py/obj: Add functions to retrieve large integers from mp_obj_t.

This commit provides helpers to retrieve integer values from
mp_obj_t when the content does not fit in a 32 bits integer,
without risking an implicit wrap due to an int overflow.

Signed-off-by: Yoctopuce dev <[email protected]>

Author: yoctopuce

ports/unix/coverage.c

@@ -488,6 +488,26 @@ static mp_obj_t extra_coverage(void) {
         // mpz_set_from_float with 0 as argument
         mpz_set_from_float(&mpz, 0);
         mp_printf(&mp_plat_print, "%f\n", mpz_as_float(&mpz));
+
+        // convert a large integer value (stored in a mpz) to mp_uint_t and to ll;
+        mp_obj_t obj_bigint = mp_obj_new_int_from_uint((mp_uint_t)0xdeadbeef);
+        mp_printf(&mp_plat_print, "%x\n", mp_obj_get_uint(obj_bigint));
+        obj_bigint = mp_obj_new_int_from_ll(0xc0ffee777c0ffeell);
+        long long value_ll = mp_obj_get_ll(obj_bigint);
+        mp_printf(&mp_plat_print, "%x%08x\n", (uint32_t)(value_ll >> 32), (uint32_t)value_ll);
+
+        // convert a large integer value (stored via a struct object) to uint and to ll
+        // `deadbeef` global is an uctypes.struct defined by extra_coverage.py
+        obj_bigint = mp_load_global(MP_QSTR_deadbeef);
+        mp_printf(&mp_plat_print, "%x\n", mp_obj_get_uint(obj_bigint));
+        value_ll = mp_obj_get_ll(obj_bigint);
+        mp_printf(&mp_plat_print, "%x%08x\n", (uint32_t)(value_ll >> 32), (uint32_t)value_ll);
+
+        // convert a smaller integer value to mp_uint_t and to ll
+        obj_bigint = mp_obj_new_int_from_uint(0xc0ffee);
+        mp_printf(&mp_plat_print, "%x\n", mp_obj_get_uint(obj_bigint));
+        value_ll = mp_obj_get_ll(obj_bigint);
+        mp_printf(&mp_plat_print, "%x%08x\n", (uint32_t)(value_ll >> 32), (uint32_t)value_ll);
     }
 
     // runtime utils
@@ -530,6 +550,22 @@ static mp_obj_t extra_coverage(void) {
             mp_obj_print_exception(&mp_plat_print, MP_OBJ_FROM_PTR(nlr.ret_val));
         }
 
+        // mp_obj_get_uint from a non-int object (should raise exception)
+        if (nlr_push(&nlr) == 0) {
+            mp_obj_get_uint(mp_const_none);
+            nlr_pop();
+        } else {
+            mp_obj_print_exception(&mp_plat_print, MP_OBJ_FROM_PTR(nlr.ret_val));
+        }
+
+        // mp_obj_int_get_ll from a non-int object (should raise exception)
+        if (nlr_push(&nlr) == 0) {
+            mp_obj_get_ll(mp_const_none);
+            nlr_pop();
+        } else {
+            mp_obj_print_exception(&mp_plat_print, MP_OBJ_FROM_PTR(nlr.ret_val));
+        }
+
         // call mp_obj_new_exception_args (it's a part of the public C API and not used in the core)
         mp_obj_print_exception(&mp_plat_print, mp_obj_new_exception_args(&mp_type_ValueError, 0, NULL));
     }

py/obj.c

@@ -314,6 +314,36 @@ mp_int_t mp_obj_get_int(mp_const_obj_t arg) {
     return val;
 }
 
