BREW Makefile生成工具功能改進——把中間文件放入獨立目錄

BREW自帶的Makefile生成工具產生的Makefile，會將中間文件（.o）生成到源代碼目錄下，這樣源代碼目錄看起來很混亂。但是如果在編譯完後刪除這些文件，又無法享受到make的只編譯改動過的源文件的速度優勢。在第二版自己編寫的BREW Makefile生成工具裏（BMG，BREW Makefile 生成工具的編寫），花了些時間解決了這個問題。

目前採用的方式：

.o目標定義爲"中間目錄/文件名"的形式，例如"objs/foo.c"

模式規則定義爲"objs/%.o : %.c"形式。經試驗不能只寫成"%.o : %.c",會提示找不到生成目標的規則,可能make的模式匹配規則只是匹配文件名。

使用GCC生成每個源文件的依賴關係到一個.d文件，再使用sed處理這個文件，給裏面的源文件名加上“objs/”前綴

使用“-include $(OBJS:.o=.d)”命令包含生成的.d文件

也有其它的更簡潔處的處理方式，可參見下面列出的參考文檔1

原來使用的是微軟的NMake程序，但是它不支持VPATH，編寫起來比較麻煩。最後改用GNU Make，但是在Windows上又遇到了路徑中斜槓和反斜槓的問題。有的Windows版GNU環境和GNU Make不支持Windows的反斜槓路徑表示法，將反斜槓解釋成轉義反斜槓，導致各種生成失敗。現在採用的GNU環境是mingw的msys，GNUWin32的make 3.8.1（Mingw版和cygwin版make目標文件涉及盤符的路徑，引號還會解析失敗，盤符路徑還要寫成unix形式）版。除上面的目標文件形式外"objs/foo.c"，均可以使用Windows反斜槓路徑。

對於BREW項目，還有一個易錯點，elf2mod.x這個GCC鏈接腳本。當時爲了啓用編譯器優化選項時AEEMod_Load仍能放到mod 0地址處，在鏈接腳本里寫下了這樣的語句

"AEEMod*.o"(.text.AEEMod_Load)

現在.o放到了獨立目錄，這裏也該做修改。例如

"objs/AEEMod*.o"(.text.AEEMod_Load)

下面附上參考資料：

1.讓 GNU Make 把中間文件放到獨立目錄

2.GNU Make 下創建目錄的問題

3.一個makefile實例

TARGET=frame

OBJS=objs/EasyText.o objs/extracter.o objs/graphics.o objs/map.o objs/mapX.o objs/object.o objs/script.o objs/simple_thread.o objs/sprite.o objs/state.o objs/ui.o objs/util.o objs/frame.o objs/AEEAppGen.o objs/AEEModGen.o objs/brew_main.o objs/GCCResolver.o

VPATH=./engine ./game c:/PROGRA~1/BREW31~1.5/sdk/src ./BREW_F~1 $(BMG)

APP_INCLUDES= -I../debug/frame -I./simple_stl -I./engine -I./inc -I$(BREWDIR_3)/inc

DEP_INCLUDES= -I../debug/frame -I./simple_stl -I./engine -I./inc

PRE_DEF=-Dsdf

BREW_HOME = $(BREWDIR)

BREW_ADDINS = $(BREWADDINS)

GCC_HOME = $(GCCHOME)

GCC_LIBPATH = $(GCCLIBPATH)

#-------------------------------------------------------------------------------

# type definitions

#-------------------------------------------------------------------------------

EXETYPE = elf

BINARY = bin

MODULE = mod

#-----------------------------------------------------------------------

# Target compile time symbol definitions

# Tells the SDK source stuffs that we're building a dynamic app.

#-----------------------------------------------------------------------

DYNAPP = -DDYNAMIC_APP

#-----------------------------------------------------------------------

# Software tool and environment definitions

# (PREFIX needs to be set to the location of your gcc cross-compiler

# and binutils. STUBTOOL needs to be the path and filename of your

# copy of makestub)

#-----------------------------------------------------------------------

AEESRCPATH = $(BREW_HOME)/src

AEEINCPATH = $(BREW_HOME)/inc

GCC = $(GCC_HOME)/bin/arm-elf-gcc

GPP = $(GCC_HOME)/bin/arm-elf-g++

LD = $(GCC_HOME)/bin/arm-elf-ld

DUMPTOOL = $(GCC_HOME)/bin/arm-elf-objdump

ELF2MODTOOLPATH = $(BREW_ADDINS)/common/bin

ELF2MODTOOL = $(ELF2MODTOOLPATH)/elf2mod.exe

GCCRESOLVEPATH = $(BMG)

