A Makefile problem

[aha_1980]

@mrdebug Are these variables actually passed to the linker call?

[mrdebug]

I think not. How can I verify?
It is a esp32 project.

[aha_1980]

@mrdebug

I think not. How can I verify?

By studying $(IDF_PATH)/make/project.mk and watching the compiler outputs?

It is a esp32 project.

That should not matter. The Makefile controls the compiler, be it native or embededded.

Regards

[mrdebug]

Sorry but I haven't got so much experience with Makefile.
Can I add some echo print line at the end of the Makefile to know if my keyword is still active?
Wich is the name of the variable that stores the library path?

[jsulm]

@mrdebug Just call make and check the output of the compiler/linker - you will see whether your paths are passed to them or not.

[mrdebug]

I don't see it

[jsulm]

@mrdebug You mean you do not see the paths being passed to compiler/linker?

[mrdebug]

No, I don't see it.

[jsulm]

@mrdebug One moment, you do NOT use QMake, but edit makefile manually, right? If so then what you did will not do anything! You need to add includes/libs to the compiler/linker calls in your make file.
Can you show the whole makefile?

[mrdebug]

Really this is my Makefile

#
# This is a project Makefile. It is assumed the directory this Makefile resides in is a
# project subdirectory.
#

PROJECT_NAME := esp32-Test01-App

INCPATH       = -I/home/denis/workspace/esp32-Test01/components/component01/include/
LIBS          = $(SUBLIBS) -L/home/denis/workspace/esp32-Test01/build/component01/ -llibcomponent01


include $(IDF_PATH)/make/project.mk

I don't using qmake.

[aha_1980]

@jsulm As I said before, I think the magic happens in $(IDF_PATH)/make/project.mk

@mrdebug: Sorry, but without makefile understanding you will not get very far.

At some point make calls your compiler and linker, and passes options to them. This is where you need to add your modifications.

Regards

[jsulm]

@mrdebug said in A Makefile problem:

$(IDF_PATH)/make/project.mk

Then check what is inside that file or post it here

[mrdebug]

#
# Main Project Makefile
# This Makefile is included directly from the user project Makefile in order to call the component.mk
# makefiles of all components (in a separate make process) to build all the libraries, then links them
# together into the final file. If so, PWD is the project dir (we assume).
#

#
# This makefile requires the environment variable IDF_PATH to be set to the top-level esp-idf directory
# where this file is located.
#

.PHONY: build-components menuconfig defconfig all build clean all_binaries check-submodules size size-components size-files size-symbols list-components

MAKECMDGOALS ?= all
all: all_binaries | check_python_dependencies
# see below for recipe of 'all' target
#
# # other components will add dependencies to 'all_binaries'. The
# reason all_binaries is used instead of 'all' is so that the flash
# target can build everything without triggering the per-component "to
# flash..." output targets.)

help:
	@echo "Welcome to Espressif IDF build system. Some useful make targets:"
	@echo ""
	@echo "make menuconfig - Configure IDF project"
	@echo "make defconfig - Set defaults for all new configuration options"
	@echo ""
	@echo "make all - Build app, bootloader, partition table"
	@echo "make flash - Flash app, bootloader, partition table to a chip"
	@echo "make clean - Remove all build output"
	@echo "make size - Display the static memory footprint of the app"
	@echo "make size-components, size-files - Finer-grained memory footprints"
	@echo "make size-symbols - Per symbol memory footprint. Requires COMPONENT=<component>"
	@echo "make erase_flash - Erase entire flash contents"
	@echo "make erase_otadata - Erase ota_data partition; First bootable partition (factory or OTAx) will be used on next boot."
	@echo "                     This assumes this project's partition table is the one flashed on the device."
	@echo "make monitor - Run idf_monitor tool to monitor serial output from app"
	@echo "make simple_monitor - Monitor serial output on terminal console"
	@echo "make list-components - List all components in the project"
	@echo ""
	@echo "make app - Build just the app"
	@echo "make app-flash - Flash just the app"
	@echo "make app-clean - Clean just the app"
	@echo "make print_flash_cmd - Print the arguments for esptool when flash"
	@echo "make check_python_dependencies - Check that the required python packages are installed"
	@echo ""
	@echo "See also 'make bootloader', 'make bootloader-flash', 'make bootloader-clean', "
	@echo "'make partition_table', etc, etc."

