头文件中的函数未定义
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【中文标题】头文件中的函数未定义【英文标题】：Functions in header file undefined 【发布时间】：2020-08-16 09:24:34 【问题描述】：我正在尝试使用 Raylib 在 C 中制作 Tilemap 系统。我的问题是，在尝试使用 Tilemap 头文件中的函数时，我总是遇到此错误：undefined reference to 'Tilemap_Init' 出于某种原因，结构工作正常，但功能不起作用。
我已经在网上搜索过，但找不到任何对我有帮助的东西。这是我的代码：
Tilemap.c
#include <stdlib.h>
#include "H/Tilemap.h"
#include "raylib.h"
Tilemap* Tilemap_Init(void)
Tilemap* tilemap;
tilemap->tiles = malloc(1 * sizeof(Tile));
tilemap->arrUsed = 0;
tilemap->arrSize = 1;
return tilemap;
void Tilemap_Destroy(Tilemap* tilemap)
free(tilemap->tiles);
tilemap->tiles = NULL;
tilemap->arrUsed = tilemap->arrSize = 0;
void Tilemap_AddTile(Tilemap* tilemap, Tile tile)
if(tilemap->arrUsed == tilemap->arrSize)
tilemap->arrSize += 2;
tilemap->tiles = realloc(tilemap->tiles, tilemap->arrSize * sizeof(Tile));
tilemap->tiles[tilemap->arrUsed++] = tile;
void Tilemap_SetTile(Tilemap* tilemap, Tile tile)
for (int i = 0; i < tilemap->arrUsed; i++)
if(tilemap->tiles[i].position.x == tile.position.x)
if(tilemap->tiles[i].position.y == tile.position.y)
tilemap->tiles[i] = tile;
Tilemap_AddTile(tilemap, tile);
void Tilemap_Render(Tilemap* tilemap)
for (int i = 0; i < tilemap->arrUsed; i++)
Tile tile = tilemap->tiles[i];
Rectangle sourceRec = 0.0f, 0.0f, tile.texture.width, tile.texture.height;
Rectangle destRec = tile.position.x, tile.position.y, tile.texture.width, tile.texture.height;
Vector2 origin = tile.texture.width, tile.texture.height;
DrawTexturePro(tile.texture, sourceRec, destRec, origin, 0.0f, WHITE);
Tilemap.h
#ifndef TILEMAP_H
#define TILEMAP_H
#ifdef __cplusplus
extern "C" // Prevents name mangling of functions
#endif
#include "raylib.h"
typedef struct
Vector2 position;
Texture2D texture;
Tile;
typedef struct
Tile* tiles;
int arrUsed;
int arrSize;
Tilemap;
Tilemap* Tilemap_Init(void);
extern void Tilemap_Destroy(Tilemap* tilemap);
void Tilemap_AddTile(Tilemap* tilemap, Tile tile);
void Tilemap_SetTile(Tilemap* tilemap, Tile tile);
void Tilemap_Render(Tilemap* tilemap);
#ifdef __cplusplus
#endif
#endif
main.c
#include "raylib.h"
#include "Scripts/H/Tilemap.h"
int main()
// Initialization
//--------------------------------------------------------------------------------------
const int screenWidth = 800;
const int screenHeight = 450;
InitWindow(screenWidth, screenHeight, "raylib");
Tilemap* tilemap = Tilemap_Init();
SetTargetFPS(60); // Set our game to run at 60 frames-per-second
//--------------------------------------------------------------------------------------
// Main game loop
while (!WindowShouldClose()) // Detect window close button or ESC key
// Update
//----------------------------------------------------------------------------------
//----------------------------------------------------------------------------------
// Draw
//----------------------------------------------------------------------------------
BeginDrawing();
ClearBackground(RAYWHITE);
DrawFPS(10, 10);
EndDrawing();
//----------------------------------------------------------------------------------
// De-Initialization
//--------------------------------------------------------------------------------------
CloseWindow(); // Close window and OpenGL context
//--------------------------------------------------------------------------------------
return 0;
和 Makefile：
.PHONY: all clean
# Define required raylib variables
PROJECT_NAME ?= ProjectStarlight
RAYLIB_VERSION ?= 3.0.0
RAYLIB_API_VERSION ?= 300
RAYLIB_PATH ?= ..\..
