STM32Cube platform, STM32U5 change only: build with ARM GCC 13.2.1.

The changes of commit a8603c0 (for the STM32Cube platform, STM32F4 case) are now applied to the STM32Cube platform STM32U5 case.

port/platform/stm32cube/mcu/stm32u5/runner/Makefile

@@ -90,10 +90,14 @@ override CFLAGS += \
 	$(DEFINES) -mcpu=cortex-m33 -mfpu=fpv5-sp-d16 -mfloat-abi=hard -mthumb -std=gnu11 -g3 -O0 -Wall \
 	-ffunction-sections -fdata-sections -fstack-usage --specs=nano.specs -MMD -MP $(U_FLAGS)
 
+# Note: the --no-warn-rwx-segments suppression was added in moving from
+# GCC ARM "10-2020-q4-major" to "13.2.rel1" as the behaviour of the linker
+# file is outside our control
 override LDFLAGS += \
 	-debug -mcpu=cortex-m33 -mfpu=fpv5-sp-d16 -mfloat-abi=hard -mthumb -static -T"$(PLATFORM_PATH)/app/STM32U575ZITX_FLASH.ld" \
 	-Wl,-Map="$(OUTPUT_DIRECTORY)/runner.map" -Wl,--gc-sections --specs=nano.specs -Wl,--start-group -lc -lm -Wl,--end-group \
-	-Wl,--defsym=RTOS2_BYTE_POOL_SIZE=753664
+	-Wl,--defsym=RTOS2_BYTE_POOL_SIZE=753664 \
+	-Wl,--no-warn-rwx-segments
 
 # Include STM32 common files; this requires STM32CUBE_HAL_PATH and will give us the
 # common parts of STM32CUBE_FW_SRC and STM32CUBE_FW_INC (i.e. the HAL etc.)

port/platform/stm32cube/src/u_port_os_pure_cmsis.c

@@ -167,11 +167,20 @@ int32_t uPortTaskDelete(const uPortTaskHandle_t taskHandle)
     // When _LITE_EXIT is enabled the stdio streams stdout, stdin and stderr are not closed
     // when deallocating the task, resulting in memory leaks if the deleted task have been using
     // these io streams.
-    // Note: The workaround below only works when a task deletes itself, which is always
-    // the case with CMSIS on FreeRTOS and is never the case otherwise (i.e. with ThreadX).
-#if defined(U_PORT_STM32_CMSIS_ON_FREERTOS) && \
-    defined(__NEWLIB__) && defined(_LITE_EXIT) && defined(_REENT_SMALL) && \
-    !defined(_REENT_GLOBAL_STDIO_STREAMS) && !defined(_UNBUF_STREAM_OPT)
+    // Note: The workaround below only works when a task deletes itself.
+    // Note: we used to switch this code in and out based on the following conditional:
+    //
+    // #if defined(__NEWLIB__) && defined(_LITE_EXIT) && defined(_REENT_SMALL) &&
+    //    !defined(_REENT_GLOBAL_STDIO_STREAMS) && !defined(_UNBUF_STREAM_OPT)
+    //
+    // However, this doesn't work for GCC ARM version 11 and later, ALL printf()'s just stop here.
+    // config.h, newlib.h and reent.h are not changed between the versions, so we can only
+    // surmise that newlib library is being built with a different set of WANT_ switches.
+    // It would be best to switch the code in or out based on the GCC version but that doesn't
+    // seem to be available in a header file.  Instead, the point at which the behaviour
+    // changed was also the point at which the newlib major version changed to 4, so we
+    // use that instead.
+#if defined(__NEWLIB__) && (__NEWLIB__ < 4)
     if (taskHandle == NULL) {
         if (stdout) {
             fclose(stdout);