# Non-interactive targets. Mostly, those for which you do not need to build a binary
NON_INTERACTIVE_TARGET += defconfig clean% %clean help list-components print_flash_cmd check_python_dependencies

# dependency checks
ifndef MAKE_RESTARTS
ifeq ("$(filter 4.% 3.81 3.82,$(MAKE_VERSION))","")
$(warning esp-idf build system only supports GNU Make versions 3.81 or newer. You may see unexpected results with other Makes.)
endif

ifdef MSYSTEM
ifneq ("$(MSYSTEM)","MINGW32")
$(warning esp-idf build system only supports MSYS2 in "MINGW32" mode. Consult the ESP-IDF documentation for details.)
endif
endif  # MSYSTEM

endif  # MAKE_RESTARTS

# can't run 'clean' along with any non-clean targets
ifneq ("$(filter clean% %clean,$(MAKECMDGOALS))" ,"")
ifneq ("$(filter-out clean% %clean,$(MAKECMDGOALS))", "")
$(error esp-idf build system doesn't support running 'clean' targets along with any others. Run 'make clean' and then run other targets separately.)
endif
endif

OS ?=

# make IDF_PATH a "real" absolute path
# * works around the case where a shell character is embedded in the environment variable value.
# * changes Windows-style C:/blah/ paths to MSYS style /c/blah
ifeq ("$(OS)","Windows_NT")
# On Windows MSYS2, make wildcard function returns empty string for paths of form /xyz
# where /xyz is a directory inside the MSYS root - so we don't use it.
SANITISED_IDF_PATH:=$(realpath $(IDF_PATH))
else
SANITISED_IDF_PATH:=$(realpath $(wildcard $(IDF_PATH)))
endif

export IDF_PATH := $(SANITISED_IDF_PATH)

ifndef IDF_PATH
$(error IDF_PATH variable is not set to a valid directory.)
endif

ifdef IDF_TARGET
ifneq ($(IDF_TARGET),esp32)
$(error GNU Make based build system only supports esp32 target, but IDF_TARGET is set to $(IDF_TARGET))
endif
else
export IDF_TARGET := esp32
endif


ifneq ("$(IDF_PATH)","$(SANITISED_IDF_PATH)")
# implies IDF_PATH was overriden on make command line.
# Due to the way make manages variables, this is hard to account for
#
# if you see this error, do the shell expansion in the shell ie
# make IDF_PATH=~/blah not make IDF_PATH="~/blah"
$(error If IDF_PATH is overriden on command line, it must be an absolute path with no embedded shell special characters)
endif

ifneq ("$(IDF_PATH)","$(subst :,,$(IDF_PATH))")
$(error IDF_PATH cannot contain colons. If overriding IDF_PATH on Windows, use MSYS Unix-style /c/dir instead of C:/dir)
endif

# disable built-in make rules, makes debugging saner
MAKEFLAGS_OLD := $(MAKEFLAGS)
MAKEFLAGS +=-rR

# Default path to the project: we assume the Makefile including this file
# is in the project directory
ifndef PROJECT_PATH
PROJECT_PATH := $(abspath $(dir $(firstword $(MAKEFILE_LIST))))
export PROJECT_PATH
endif

# A list of the "common" makefiles, to use as a target dependency
COMMON_MAKEFILES := $(abspath $(IDF_PATH)/make/project.mk $(IDF_PATH)/make/common.mk $(IDF_PATH)/make/version.mk $(IDF_PATH)/make/component_wrapper.mk $(firstword $(MAKEFILE_LIST)))
export COMMON_MAKEFILES

# The directory where we put all objects/libraries/binaries. The project Makefile can
# configure this if needed.
ifndef BUILD_DIR_BASE
BUILD_DIR_BASE := $(PROJECT_PATH)/build
endif
export BUILD_DIR_BASE

# Component directories. These directories are searched for components (either the directory is a component,
# or the directory contains subdirectories which are components.)
# The project Makefile can override these component dirs, or add extras via EXTRA_COMPONENT_DIRS
ifndef COMPONENT_DIRS
EXTRA_COMPONENT_DIRS ?=
COMPONENT_DIRS := $(PROJECT_PATH)/components $(EXTRA_COMPONENT_DIRS) $(IDF_PATH)/components $(PROJECT_PATH)/main
endif
# Make sure that every directory in the list is an absolute path without trailing slash.
# This is necessary to split COMPONENT_DIRS into SINGLE_COMPONENT_DIRS and MULTI_COMPONENT_DIRS below. 
COMPONENT_DIRS := $(foreach cd,$(COMPONENT_DIRS),$(abspath $(cd)))
export COMPONENT_DIRS

ifdef SRCDIRS
$(warning SRCDIRS variable is deprecated. These paths can be added to EXTRA_COMPONENT_DIRS or COMPONENT_DIRS instead.)
COMPONENT_DIRS += $(abspath $(SRCDIRS))
endif

# List of component directories, i.e. directories which contain a component.mk file 
SINGLE_COMPONENT_DIRS := $(abspath $(dir $(dir $(foreach cd,$(COMPONENT_DIRS),\
                             $(wildcard $(cd)/component.mk)))))

# List of components directories, i.e. directories which may contain components 
MULTI_COMPONENT_DIRS := $(filter-out $(SINGLE_COMPONENT_DIRS),$(COMPONENT_DIRS))