# Define compiler path on Windows
COMPILER_PATH ?= C:/raylib/mingw/bin
# Define default options
# One of PLATFORM_DESKTOP, PLATFORM_RPI, PLATFORM_android, PLATFORM_WEB
PLATFORM ?= PLATFORM_DESKTOP
# Locations of your newly installed library and associated headers. See ../src/Makefile
# On Linux, if you have installed raylib but cannot compile the examples, check that
# the *_INSTALL_PATH values here are the same as those in src/Makefile or point to known locations.
# To enable system-wide compile-time and runtime linking to libraylib.so, run ../src/$ sudo make install RAYLIB_LIBTYPE_SHARED.
# To enable compile-time linking to a special version of libraylib.so, change these variables here.
# To enable runtime linking to a special version of libraylib.so, see EXAMPLE_RUNTIME_PATH below.
# If there is a libraylib in both EXAMPLE_RUNTIME_PATH and RAYLIB_INSTALL_PATH, at runtime,
# the library at EXAMPLE_RUNTIME_PATH, if present, will take precedence over the one at RAYLIB_INSTALL_PATH.
# RAYLIB_INSTALL_PATH should be the desired full path to libraylib. No relative paths.
DESTDIR ?= /usr/local
RAYLIB_INSTALL_PATH ?= $(DESTDIR)/lib
# RAYLIB_H_INSTALL_PATH locates the installed raylib header and associated source files.
RAYLIB_H_INSTALL_PATH ?= $(DESTDIR)/include
# Library type used for raylib: STATIC (.a) or SHARED (.so/.dll)
RAYLIB_LIBTYPE ?= STATIC
# Build mode for project: DEBUG or RELEASE
BUILD_MODE ?= RELEASE
# Use external GLFW library instead of rglfw module
# TODO: Review usage on Linux. Target version of choice. Switch on -lglfw or -lglfw3
USE_EXTERNAL_GLFW ?= FALSE
# Use Wayland display server protocol on Linux desktop
# by default it uses X11 windowing system
USE_WAYLAND_DISPLAY ?= FALSE
# Determine PLATFORM_OS in case PLATFORM_DESKTOP selected
ifeq ($(PLATFORM),PLATFORM_DESKTOP)
# No uname.exe on MinGW!, but OS=Windows_NT on Windows!
# ifeq ($(UNAME),Msys) -> Windows
ifeq ($(OS),Windows_NT)
PLATFORM_OS=WINDOWS
export PATH := $(COMPILER_PATH):$(PATH)
else
UNAMEOS=$(shell uname)
ifeq ($(UNAMEOS),Linux)
PLATFORM_OS=LINUX
endif
ifeq ($(UNAMEOS),FreeBSD)
PLATFORM_OS=BSD
endif
ifeq ($(UNAMEOS),OpenBSD)
PLATFORM_OS=BSD
endif
ifeq ($(UNAMEOS),NetBSD)
PLATFORM_OS=BSD
endif
ifeq ($(UNAMEOS),DragonFly)
PLATFORM_OS=BSD
endif
ifeq ($(UNAMEOS),Darwin)
PLATFORM_OS=OSX
endif
endif
endif
ifeq ($(PLATFORM),PLATFORM_RPI)
UNAMEOS=$(shell uname)
ifeq ($(UNAMEOS),Linux)
PLATFORM_OS=LINUX
endif
endif
# RAYLIB_PATH adjustment for different platforms.
# If using GNU make, we can get the full path to the top of the tree. Windows? BSD?
# Required for ldconfig or other tools that do not perform path expansion.
ifeq ($(PLATFORM),PLATFORM_DESKTOP)
ifeq ($(PLATFORM_OS),LINUX)
RAYLIB_PREFIX ?= ..
