[BUILD] Use -Os for F3, -O2 for F4/F7 with cmake

CMakeLists.txt

@@ -9,6 +9,10 @@ endif()
 
 set(CMAKE_TOOLCHAIN_FILE "${CMAKE_CURRENT_SOURCE_DIR}/cmake/${TOOLCHAIN}.cmake")
 
+if(CMAKE_BUILD_TYPE STREQUAL "Release" OR CMAKE_BUILD_TYPE STREQUAL "RelWithDebInfo")
+    set(IS_RELEASE_BUILD ON)
+endif()
+
 project(INAV VERSION 2.5.0)
 
 ENABLE_LANGUAGE(ASM)

cmake/arm-none-eabi.cmake

@@ -33,7 +33,7 @@ set(CMAKE_CXX_COMPILER "${TOOLCHAIN_BIN_DIR}/${TARGET_TRIPLET}-g++${TOOL_EXECUTA
 set(CMAKE_OBJCOPY "${TOOLCHAIN_BIN_DIR}/${TARGET_TRIPLET}-objcopy${TOOL_EXECUTABLE_SUFFIX}" CACHE INTERNAL "objcopy tool")
 set(CMAKE_OBJDUMP "${TOOLCHAIN_BIN_DIR}/${TARGET_TRIPLET}-objdump${TOOL_EXECUTABLE_SUFFIX}" CACHE INTERNAL "objdump tool")
 set(CMAKE_SIZE "${TOOLCHAIN_BIN_DIR}/${TARGET_TRIPLET}-size${TOOL_EXECUTABLE_SUFFIX}" CACHE INTERNAL "size tool")
-set(CMAKE_DEBUGER "${TOOLCHAIN_BIN_DIR}/${TARGET_TRIPLET}-gdb${TOOL_EXECUTABLE_SUFFIX}" CACHE INTERNAL "debuger")
+set(CMAKE_DEBUGGER "${TOOLCHAIN_BIN_DIR}/${TARGET_TRIPLET}-gdb${TOOL_EXECUTABLE_SUFFIX}" CACHE INTERNAL "debugger")
 set(CMAKE_CPPFILT "${TOOLCHAIN_BIN_DIR}/${TARGET_TRIPLET}-c++filt${TOOL_EXECUTABLE_SUFFIX}" CACHE INTERNAL "c++filt")
 set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
 set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
@@ -43,11 +43,15 @@ set(CMAKE_EXECUTABLE_SUFFIX ".elf")
 if(NOT CMAKE_CONFIGURATION_TYPES)
     set(CMAKE_CONFIGURATION_TYPES Debug Release RelWithDebInfo)
 endif()
-set(CMAKE_BUILD_TYPE RelWithDebInfo CACHE STRING "Build Type" FORCE)
+if(CMAKE_BUILD_TYPE STREQUAL "")
+    set(CMAKE_BUILD_TYPE RelWithDebInfo)
+endif()
+set(CMAKE_BUILD_TYPE ${CMAKE_BUILD_TYPE} CACHE STRING "Build Type" FORCE)
 set_property(CACHE CMAKE_BUILD_TYPE PROPERTY STRINGS ${CMAKE_CONFIGURATION_TYPES})
 
 set(arm_none_eabi_debug "-Og -g")
-set(arm_none_eabi_release "-Os -DNDEBUG -flto -fuse-linker-plugin")
+# We set -Os or -O2 depending on the MCU family
+set(arm_none_eabi_release "-DNDEBUG -flto -fuse-linker-plugin")
 set(arm_none_eabi_relwithdebinfo "-ggdb3 ${arm_none_eabi_release}")
 
 SET(CMAKE_C_FLAGS_DEBUG ${arm_none_eabi_debug} CACHE INTERNAL "c compiler flags debug")

cmake/stm32f3.cmake

@@ -61,6 +61,11 @@ set(STM32F303_DEFINITIONS
 function(target_stm32f3xx name startup ldscript)
     # F3 targets don't support MSC
     target_stm32(${name} ${startup} ${ldscript} DISABLE_MSC ${ARGN})
+    # F3 targets don't use -O2 to save size
+    if (IS_RELEASE_BUILD)
+        target_compile_options(${name} PRIVATE "-Os")
+        target_link_options(${name} PRIVATE "-Os")
+    endif()
     target_sources(${name} PRIVATE ${STM32_STDPERIPH_SRC} ${STM32F3_STDPERIPH_SRC} ${STM32F3_SRC})
     target_compile_options(${name} PRIVATE ${CORTEX_M4F_COMMON_OPTIONS} ${CORTEX_M4F_COMPILE_OPTIONS})
     target_include_directories(${name} PRIVATE ${STM32F3_INCLUDE_DIRS})

cmake/stm32f4.cmake

@@ -77,6 +77,10 @@ set(STM32F4_DEFINITIONS
 
 function(target_stm32f4xx name startup ldscript)
     target_stm32(${name} ${startup} ${ldscript} ${ARGN})
+    if (IS_RELEASE_BUILD)
+        target_compile_options(${name} PRIVATE "-O2")
+        target_link_options(${name} PRIVATE "-O2")
+    endif()
     target_sources(${name} PRIVATE ${STM32_STDPERIPH_SRC} ${STM32F4_SRC})
     target_compile_options(${name} PRIVATE ${CORTEX_M4F_COMMON_OPTIONS} ${CORTEX_M4F_COMPILE_OPTIONS})
     target_include_directories(${name} PRIVATE ${STM32F4_INCLUDE_DIRS})

cmake/stm32f7.cmake

@@ -84,6 +84,10 @@ set(STM32F7_DEFINITIONS
 
 function(target_stm32f7xx name startup ldscript)
     target_stm32(${name} ${startup} ${ldscript} ${ARGN})
+    if (IS_RELEASE_BUILD)
+        target_compile_options(${name} PRIVATE "-O2")
+        target_link_options(${name} PRIVATE "-O2")
+    endif()
     target_sources(${name} PRIVATE ${STM32F7_HAL_SRC} ${STM32F7_SRC})
     target_compile_options(${name} PRIVATE ${CORTEX_M7_COMMON_OPTIONS} ${CORTEX_M7_COMPILE_OPTIONS})
     target_include_directories(${name} PRIVATE ${STM32F7_INCLUDE_DIRS})