# The project Makefile can define a list of components, but if it does not do this
# we just take all available components in the component dirs.
# A component is COMPONENT_DIRS directory, or immediate subdirectory,
# which contains a component.mk file.
#
# Use the "make list-components" target to debug this step.
ifndef COMPONENTS
# Find all component names. The component names are the same as the
# directories they're in, so /bla/components/mycomponent/component.mk -> mycomponent.
# We need to do this for MULTI_COMPONENT_DIRS only, since SINGLE_COMPONENT_DIRS
# are already known to contain component.mk.
COMPONENTS := $(dir $(foreach cd,$(MULTI_COMPONENT_DIRS),$(wildcard $(cd)/*/component.mk))) \
              $(SINGLE_COMPONENT_DIRS)
COMPONENTS := $(sort $(foreach comp,$(COMPONENTS),$(lastword $(subst /, ,$(comp)))))
endif
# After a full manifest of component names is determined, subtract the ones explicitly
# omitted by the project Makefile.
EXCLUDE_COMPONENTS ?=
ifdef EXCLUDE_COMPONENTS
COMPONENTS := $(filter-out $(subst ",,$(EXCLUDE_COMPONENTS)), $(COMPONENTS))
# to keep syntax highlighters happy: "))
endif
export COMPONENTS

# Resolve all of COMPONENTS into absolute paths in COMPONENT_PATHS.
# For each entry in COMPONENT_DIRS:
# - either this is directory with multiple components, in which case check that
#   a subdirectory with component name exists, and it contains a component.mk file.
# - or, this is a directory of a single component, in which case the name of this
#   directory has to match the component name
#
# If a component name exists in multiple COMPONENT_DIRS, we take the first match.
#
# NOTE: These paths must be generated WITHOUT a trailing / so we
# can use $(notdir x) to get the component name.
COMPONENT_PATHS := $(foreach comp,$(COMPONENTS),\
                        $(firstword $(foreach cd,$(COMPONENT_DIRS),\
                            $(if $(findstring $(cd),$(MULTI_COMPONENT_DIRS)),\
                                 $(abspath $(dir $(wildcard $(cd)/$(comp)/component.mk))),)\
                            $(if $(findstring $(cd),$(SINGLE_COMPONENT_DIRS)),\
                                 $(if $(filter $(comp),$(notdir $(cd))),$(cd),),)\
                   )))
export COMPONENT_PATHS

TEST_COMPONENTS ?=
TEST_EXCLUDE_COMPONENTS ?=
TESTS_ALL ?=

# If TESTS_ALL set to 1, set TEST_COMPONENTS_LIST to all components.
# Otherwise, use the list supplied in TEST_COMPONENTS.
ifeq ($(TESTS_ALL),1)
TEST_COMPONENTS_LIST := $(filter-out $(TEST_EXCLUDE_COMPONENTS), $(COMPONENTS))
else
TEST_COMPONENTS_LIST := $(TEST_COMPONENTS)
endif

TEST_COMPONENT_PATHS := $(foreach comp,$(TEST_COMPONENTS_LIST),$(firstword $(foreach dir,$(COMPONENT_DIRS),$(wildcard $(dir)/$(comp)/test))))
TEST_COMPONENT_NAMES := $(foreach comp,$(TEST_COMPONENT_PATHS),$(lastword $(subst /, ,$(dir $(comp))))_test)

# Set default values that were not previously defined
CC ?= gcc
LD ?= ld
AR ?= ar
OBJCOPY ?= objcopy
OBJDUMP ?= objdump
SIZE ?= size

# Set host compiler and binutils
HOSTCC := $(CC)
HOSTLD := $(LD)
HOSTAR := $(AR)
HOSTOBJCOPY := $(OBJCOPY)
HOSTSIZE := $(SIZE)
export HOSTCC HOSTLD HOSTAR HOSTOBJCOPY SIZE

# Set variables common to both project & component (includes config)
include $(IDF_PATH)/make/common.mk

# Notify users when some of the required python packages are not installed
.PHONY: check_python_dependencies
check_python_dependencies:
ifndef IS_BOOTLOADER_BUILD
	$(PYTHON) $(IDF_PATH)/tools/check_python_dependencies.py
endif

# include the config generation targets (dependency: COMPONENT_PATHS)
#
# (bootloader build doesn't need this, config is exported from top-level)
ifndef IS_BOOTLOADER_BUILD
include $(IDF_PATH)/make/project_config.mk
endif