RAYLIB_PATH = $(realpath $(RAYLIB_PREFIX))
endif
endif
# Default path for raylib on Raspberry Pi, if installed in different path, update it!
# This is not currently used by src/Makefile. Not sure of its origin or usage. Refer to wiki.
# TODO: update install: target in src/Makefile for RPI, consider relation to LINUX.
ifeq ($(PLATFORM),PLATFORM_RPI)
RAYLIB_PATH ?= /home/pi/raylib
endif
ifeq ($(PLATFORM),PLATFORM_WEB)
# Emscripten required variables
EMSDK_PATH ?= C:/emsdk
EMSCRIPTEN_VERSION ?= 1.38.31
CLANG_VERSION = e$(EMSCRIPTEN_VERSION)_64bit
PYTHON_VERSION = 2.7.13.1_64bit\python-2.7.13.amd64
NODE_VERSION = 8.9.1_64bit
export PATH = $(EMSDK_PATH);$(EMSDK_PATH)\clang\$(CLANG_VERSION);$(EMSDK_PATH)\node\$(NODE_VERSION)\bin;$(EMSDK_PATH)\python\$(PYTHON_VERSION);$(EMSDK_PATH)\emscripten\$(EMSCRIPTEN_VERSION);C:\raylib\MinGW\bin:$$(PATH)
EMSCRIPTEN = $(EMSDK_PATH)\emscripten\$(EMSCRIPTEN_VERSION)
endif
# Define raylib release directory for compiled library.
# RAYLIB_RELEASE_PATH points to provided binaries or your freshly built version
RAYLIB_RELEASE_PATH ?= $(RAYLIB_PATH)/src
# EXAMPLE_RUNTIME_PATH embeds a custom runtime location of libraylib.so or other desired libraries
# into each example binary compiled with RAYLIB_LIBTYPE=SHARED. It defaults to RAYLIB_RELEASE_PATH
# so that these examples link at runtime with your version of libraylib.so in ../release/libs/linux
# without formal installation from ../src/Makefile. It aids portability and is useful if you have
# multiple versions of raylib, have raylib installed to a non-standard location, or want to
# bundle libraylib.so with your game. Change it to your liking.
# NOTE: If, at runtime, there is a libraylib.so at both EXAMPLE_RUNTIME_PATH and RAYLIB_INSTALL_PATH,
# The library at EXAMPLE_RUNTIME_PATH, if present, will take precedence over RAYLIB_INSTALL_PATH,
# Implemented for LINUX below with CFLAGS += -Wl,-rpath,$(EXAMPLE_RUNTIME_PATH)
# To see the result, run readelf -d core/core_basic_window; looking at the RPATH or RUNPATH attribute.
# To see which libraries a built example is linking to, ldd core/core_basic_window;
# Look for libraylib.so.1 => $(RAYLIB_INSTALL_PATH)/libraylib.so.1 or similar listing.
EXAMPLE_RUNTIME_PATH ?= $(RAYLIB_RELEASE_PATH)
# Define default C compiler: gcc
# NOTE: define g++ compiler if using C++
CC = gcc
ifeq ($(PLATFORM),PLATFORM_DESKTOP)
ifeq ($(PLATFORM_OS),OSX)
# OSX default compiler
CC = clang
endif
ifeq ($(PLATFORM_OS),BSD)
# FreeBSD, OpenBSD, NetBSD, DragonFly default compiler
CC = clang
endif
endif
ifeq ($(PLATFORM),PLATFORM_RPI)
ifeq ($(USE_RPI_CROSS_COMPILER),TRUE)
# Define RPI cross-compiler
#CC = armv6j-hardfloat-linux-gnueabi-gcc
CC = $(RPI_TOOLCHAIN)/bin/arm-linux-gnueabihf-gcc
endif
endif
ifeq ($(PLATFORM),PLATFORM_WEB)
# html5 emscripten compiler
# WARNING: To compile to HTML5, code must be redesigned
# to use emscripten.h and emscripten_set_main_loop()
CC = emcc
endif
# Define default make program: Mingw32-make
MAKE = mingw32-make
ifeq ($(PLATFORM),PLATFORM_DESKTOP)
ifeq ($(PLATFORM_OS),LINUX)
MAKE = make
endif
ifeq ($(PLATFORM_OS),OSX)
MAKE = make
endif
endif
