编译原理程序设计实践(八)— 主程序代码和makefile文件

int main(int argc, char* argv[])
{
	for (char ch = ' ';ch <= '^';++ch) /* 这个循环把ssym数组全部填nul */
		ssym[ch - ' '] = nul ;
	/* changed because of different character set
	note the typos below in the original where
	the alfas were not given the correct space */
	/* 下面初始化保留字表，保留字长度不到10个字符的，多余位置用空格填充，便于词法分析时以二分法来查找保留字 */
	memcpy(word[1-1] , "begin     " ,al);
	memcpy(word[2-1] , "call      " ,al);
	memcpy(word[3-1] , "const     " ,al);
	memcpy(word[4-1] , "do        " ,al);
	memcpy(word[5-1] , "end       " ,al);
	memcpy(word[6-1] , "if        " ,al);
	memcpy(word[7-1] , "odd       " ,al);
	memcpy(word[8-1] , "procedure " ,al);
	memcpy(word[9-1] , "read      " ,al);
	memcpy(word[10-1] , "then      " ,al);
	memcpy(word[11-1] , "var       " ,al);
	memcpy(word[12-1] , "while     " ,al);
	memcpy(word[13-1] , "write     " ,al);

	/* 保留字符号列表，在上面的保留字表中找到保留字后可以本表中相应位置该保留字的类型 */
	wsym[1-1] = beginsym ;
	wsym[2-1] = callsym ;
	wsym[3-1] = constsym ;
	wsym[4-1] = dosym ;
	wsym[5-1] = endsym ;
	wsym[6-1] = ifsym ;
	wsym[7-1] = oddsym ;
	wsym[8-1] = procsym ;
	wsym[9-1] = readsym ;
	wsym[10-1] = thensym ;
	wsym[11-1] = varsym ;
	wsym[12-1] = whilesym ;
	wsym[13-1] = writesym ;
	/* 初始化符号表，把可能出现的符号赋上相应的类型，其余符号由于开始处的循环所赋的类型均为nul */
	ssym['+'-' '] = plus ;
	ssym['-'-' '] = minus ;
	ssym['*'-' '] = times ;
	ssym['/'-' '] = slash ;
	ssym['('-' '] = lparen ;
	ssym[')'-' '] = rparen ;
	ssym['='-' '] = eql ;
	ssym[','-' '] = comma ;
	ssym['.'-' '] = period ;
	ssym['#'-' '] = neq ;
	ssym[';'-' '] = semicolon ;
	/* 初始化类PCODE助记符表，这个表主要供输出类PCODE代码之用 */
	memcpy(	&mnemonic[lit][0] , " lit " ,5);
	memcpy(	&mnemonic[opr][0] , " opr " ,5);
	memcpy(	&mnemonic[lod][0] , " lod " ,5);
	memcpy(	&mnemonic[sto][0] , " sto " ,5);
	memcpy(	&mnemonic[cal][0] , " cal " ,5);
	memcpy(	&mnemonic[_int][0] , " int " ,5);
	memcpy(	&mnemonic[jmp][0] , " jmp " ,5);
	memcpy(	&mnemonic[jpc][0] , " jpc " ,5);
	/* 我修改的代码：书上此处均为'xxx  '形式，即助记符后两个空格，通过上网查询原版程序确认为助词符前后各一空格。 */
	/* 这样改的目的是使后面的输出结果比较美观 */
	declbegsys = symset{constsym, varsym, procsym} ;
	statbegsys = symset{beginsym, callsym, ifsym, whilesym} ;
	facbegsys = symset{ident, number, lparen} ;
	/* page(output) */
	/* 由于Turbo Pascal 7.0的文本文件处理方法与源程序中使用的方法有很大不同，因此下面的有关文件处理的代码进行了不少更改。 */
	fa1.open("fa1.txt");/* 把文本文件fa1与fa1.txt文件关联起来，用于输出生成的类PCODE代码 */
	cout<<"input file?  "; /* 提示输入PL/0源程序名 */
	fa1<< "input file? "; /* 同样的提示输出到fa1.txt文件 */
	cin>>fname; /* 获得键盘输入的文件名 */
	fa1<<fname<<endl; /* 把键盘输入打印到fa1.txt文件 */
	fin.open(fname);  /* 把PL/0的源程序文件与fin关联 */

	cout<<"list object code ?"; /* 提示是否要列出类PCODE代码 */
	cin.ignore(1,'\n');
	cin.getline(fname,al); /* 获得用户输入 */
	//cout<<fname<<endl;
	fa1<< "list object code ?"<< endl; /* 同样的提示写到fa1.txt文件中 */
	listswitch = (fname[0] == 'Y'); /* 如果输入'y'开头的字符串，把listswitch标志置true，否则为false */
	//cout<<boolalpha<<listswitch<<endl;
	