#####################################################################
# If SDKCONFIG_MAKEFILE hasn't been generated yet (detected if no
# CONFIG_IDF_TARGET), stop the Makefile pass now to allow config to
# be created. make will build SDKCONFIG_MAKEFILE and restart,
# reevaluating everything from the top.
#
# This is important so config is present when the
# component_project_vars.mk files are generated.
#
# (After both files exist, if SDKCONFIG_MAKEFILE is updated then the
# normal dependency relationship will trigger a regeneration of
# component_project_vars.mk)
#
#####################################################################
ifndef CONFIG_IDF_TARGET
ifdef IS_BOOTLOADER_BUILD  # we expect config to always have been expanded by top level project
$(error "Internal error: config has not been passed correctly to bootloader subproject")
endif
ifdef MAKE_RESTARTS
$(warning "Config was not evaluated after the first pass of 'make'")
endif
else  # CONFIG_IDF_TARGET
#####################################################################
# Config is valid, can include rest of the Project Makefile
#####################################################################


# Initialise project-wide variables which can be added to by
# each component.
#
# These variables are built up via the component_project_vars.mk
# generated makefiles (one per component).
#
# See docs/build-system.rst for more details.
COMPONENT_INCLUDES :=
COMPONENT_LDFLAGS :=
COMPONENT_SUBMODULES :=
COMPONENT_LIBRARIES :=
COMPONENT_LDFRAGMENTS :=

# COMPONENT_PROJECT_VARS is the list of component_project_vars.mk generated makefiles
# for each component.
#
# Including $(COMPONENT_PROJECT_VARS) builds the COMPONENT_INCLUDES,
# COMPONENT_LDFLAGS variables and also targets for any inter-component
# dependencies.
#
# See the component_project_vars.mk target in component_wrapper.mk
COMPONENT_PROJECT_VARS := $(addsuffix /component_project_vars.mk,$(notdir $(COMPONENT_PATHS) ) $(TEST_COMPONENT_NAMES))
COMPONENT_PROJECT_VARS := $(addprefix $(BUILD_DIR_BASE)/,$(COMPONENT_PROJECT_VARS))
# this line is -include instead of include to prevent a spurious error message on make 3.81
-include $(COMPONENT_PROJECT_VARS)

# Also add top-level project include path, for top-level includes
COMPONENT_INCLUDES += $(abspath $(BUILD_DIR_BASE)/include/)

export COMPONENT_INCLUDES

all:
ifdef CONFIG_SECURE_BOOT_ENABLED
	@echo "(Secure boot enabled, so bootloader not flashed automatically. See 'make bootloader' output)"
ifndef CONFIG_SECURE_BOOT_BUILD_SIGNED_BINARIES
	@echo "App built but not signed. Sign app & partition data before flashing, via espsecure.py:"
	@echo "espsecure.py sign_data --keyfile KEYFILE $(APP_BIN)"
	@echo "espsecure.py sign_data --keyfile KEYFILE $(PARTITION_TABLE_BIN)"
endif
	@echo "To flash app & partition table, run 'make flash' or:"
else
	@echo "To flash all build output, run 'make flash' or:"
endif
	@echo $(ESPTOOLPY_WRITE_FLASH) $(ESPTOOL_ALL_FLASH_ARGS)


# If we have `version.txt` then prefer that for extracting IDF version
ifeq ("$(wildcard ${IDF_PATH}/version.txt)","")
IDF_VER_T := $(shell cd ${IDF_PATH} && git describe --always --tags --dirty)
else
IDF_VER_T := $(shell cat ${IDF_PATH}/version.txt)
endif
IDF_VER := $(shell echo "$(IDF_VER_T)"  | cut -c 1-31)

# Set default LDFLAGS
EXTRA_LDFLAGS ?=
LDFLAGS ?= -nostdlib \
	-u call_user_start_cpu0	\
	$(EXTRA_LDFLAGS) \
	-Wl,--gc-sections	\
	-Wl,-static	\
	-Wl,--start-group	\
	$(COMPONENT_LDFLAGS) \
	-lgcc \
	-lstdc++ \
	-lgcov \
	-Wl,--end-group \
	-Wl,-EL

# Set default CPPFLAGS, CFLAGS, CXXFLAGS
# These are exported so that components can use them when compiling.
# If you need your component to add CFLAGS/etc for it's own source compilation only, set CFLAGS += in your component's Makefile.
# If you need your component to add CFLAGS/etc globally for all source
#  files, set CFLAGS += in your component's Makefile.projbuild
# If you need to set CFLAGS/CPPFLAGS/CXXFLAGS at project level, set them in application Makefile
#  before including project.mk. Default flags will be added before the ones provided in application Makefile.

