Fix compile-time conversion MMU2 ErrorCode -> Prusa-Error-Code

and hide some of the implementation details into mmu2_error_converter.cpp
which makes the code in mmu_reporting.cpp much easier to read.

Firmware/mmu2.cpp

@@ -607,22 +607,8 @@ void MMU2::ReportError(ErrorCode ec) {
 
     if( ec != lastErrorCode ){ // deduplicate: only report changes in error codes into the log
         lastErrorCode = ec;
-
-        // Log error format: MMU2:E=32766 ErrorTitle TextDescription
-
-        // The longest error description in errors_list.h is 144 bytes.
-        // and the longest error title is 20 bytes. msg buffer needs
-        // to have enough space to fit both.
-        char msg[192];
-        int len = snprintf(msg, sizeof(msg), "MMU2:E=%hu ", (uint16_t)ec);
-        // Append a human readable form of the error code(s)
-        TranslateErr((uint16_t)ec, &msg[len], 192 - len);
-
-        // beware - the prefix in the message ("MMU2") will get stripped by the logging subsystem
-        // and a correct MMU2 component will be assigned accordingly - see appmain.cpp
-        // Therefore I'm not calling MMU2_ERROR_MSG or MMU2_ECHO_MSG here
         SERIAL_ECHO_START;
-        SERIAL_ECHOLN(msg);
+        SERIAL_ECHOLNRPGM( PrusaErrorTitle(PrusaErrorCodeIndex((uint16_t)ec)) );
     }
 
     static_assert(mmu2Magic[0] == 'M' 

Firmware/mmu2/buttons.h

@@ -0,0 +1,22 @@
+#pragma once
+#include <stdint.h>
+
+// Helper macros to parse the operations from Btns()
+#define BUTTON_OP_HI_NIBBLE(X) ( ( X & 0xF0 ) >> 4 )
+#define BUTTON_OP_LO_NIBBLE(X) ( X & 0x0F )
+
+namespace MMU2 {
+
+/// Will be mapped onto dialog button responses in the FW
+/// Those responses have their unique+translated texts as well
+enum class ButtonOperations : uint8_t {
+    NoOperation = 0,
+    Retry       = 1,
+    Continue    = 2,
+    RestartMMU  = 3,
+    Unload      = 4,
+    StopPrint   = 5,
+    DisableMMU  = 6,
+};
+
+} // namespace MMU2

Firmware/mmu2/errors_list.h

@@ -1,9 +1,11 @@
 // Extracted from Prusa-Error-Codes repo
 // Subject to automation and optimization
+// BEWARE - this file shall be included only into mmu2_error_converter.cpp, not anywhere else!
 #pragma once
 #include "inttypes.h"
 #include "../language.h"
 #include <avr/pgmspace.h>
+#include "buttons.h"
 
 namespace MMU2 {
 
@@ -72,7 +74,7 @@ typedef enum : uint16_t {
 // and inadvertedly falls back to copying the whole structure into RAM (which is obviously unwanted).
 // But since this file ought to be generated in the future from yaml prescription,
 // it really makes no difference if there are "nice" data structures or plain arrays.
-static const uint16_t errorCodes[] PROGMEM = {
+static const constexpr uint16_t errorCodes[] PROGMEM = {
     ERR_MECHANICAL_FINDA_DIDNT_TRIGGER,
     ERR_MECHANICAL_FINDA_DIDNT_GO_OFF,
     ERR_MECHANICAL_FSENSOR_DIDNT_TRIGGER,
@@ -260,19 +262,6 @@ static const char * const errorDescs[] PROGMEM = {
     descUNLOAD_MANUALLY
 };
 
-
-/// Will be mapped onto dialog button responses in the FW
-/// Those responses have their unique+translated texts as well
-enum class ButtonOperations : uint8_t {
-    NoOperation = 0,
-    Retry       = 1,
-    Continue    = 2,
-    RestartMMU  = 3,
-    Unload      = 4,
-    StopPrint   = 5,
-    DisableMMU  = 6,
-};
-
 // we have max 3 buttons/operations to select from
 // one of them is "More" to show the explanation text normally hidden in the next screens.
 // 01234567890123456789
@@ -297,10 +286,6 @@ static const char * const btnOperation[] PROGMEM = {
     btnDisableMMU
 };
 
-// Helper macros to parse the operations from Btns()
-#define BUTTON_OP_HI_NIBBLE(X) ( ( X & 0xF0 ) >> 4 )
-#define BUTTON_OP_LO_NIBBLE(X) ( X & 0x0F )
-
 // We have 8 different operations/buttons at this time, so we need at least 4 bits to encode each.
 // Since one of the buttons is always "More", we can skip that one.
 // Therefore we need just 1 byte to describe the necessary buttons for each screen.
@@ -350,4 +335,8 @@ static const uint8_t errorButtons[] PROGMEM = {
     Btns(ButtonOperations::Retry, ButtonOperations::NoOperation),
 };
 