+#if MICROPY_LONGINT_IMPL != MICROPY_LONGINT_IMPL_NONE
+mp_uint_t mp_obj_get_uint(mp_const_obj_t arg) {
+    if (!mp_obj_is_exact_type(arg, &mp_type_int)) {
+        mp_obj_t as_int = mp_unary_op(MP_UNARY_OP_INT_MAYBE, (mp_obj_t)arg);
+        if (as_int == MP_OBJ_NULL) {
+            mp_raise_TypeError_int_conversion(arg);
+        }
+        arg = as_int;
+    }
+    return mp_obj_int_get_uint_checked(arg);
+}
+
+long long mp_obj_get_ll(mp_const_obj_t arg) {
+    if (!mp_obj_is_exact_type(arg, &mp_type_int)) {
+        mp_obj_t as_int = mp_unary_op(MP_UNARY_OP_INT_MAYBE, (mp_obj_t)arg);
+        if (as_int == MP_OBJ_NULL) {
+            mp_raise_TypeError_int_conversion(arg);
+        }
+        arg = as_int;
+    }
+    if (mp_obj_is_small_int(arg)) {
+        return MP_OBJ_SMALL_INT_VALUE(arg);
+    } else {
+        long long res;
+        mp_obj_int_to_bytes_impl((mp_obj_t)arg, MP_ENDIANNESS_BIG, sizeof(res), (byte *)&res);
+        return res;
+    }
+}
+#endif
+
 mp_int_t mp_obj_get_int_truncated(mp_const_obj_t arg) {
     if (mp_obj_is_int(arg)) {
         return mp_obj_int_get_truncated(arg);

py/obj.h

@@ -1051,6 +1051,8 @@ static inline bool mp_obj_is_integer(mp_const_obj_t o) {
 }
 
 mp_int_t mp_obj_get_int(mp_const_obj_t arg);
+mp_uint_t mp_obj_get_uint(mp_const_obj_t arg);
+long long mp_obj_get_ll(mp_const_obj_t arg);
 mp_int_t mp_obj_get_int_truncated(mp_const_obj_t arg);
 bool mp_obj_get_int_maybe(mp_const_obj_t arg, mp_int_t *value);
 #if MICROPY_PY_BUILTINS_FLOAT

py/objint_longlong.c

@@ -295,6 +295,22 @@ mp_int_t mp_obj_int_get_checked(mp_const_obj_t self_in) {
     return mp_obj_int_get_truncated(self_in);
 }
 
+mp_uint_t mp_obj_int_get_uint_checked(mp_const_obj_t self_in) {
+    if (mp_obj_is_small_int(self_in)) {
+        if (MP_OBJ_SMALL_INT_VALUE(self_in) >= 0) {
+            return MP_OBJ_SMALL_INT_VALUE(self_in);
+        }
+    } else {
+        const mp_obj_int_t *self = self_in;
+        long long value = self->val;
+        mp_uint_t truncated = (mp_uint_t)value;
+        if (value >= 0 && (long long)truncated == value) {
+            return truncated;
+        }
+    }
+    mp_raise_msg(&mp_type_OverflowError, MP_ERROR_TEXT("overflow converting long int to machine word"));
+}
+
 #if MICROPY_PY_BUILTINS_FLOAT
 mp_float_t mp_obj_int_as_float_impl(mp_obj_t self_in) {
     assert(mp_obj_is_exact_type(self_in, &mp_type_int));

tests/ports/unix/extra_coverage.py

@@ -6,6 +6,16 @@
 
 import errno
 import io
+import uctypes
+
+# create an int-like variable used for coverage of `mp_obj_get_ll`
+buf = bytearray(b"\xde\xad\xbe\xef")
+struct = uctypes.struct(
+    uctypes.addressof(buf),
+    {"f32": uctypes.UINT32 | 0},
+    uctypes.BIG_ENDIAN,
+)
+deadbeef = struct.f32
 
 data = extra_coverage()
 

tests/ports/unix/extra_coverage.py.exp

@@ -94,6 +94,12 @@ data
 1
 0
 0.000000
+deadbeef
+c0ffee777c0ffee
+deadbeef
+0deadbeef
+c0ffee
+000c0ffee
 # runtime utils
 TypeError: unsupported type for __abs__: 'str'
 TypeError: unsupported types for __divmod__: 'str', 'str'
@@ -102,6 +108,8 @@ TypeError: unsupported types for __divmod__: 'str', 'str'
 2
 OverflowError: overflow converting long int to machine word
 OverflowError: overflow converting long int to machine word
+TypeError: can't convert NoneType to int
+TypeError: can't convert NoneType to int
 ValueError: 
 Warning: test
 # format float