# CPPFLAGS used by C preprocessor
# If any flags are defined in application Makefile, add them at the end.
CPPFLAGS ?=
EXTRA_CPPFLAGS ?=
CPPFLAGS := -DESP_PLATFORM -D IDF_VER=\"$(IDF_VER)\" -MMD -MP $(CPPFLAGS) $(EXTRA_CPPFLAGS)
PROJECT_VER ?=
export IDF_VER
export PROJECT_NAME
export PROJECT_VER

# Warnings-related flags relevant both for C and C++
COMMON_WARNING_FLAGS = -Wall -Werror=all \
	-Wno-error=unused-function \
	-Wno-error=unused-but-set-variable \
	-Wno-error=unused-variable \
	-Wno-error=deprecated-declarations \
	-Wextra \
	-Wno-unused-parameter -Wno-sign-compare

ifdef CONFIG_COMPILER_DISABLE_GCC8_WARNINGS
COMMON_WARNING_FLAGS += -Wno-parentheses \
	-Wno-sizeof-pointer-memaccess \
	-Wno-clobbered \
	-Wno-format-overflow \
	-Wno-stringop-truncation \
	-Wno-misleading-indentation \
	-Wno-cast-function-type \
	-Wno-implicit-fallthrough \
	-Wno-unused-const-variable \
	-Wno-switch-unreachable \
	-Wno-format-truncation \
	-Wno-memset-elt-size \
	-Wno-int-in-bool-context
endif

ifdef CONFIG_COMPILER_WARN_WRITE_STRINGS
COMMON_WARNING_FLAGS += -Wwrite-strings
endif #CONFIG_COMPILER_WARN_WRITE_STRINGS

# Flags which control code generation and dependency generation, both for C and C++
COMMON_FLAGS = \
	-Wno-frame-address \
	-ffunction-sections -fdata-sections \
	-fstrict-volatile-bitfields \
	-mlongcalls \
	-nostdlib

ifndef IS_BOOTLOADER_BUILD
# stack protection (only one option can be selected in menuconfig)
ifdef CONFIG_COMPILER_STACK_CHECK_MODE_NORM
COMMON_FLAGS += -fstack-protector
endif
ifdef CONFIG_COMPILER_STACK_CHECK_MODE_STRONG
COMMON_FLAGS += -fstack-protector-strong
endif
ifdef CONFIG_COMPILER_STACK_CHECK_MODE_ALL
COMMON_FLAGS += -fstack-protector-all
endif
endif

# Optimization flags are set based on menuconfig choice
ifdef CONFIG_COMPILER_OPTIMIZATION_LEVEL_RELEASE
OPTIMIZATION_FLAGS = -Os -freorder-blocks
else
OPTIMIZATION_FLAGS = -Og
endif

ifdef CONFIG_COMPILER_OPTIMIZATION_ASSERTIONS_DISABLE
CPPFLAGS += -DNDEBUG
endif

# IDF uses some GNU extension from libc
CPPFLAGS += -D_GNU_SOURCE

# Enable generation of debugging symbols
# (we generate even in Release mode, as this has no impact on final binary size.)
DEBUG_FLAGS ?= -ggdb

# List of flags to pass to C compiler
# If any flags are defined in application Makefile, add them at the end.
CFLAGS ?=
EXTRA_CFLAGS ?=
CFLAGS := $(strip \
	-std=gnu99 \
	$(OPTIMIZATION_FLAGS) $(DEBUG_FLAGS) \
	$(COMMON_FLAGS) \
	$(COMMON_WARNING_FLAGS) -Wno-old-style-declaration \
	$(CFLAGS) \
	$(EXTRA_CFLAGS))

# List of flags to pass to C++ compiler
# If any flags are defined in application Makefile, add them at the end.
CXXFLAGS ?=
EXTRA_CXXFLAGS ?=
CXXFLAGS := $(strip \
	-std=gnu++11 \
	-fno-rtti \
	$(OPTIMIZATION_FLAGS) $(DEBUG_FLAGS) \
	$(COMMON_FLAGS) \
	$(COMMON_WARNING_FLAGS) \
	$(CXXFLAGS) \
	$(EXTRA_CXXFLAGS))

ifdef CONFIG_COMPILER_CXX_EXCEPTIONS
CXXFLAGS += -fexceptions
else
CXXFLAGS += -fno-exceptions
endif

ARFLAGS := cru

export CFLAGS CPPFLAGS CXXFLAGS ARFLAGS

# Set target compiler. Defaults to whatever the user has
# configured as prefix + ye olde gcc commands
CC := $(call dequote,$(CONFIG_SDK_TOOLPREFIX))gcc
CXX := $(call dequote,$(CONFIG_SDK_TOOLPREFIX))c++
LD := $(call dequote,$(CONFIG_SDK_TOOLPREFIX))ld
AR := $(call dequote,$(CONFIG_SDK_TOOLPREFIX))ar
OBJCOPY := $(call dequote,$(CONFIG_SDK_TOOLPREFIX))objcopy
OBJDUMP := $(call dequote,$(CONFIG_SDK_TOOLPREFIX))objdump
SIZE := $(call dequote,$(CONFIG_SDK_TOOLPREFIX))size
export CC CXX LD AR OBJCOPY OBJDUMP SIZE

COMPILER_VERSION_STR := $(shell $(CC) -dumpversion)
COMPILER_VERSION_NUM := $(subst .,,$(COMPILER_VERSION_STR))
GCC_NOT_5_2_0 := $(shell expr $(COMPILER_VERSION_STR) != "5.2.0")
export COMPILER_VERSION_STR COMPILER_VERSION_NUM GCC_NOT_5_2_0