+static_assert( sizeof(errorCodes) / sizeof(errorCodes[0]) == sizeof(errorDescs) / sizeof (errorDescs[0]));
+static_assert( sizeof(errorCodes) / sizeof(errorCodes[0]) == sizeof(errorTitles) / sizeof (errorTitles[0]));
+static_assert( sizeof(errorCodes) / sizeof(errorCodes[0]) == sizeof(errorButtons) / sizeof (errorButtons[0]));
+
 } // namespace MMU2

Firmware/mmu2_error_converter.cpp

@@ -20,16 +20,17 @@ constexpr InputIt find_if_cx(InputIt first, InputIt last, UnaryPredicate p) {
 // Making a constexpr FindError should instruct the compiler to optimize the ConvertMMUErrorCode
 // in such a way that no searching will ever be done at runtime.
 // A call to FindError then compiles to a single instruction even on the AVR.
-static constexpr uint16_t FindErrorIndex(uint32_t pec) {
-    constexpr uint32_t errorCodesSize = sizeof(errorCodes) / sizeof(errorCodes[0]);
-    constexpr auto errorCodesEnd = errorCodes + errorCodesSize;
-    auto i = find_if_cx(errorCodes, errorCodesEnd, [pec](uint16_t ed) -> bool {
-        return ed == pec;
-    });
-    return i != errorCodesEnd ? *i : errorCodes[errorCodesSize - 1];
+static constexpr uint8_t FindErrorIndex(uint16_t pec) {
+    constexpr uint16_t errorCodesSize = sizeof(errorCodes) / sizeof(errorCodes[0]);
+    constexpr const auto *errorCodesEnd = errorCodes + errorCodesSize;
+    const auto *i = find_if_cx(errorCodes, errorCodesEnd, [pec](uint16_t ed){ return ed == pec; });
+    return (i != errorCodesEnd) ? (i-errorCodes) : (errorCodesSize - 1);
 }
 
-const uint16_t MMUErrorCodeIndex(uint16_t ec) {
+// check that the searching algoritm works
+static_assert( FindErrorIndex(ERR_MECHANICAL_FINDA_DIDNT_TRIGGER) == 0);
+
+uint8_t PrusaErrorCodeIndex(uint16_t ec) {
     switch (ec) {
     case (uint16_t)ErrorCode::FINDA_DIDNT_SWITCH_ON:
         return FindErrorIndex(ERR_MECHANICAL_FINDA_DIDNT_TRIGGER);
@@ -66,9 +67,9 @@ const uint16_t MMUErrorCodeIndex(uint16_t ec) {
         return FindErrorIndex(ERR_SYSTEM_UNLOAD_MANUALLY);
     }
 
-//    // TMC-related errors - multiple of these can occur at once
-//    // - in such a case we report the first which gets found/converted into Prusa-Error-Codes (usually the fact, that one TMC has an issue is serious enough)
-//    // By carefully ordering the checks here we can prioritize the errors being reported to the user.
+    // TMC-related errors - multiple of these can occur at once
+    // - in such a case we report the first which gets found/converted into Prusa-Error-Codes (usually the fact, that one TMC has an issue is serious enough)
+    // By carefully ordering the checks here we can prioritize the errors being reported to the user.
     if (ec & (uint16_t)ErrorCode::TMC_PULLEY_BIT) {
         if (ec & (uint16_t)ErrorCode::TMC_IOIN_MISMATCH)
             return FindErrorIndex(ERR_ELECTRICAL_PULLEY_TMC_DRIVER_ERROR);
@@ -110,19 +111,32 @@ const uint16_t MMUErrorCodeIndex(uint16_t ec) {
             return FindErrorIndex(ERR_TEMPERATURE_IDLER_TMC_OVERHEAT_ERROR);
     }
 
-//    // if nothing got caught, return a generic error
-//    return FindError(ERR_OTHER);
+    // if nothing got caught, return a generic runtime error
+    return FindErrorIndex(ERR_SYSTEM_FW_RUNTIME_ERROR);
+}
+
+uint16_t PrusaErrorCode(uint8_t i){
+    return pgm_read_word(errorCodes + i);
+}
+
+const char * const PrusaErrorTitle(uint8_t i){
+    return (const char * const)pgm_read_ptr(errorTitles + i);
+}
+
+const char * const PrusaErrorDesc(uint8_t i){
+    return (const char * const)pgm_read_ptr(errorDescs + i);
+}
+
+uint8_t PrusaErrorButtons(uint8_t i){
+    return pgm_read_byte(errorButtons + i);
+}
+
+const char * const PrusaErrorButtonTitle(uint8_t bi){
+    return (const char * const)pgm_read_ptr(btnOperation + bi);
 }
 