# Define compiler flags:
# -O0 defines optimization level (no optimization, better for debugging)
# -O1 defines optimization level
# -g include debug information on compilation
# -s strip unnecessary data from build -> do not use in debug builds
# -Wall turns on most, but not all, compiler warnings
# -std=c99 defines C language mode (standard C from 1999 revision)
# -std=gnu99 defines C language mode (GNU C from 1999 revision)
# -Wno-missing-braces ignore invalid warning (GCC bug 53119)
# -D_DEFAULT_SOURCE use with -std=c99 on Linux and PLATFORM_WEB, required for timespec
CFLAGS += -Wall -std=c99 -D_DEFAULT_SOURCE -Wno-missing-braces
ifeq ($(BUILD_MODE),DEBUG)
CFLAGS += -g -O0
else
CFLAGS += -s -O1
endif
# Additional flags for compiler (if desired)
#CFLAGS += -Wextra -Wmissing-prototypes -Wstrict-prototypes
ifeq ($(PLATFORM),PLATFORM_DESKTOP)
ifeq ($(PLATFORM_OS),WINDOWS)
# resource file contains windows executable icon and properties
# -Wl,--subsystem,windows hides the console window
CFLAGS += $(RAYLIB_PATH)/src/raylib.rc.data -Wl,--subsystem,windows
endif
ifeq ($(PLATFORM_OS),LINUX)
ifeq ($(RAYLIB_LIBTYPE),STATIC)
CFLAGS += -D_DEFAULT_SOURCE
endif
ifeq ($(RAYLIB_LIBTYPE),SHARED)
# Explicitly enable runtime link to libraylib.so
CFLAGS += -Wl,-rpath,$(EXAMPLE_RUNTIME_PATH)
endif
endif
endif
ifeq ($(PLATFORM),PLATFORM_RPI)
CFLAGS += -std=gnu99
endif
ifeq ($(PLATFORM),PLATFORM_WEB)
# -Os # size optimization
# -O2 # optimization level 2, if used, also set --memory-init-file 0
# -s USE_GLFW=3 # Use glfw3 library (context/input management)
# -s ALLOW_MEMORY_GROWTH=1 # to allow memory resizing -> WARNING: Audio buffers could FAIL!
# -s TOTAL_MEMORY=16777216 # to specify heap memory size (default = 16MB)
# -s USE_PTHREADS=1 # multithreading support
# -s WASM=0 # disable Web Assembly, emitted by default
# -s EMTERPRETIFY=1 # enable emscripten code interpreter (very slow)
# -s EMTERPRETIFY_ASYNC=1 # support synchronous loops by emterpreter
# -s FORCE_FILESYSTEM=1 # force filesystem to load/save files data
# -s ASSERTIONS=1 # enable runtime checks for common memory allocation errors (-O1 and above turn it off)
# --profiling # include information for code profiling
# --memory-init-file 0 # to avoid an external memory initialization code file (.mem)
# --preload-file resources # specify a resources folder for data compilation
CFLAGS += -Os -s USE_GLFW=3 -s TOTAL_MEMORY=16777216 --preload-file resources
ifeq ($(BUILD_MODE), DEBUG)
CFLAGS += -s ASSERTIONS=1 --profiling
endif
# Define a custom shell .html and output extension
CFLAGS += --shell-file $(RAYLIB_PATH)/src/shell.html
EXT = .html
endif
# Define include paths for required headers
# NOTE: Several external required libraries (stb and others)
INCLUDE_PATHS = -I. -I$(RAYLIB_PATH)/src -I$(RAYLIB_PATH)/src/external
# Define additional directories containing required header files
ifeq ($(PLATFORM),PLATFORM_RPI)
# RPI required libraries
INCLUDE_PATHS += -I/opt/vc/include
INCLUDE_PATHS += -I/opt/vc/include/interface/vmcs_host/linux
INCLUDE_PATHS += -I/opt/vc/include/interface/vcos/pthreads
endif
ifeq ($(PLATFORM),PLATFORM_DESKTOP)
ifeq ($(PLATFORM_OS),BSD)
# Consider -L$(RAYLIB_H_INSTALL_PATH)
INCLUDE_PATHS += -I/usr/local/include
endif
ifeq ($(PLATFORM_OS),LINUX)
