Discuss here different C compiler set ups, and compiling executables for the ESP8266

User avatar
By mog
#6488 Hi

I'e been trying to use the builtin c++ header files like <iostream> and <vector> but when i try to modify the makefile (which I'll add to the end of my post) I'm starting to get into some dependency/language problems. The further i dig and add to include path the more problems I have.

First of all I've found that the iostream and vector files are under /opt/Espressif/ESP8266_SDK/include/xcc/c++ where I've got my SDK installed. And that's ok so I added this to EXTRA_INCDIR in the makefile. After that building failed due to missing "bits/c++config.h" and I've found this under /opt/Espressif/ESP8266_SDK/include/xcc/c++/xtensa-elf... Cool. But after that the build fails with some puzzling errors starting with

Code: Select all/opt/Espressif/ESP8266_SDK/include/xcc/c++/xtensa-elf/bits/c++config.h:149:1: error: unknown type name 'namespace'
 _GLIBCXX_BEGIN_NAMESPACE(std)
 ^
/opt/Espressif/ESP8266_SDK/include/xcc/c++/xtensa-elf/bits/c++config.h:149:1: error: expected ',' or ';' before '{' token
 _GLIBCXX_BEGIN_NAMESPACE(std)
...


I'm not really fluent in making C compilation setup but this is clearly something else than just missing includes. I've tried adding -std=c99 to compiler flags but this is not the case.

I don't really understand what's the problem here. I'm trying to use standard stuff which is actually a part of the SDK and something seems to fail. I'm using a very simple makefile which was a part of a simple blink example I've been using to learn whilh works perfectly and looks like this:

Code: Select all# tnx to mamalala
# Changelog
# Changed the variables to include the header file directory
# Added global var for the XTENSA tool root
#
# This make file still needs some work.
#
#
# Output directors to store intermediate compiled files
# relative to the project directory
BUILD_BASE   = build
FW_BASE      = firmware

# Base directory for the compiler
XTENSA_TOOLS_ROOT ?= /opt/Espressif/crosstool-NG/builds/xtensa-lx106-elf/bin

# base directory of the ESP8266 SDK package, absolute
SDK_BASE   ?= /opt/Espressif/ESP8266_SDK

#Esptool.py path and port
ESPTOOL      ?= esptool.py
ESPPORT      ?= /dev/ttyUSB0

# name for the target project
TARGET      = app

# which modules (subdirectories) of the project to include in compiling
MODULES      = driver user
EXTRA_INCDIR    = include /opt/Espressif/include \
   /opt/Espressif/ESP8266_SDK/include/xcc/c++ \
   /opt/Espressif/ESP8266_SDK/include/xcc/c++/xtensa-elf

# libraries used in this project, mainly provided by the SDK
LIBS      = c gcc hal pp phy net80211 lwip wpa main

# compiler flags using during compilation of source files
CFLAGS      = -Os -g -O2 -Wpointer-arith -std=c99 -Wundef -Werror -Wl,-EL -fno-inline-functions -nostdlib -mlongcalls -mtext-section-literals  -D__ets__ -DICACHE_FLASH

# linker flags used to generate the main object file
LDFLAGS      = -nostdlib -Wl,--no-check-sections -u call_user_start -Wl,-static

# linker script used for the above linkier step
LD_SCRIPT   = eagle.app.v6.ld

# various paths from the SDK used in this project
SDK_LIBDIR   = lib
SDK_LDDIR   = ld
SDK_INCDIR   = include include/json

# we create two different files for uploading into the flash
# these are the names and options to generate them
FW_FILE_1   = 0x00000
FW_FILE_1_ARGS   = -bo $@ -bs .text -bs .data -bs .rodata -bc -ec
FW_FILE_2   = 0x40000
FW_FILE_2_ARGS   = -es .irom0.text $@ -ec

# select which tools to use as compiler, librarian and linker
CC      := $(XTENSA_TOOLS_ROOT)/xtensa-lx106-elf-gcc
AR      := $(XTENSA_TOOLS_ROOT)/xtensa-lx106-elf-ar
LD      := $(XTENSA_TOOLS_ROOT)/xtensa-lx106-elf-gcc



####
#### no user configurable options below here
####
FW_TOOL      ?= /usr/bin/esptool
SRC_DIR      := $(MODULES)
BUILD_DIR   := $(addprefix $(BUILD_BASE)/,$(MODULES))

SDK_LIBDIR   := $(addprefix $(SDK_BASE)/,$(SDK_LIBDIR))
SDK_INCDIR   := $(addprefix -I$(SDK_BASE)/,$(SDK_INCDIR))

SRC      := $(foreach sdir,$(SRC_DIR),$(wildcard $(sdir)/*.c))
OBJ      := $(patsubst %.c,$(BUILD_BASE)/%.o,$(SRC))
LIBS      := $(addprefix -l,$(LIBS))
APP_AR      := $(addprefix $(BUILD_BASE)/,$(TARGET)_app.a)
TARGET_OUT   := $(addprefix $(BUILD_BASE)/,$(TARGET).out)

