panic in debug mode if sleep methods are called in an exception handler (unless PICO_ALLOW_SLEEP_IN_EXCEPTION is set)

src/common/pico_time/time.c

@@ -325,6 +325,11 @@ static int64_t sev_callback(__unused alarm_id_t id, __unused void *user_data) {
 #endif
 
 void sleep_until(absolute_time_t t) {
+#if PICO_ON_DEVICE && !PICO_ALLOW_SLEEP_IN_EXCEPTION && !defined(NDEBUG)
+    if (__get_current_exception()) {
+        panic("Attempted to sleep inside of an exception handler");
+    }
+#endif
 #if !PICO_TIME_DEFAULT_ALARM_POOL_DISABLED
     uint64_t t_us = to_us_since_boot(t);
     uint64_t t_before_us = t_us - PICO_TIME_SLEEP_OVERHEAD_ADJUST_US;

src/rp2_common/hardware_irq/irq.c

@@ -13,7 +13,6 @@
 #include "pico/assert.h"
 
 extern void __unhandled_user_irq(void);
-extern uint __get_current_exception(void);
 
 static inline irq_handler_t *get_vtable(void) {
     return (irq_handler_t *) scb_hw->vtor;

src/rp2_common/pico_platform/include/pico/platform.h

@@ -163,6 +163,12 @@ return a;
 
 #define __check_type_compatible(type_a, type_b) static_assert(__builtin_types_compatible_p(type_a, type_b), __STRING(type_a) " is not compatible with " __STRING(type_b));
 
+/**
+ * Get the current exception level on this core
+ * \return the exception number if the CPU is handling an exception, or 0 otherwise
+ */
+extern uint __get_current_exception(void);
+
 #ifdef __cplusplus
 }
 #endif

src/rp2_common/pico_runtime/runtime.c

@@ -124,9 +124,7 @@ void runtime_init(void) {
 #endif
 
 #ifndef NDEBUG
-    uint32_t xpsr;
+    if (__get_current_exception()) {
-    __asm volatile ("mrs %0, XPSR" : "=r" (xpsr)::);
-    if (xpsr & 0xffu) {
         // crap; started in exception handler
         __asm ("bkpt #0");
     }