-void TranslateErr(uint16_t ec, char *dst, size_t dstSize) { 
-    uint16_t ei = MMUErrorCodeIndex(ec);
-    // just to prevent the compiler from stripping the data structures from the final binary for now
-    *dst = errorButtons[ei];
-    snprintf(
-        dst, dstSize, "%S %S",
-        static_cast<const char * const>(pgm_read_ptr(&errorTitles[ei])),
-        static_cast<const char * const>(pgm_read_ptr(&errorDescs[ei]))
-    );
+const char * const PrusaErrorButtonMore(){
+    return btnMore;
 }
 
 } // namespace MMU2

Firmware/mmu2_error_converter.h

@@ -3,6 +3,32 @@
 #include <stddef.h>
 
 namespace MMU2 {
-const uint16_t MMUErrorCodeIndex(uint16_t ec);
-void TranslateErr(uint16_t ec, char *dst, size_t dstSize);
-}
+
+/// Translates MMU2::ErrorCode into an index of Prusa-Error-Codes
+/// Basically this is the way to obtain an index into all other functions in this API
+uint8_t PrusaErrorCodeIndex(uint16_t ec);
+
+/// @returns pointer to a PROGMEM string representing the Title of the Prusa-Error-Codes error
+/// @param i index of the error - obtained by calling ErrorCodeIndex
+const char * const PrusaErrorTitle(uint8_t i);
+
+/// @returns pointer to a PROGMEM string representing the multi-page Description of the Prusa-Error-Codes error
+/// @param i index of the error - obtained by calling ErrorCodeIndex
+const char * const PrusaErrorDesc(uint8_t i);
+
+/// @returns the actual numerical value of the Prusa-Error-Codes error
+/// @param i index of the error - obtained by calling ErrorCodeIndex
+uint16_t PrusaErrorCode(uint8_t i);
+
+/// @returns Btns pair of buttons for a particular Prusa-Error-Codes error
+/// @param i index of the error - obtained by calling ErrorCodeIndex
+uint8_t PrusaErrorButtons(uint8_t i);
+
+/// @returns pointer to a PROGMEM string representing the Title of a button
+/// @param i index of the error - obtained by calling PrusaErrorButtons + extracting low or high nibble from the Btns pair
+const char * const PrusaErrorButtonTitle(uint8_t bi);
+
+/// @returns pointer to a PROGMEM string representing the "More" button
+const char * const PrusaErrorButtonMore();
+
+} // namespace MMU2

Firmware/mmu2_reporting.cpp

@@ -1,8 +1,9 @@
 #include "mmu2_reporting.h"
 #include "mmu2_error_converter.h"
 #include "mmu2/error_codes.h"
-#include "mmu2/errors_list.h"
+#include "mmu2/buttons.h"
 #include "ultralcd.h"
+#include "language.h"
 
 namespace MMU2 {
 
@@ -26,13 +27,13 @@ void ReportErrorHook(CommandInProgress cip, uint16_t ec) {
     //! |prusa3d.com/ERR04504|     <- URL 20 characters
     //! |                    |     <- empty line
     //! |>Retry  >Done >MoreW|     <- buttons
-    const uint16_t ei = MMUErrorCodeIndex((uint16_t)ec);
+    const uint8_t ei = PrusaErrorCodeIndex(ec);
     uint8_t choice_selected = 0;
     bool two_choices = false;
 
     // Read and determine what operations should be shown on the menu
     // Note: uint16_t is used here to avoid compiler warning. uint8_t is only half the size of void*
-    const uint8_t button_operation   = reinterpret_cast<uint16_t>(const_cast<void*>(pgm_read_ptr(&errorButtons[ei])));
+    const uint8_t button_operation   = PrusaErrorButtons(ei);
     const uint8_t button_high_nibble = BUTTON_OP_HI_NIBBLE(button_operation);
     const uint8_t button_low_nibble  = BUTTON_OP_LO_NIBBLE(button_operation);
 
@@ -46,23 +47,18 @@ void ReportErrorHook(CommandInProgress cip, uint16_t ec) {
 back_to_choices:
     lcd_clear();
     lcd_update_enable(false);
-
+     
     // Print title and header
-    lcd_printf_P(PSTR("%S\nprusa3d.com/ERR04%hu"),
-        static_cast<const char * const>(pgm_read_ptr(&errorTitles[ei])),
-        reinterpret_cast<uint16_t>(const_cast<void*>(pgm_read_ptr(&errorCodes[ei])))
-    );
+    lcd_printf_P(PSTR("%S\nprusa3d.com/ERR04%hu"), _T(PrusaErrorTitle(ei)), PrusaErrorCode(ei) );
 