# Reset everything.
# Precedence: immediately local, installed version, raysan5 provided libs -I$(RAYLIB_H_INSTALL_PATH) -I$(RAYLIB_PATH)/release/include
INCLUDE_PATHS = -I$(RAYLIB_H_INSTALL_PATH) -isystem. -isystem$(RAYLIB_PATH)/src -isystem$(RAYLIB_PATH)/release/include -isystem$(RAYLIB_PATH)/src/external
endif
endif
# Define library paths containing required libs.
LDFLAGS = -L. -L$(RAYLIB_RELEASE_PATH) -L$(RAYLIB_PATH)/src
ifeq ($(PLATFORM),PLATFORM_DESKTOP)
ifeq ($(PLATFORM_OS),BSD)
# Consider -L$(RAYLIB_INSTALL_PATH)
LDFLAGS += -L. -Lsrc -L/usr/local/lib
endif
ifeq ($(PLATFORM_OS),LINUX)
# Reset everything.
# Precedence: immediately local, installed version, raysan5 provided libs
LDFLAGS = -L. -L$(RAYLIB_INSTALL_PATH) -L$(RAYLIB_RELEASE_PATH)
endif
endif
ifeq ($(PLATFORM),PLATFORM_RPI)
LDFLAGS += -L/opt/vc/lib
endif
# Define any libraries required on linking
# if you want to link libraries (libname.so or libname.a), use the -lname
ifeq ($(PLATFORM),PLATFORM_DESKTOP)
ifeq ($(PLATFORM_OS),WINDOWS)
# Libraries for Windows desktop compilation
# NOTE: WinMM library required to set high-res timer resolution
LDLIBS = -lraylib -lopengl32 -lgdi32 -lwinmm
# Required for physac examples
#LDLIBS += -static -lpthread
endif
ifeq ($(PLATFORM_OS),LINUX)
# Libraries for Debian GNU/Linux desktop compiling
# NOTE: Required packages: libegl1-mesa-dev
LDLIBS = -lraylib -lGL -lm -lpthread -ldl -lrt
# On X11 requires also below libraries
LDLIBS += -lX11
# NOTE: It seems additional libraries are not required any more, latest GLFW just dlopen them
#LDLIBS += -lXrandr -lXinerama -lXi -lXxf86vm -lXcursor
# On Wayland windowing system, additional libraries requires
ifeq ($(USE_WAYLAND_DISPLAY),TRUE)
LDLIBS += -lwayland-client -lwayland-cursor -lwayland-egl -lxkbcommon
endif
# Explicit link to libc
ifeq ($(RAYLIB_LIBTYPE),SHARED)
LDLIBS += -lc
endif
endif
ifeq ($(PLATFORM_OS),OSX)
# Libraries for OSX 10.9 desktop compiling
# NOTE: Required packages: libopenal-dev libegl1-mesa-dev
LDLIBS = -lraylib -framework OpenGL -framework OpenAL -framework Cocoa
endif
ifeq ($(PLATFORM_OS),BSD)
# Libraries for FreeBSD, OpenBSD, NetBSD, DragonFly desktop compiling
# NOTE: Required packages: mesa-libs
LDLIBS = -lraylib -lGL -lpthread -lm
# On XWindow requires also below libraries
LDLIBS += -lX11 -lXrandr -lXinerama -lXi -lXxf86vm -lXcursor
endif
ifeq ($(USE_EXTERNAL_GLFW),TRUE)
# NOTE: It could require additional packages installed: libglfw3-dev
LDLIBS += -lglfw
endif
endif
ifeq ($(PLATFORM),PLATFORM_RPI)
# Libraries for Raspberry Pi compiling
# NOTE: Required packages: libasound2-dev (ALSA)
LDLIBS = -lraylib -lbrcmGLESv2 -lbrcmEGL -lpthread -lrt -lm -lbcm_host -ldl
endif
ifeq ($(PLATFORM),PLATFORM_WEB)