CPPFLAGS += -DGCC_NOT_5_2_0=$(GCC_NOT_5_2_0)
export CPPFLAGS


# the app is the main executable built by the project
APP_ELF:=$(BUILD_DIR_BASE)/$(PROJECT_NAME).elf
APP_MAP:=$(APP_ELF:.elf=.map)
APP_BIN:=$(APP_ELF:.elf=.bin)

# include linker script generation utils makefile
include $(IDF_PATH)/make/ldgen.mk

$(eval $(call ldgen_create_commands))

# Include any Makefile.projbuild file letting components add
# configuration at the project level
define includeProjBuildMakefile
ifeq ("$(V)","1")
$$(info including $(1)/Makefile.projbuild...)
endif
COMPONENT_PATH := $(1)
include $(1)/Makefile.projbuild
endef
$(foreach componentpath,$(COMPONENT_PATHS), \
	$(if $(wildcard $(componentpath)/Makefile.projbuild), \
		$(eval $(call includeProjBuildMakefile,$(componentpath)))))

# ELF depends on the library archive files for COMPONENT_LIBRARIES
# the rules to build these are emitted as part of GenerateComponentTarget below
#
# also depends on additional dependencies (linker scripts & binary libraries)
# stored in COMPONENT_LINKER_DEPS, built via component.mk files' COMPONENT_ADD_LINKER_DEPS variable
COMPONENT_LINKER_DEPS ?=
$(APP_ELF): $(foreach libcomp,$(COMPONENT_LIBRARIES),$(BUILD_DIR_BASE)/$(libcomp)/lib$(libcomp).a) $(COMPONENT_LINKER_DEPS) $(COMPONENT_PROJECT_VARS)
	$(summary) LD $(patsubst $(PWD)/%,%,$@)
	$(CC) $(LDFLAGS) -o $@ -Wl,-Map=$(APP_MAP)

app: $(APP_BIN) partition_table_get_info
ifeq ("$(CONFIG_SECURE_BOOT_ENABLED)$(CONFIG_SECURE_BOOT_BUILD_SIGNED_BINARIES)","y") # secure boot enabled, but remote sign app image
	@echo "App built but not signed. Signing step via espsecure.py:"
	@echo "espsecure.py sign_data --keyfile KEYFILE $(APP_BIN)"
	@echo "Then flash app command is:"
	@echo $(ESPTOOLPY_WRITE_FLASH) $(APP_OFFSET) $(APP_BIN)
else
	@echo "App built. Default flash app command is:"
	@echo $(ESPTOOLPY_WRITE_FLASH) $(APP_OFFSET) $(APP_BIN)
endif

all_binaries: $(APP_BIN)

$(BUILD_DIR_BASE):
	mkdir -p $(BUILD_DIR_BASE)

# Macro for the recursive sub-make for each component
# $(1) - component directory
# $(2) - component name only
#
# Is recursively expanded by the GenerateComponentTargets macro
define ComponentMake
+$(MAKE) -C $(BUILD_DIR_BASE)/$(2) -f $(IDF_PATH)/make/component_wrapper.mk COMPONENT_MAKEFILE=$(1)/component.mk COMPONENT_NAME=$(2)
endef

# Generate top-level component-specific targets for each component
# $(1) - path to component dir
# $(2) - name of component
#
define GenerateComponentTargets
.PHONY: component-$(2)-build component-$(2)-clean

component-$(2)-build: check-submodules $(call prereq_if_explicit, component-$(2)-clean) | $(BUILD_DIR_BASE)/$(2)
	$(call ComponentMake,$(1),$(2)) build

component-$(2)-clean: | $(BUILD_DIR_BASE)/$(2) $(BUILD_DIR_BASE)/$(2)/component_project_vars.mk
	$(call ComponentMake,$(1),$(2)) clean

$(BUILD_DIR_BASE)/$(2):
	@mkdir -p $(BUILD_DIR_BASE)/$(2)

# tell make it can build any component's library by invoking the -build target
# (this target exists for all components even ones which don't build libraries, but it's
# only invoked for the targets whose libraries appear in COMPONENT_LIBRARIES and hence the
# APP_ELF dependencies.)
$(BUILD_DIR_BASE)/$(2)/lib$(2).a: component-$(2)-build
	$(details) "Target '$$^' responsible for '$$@'" # echo which build target built this file

# add a target to generate the component_project_vars.mk files that
# are used to inject variables into project make pass (see matching
# component_project_vars.mk target in component_wrapper.mk).
#
# If any component_project_vars.mk file is out of date, the make
# process will call this target to rebuild it and then restart.
#
$(BUILD_DIR_BASE)/$(2)/component_project_vars.mk: $(1)/component.mk $(COMMON_MAKEFILES) $(SDKCONFIG_MAKEFILE) | $(BUILD_DIR_BASE)/$(2)
	$(call ComponentMake,$(1),$(2)) component_project_vars.mk
endef

