py/objfloat, py/modmath: Ensure M_PI and M_E defined.
In some compliation enviroments (e.g. mbed online compiler) with
strict standards compliance, <math.h> does not define constants such
as M_PI. Provide fallback definitions of M_E and M_PI where needed.
diff --git a/py/objfloat.c b/py/objfloat.c
index aa37f9a..85b8b13 100644
--- a/py/objfloat.c
+++ b/py/objfloat.c
@@ -41,6 +41,14 @@
#if MICROPY_OBJ_REPR != MICROPY_OBJ_REPR_C && MICROPY_OBJ_REPR != MICROPY_OBJ_REPR_D
+// M_E and M_PI are not part of the math.h standard and may not be defined
+#ifndef M_E
+#define M_E (2.7182818284590452354)
+#endif
+#ifndef M_PI
+#define M_PI (3.14159265358979323846)
+#endif
+
typedef struct _mp_obj_float_t {
mp_obj_base_t base;
mp_float_t value;