Too much use memory even though only basic project.

[HY-PARK]

Below picture express memory usage about basic project(empty main).
I think that need to insert gcc compiler option for remove unused function.

[GabrielKim]

Could you tell me the current GCC Option? (CMAKE_C_FLAGS)
It maybe not apply to 'c flag' option when compile.
you will dumping a log after command "cmake -LAH".

[HY-PARK]

Below is my default dumping log..

-- The C compiler identification is GNU 4.9.2
-- Check for working C compiler: /usr/bin/avr-gcc
-- Check for working C compiler: /usr/bin/avr-gcc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Detecting C compile features
-- Detecting C compile features - done
-- Configuring done
-- Generating done
-- Build files have been written to: /home/risc-v/targetexpert/TESuit/Projects/TESuit_Test/build
-- Cache values
// ar
CMAKE_AR:STRING=avr-nr

// Choose the type of build, options are: None Debug Release RelWithDebInfo MinSizeRel ...
CMAKE_BUILD_TYPE:STRING=

// Enable/Disable color output during build.
CMAKE_COLOR_MAKEFILE:BOOL=ON

// C compiler
CMAKE_C_COMPILER:STRING=/usr/bin/avr-gcc

// A wrapper around 'ar' adding the appropriate '--plugin' option for the GCC compiler
CMAKE_C_COMPILER_AR:FILEPATH=/usr/bin/gcc-ar

// A wrapper around 'ranlib' adding the appropriate '--plugin' option for the GCC compiler
CMAKE_C_COMPILER_RANLIB:FILEPATH=/usr/bin/gcc-ranlib

// Flags used by the C compiler during all build types.
CMAKE_C_FLAGS:STRING=

// Flags used by the C compiler during DEBUG builds.
CMAKE_C_FLAGS_DEBUG:STRING=-g

// Flags used by the C compiler during MINSIZEREL builds.
CMAKE_C_FLAGS_MINSIZEREL:STRING=-Os -DNDEBUG

// Flags used by the C compiler during RELEASE builds.
CMAKE_C_FLAGS_RELEASE:STRING=-O3 -DNDEBUG

// Flags used by the C compiler during RELWITHDEBINFO builds.
CMAKE_C_FLAGS_RELWITHDEBINFO:STRING=-O2 -g -DNDEBUG

// Flags used by the linker during all build types.
CMAKE_EXE_LINKER_FLAGS:STRING=

// Flags used by the linker during DEBUG builds.
CMAKE_EXE_LINKER_FLAGS_DEBUG:STRING=

// Flags used by the linker during MINSIZEREL builds.
CMAKE_EXE_LINKER_FLAGS_MINSIZEREL:STRING=

// Flags used by the linker during RELEASE builds.
CMAKE_EXE_LINKER_FLAGS_RELEASE:STRING=

// Flags used by the linker during RELWITHDEBINFO builds.
CMAKE_EXE_LINKER_FLAGS_RELWITHDEBINFO:STRING=

// Enable/Disable output of compile commands during generation.
CMAKE_EXPORT_COMPILE_COMMANDS:BOOL=OFF

// Install path prefix, prepended onto install directories.
CMAKE_INSTALL_PREFIX:PATH=/usr/local

// Default Linker
CMAKE_LINKER:STRING=/usr/bin/avr-ld

// Path to a program.
CMAKE_MAKE_PROGRAM:FILEPATH=/usr/bin/make

// Flags used by the linker during the creation of modules during all build types.
CMAKE_MODULE_LINKER_FLAGS:STRING=

// Flags used by the linker during the creation of modules during DEBUG builds.
CMAKE_MODULE_LINKER_FLAGS_DEBUG:STRING=

// Flags used by the linker during the creation of modules during MINSIZEREL builds.
CMAKE_MODULE_LINKER_FLAGS_MINSIZEREL:STRING=

// Flags used by the linker during the creation of modules during RELEASE builds.
CMAKE_MODULE_LINKER_FLAGS_RELEASE:STRING=

// Flags used by the linker during the creation of modules during RELWITHDEBINFO builds.
CMAKE_MODULE_LINKER_FLAGS_RELWITHDEBINFO:STRING=

// nm
CMAKE_NM:STRING=avr-nm

// Path to a program.
CMAKE_OBJCOPY:FILEPATH=/usr/bin/objcopy

// Path to a program.
CMAKE_OBJDUMP:FILEPATH=/usr/bin/objdump

// ranlib
CMAKE_RANLIB:STRING=avr-ranlib

// Flags used by the linker during the creation of shared libraries during all build types.
CMAKE_SHARED_LINKER_FLAGS:STRING=

// Flags used by the linker during the creation of shared libraries during DEBUG builds.
CMAKE_SHARED_LINKER_FLAGS_DEBUG:STRING=

// Flags used by the linker during the creation of shared libraries during MINSIZEREL builds.
CMAKE_SHARED_LINKER_FLAGS_MINSIZEREL:STRING=

// Flags used by the linker during the creation of shared libraries during RELEASE builds.
CMAKE_SHARED_LINKER_FLAGS_RELEASE:STRING=

// Flags used by the linker during the creation of shared libraries during RELWITHDEBINFO builds.
CMAKE_SHARED_LINKER_FLAGS_RELWITHDEBINFO:STRING=

// If set, runtime paths are not added when installing shared libraries, but are added when building.
CMAKE_SKIP_INSTALL_RPATH:BOOL=NO

// If set, runtime paths are not added when using shared libraries.
CMAKE_SKIP_RPATH:BOOL=NO

// Flags used by the linker during the creation of static libraries during all build types.
CMAKE_STATIC_LINKER_FLAGS:STRING=

// Flags used by the linker during the creation of static libraries during DEBUG builds.
CMAKE_STATIC_LINKER_FLAGS_DEBUG:STRING=

// Flags used by the linker during the creation of static libraries during MINSIZEREL builds.
CMAKE_STATIC_LINKER_FLAGS_MINSIZEREL:STRING=

// Flags used by the linker during the creation of static libraries during RELEASE builds.
CMAKE_STATIC_LINKER_FLAGS_RELEASE:STRING=

// Flags used by the linker during the creation of static libraries during RELWITHDEBINFO builds.
CMAKE_STATIC_LINKER_FLAGS_RELWITHDEBINFO:STRING=

// strip
CMAKE_STRIP:STRING=avr-strip

// If this value is on, makefiles will be generated without the .SILENT directive, and all commands will be echoed to the console during the make.  This is useful for debugging only. With Visual Studio IDE projects all commands are done without /nologo.
CMAKE_VERBOSE_MAKEFILE:BOOL=FALSE

---

Also I insert 2 compiler option -fdata-sections -ffunction-sections and build
So i get a better memory usage like this :)

[Mike7Chu]

It is better idea adding options such as -fdata-sections -ffunction-sections.
It is useful to optimize at linking.
These options use Arduino Sketch.
But It can't use with debugging option.

[Mike7Chu]

There are more information.
I'm not sure the information is exact, but It is worth trying later.
More information to optimize at building

[HY-PARK]

@Mike7Chu
Very very thx your opinion.
In my opinion that we need use the linker flag.
Because Debugging issues are definitely not common
This link will help you.(https://community.nxp.com/thread/389145)

Also I thank your opinion. I don't have any chance to think about these flag. It was a nice chance to me!