feat(build): Add config to disable warn be considered as errors

The -Werror=all activates error for all warnings in -Wall, however, it
does not activate error for other default warnings, such as:
- int-conversion (pointer from integer w/o a cast)
- incompatible-pointer-types
- discarded-qualifiers

Which are IMO even more important that -Wall.

This commit fixes that by activating error for all warnings (i.e. from
-Wall and default ones) and removing those from -Wextra, as the culprit
commit seemed to address.

Fixes: 60f29236f6 "Build system: Raise warning level" (2016-11-16)

In order to avoid long analysis during esp-idf upgrade, provide a way to
restore the previous -Werror=all behavior that consider only warnings
from -Wall (and not default ones).

Also add a hint to use the Kconfig option on compilation error, but warn
that fixing the code is the preferred way.

Merges https://github.com/espressif/esp-idf/pull/11239

Suggested-By: Ivan Grokhotkov <ivan@espressif.com>

CMakeLists.txt

@@ -201,6 +201,17 @@ if(CONFIG_COMPILER_DISABLE_GCC13_WARNINGS)
                                     "-Wno-dangling-reference")
 endif()
 
+if(CONFIG_COMPILER_DISABLE_DEFAULT_ERRORS)
+    set(compiler_flags "-Wno-error")
+    if(NOT CMAKE_C_COMPILER_ID MATCHES "Clang")
+        list(APPEND compiler_flags "-Werror=all")
+    endif()
+
+    list(APPEND compile_options ${compiler_flags})
+    list(APPEND c_compile_options ${compiler_flags})
+    list(APPEND cxx_compile_options ${compiler_flags})
+endif()
+
 # GCC-specific options
 if(CMAKE_C_COMPILER_ID STREQUAL "GNU")
     list(APPEND compile_options "-fstrict-volatile-bitfields")

Kconfig

@@ -541,6 +541,20 @@ mainmenu "Espressif IoT Development Framework Configuration"
 
                 This option can be enabled for RISC-V targets only.
 
+        config COMPILER_DISABLE_DEFAULT_ERRORS
+            bool "Disable errors for default warnings"
+            default "y"
+            help
+                Enable this option if you do not want default warnings to be considered as errors,
+                especially when updating IDF.
+
+                This is a temporary flag that could help to allow upgrade while having
+                some time to address the warnings raised by those default warnings.
+                Alternatives are:
+                1) fix code (preferred),
+                2) remove specific warnings,
+                3) do not consider specific warnings as error.
+
         config COMPILER_DISABLE_GCC12_WARNINGS
             bool "Disable new warnings introduced in GCC 12"
             default "n"

tools/cmake/build.cmake

@@ -101,12 +101,13 @@ function(__build_set_default_build_specifications)
                                     "-fdata-sections"
                                     # warning-related flags
                                     "-Wall"
-                                    "-Werror=all"
+                                    "-Werror"
                                     "-Wno-error=unused-function"
                                     "-Wno-error=unused-variable"
                                     "-Wno-error=unused-but-set-variable"
                                     "-Wno-error=deprecated-declarations"
                                     "-Wextra"
+                                    "-Wno-error=extra"
                                     "-Wno-unused-parameter"
                                     "-Wno-sign-compare"
                                     # ignore multiple enum conversion warnings since gcc 11

tools/idf_py_actions/hints.yml

@@ -320,6 +320,11 @@
     re: "Error: libusb_open\\(\\) failed with LIBUSB_ERROR_NOT_FOUND"
     hint: "Device drivers are not correct.\nPlease check configuration of USB drivers: https://docs.espressif.com/projects/esp-idf/en/latest/esp32/api-guides/jtag-debugging/configure-ft2232h-jtag.html?highlight=zadig#configure-usb-drivers"
 
+-
+    re: "-Werror=(address-of-packed-member|aggressive-loop-optimizations|attribute-warning|builtin-macro-redefined|cpp|designated-init|deprecated-declarations|discarded-array-qualifiers|discarded-qualifiers|div-by-zero|endif-labels|free-nonheap-object|if-not-aligned|ignored-attributes|incompatible-pointer-types|int-conversion|int-to-pointer-cast|lto-type-mismatch|multichar|overflow|override-init-side-effects|packed-bitfield-compat|pointer-compare|pointer-to-int-cast|return-local-addr|scalar-storage-order|shift-count-negative|shift-count-overflow|sizeof-array-argument|stringop-truncation| switch-bool|switch-outside-range|varargs)"
+    hint: "The error(s) '{}' may appear after IDF upgrade since previous versions were not considering those warnings as errors.\nTo suppress these warnings use 'idf.py menuconfig' to enable configure option 'Compiler options' -> 'Disabe errors for default warnings'\nPlease note that this is not a permanent solution, and this option will be removed in a future update of the ESP-IDF.\nIt is strongly recommended to fix all warnings, as they may indicate potential issues!"
+    match_to_output: True
+
 -
     re: "(-Werror=address|-Werror=use-after-free)"
     hint: "The warning(s) '{}' may appear after compiler update above GCC-12\nTo suppress these warnings use 'idf.py menuconfig' to enable configure option 'Compiler options' -> 'Disable new warnings introduced in GCC 12'\nPlease note that this is not a permanent solution, and this option will be removed in a future update of the ESP-IDF.\nIt is strongly recommended to fix all warnings, as they may indicate potential issues!"

tools/test_apps/configs/sdkconfig.debug_helpers

@@ -5,3 +5,4 @@ CONFIG_FREERTOS_WATCHPOINT_END_OF_STACK=y
 CONFIG_COMPILER_STACK_CHECK_MODE_STRONG=y
 CONFIG_COMPILER_STACK_CHECK=y
 CONFIG_FREERTOS_USE_LIST_DATA_INTEGRITY_CHECK_BYTES=y
+CONFIG_COMPILER_DISABLE_DEFAULT_ERRORS=n

tools/test_apps/system/build_test/sdkconfig.ci.werror

@@ -0,0 +1 @@
+CONFIG_COMPILER_DISABLE_DEFAULT_ERRORS=n