build: add CONFIG_APP_REPRODUCIBLE_BUILD menuconfig option to produce reproducible binaries

.gitlab/ci/host-test.yml

@@ -64,6 +64,23 @@ test_ldgen_on_host:
   variables:
     LC_ALL: C.UTF-8
 
+test_reproducible_build:
+  extends: .host_test_template
+  script:
+    - ./tools/ci/test_reproducible_build.sh
+  artifacts:
+    when: on_failure
+    paths:
+      - "**/sdkconfig"
+      - "**/build*/*.bin"
+      - "**/build*/*.elf"
+      - "**/build*/*.map"
+      - "**/build*/flasher_args.json"
+      - "**/build*/*.bin"
+      - "**/build*/bootloader/*.bin"
+      - "**/build*/partition_table/*.bin"
+    expire_in: 1 week
+
 .host_fuzzer_test_template:
   extends:
     - .host_test_template

.gitlab/ci/rules.yml

@@ -131,6 +131,8 @@
   - "tools/detect_python.sh"
   - "tools/detect_python.fish"
 
+  - "tools/ci/test_reproducible_build.sh"
+
 .patterns-windows: &patterns-windows
   - "tools/windows/**/*"
 

CMakeLists.txt

@@ -147,7 +147,13 @@ endif()
 if(NOT ${CMAKE_C_COMPILER_VERSION} VERSION_LESS 8.0.0)
     if(CONFIG_COMPILER_HIDE_PATHS_MACROS)
         list(APPEND compile_options "-fmacro-prefix-map=${CMAKE_SOURCE_DIR}=.")
-        list(APPEND compile_options "-fmacro-prefix-map=${IDF_PATH}=IDF")
+        list(APPEND compile_options "-fmacro-prefix-map=${IDF_PATH}=/IDF")
+    endif()
+
+    if(CONFIG_APP_REPRODUCIBLE_BUILD)
+        list(APPEND compile_options "-fdebug-prefix-map=${IDF_PATH}=/IDF")
+        list(APPEND compile_options "-fdebug-prefix-map=${PROJECT_DIR}=/IDF_PROJECT")
+        list(APPEND compile_options "-fdebug-prefix-map=${BUILD_DIR}=/IDF_BUILD")
     endif()
 endif()
 

Kconfig

@@ -201,6 +201,13 @@ mainmenu "Espressif IoT Development Framework Configuration"
         config APP_BUILD_USE_FLASH_SECTIONS
             bool # Whether to place code/data into memory-mapped flash sections
 
+        config APP_REPRODUCIBLE_BUILD
+            bool "Enable reproducible build"
+            default n
+            select COMPILER_HIDE_PATHS_MACROS
+            help
+                If enabled, all date, time, and path information would be eliminated.
+
     endmenu # Build type
 
     source "$COMPONENT_KCONFIGS_PROJBUILD_SOURCE_FILE"

components/app_update/esp_app_desc.c

@@ -32,7 +32,7 @@ const __attribute__((section(".rodata_desc"))) esp_app_desc_t esp_app_desc = {
     .secure_version = 0,
 #endif
 
-#ifdef CONFIG_APP_COMPILE_TIME_DATE
+#if defined(CONFIG_APP_COMPILE_TIME_DATE) && !defined(CONFIG_APP_REPRODUCIBLE_BUILD)
     .time = __TIME__,
     .date = __DATE__,
 #else

components/bootloader_support/src/bootloader_init.c

@@ -91,5 +91,7 @@ void bootloader_enable_random(void)
 void bootloader_print_banner(void)
 {
     ESP_LOGI(TAG, "ESP-IDF %s 2nd stage bootloader", IDF_VER);
+#ifndef CONFIG_APP_REPRODUCIBLE_BUILD
     ESP_LOGI(TAG, "compile time " __TIME__);
+#endif
 }

tools/ci/executable-list.txt

@@ -67,6 +67,7 @@ tools/ci/test_build_system.sh
 tools/ci/test_build_system_cmake.sh
 tools/ci/test_check_kconfigs.py
 tools/ci/test_configure_ci_environment.sh
+tools/ci/test_reproducible_build.sh
 tools/cmake/convert_to_cmake.py
 tools/docker/entrypoint.sh
 tools/docker/hooks/build

tools/ci/test_reproducible_build.sh

@@ -0,0 +1,26 @@
+#!/usr/bin/env bash
+
+set -euo
+
+for path in \
+  "examples/get-started/hello_world" \
+  "examples/bluetooth/nimble/blecent"; do
+  cd "${IDF_PATH}/${path}"
+
+  echo "CONFIG_APP_REPRODUCIBLE_BUILD=y" >>sdkconfig.defaults
+  rm -f sdkconfig
+
+  idf.py -B build_first fullclean build
+  idf.py -B build_second fullclean build
+
+  for item in \
+    "partition_table/partition-table.bin" \
+    "bootloader/bootloader.bin" \
+    "bootloader/bootloader.elf" \
+    "bootloader/bootloader.map" \
+    "*.bin" \
+    "*.elf" \
+    "*.map"; do
+    diff -s build_first/${item} build_second/${item} # use glob, don't use double quotes
+  done
+done