$(foreach component,$(COMPONENT_PATHS),$(eval $(call GenerateComponentTargets,$(component),$(notdir $(component)))))
$(foreach component,$(TEST_COMPONENT_PATHS),$(eval $(call GenerateComponentTargets,$(component),$(lastword $(subst /, ,$(dir $(component))))_test)))

app-clean: $(addprefix component-,$(addsuffix -clean,$(notdir $(COMPONENT_PATHS))))
	$(summary) RM $(APP_ELF)
	rm -f $(APP_ELF) $(APP_BIN) $(APP_MAP)

size: $(APP_ELF) | check_python_dependencies
	$(PYTHON) $(IDF_PATH)/tools/idf_size.py $(APP_MAP)

size-files: $(APP_ELF) | check_python_dependencies
	$(PYTHON) $(IDF_PATH)/tools/idf_size.py --files $(APP_MAP)

size-components: $(APP_ELF) | check_python_dependencies
	$(PYTHON) $(IDF_PATH)/tools/idf_size.py --archives $(APP_MAP)

size-symbols: $(APP_ELF) | check_python_dependencies
ifndef COMPONENT
	$(error "ERROR: Please enter the component to look symbols for, e.g. COMPONENT=heap")
else
	$(PYTHON) $(IDF_PATH)/tools/idf_size.py --archive_details lib$(COMPONENT).a $(APP_MAP)
endif

# NB: this ordering is deliberate (app-clean & bootloader-clean before
# _config-clean), so config remains valid during all component clean
# targets
config-clean: app-clean bootloader-clean
clean: app-clean bootloader-clean config-clean ldgen-clean

# phony target to check if any git submodule listed in COMPONENT_SUBMODULES are missing
# or out of date, and exit if so. Components can add paths to this variable.
#
# This only works for components inside IDF_PATH
check-submodules:
# Check if .gitmodules exists, otherwise skip submodule check, assuming flattened structure
ifneq ("$(wildcard ${IDF_PATH}/.gitmodules)","")

# Dump the git status for the whole working copy once, then grep it for each submodule. This saves a lot of time on Windows.
GIT_STATUS := $(shell cd ${IDF_PATH} && git status --porcelain --ignore-submodules=dirty)

# Generate a target to check this submodule
# $(1) - submodule directory, relative to IDF_PATH
define GenerateSubmoduleCheckTarget
check-submodules: $(IDF_PATH)/$(1)/.git
$(IDF_PATH)/$(1)/.git:
	@echo "WARNING: Missing submodule $(1)..."
	[ -e ${IDF_PATH}/.git ] || { echo "ERROR: esp-idf must be cloned from git to work."; exit 1; }
	[ -x "$(shell which git)" ] || { echo "ERROR: Need to run 'git submodule init $(1)' in esp-idf root directory."; exit 1; }
	@echo "Attempting 'git submodule update --init $(1)' in esp-idf root directory..."
	cd ${IDF_PATH} && git submodule update --init $(1)

# Parse 'git status' output to check if the submodule commit is different to expected
ifneq ("$(filter $(1),$(GIT_STATUS))","")
$$(info WARNING: esp-idf git submodule $(1) may be out of date. Run 'git submodule update' in IDF_PATH dir to update.)
endif
endef

# filter/subst in expression ensures all submodule paths begin with $(IDF_PATH), and then strips that prefix
# so the argument is suitable for use with 'git submodule' commands
$(foreach submodule,$(subst $(IDF_PATH)/,,$(filter $(IDF_PATH)/%,$(COMPONENT_SUBMODULES))),$(eval $(call GenerateSubmoduleCheckTarget,$(submodule))))
endif # End check for .gitmodules existence


# PHONY target to list components in the build and their paths
list-components:
	$(info $(call dequote,$(SEPARATOR)))
	$(info COMPONENT_DIRS (components searched for here))
	$(foreach cd,$(COMPONENT_DIRS),$(info $(cd)))
	$(info $(call dequote,$(SEPARATOR)))
	$(info TEST_COMPONENTS (list of test component names))
	$(info $(TEST_COMPONENTS_LIST))
	$(info $(call dequote,$(SEPARATOR)))
	$(info TEST_EXCLUDE_COMPONENTS (list of test excluded names))
	$(info $(if $(EXCLUDE_COMPONENTS) || $(TEST_EXCLUDE_COMPONENTS),$(EXCLUDE_COMPONENTS) $(TEST_EXCLUDE_COMPONENTS),(none provided)))
	$(info $(call dequote,$(SEPARATOR)))
	$(info COMPONENT_PATHS (paths to all components):)
	$(foreach cp,$(COMPONENT_PATHS),$(info $(cp)))

