From 57edda15a0dbff375f1a6f023170061964151cb6 Mon Sep 17 00:00:00 2001
From: Felipe Neves <felipe.neves@espressif.com>
Date: Mon, 6 Jan 2020 17:28:37 -0300
Subject: [PATCH] shared_stack: added minimal stack size for shared stack,
 configurable via menuconfig

---
 components/esp_common/Kconfig                 |  7 ++++
 .../include/esp_expression_with_stack.h       | 37 +++++++++++--------
 .../newlib/test/test_shared_stack_printf.c    |  2 +
 3 files changed, 30 insertions(+), 16 deletions(-)

diff --git a/components/esp_common/Kconfig b/components/esp_common/Kconfig
index bbed1dca1e..d236d804fa 100644
--- a/components/esp_common/Kconfig
+++ b/components/esp_common/Kconfig
@@ -77,6 +77,13 @@ menu "Common ESP-related"
             FreeRTOS timer task size, see "FreeRTOS timer task stack size" option
             in "FreeRTOS" menu.
 
+    config ESP_MINIMAL_SHARED_STACK_SIZE
+        int "Minimal allowed size for shared stack"
+        default 2048
+        help
+            Minimal value of size, in bytes, accepted to execute a expression
+            with shared stack.
+
     choice ESP_CONSOLE_UART
         prompt "UART for console output"
         default ESP_CONSOLE_UART_DEFAULT
diff --git a/components/esp_common/include/esp_expression_with_stack.h b/components/esp_common/include/esp_expression_with_stack.h
index 3aa12a2538..cd1e4765a8 100644
--- a/components/esp_common/include/esp_expression_with_stack.h
+++ b/components/esp_common/include/esp_expression_with_stack.h
@@ -11,14 +11,16 @@
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.
-
-#ifndef __ESP_EXPRESSION_WITH_STACK_H
-#define __ESP_EXPRESSION_WITH_STACK_H
+#pragma once
 
 #include "freertos/FreeRTOS.h"
 #include "freertos/semphr.h"
 #include "esp_debug_helpers.h"
+#include "esp_log.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
 
 /**
  * @brief Executes a 1-line expression with a application alocated stack
@@ -26,20 +28,21 @@
  * @param stack Pointer to user alocated stack
  * @param stack_size Size of current stack in bytes
  * @param expression Expression or function to be executed using the stack
+ * @note  if either lock, stack or stack size is invalid, the expression will
+ *          be called using the current stack.
  */
-#define ESP_EXECUTE_EXPRESSION_WITH_STACK(lock, stack, stack_size, expression)  \
-({                                                                  \
-    if (lock && stack && stack_size) {                              \
-        uint32_t backup;                                            \
-        xSemaphoreTake(lock, portMAX_DELAY);                        \
-        StackType_t *top_of_stack = esp_switch_stack_setup(stack, stack_size);\
-        esp_switch_stack_enter(top_of_stack, &backup);              \
-        {                                                           \
-            expression;                                             \
-        }                                                           \
-        esp_switch_stack_exit(&backup);                             \
-        xSemaphoreGive(lock);                                       \
-    }                                                               \
+#define ESP_EXECUTE_EXPRESSION_WITH_STACK(lock, stack, stack_size, expression)      \
+({                                                                                  \
+    assert(lock && stack && (stack_size >= CONFIG_ESP_MINIMAL_SHARED_STACK_SIZE));  \
+    uint32_t backup;                                                                \
+    xSemaphoreTake(lock, portMAX_DELAY);                                            \
+    StackType_t *top_of_stack = esp_switch_stack_setup(stack, stack_size);          \
+    esp_switch_stack_enter(top_of_stack, &backup);                                  \
+    {                                                                               \
+        expression;                                                                 \
+    }                                                                               \
+    esp_switch_stack_exit(&backup);                                                 \
+    xSemaphoreGive(lock);                                                           \
 })
 
 /**
@@ -66,4 +69,6 @@ extern void esp_switch_stack_enter(StackType_t *stack, uint32_t *backup_stack);
  */
 extern void esp_switch_stack_exit(uint32_t *backup_stack);
 
+#ifdef __cplusplus
+}
 #endif
\ No newline at end of file
diff --git a/components/newlib/test/test_shared_stack_printf.c b/components/newlib/test/test_shared_stack_printf.c
index 9b020f5815..81997a5a9a 100644
--- a/components/newlib/test/test_shared_stack_printf.c
+++ b/components/newlib/test/test_shared_stack_printf.c
@@ -1,4 +1,5 @@
 #include <stdio.h>
+#include <string.h>
 #include "unity.h"
 #include "freertos/FreeRTOS.h"
 #include "freertos/task.h"
@@ -29,3 +30,4 @@ TEST_CASE("test printf using shared buffer stack", "[newlib]")
     vSemaphoreDelete(printf_lock);   
     free(shared_stack);
 }
+