在一个生成文件中编译 C++ 和 C

我有一个使用arm-none-eabi-gcc工具链为ARM设备编写和开发的项目。它使用仅适用于 C 编译的自定义生成文件。我们试图过渡到一个主要C++项目，同时保留 C 源文件，但我在更新 makefile 时遇到了问题。我知道这个问题已经被问过几次了，但没有一个能够完全解决我们的问题。如何包含 C 源文件和头文件以编译 g++ 和 cpp 文件？

我非常感谢任何愿意并能够查看我们的 makefile 以帮助解决编译问题的人。makefile很长，所以这里有一个有点删节的版本，应该包括所有关键的内容。

请记住，我在这里只包含 makefile，而不是 platform_id.mk 或 $(PLATFORM_MCU(.mk，但我对这些文件非常有信心。

BIN_NAME = $(PLATFORM)_firmware.bin
ifdef PLATFORM
include $(PROJECT_ROOT)build/platform_id.mk
include $(PROJECT_ROOT)hal/$(PLATFORM_MCU)/$(PLATFORM_MCU).mk
include $(PROJECT_ROOT)build/$(PLATFORM_MCU_CORE)/$(PLATFORM_MCU_CORE).mk
else
$(error "Platform not defined. Used the -e flag to define the platform in the environment
endif
$(info $(msg))
# C compiler flags
CFLAGS +=
-std=c99
-Og
-g3
-Wall
-fdata-sections
-ffunction-sections
-MMD
-DHAVE_MMAP=0
-Dmalloc_getpagesize=8
-DMORECORE_CLEARS=0
-DDEFAULT_TRIM_THRESHOLD=8
# C++ compiler flags
CXXFLAGS +=
-Wall
-D__STDC_LIMIT_MACROS
# C Pre Processor flags
CPPFLAGS +=
# Undefine WIN32 variable if building on Windows host
ifdef WIN32
CFLAGS += -UWIN32
msg = You're on a windows host.
else
msg = You're not on a windows host.
endif
ifdef TOOLCHAIN
AR = $(TOOLCHAIN)-ar
CC = $(TOOLCHAIN)-gcc
CXX = $(TOOLCHAIN)-g++
endif
# Binary make targets
TARGET = out/$(PLATFORM_MCU)/$(BIN_NAME)

# Binary Sources
VPATH += $(wildcard */src/)
# extract all *.c filenames, don't pull the filepath with it
C_SRCS += $(notdir $(wildcard */src/*.c))
# extract all *.cpp filesnames, don't pull the filepath with it
CXX_SRCS += $(notdir $(wildcard */src/*.cpp))
# extract all *.s filenames, don't pull the filepath with it
S_SRCS += $(notdir $(wildcard */src/*.s))
# Objects
OBJECTS_C += $(patsubst %.c,out/$(PLATFORM_MCU)/obj/%.o,$(C_SRCS))
OBJECTS_CXX += $(patsubst %.cpp,out/$(PLATFORM_MCU)/obj/%.o,$(CXX_SRCS))
# Dependencies
DEP_C := $(OBJECTS_C:.o=.d)
DEP_CXX := $(OBJECTS_CXX:.o=.d)

# Includes
NULL =
SPACE = $(NULL) $(NULL)
INCLUDE_SRC = $(subst $(SPACE),$(SPACE)-I,$(VPATH))
PATH_INC = $(wildcard */inc/)
INCLUDE_INC = $(subst $(SPACE),$(SPACE)-I,$(PATH_INC))
C_INC +=
-I$(INCLUDE_INC) 
-I$(INCLUDE_SRC)

# Clean and precious
PRECIOUS += out/$(PLATFORM_MCU)/obj/%.o
CLEAN += out/$(PLATFORM_MCU)/
# all
all: $(TARGET)
# Create binary
$(TARGET): $(OBJECTS_C) $(OBJECTS_CXX) $(S_SRCS)
@mkdir -p $(dir $@)
$(CXX) $(CXXFLAGS) $(C_INC) -T$(LDFILE) $(LFLAGS) -o $@
$(TOOLCHAIN)-objcopy -O binary $@ $(basename $@).bin
# Compile from cpp files. Compilation works when this is removed (and toolchain and files are tweaked to represent that)
out/$(PLATFORM_MCU)/obj/%.o: %.cpp
@mkdir -p $(dir $@)
$(CXX) $(CXXFLAGS) $(C_INC) -o $@ -c $<
-include $(DEP_CXX)
# Create binary from c files
out/$(PLATFORM_MCU)/obj/%.o: %.c
@mkdir -p $(dir $@)
$(CC) $(CFLAGS) $(C_INC) -o $@ -c $<
-include $(DEP_C)
.PRECIOUS: $(PRECIOUS)

.PHONY: all clean

clean:
rm -rf $(CLEAN)

在运行make -e PLATFORM=test错误很多，主要说明 c 源代码中的各种函数没有定义。现在 main.cpp 只不过是int main()和包含到包含大多数其他 C 头文件的头文件中。

下面是编译器错误之一的示例：

hal/atsamg55/sam/drivers/usart/usart.h:333:47: error: 'p_usart' was not declared in this scope
uint32_t usart_get_writeprotect_status(Usart *p_usart);

这是主要的.cpp

#include "headers.h"
int main(){   
while(1)
{
}
return 0;
}

再次感谢您提供的任何帮助。