ImGui can't find any definitions - c++

Question

OS: Windows10
Editor: VScode
Build: CMake
Compiler: GCC(actually MinGW)
ImGui branch: master (I didn't use the release tag branch), GLFW+OpenGL3 implementations
Here is the situation, I'm rewriting my learnOpenGL project with some more features added to it, like using yaml to do the initialization config. Now I want to add a visual config window when I run my opengl demo, so I could adjust colors or shader options or whatever.
I choose ImGui and followed many tutorials from other sites, when I add ImGui cpp files and compile them into a static library, the imgui_gui.cpp(not only this one) can't find any definitions of functions it contains(nearly all).
Below is the structure of my demo's workspace(simplified):
I:.
├───.vscode
├───CMakeLists.txt
├───app
│ ├───CMakeLists.txt
│ └───ImGui_test.cpp
├───bin
├───build
├───config
├───images
├───include
│ ├───glad
│ ├───GLFW
│ ├───glm
│ ├───ImGui
│ │ ├───imconfig.h
│ │ ├───imgui.h
│ │ ├───imgui_impl_glfw.h
│ │ ├───imgui_impl_opengl3.h
│ │ ├───imgui_impl_opengl3_loader.h
│ │ ├───imgui_internal.h
│ │ ├───imstb_rectpack.h
│ │ ├───imstb_textedit.h
│ │ └───imstb_truetype.h
│ ├───KHR
│ ├───myImplement
│ ├───stb_image
│ └───yaml-cpp
├───lib
│ ├───libglfw3.a
│ ├───libimgui.a
│ ├───libmysrc.a
│ └───libyaml-cpp.dll
├───model
├───shader
│ ├───shader_fragment
│ └───shader_vertex
└───src
├───CMakeLists.txt
├───config.cpp
├───glad.c
├───shader.cpp
├───stb_image.cpp
└───ImGui
├───imgui.cpp
├───imgui_demo.cpp
├───imgui_draw.cpp
├───imgui_impl_glfw.cpp
├───imgui_impl_opengl3.cpp
└───imgui_widgets.cpp
The problem is, when I compile other opengl demos, this build system works fine, all static and dynamic libraries can be found and linked properly(glfw, yaml, opengl32, and the lib made of cpp files from the 'src' dir except for the cpp files in the 'ImGui' dir), but adding libimgui.a seems not providing correct definitions for demos that contains any imgui function.
// a piece of error in cmd
// undefined reference of imgui.cpp(part of)
I:/VScode_projects/shader_toy/src/ImGui/imgui.cpp:2557: undefined reference to `ImGui::TableEndRow(ImGuiTable*)'
../../lib/libimgui.a(imgui.cpp.obj): In function `ImGuiListClipper::Begin(int, float)':
I:/VScode_projects/shader_toy/src/ImGui/imgui.cpp:2595: undefined reference to `ImGui::TableEndRow(ImGuiTable*)'
../../lib/libimgui.a(imgui.cpp.obj): In function `ImGuiListClipper::Step()':
I:/VScode_projects/shader_toy/src/ImGui/imgui.cpp:2652: undefined reference to `ImGui::TableEndRow(ImGuiTable*)'
../../lib/libimgui.a(imgui.cpp.obj): In function `ImGui::GcCompactTransientMiscBuffers()':
I:/VScode_projects/shader_toy/src/ImGui/imgui.cpp:3357: undefined reference to `ImGui::TableGcCompactSettings()'
../../lib/libimgui.a(imgui.cpp.obj): In function `ImGui::NewFrame()':
I:/VScode_projects/shader_toy/src/ImGui/imgui.cpp:4516: undefined reference to `ImGui::TableGcCompactTransientBuffers(ImGuiTable*)'
I:/VScode_projects/shader_toy/src/ImGui/imgui.cpp:4519: undefined reference to `ImGui::TableGcCompactTransientBuffers(ImGuiTableTempData*)'
../../lib/libimgui.a(imgui.cpp.obj): In function `ImGui::Initialize()':
// undefined reference in imgui_demo.cpp(part of)
../../lib/libimgui.a(imgui_demo.cpp.obj): In function `ShowPlaceholderObject':
I:/VScode_projects/shader_toy/src/ImGui/imgui_demo.cpp:7096: undefined reference to `ImGui::TableNextRow(int, float)'
I:/VScode_projects/shader_toy/src/ImGui/imgui_demo.cpp:7097: undefined reference to `ImGui::TableSetColumnIndex(int)'
I:/VScode_projects/shader_toy/src/ImGui/imgui_demo.cpp:7100: undefined reference to `ImGui::TableSetColumnIndex(int)'