# print flash command, so users can dump this to config files and download somewhere without idf
print_flash_cmd: partition_table_get_info blank_ota_data
	echo $(ESPTOOL_WRITE_FLASH_OPTIONS) $(ESPTOOL_ALL_FLASH_ARGS) | sed -e 's:'$(PWD)/build/'::g'

# Check toolchain version using the output of xtensa-esp32-elf-gcc --version command.
# The output normally looks as follows
#     xtensa-esp32-elf-gcc (crosstool-NG crosstool-ng-1.22.0-80-g6c4433a) 5.2.0
# The part in brackets is extracted into TOOLCHAIN_COMMIT_DESC variable
ifdef CONFIG_SDK_TOOLPREFIX
ifndef MAKE_RESTARTS

TOOLCHAIN_HEADER := $(shell $(CC) --version | head -1)
TOOLCHAIN_PATH := $(shell which $(CC))
TOOLCHAIN_COMMIT_DESC := $(shell $(CC) --version | sed -E -n 's|.*\(crosstool-NG (.*)\).*|\1|gp')
TOOLCHAIN_GCC_VER := $(COMPILER_VERSION_STR)

# Officially supported version(s)
include $(IDF_PATH)/tools/toolchain_versions.mk

ifndef IS_BOOTLOADER_BUILD
$(info Toolchain path: $(TOOLCHAIN_PATH))
endif

ifdef TOOLCHAIN_COMMIT_DESC
ifeq (,$(findstring $(SUPPORTED_TOOLCHAIN_COMMIT_DESC),$(TOOLCHAIN_COMMIT_DESC)))
$(info WARNING: Toolchain version is not supported: $(TOOLCHAIN_COMMIT_DESC))
$(info Expected to see version: $(SUPPORTED_TOOLCHAIN_COMMIT_DESC))
$(info Please check ESP-IDF setup instructions and update the toolchain, or proceed at your own risk.)
else
ifndef IS_BOOTLOADER_BUILD
$(info Toolchain version: $(TOOLCHAIN_COMMIT_DESC))
endif
endif
ifeq (,$(findstring $(TOOLCHAIN_GCC_VER), $(SUPPORTED_TOOLCHAIN_GCC_VERSIONS)))
$(info WARNING: Compiler version is not supported: $(TOOLCHAIN_GCC_VER))
$(info Expected to see version(s): $(SUPPORTED_TOOLCHAIN_GCC_VERSIONS))
$(info Please check ESP-IDF setup instructions and update the toolchain, or proceed at your own risk.)
else
ifndef IS_BOOTLOADER_BUILD
$(info Compiler version: $(TOOLCHAIN_GCC_VER))
endif
endif
else
$(info WARNING: Failed to find Xtensa toolchain, may need to alter PATH or set one in the configuration menu)
endif # TOOLCHAIN_COMMIT_DESC

endif #MAKE_RESTARTS
endif #CONFIG_SDK_TOOLPREFIX

#####################################################################
endif #CONFIG_IDF_TARGET

[VRonin]

This makefile calls a bunch of other makefiles. In one of them it's very likely LIBS gets overridden

[mrdebug]

Is there a way to restore its value?

[jsulm]

@mrdebug Is there actually any documentation for this esp32? Maybe it is described somewhere?

[aha_1980]

@mrdebug

Looking at this:

Set default LDFLAGS
EXTRA_LDFLAGS ?=
LDFLAGS ?= -nostdlib
-u call_user_start_cpu0
$(EXTRA_LDFLAGS)
-Wl,--gc-sections
-Wl,-static
-Wl,--start-group
$(COMPONENT_LDFLAGS)
-lgcc
-lstdc++
-lgcov
-Wl,--end-group
-Wl,-EL

I think the correct way is to add your values to EXTRA_LDFLAGS in your Makefile before inserting $(IDF_PATH)/make/project.mk

At least it looks like that is the way it was designed.

Regards

[mrdebug]

Absolutely not.
I have already asked in the Espressif official forum without any reply.
I have asked here because this forum is read by top level developers.

There is another way, it is to use cmake. With cmake everithing works.
The problem is the IDE.
I need to use an IDE to develop, such as Eclipse (the only one). The problem is that Eclipse does not considered the CMakeLists.txt file. It considers only the Makefile file because Eclipse manages the Esp32 projects as Makefile projects.

To use Eclipse is not mandatory (I hate Eclipse) but it is the only one.

[mrdebug]

Ok now I try

[aha_1980]

@mrdebug

I need to use an IDE to develop, such as Eclipse (the only one). The problem is that Eclipse does not considered the CMakeLists.txt file. It considers only the Makefile file because Eclipse manages the Esp32 projects as Makefile projects.

Why not use QtCreator? https://doc.qt.io/qtcreator/creator-project-generic.html is exactly for that use case with existing makefiles.

I use them for Atmel ATMEGA projects, e.g.

Regards