From f891eac827a5a0dd70519634d37639a1f96132d3 Mon Sep 17 00:00:00 2001
From: Roland Dobai <dobai.roland@gmail.com>
Date: Thu, 22 Feb 2018 13:46:55 +0100
Subject: [PATCH] ESP32: Optionally disable lookup-tables for esp_err_to_name

---
 components/esp32/Kconfig              | 10 ++++++++++
 components/esp32/esp_err_to_name.c    | 13 ++++++++++++-
 components/esp32/esp_err_to_name.c.in | 13 ++++++++++++-
 3 files changed, 34 insertions(+), 2 deletions(-)

diff --git a/components/esp32/Kconfig b/components/esp32/Kconfig
index 4ac1685d0f..739bfa7fc0 100644
--- a/components/esp32/Kconfig
+++ b/components/esp32/Kconfig
@@ -802,6 +802,16 @@ config COMPATIBLE_PRE_V2_1_BOOTLOADERS
 
         Enabling this setting adds approximately 1KB to the app's IRAM usage.
 
+config ESP_ERR_TO_NAME_LOOKUP
+    bool "Enable lookup of error code strings"
+    default "y"
+    help
+        Functions esp_err_to_name() and esp_err_to_name_r() return string
+        representations of error codes from a pre-generated lookup table.
+        This option can be used to turn off the use of the look-up table in
+        order to save memory but this comes at the price of sacrificing
+        distinguishable (meaningful) output string representations.
+
 endmenu  # ESP32-Specific
 
 menu Wi-Fi
diff --git a/components/esp32/esp_err_to_name.c b/components/esp32/esp_err_to_name.c
index a706a68a58..594c30203c 100644
--- a/components/esp32/esp_err_to_name.c
+++ b/components/esp32/esp_err_to_name.c
@@ -38,6 +38,7 @@
 #include "tcpip_adapter.h"
 #endif
 
+#ifdef CONFIG_ESP_ERR_TO_NAME_LOOKUP
 #define ERR_TBL_IT(err)    {err, #err}
 
 typedef struct {
@@ -359,11 +360,18 @@ static const esp_err_msg_t esp_err_msg_table[] = {
     ERR_TBL_IT(ESP_ERR_FLASH_OP_TIMEOUT),                   /* 65554 0x10012 */
 #   endif
 };
+#endif //CONFIG_ESP_ERR_TO_NAME_LOOKUP
 
-static const char esp_unknown_msg[] = "UNKNOWN ERROR";
+static const char esp_unknown_msg[] =
+#ifdef CONFIG_ESP_ERR_TO_NAME_LOOKUP
+    "ERROR";
+#else
+    "UNKNOWN ERROR";
+#endif //CONFIG_ESP_ERR_TO_NAME_LOOKUP
 
 const char *esp_err_to_name(esp_err_t code)
 {
+#ifdef CONFIG_ESP_ERR_TO_NAME_LOOKUP
     int i;
 
     for (i = 0; i < sizeof(esp_err_msg_table)/sizeof(esp_err_msg_table[0]); ++i) {
@@ -371,12 +379,14 @@ const char *esp_err_to_name(esp_err_t code)
             return esp_err_msg_table[i].msg;
         }
     }
+#endif //CONFIG_ESP_ERR_TO_NAME_LOOKUP
 
     return esp_unknown_msg;
 }
 
 const char *esp_err_to_name_r(esp_err_t code, char *buf, size_t buflen)
 {
+#ifdef CONFIG_ESP_ERR_TO_NAME_LOOKUP
     int i;
 
     for (i = 0; i < sizeof(esp_err_msg_table)/sizeof(esp_err_msg_table[0]); ++i) {
@@ -385,6 +395,7 @@ const char *esp_err_to_name_r(esp_err_t code, char *buf, size_t buflen)
             return buf;
         }
     }
+#endif //CONFIG_ESP_ERR_TO_NAME_LOOKUP
 
     if (strerror_r(code, buf, buflen) == 0) {
         return buf;
diff --git a/components/esp32/esp_err_to_name.c.in b/components/esp32/esp_err_to_name.c.in
index 86085bb885..b6b87312e9 100644
--- a/components/esp32/esp_err_to_name.c.in
+++ b/components/esp32/esp_err_to_name.c.in
@@ -6,6 +6,7 @@
 #endif
 @HEADERS@
 
+#ifdef CONFIG_ESP_ERR_TO_NAME_LOOKUP
 #define ERR_TBL_IT(err)    {err, #err}
 
 typedef struct {
@@ -16,11 +17,18 @@ typedef struct {
 static const esp_err_msg_t esp_err_msg_table[] = {
 @ERROR_ITEMS@
 };
+#endif //CONFIG_ESP_ERR_TO_NAME_LOOKUP
 
-static const char esp_unknown_msg[] = "UNKNOWN ERROR";
+static const char esp_unknown_msg[] =
+#ifdef CONFIG_ESP_ERR_TO_NAME_LOOKUP
+    "ERROR";
+#else
+    "UNKNOWN ERROR";
+#endif //CONFIG_ESP_ERR_TO_NAME_LOOKUP
 
 const char *esp_err_to_name(esp_err_t code)
 {
+#ifdef CONFIG_ESP_ERR_TO_NAME_LOOKUP
     int i;
 
     for (i = 0; i < sizeof(esp_err_msg_table)/sizeof(esp_err_msg_table[0]); ++i) {
@@ -28,12 +36,14 @@ const char *esp_err_to_name(esp_err_t code)
             return esp_err_msg_table[i].msg;
         }
     }
+#endif //CONFIG_ESP_ERR_TO_NAME_LOOKUP
 
     return esp_unknown_msg;
 }
 
 const char *esp_err_to_name_r(esp_err_t code, char *buf, size_t buflen)
 {
+#ifdef CONFIG_ESP_ERR_TO_NAME_LOOKUP
     int i;
 
     for (i = 0; i < sizeof(esp_err_msg_table)/sizeof(esp_err_msg_table[0]); ++i) {
@@ -42,6 +52,7 @@ const char *esp_err_to_name_r(esp_err_t code, char *buf, size_t buflen)
             return buf;
         }
     }
+#endif //CONFIG_ESP_ERR_TO_NAME_LOOKUP
 
     if (strerror_r(code, buf, buflen) == 0) {
         return buf;