Issue in exporting sample to GCC (ARM Embedded) toolchain on mbed online compiler

[TomoYamanaka]

Description

• Type: Bug
• Priority: Major

---

Bug

As shown below, it seems that '-include mbed_config.h' is specified for g++ compiler
option only when exporting a program to GCC ARM Embedded on mbed online compiler.

CC_FLAGS = $(CPU) -c -g -fno-common -fmessage-length=0 -Wall -Wextra -Wno-unused-parameter -Wno-missing-field-initializers
CC_FLAGS += -fno-exceptions -fno-builtin -ffunction-sections -fdata-sections -fno-delete-null-pointer-checks -fomit-frame-pointer
CC_FLAGS += -MMD -MP


CPPC_FLAGS = -c -Wall -Wextra -Wno-unused-parameter -Wno-missing-field-initializers -fmessage-length=0 -fno-exceptions 
*snip* -DDEVICE_SPISLAVE=1 -DDEVICE_ANALOGIN=1 -DDEVICE_PWMOUT=1 -include mbed_config.h -MMD -MP

We think -include mbed_config.h should be needed not only for CPPC_FLAGS, but also for both CC_FLAGS and CPPC_FLAGS.
Otherwise, a compilation error should occur.

Please note that the issue might not occur if mbed export command is used for export.

Could you give us your opinion about the above?

[0xc0170]

cc @theotherjimmy

[theotherjimmy]

@TomoYamanaka That's a good point. That's why the tools already export a the exact commands that would be used to compile when run throught mbed-cli. If you export a project in the online compiler to GCC (ARM Embedded) you will see:

C_FLAGS += -include
C_FLAGS += mbed_config.h

#[snip]
CXX_FLAGS += -include
CXX_FLAGS += mbed_config.h

Which is what you are asking for, I think.

[TomoYamanaka]

@theotherjimmy

It was confirmed that at present, mbed_config.h specified as the include file for both gcc and g++ though I’m not sure when it was updated.

However, we faced another issue.
If we try to build the program using Makefile, we face the following error:

c:/program files (x86)/gnu tools arm embedded/4.9 2015q3/bin/../lib/gcc/arm-none-eabi/4.9.3/../../../../arm-none-eabi/lib/armv7-ar/thumb/fpu\libc.a(lib_a-fflush.o): In function `__sflush_r':
fflush.c:(.text.__sflush_r+0x7e): undefined reference to `__wrap__free_r'
c:/program files (x86)/gnu tools arm embedded/4.9 2015q3/bin/../lib/gcc/arm-none-eabi/4.9.3/../../../../arm-none-eabi/lib/armv7-ar/thumb/fpu\libc.a(lib_a-fclose.o): In function `_fclose_r':
fclose.c:(.text._fclose_r+0x4a): undefined reference to `__wrap__free_r'
fclose.c:(.text._fclose_r+0x58): undefined reference to `__wrap__free_r'
fclose.c:(.text._fclose_r+0x7a): undefined reference to `__wrap__free_r'
c:/program files (x86)/gnu tools arm embedded/4.9 2015q3/bin/../lib/gcc/arm-none-eabi/4.9.3/../../../../arm-none-eabi/lib/armv7-ar/thumb/fpu\libc.a(lib_a-svfprintf.o): In function `_svfprintf_r':
vfprintf.c:(.text._svfprintf_r+0x11e4): undefined reference to `__wrap__malloc_r'
c:/program files (x86)/gnu tools arm embedded/4.9 2015q3/bin/../lib/gcc/arm-none-eabi/4.9.3/../../../../arm-none-eabi/lib/armv7-ar/thumb/fpu\libc.a(lib_a-mprec.o): In function `_Balloc':
mprec.c:(.text._Balloc+0x24): undefined reference to `__wrap__calloc_r'
mprec.c:(.text._Balloc+0x40): undefined reference to `__wrap__calloc_r'
c:/program files (x86)/gnu tools arm embedded/4.9 2015q3/bin/../lib/gcc/arm-none-eabi/4.9.3/../../../../arm-none-eabi/lib/armv7-ar/thumb/fpu\libc.a(lib_a-svfiprintf.o): In function `__ssprint_r':
vfprintf.c:(.text.__ssprint_r+0x60): undefined reference to `__wrap__malloc_r'
vfprintf.c:(.text.__ssprint_r+0xc8): undefined reference to `__wrap__realloc_r'
vfprintf.c:(.text.__ssprint_r+0xd6): undefined reference to `__wrap__free_r'
collect2.exe: error: ld returned 1 exit status

In Makefile generated by online compiler, the following linker option is specified:
'-Wl,--wrap,_malloc_r' '-Wl,--wrap,_free_r' '-Wl,--wrap,_realloc_r' '-Wl,--wrap,_calloc_r'

and _malloc_r' '-Wl,--wrap,_free_r' '-Wl,--wrap,_realloc_r' '-Wl,--wrap,_calloc_r' is declared in mbed_alloc_wrappers.cpp only, so the above error occurs.
It seems that mbed-dev should be imported instead of mbed in order to build the program without changing the option. Or the above option is removed, the program should be built successfully.

Could you give us your opinion about the above?

[theotherjimmy]

What exactly are you exporting @TomoYamanaka ?

[theotherjimmy]

I think this is related to #3728

[Osamu-Nakamura]

@theotherjimmy
We imported mbed_blinky with updating all the libraries, then exported it to GCC (ARM Embedded).

[TomoYamanaka]

@theotherjimmy

How about the status of this issue?

[bomilkar]

exact same issue here.
Would also like to know how to resolve this.

[theotherjimmy]

I think this is just the flags being out of date. I can reproduce this issue. I'm going to see if I can solve it.

[bomilkar]

Which flags do you think are out of date?
It looks to me as if there are references in libc.a which cannot be resolved. Something seem to be missing.

[bomilkar]

Update:

I changed the Makefile as follows:
remove this from LD: '-Wl,--wrap,_malloc_r' '-Wl,--wrap,_free_r' '-Wl,--wrap,_realloc_r' '-Wl,--wrap,_calloc_r'
remove this from LD_FLAGS: -Wl,--wrap,_malloc_r -Wl,--wrap,_free_r -Wl,--wrap,_realloc_r -Wl,--wrap,_calloc_r

With these 2 changes it woks for several projects.

[SuburbanDSP]

I just did a test export tonight to Nucleo-STM32L476RG. I found similar issues as Tomo Yamanaka. Fwiw project has mixed C and C++.

I removed the linker flags similarly to bomilkar, but with more functions wrapped, including exit() and atexit() from LD_FLAGS and it built perfectly, haven't executed yet.

btw, this machine is Ubuntu 14.04.4 LTS and
arm-none-eabi-gcc --version
arm-none-eabi-gcc (GNU Tools for ARM Embedded Processors) 4.9.3 20150529 (release) [ARM/embedded-4_9-branch revision 227977]
Copyright (C) 2014 Free Software Foundation, Inc.

[0xc0170]

I think this is just the flags being out of date. I can reproduce this issue. I'm going to see if I can solve it.

@theotherjimmy Could you reproduce this?