# Libraries for web (HTML5) compiling
LDLIBS = $(RAYLIB_RELEASE_PATH)/libraylib.bc
endif
# Define a recursive wildcard function
#rwildcard=$(foreach d,$(wildcard $1*),$(call rwildcard,$d/,$2) $(filter $(subst *,%,$2),$d))
# Define all source files required
#SRC_DIR = src
#OBJ_DIR = obj
# Define all object files from source files
#SRC = $(call rwildcard, *.c, *.h)
PROJECT_SOURCE_FILES ?= \
main.c \
Scipts/C/Tilemap.c
OBJS = $(patsubst %.c, %.o, $(PROJECT_SOURCE_FILES))
#OBJS = $(SRC:$(SRC_DIR)/%.c=$(OBJ_DIR)/%.o)
#OBJS ?= main.c
# For Android platform we call a custom Makefile.Android
ifeq ($(PLATFORM),PLATFORM_ANDROID)
MAKEFILE_PARAMS = -f Makefile.Android
export PROJECT_NAME
export SRC_DIR
else
MAKEFILE_PARAMS = $(PROJECT_NAME)
endif
# Default target entry
# NOTE: We call this Makefile target or Makefile.Android target
all:
$(MAKE) $(MAKEFILE_PARAMS)
# Project target defined by PROJECT_NAME
$(PROJECT_NAME): $(OBJS)
$(CC) -o $(PROJECT_NAME)$(EXT) $(OBJS) $(CFLAGS) $(INCLUDE_PATHS) $(LDFLAGS) $(LDLIBS) -D$(PLATFORM)
# Compile source files
# NOTE: This pattern will compile every module defined on $(OBJS)
#%.o: %.c
$(OBJ_DIR)/%.o: $(SRC_DIR)/%.c
$(CC) -c $< -o $@ $(CFLAGS) $(INCLUDE_PATHS) -D$(PLATFORM)
# Clean everything
clean:
ifeq ($(PLATFORM),PLATFORM_DESKTOP)
ifeq ($(PLATFORM_OS),WINDOWS)
del *.o *.exe /s
endif
ifeq ($(PLATFORM_OS),LINUX)
find -type f -executable | xargs file -i | grep -E 'x-object|x-archive|x-sharedlib|x-executable' | rev | cut -d ':' -f 2- | rev | xargs rm -fv
endif
ifeq ($(PLATFORM_OS),OSX)
find . -type f -perm +ugo+x -delete
rm -f *.o
endif
endif
ifeq ($(PLATFORM),PLATFORM_RPI)
find . -type f -executable -delete
rm -fv *.o
endif
ifeq ($(PLATFORM),PLATFORM_WEB)
del *.o *.html *.js
endif
@echo Cleaning done
【问题讨论】：
我在您显示的代码中没有看到Tilemap_Init 的调用，这让我认为错误在不同的文件中......无关，但tilemap 的初始化在Tilemap_Init 不会那样工作。您在那里取消引用未初始化的指针。
问题可能出在 makefile 中吗？我以前从未使用过 makefile，我只是使用了 raylib 示例中的示例之一，它使用了多个 .c 文件。但我认为这没有多大意义，因为我可以在其他 .c 文件中使用这些结构。
显示使用Tilemap_Init的源代码（如果超过几行，则将其缩减为minimal reproducible example）。显示您用于构建、链接和运行程序的命令。
我刚刚将main.c文件和Makefile添加到帖子中
【参考方案1】：
OBJS = $(patsubst %.c, %.o, $(PROJECT_SOURCE_FILES))
#OBJS = $(SRC:$(SRC_DIR)/%.c=$(OBJ_DIR)/%.o)
#OBJS ?= main.c
这看起来像是在尝试解决问题。让我们看看：
(PROJECT_NAME): $(OBJS)
$(CC) -o $(PROJECT_NAME)$(EXT) $(OBJS) ...
所以你有main.c 和Scipts/C/Tilemap.c。对应的OBJS 将是main.o 和Scipts/C/Tilemap.o，因为patsubst 只是将.c 替换为.o。不过……
$(OBJ_DIR)/%.o: $(SRC_DIR)/%.c
$(CC) -c $< -o $@ $(CFLAGS) $(INCLUDE_PATHS) -D$(PLATFORM)
这会编译存在于$(SRC_DIR) 中的.c 文件并将编译结果放入$(OBJ_DIR)。这两个变量都在您的 Makefile 中被注释掉。此规则既不能编译main.c 和Scipts/C/Tilemap.c，也不能同时生成main.o 和Scipts/C/Tilemap.o，因为它们位于不同的目录中。
简而言之，Makefile 坏了。
【讨论】：
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