     // Render the choices and store selection in 'choice_selected'
     choice_selected = lcd_show_multiscreen_message_with_choices_and_wait_P(
         NULL, // NULL, since title screen is not in PROGMEM
         false,
         two_choices ? LEFT_BUTTON_CHOICE : MIDDLE_BUTTON_CHOICE,
-        static_cast<const char * const>(pgm_read_ptr(&btnOperation[button_low_nibble - 1])),
-        two_choices ?
-            btnMore
-            : static_cast<const char * const>(pgm_read_ptr(&btnOperation[button_high_nibble - 1])),
-        two_choices ? nullptr : btnMore,
+        _T(PrusaErrorButtonTitle(button_low_nibble - 1)),
+        _T(two_choices ? PrusaErrorButtonMore() : PrusaErrorButtonTitle(button_high_nibble - 1)),
+        two_choices ? nullptr : _T(PrusaErrorButtonMore()),
         two_choices ? 
             10 // If two choices, allow the first choice to have more characters
             : 7
@@ -72,9 +68,7 @@ back_to_choices:
         || (!two_choices && choice_selected == RIGHT_BUTTON_CHOICE)) // Three choices and right most button selected
     {
         // 'More' show error description
-        lcd_show_fullscreen_message_and_wait_P(
-            static_cast<const char * const>(pgm_read_ptr(&errorDescs[ei]))
-        );
+        lcd_show_fullscreen_message_and_wait_P(_T(PrusaErrorDesc(ei)));
 
         // Return back to the choice menu
         goto back_to_choices;
@@ -115,7 +109,7 @@ back_to_choices:
 
 void ReportProgressHook(CommandInProgress cip, uint16_t ec) {
     custom_message_type = CustomMsg::MMUProgress;
-    lcd_setstatuspgm( ProgressCodeToText(ec) );
+    lcd_setstatuspgm( _T(ProgressCodeToText(ec)) );
 }
 
 Buttons ButtonPressed(uint16_t ec) { 

Firmware/ultralcd.cpp

@@ -3233,8 +3233,8 @@ void lcd_show_choices_prompt_P(uint8_t selected, const char *first_choice, const
 //! @retval 1 first choice selected by user
 //! @retval 2 third choice selected by user
 //! @retval -1 screen timed out (only possible if allow_timeouting is true)
-int8_t lcd_show_multiscreen_message_with_choices_and_wait_P(const char *msg, bool allow_timeouting, uint8_t default_selection,
-        const char *first_choice, const char *second_choice, const char *third_choice, uint8_t second_col)
+int8_t lcd_show_multiscreen_message_with_choices_and_wait_P(const char * const msg, bool allow_timeouting, uint8_t default_selection,
+       const char * const first_choice, const char * const second_choice, const char * const third_choice, uint8_t second_col)
 {
 	const char *msg_next = msg ? lcd_display_message_fullscreen_P(msg) : NULL;
 	bool multi_screen = msg_next != NULL;

Firmware/ultralcd.h

@@ -82,8 +82,8 @@ extern void lcd_show_fullscreen_message_and_wait_P(const char *msg);
 extern int8_t lcd_show_yes_no_and_wait(bool allow_timeouting = true, uint8_t default_selection = MIDDLE_BUTTON_CHOICE);
 // 1: no, 0: yes, -1: timeouted
 extern int8_t lcd_show_fullscreen_message_yes_no_and_wait_P(const char *msg, bool allow_timeouting = true, uint8_t default_selection = MIDDLE_BUTTON_CHOICE);
-extern int8_t lcd_show_multiscreen_message_with_choices_and_wait_P(const char *msg, bool allow_timeouting, uint8_t default_selection,
-        const char *first_choice, const char *second_choice, const char *third_choice = nullptr, uint8_t second_col = 7);
+extern int8_t lcd_show_multiscreen_message_with_choices_and_wait_P(const char * const msg, bool allow_timeouting, uint8_t default_selection,
+        const char * const first_choice, const char * const second_choice, const char * const third_choice = nullptr, uint8_t second_col = 7);
 extern int8_t lcd_show_multiscreen_message_yes_no_and_wait_P(const char *msg, bool allow_timeouting = true, uint8_t default_selection = MIDDLE_BUTTON_CHOICE);
 // Ask the user to move the Z axis up to the end stoppers and let
 // the user confirm that it has been done.