+(** Check that a scalar value is correct (the integer value it contains is in range) *)
+let check_scalar_value_in_range (v : scalar_value) : bool =
+  let i = scalar_value_get_value v in
+  let int_ty = scalar_value_get_integer_type v in
+  check_int_in_range int_ty i