#-----------------------------------------------------------------------

# Compiler optimization options

# -O0 disables compiler optimizations. Other options probably work as

# well. Set to taste.

#-----------------------------------------------------------------------

OPT = -Os

#-----------------------------------------------------------------------

# Compiler code generation options

# Add $(TARG) to the CODE line if you're building a Thumb binary (at

# the moment, this doesn't work).

#-----------------------------------------------------------------------

END = -mlittle-endian

TARG = -mthumb

CODE = $(END) -fshort-enums -fno-builtin -ffunction-sections -fno-exceptions -fno-unwind-tables -fno-rtti -fshort-wchar

#-----------------------------------------------------------------------

# Include file search path options

# (change this to point to where the BREW SDK headers are located)

#-----------------------------------------------------------------------

INC = -I$(AEEINCPATH) -I$(GCC_LIBPATH)/include -I$(GCC_HOME)/arm-elf/include $(APP_INCLUDES)

#-----------------------------------------------------------------------

# Library search path options

# (You can change this to point to where your interworking version of

# libgcc.a resides)

#-----------------------------------------------------------------------

LIBDIRS = -L$(GCC_LIBPATH)

#-----------------------------------------------------------------------

# Nothing below here (except for the dependencies at the bottom of the

# file) should need to be changed for a reasonably normal compilation.

#-----------------------------------------------------------------------

# Processor architecture options

# Sets the designated target processor for this applet.

# Currently, all BREW phones use the ARM 7t chip

#-----------------------------------------------------------------------

CPU = -mcpu=arm7tdmi

#-----------------------------------------------------------------------

# ARM Procedure Call Standard (APCS) options

# -fPIC sets posititon independent code. Other option: -fpic

# -mthumb-interwork enables switching between ARM and Thumb code

# -mapcs-frame runs on systems with the frame ptr. specified in the

# APCS

#-----------------------------------------------------------------------

ROPI =

INTRWK = -mthumb-interwork

APCS = -mapcs-frame $(ROPI) $(INTRWK)

#-----------------------------------------------------------------------

# Compiler output options

# -c sets object file output only

#-----------------------------------------------------------------------

OUT = -c

#-----------------------------------------------------------------------

# Compiler/assembler debug Options

# -g is the standard flag to leave debugging information in the

# object files.

#-----------------------------------------------------------------------

DBG = -g

#-----------------------------------------------------------------------

# Linker Options

# -o sets the output filename

#-----------------------------------------------------------------------

LINK_CMD = -Ttext 0 --emit-relocs -entry AEEMod_Load -o

LIBS =-lc -lgcc

#-----------------------------------------------------------------------

# HEXTOOL Options

#-----------------------------------------------------------------------

BINFORMAT = -O binary

#-----------------------------------------------------------------------

# Compiler flag definitions

#-----------------------------------------------------------------------

CFLAGS0 = $(OUT) $(DYNAPP) $(CPU) $(APCS) $(CODE) $(DBG)

CFLAGS = $(CFLAGS0) $(OPT) $(PRE_DEF)

#-----------------------------------------------------------------------

# Linker flag definitions

#-----------------------------------------------------------------------

LDFLAGS = $(LIBDIRS) --script $(GCCRESOLVEPATH)/elf2mod_objs.x

#-----------------------------------------------------------------------

# Default target

#-----------------------------------------------------------------------

default: $(TARGET).$(MODULE)

#-----------------------------------------------------------------------

# All target

#-----------------------------------------------------------------------

.DELETE_ON_ERROR:

all: $(TARGET).$(MODULE)

-include $(OBJS:.o=.d)

objs/%.o : %.c | objs