LD_SCRIPT   := $(addprefix -T$(SDK_BASE)/$(SDK_LDDIR)/,$(LD_SCRIPT))

INCDIR   := $(addprefix -I,$(SRC_DIR))
EXTRA_INCDIR   := $(addprefix -I,$(EXTRA_INCDIR))
MODULE_INCDIR   := $(addsuffix /include,$(INCDIR))

FW_FILE_1   := $(addprefix $(FW_BASE)/,$(FW_FILE_1).bin)
FW_FILE_2   := $(addprefix $(FW_BASE)/,$(FW_FILE_2).bin)

V ?= $(VERBOSE)
ifeq ("$(V)","1")
Q :=
vecho := @true
else
Q := @
vecho := @echo
endif

vpath %.c $(SRC_DIR)

define compile-objects
$1/%.o: %.c
   $(vecho) "CC $$<"
   $(Q) $(CC) $(INCDIR) $(MODULE_INCDIR) $(EXTRA_INCDIR) $(SDK_INCDIR) $(CFLAGS)  -c $$< -o $$@
endef

.PHONY: all checkdirs flash clean

all: checkdirs $(TARGET_OUT) $(FW_FILE_1) $(FW_FILE_2)

$(FW_FILE_1): $(TARGET_OUT)
   $(vecho) "FW $@"
   $(Q) $(FW_TOOL) -eo $(TARGET_OUT) $(FW_FILE_1_ARGS)

$(FW_FILE_2): $(TARGET_OUT)
   $(vecho) "FW $@"
   $(Q) $(FW_TOOL) -eo $(TARGET_OUT) $(FW_FILE_2_ARGS)

$(TARGET_OUT): $(APP_AR)
   $(vecho) "LD $@"
   $(Q) $(LD) -L$(SDK_LIBDIR) $(LD_SCRIPT) $(LDFLAGS) -Wl,--start-group $(LIBS) $(APP_AR) -Wl,--end-group -o $@

$(APP_AR): $(OBJ)
   $(vecho) "AR $@"
   $(Q) $(AR) cru $@ $^

checkdirs: $(BUILD_DIR) $(FW_BASE)

$(BUILD_DIR):
   $(Q) mkdir -p $@

firmware:
   $(Q) mkdir -p $@

flash: firmware/0x00000.bin firmware/0x40000.bin
   -$(ESPTOOL) --port $(ESPPORT) write_flash 0x00000 firmware/0x00000.bin 0x40000 firmware/0x40000.bin

clean:
   $(Q) rm -f $(APP_AR)
   $(Q) rm -f $(TARGET_OUT)
   $(Q) rm -rf $(BUILD_DIR)
   $(Q) rm -rf $(BUILD_BASE)


   $(Q) rm -f $(FW_FILE_1)
   $(Q) rm -f $(FW_FILE_2)
   $(Q) rm -rf $(FW_BASE)

$(foreach bdir,$(BUILD_DIR),$(eval $(call compile-objects,$(bdir))))


does somebody know what is the problem here? I've found this thread viewtopic.php?f=9&t=478&p=2245&hilit=iostream#p2245 but doesn't seem directly linked to the case I'm having :/
User avatar
By alonewolfx2
#6493 I wonder one thing. Why you are using iostream class? For filesystem or anything else?
User avatar
By igrr
#6502
mog wrote:
Code: Select all/opt/Espressif/ESP8266_SDK/include/xcc/c++/xtensa-elf/bits/c++config.h:149:1: error: unknown type name 'namespace'


Code: Select alldefine compile-objects
$1/%.o: %.c
   $(vecho) "CC $$<"
   $(Q) $(CC) $(INCDIR) $(MODULE_INCDIR) $(EXTRA_INCDIR) $(SDK_INCDIR) $(CFLAGS)  -c $$< -o $$@
endef



Apparently the makefile you are using compiles .c files as C code, and you obviously want C++ if you use vector and iostream.
You should create rules to compile *.c files, say, to *.c.o and *.cpp to *.cpp.o, and modify the linker rule accordingly.
You should use also use g++ to compile .cpp files instead of gcc.

When you succeed with that part you may get a bunch of errors regarding missing _sbrk_r function. To fix those you will likely have to override new, new[], delete, and delete[] operators to use os_malloc & os_free provided in the Espressif SDK.
User avatar
By jcmvbkbc
#6504
igrr wrote:Apparently the makefile you are using compiles .c files as C code, and you obviously want C++ if you use vector and iostream.
You should create rules to compile *.c files, say, to *.c.o and *.cpp to *.cpp.o, and modify the linker rule accordingly.
You should use also use g++ to compile .cpp files instead of gcc.


The following makefile worked for me with sdk 0.9.2: https://gist.github.com/jcmvbkbc/795b51494aea52bf2d1e
It probably needs a list of libs updated to work with the latest SDK.