I:/VScode_projects/shader_toy/src/ImGui/imgui_demo.cpp:7116: undefined reference to `ImGui::TableNextRow(int, float)'
I:/VScode_projects/shader_toy/src/ImGui/imgui_demo.cpp:7117: undefined reference to `ImGui::TableSetColumnIndex(int)'
I:/VScode_projects/shader_toy/src/ImGui/imgui_demo.cpp:7122: undefined reference to `ImGui::TableSetColumnIndex(int)'
I:/VScode_projects/shader_toy/src/ImGui/imgui_demo.cpp:7128: undefined reference to `ImGui::NextColumn()'
Also, three CMakeLists.txt in root directory, src and app:
// CMakeLists.txt in root directory
CMAKE_MINIMUM_REQUIRED(VERSION 3.19)
PROJECT(shader_toy)
SET(CMAKE_BUILD_TYPE "Debug")
SET(CMAKE_CXX_STANDARD 14)
SET(EXECUTABLE_OUTPUT_PATH ${PROJECT_SOURCE_DIR}/bin)
SET(LIBRARY_OUTPUT_PATH ${PROJECT_SOURCE_DIR}/lib)
INCLUDE_DIRECTORIES(${PROJECT_SOURCE_DIR}/include)
LINK_DIRECTORIES(${PROJECT_SOURCE_DIR}/lib)
SET(GL_LIB opengl32)
OPTION(DEBUG "debug switch" OFF)
OPTION(GEN_SHARED_LIB "generate shared lib .so" OFF)
OPTION(GEN_STATIC_LIB "generate static lib .a" ON)
ADD_SUBDIRECTORY(${PROJECT_SOURCE_DIR}/src)
ADD_SUBDIRECTORY(${PROJECT_SOURCE_DIR}/app)
//CMakeLists.txt in src directory
AUX_SOURCE_DIRECTORY(. SRC_LIST)
AUX_SOURCE_DIRECTORY(ImGui IMGUI_LIST)
IF(DEBUG)
ADD_DEFINITIONS(-DDEBUG)
ENDIF()
IF(SRC_LIST)
ADD_LIBRARY(mysrc STATIC ${SRC_LIST})
ENDIF()
IF(IMGUI_LIST)
ADD_LIBRARY(imgui STATIC ${IMGUI_LIST})
ENDIF()
MESSAGE("following source files will be linked into library:")
MESSAGE("------------------- SRC LIST -------------------")
FOREACH(src ${SRC_LIST})
MESSAGE("${src}")
ENDFOREACH()
MESSAGE("------------------- LIST END -------------------")
// CMakeLists.txt in app directory
AUX_SOURCE_DIRECTORY(. APP_LIST)
IF (DEBUG)
ADD_DEFINITIONS(-DDEBUG)
MESSAGE("DEBUG set to ON")
ENDIF()
FILE(GLOB LIB_LIST ${PROJECT_SOURCE_DIR}/lib/*.dll ${PROJECT_SOURCE_DIR}/lib/*.a)
IF (LIB_LIST)
FOREACH (lib ${LIB_LIST})
MESSAGE("lib found: ${lib}")
ENDFOREACH ()
ENDIF()
FOREACH (app ${APP_LIST})
GET_FILENAME_COMPONENT(output ${app} NAME_WE)
ADD_EXECUTABLE(${output} ${app})
IF (LIB_LIST)
FOREACH (lib ${LIB_LIST})
GET_FILENAME_COMPONENT(lib_name ${lib} NAME_WE)
GET_FILENAME_COMPONENT(lib_post ${lib} LAST_EXT)
IF (NOT lib_post)
MESSAGE(FATAL_ERROR "lib format not recognized\n")
ENDIF()
IF (NOT(lib_post STREQUAL ".a" OR lib_post STREQUAL ".so" OR lib_post STREQUAL ".lib" OR lib_post STREQUAL ".dll"))
MESSAGE(FATAL_ERROR "lib format not recognized: ${lib_post}\n")
ENDIF()
STRING(SUBSTRING ${lib_name} 3 -1 lib_name_without_prefix)
MESSAGE("${output} will be linked with: ${lib_name_without_prefix}")
TARGET_LINK_LIBRARIES(${output} ${lib_name_without_prefix})
ENDFOREACH()
MESSAGE("${output} will be linked with: ${GL_LIB}")
TARGET_LINK_LIBRARIES(${output} ${GL_LIB})
ENDIF()
ENDFOREACH()
I know 'undefined reference' is a common linking error in cpp projects, I have fixed many similar problems in my previous cpp projects, but I can't figure out what goes wrong in this one, actually, I have used global search(Ctrl+Shift+f) on these undefined reference functions in VScode, they do don't have formal definitions in any file! All references in search results is the usage or declaration, but no definitions! I don't understand, may be definitions will be generated in compiling???
Will it be the problem in:
wrong platform
missed steps in compiling / incorrect compile methods
wrong OpenGL version(as I don't know which version the opengl32.lib from Windows10 implements)
wrong repo, I should download the release tag instead of master branch
missing definition files, I forget to copy them into my workspace
If you have used the ImGui library, any advice would be appreciate! Thank you!