	err = 0 ; /* 出错次数置0 */
	cc = -1 ; /* 词法分析行缓冲区指针置0 */
	cx = 0 ; /* 类PCODE代码表指针置0 */
	ll = -1 ; /* 词法分析行缓冲区长度置0 */
	ch = ' '; /* 词法分析当前字符为空格 */
	kk = al-1 ; /* 置kk的值为允许的标识符的最长长度，具体用意见getsym过程注释 */
	try{
		fa.open("fa.txt"); /* 把fa.txt与fa关联。fa用于输出源程序 */
		getsym( ); /* 首次调用词法分析子程序，获取源程序的第一个词（token） */
		block(0, 0, symset{period}+declbegsys + statbegsys); /* 开始进行主程序（也就是第一个分程序）的语法分析 */
		/* 主程序所在层为0层，符号表暂时为空，符号表指针指0号位置 */
		fa.close( ); /* 关闭文件 */
		fa1.close( ); /* 关闭文件 */
		if  (sym != period) /* 主程序分析结束，应遇到表明程序结束的句号 */
			error(9); /* 如果不是句号，出现9号错误 */
		/* 以上可知，一个合法的PL/0源程序应由分程序和句号构成。 */
		if  (err == 0)/* 如果出错次数为0，可以开始解释执行编译产生的代码 */
		{
			fa2.open("fa2.txt"); /* 把文本文件fa2与fa2.txt文件关联起来，用于输出类PCODE代码运行结果 */
			interpret(); /* 开始解释执行类PCODE代码 */
		}
		else
			cout<<"errors in pl/0 program"; /* 如果有错误，提示程序有错误 */
	}
	catch(int )
	{
		
	}
	fin.close( ); /* 关闭源程序文件 */
	cout<<endl;

	return 0; 
} 

makefile如下

#############################################################   
# Generic Makefile for C/C++ Program   
#   
# License: GPL (General Public License)   
# Author:  whyglinux <whyglinux AT gmail DOT com>   
# Date:    2006/03/04 (version 0.1)   
#          2007/03/24 (version 0.2)   
#          2007/04/09 (version 0.3)   
#          2007/06/26 (version 0.4)   
#          2008/04/05 (version 0.5)   
#   
# Description:   
# ------------   
# This is an easily customizable makefile template. The purpose is to   
# provide an instant building environment for C/C++ programs.   
#   
# It searches all the C/C++ source files in the specified directories,   
# makes dependencies, compiles and links to form an executable.   
#   
# Besides its default ability to build C/C++ programs which use only   
# standard C/C++ libraries, you can customize the Makefile to build   
# those using other libraries. Once done, without any changes you can   
# then build programs using the same or less libraries, even if source   
# files are renamed, added or removed. Therefore, it is particularly   
# convenient to use it to build codes for experimental or study use.   
#   
# GNU make is expected to use the Makefile. Other versions of makes   
# may or may not work.   
#   
# Usage:   
# ------   
# 1. Copy the Makefile to your program directory.   
# 2. Customize in the "Customizable Section" only if necessary:   
#    * to use non-standard C/C++ libraries, set pre-processor or compiler   
#      options to <MY_CFLAGS> and linker ones to <MY_LIBS>   
#      (See Makefile.gtk+-2.0 for an example)   
#    * to search sources in more directories, set to <SRCDIRS>   
#    * to specify your favorite program name, set to <PROGRAM>   
# 3. Type make to start building your program.   
#   
# Make Target:   
# ------------   
# The Makefile provides the following targets to make:   
#   $ make           compile and link   
#   $ make NODEP=yes compile and link without generating dependencies   
#   $ make objs      compile only (no linking)   
#   $ make tags      create tags for Emacs editor   
#   $ make ctags     create ctags for VI editor   
#   $ make clean     clean objects and the executable file   
#   $ make distclean clean objects, the executable and dependencies   
#   $ make help      get the usage of the makefile   
#   
#===========================================================================   
  
## Customizable Section: adapt those variables to suit your program.   
##==========================================================================   
  
# The pre-processor and compiler options.   
MY_CFLAGS =   
  
# The linker options.   
MY_LIBS   =   
  
# The pre-processor options used by the cpp (man cpp for more).   
CPPFLAGS  = -Wall   
  
# The options used in linking as well as in any direct use of ld.   
LDFLAGS   =   
  
# The directories in which source files reside.   
# If not specified, only the current directory will be serached.   
SRCDIRS   =   
  
# The executable file name.   
# If not specified, current directory name or `a.out' will be used.   
PROGRAM   =   main
  
## Implicit Section: change the following only when necessary.   
##==========================================================================   
  
# The source file types (headers excluded).   
# .c indicates C source files, and others C++ ones.   
SRCEXTS = .c .C .cc .cpp .CPP .c++ .cxx .cp   
  
# The header file types.   
HDREXTS = .h .H .hh .hpp .HPP .h++ .hxx .hp   
  
# The pre-processor and compiler options.   
# Users can override those variables from the command line.   
CFLAGS  = -g -O2   
CXXFLAGS= -g -O2   -std=c++0x
  
# The C program compiler.   
#CC     = gcc   
  
# The C++ program compiler.   
CXX    = g++   
  
# Un-comment the following line to compile C programs as C++ ones.   
CC     = $(CXX)   
  
# The command used to delete file.   
RM     = rm -f   
  
ETAGS = etags   
ETAGSFLAGS =   
  
CTAGS = ctags   
CTAGSFLAGS =   
  
## Stable Section: usually no need to be changed. But you can add more.   
##==========================================================================   
SHELL   = /bin/sh   
EMPTY   =   
SPACE   = $(EMPTY) $(EMPTY)   
ifeq ($(PROGRAM),)   
  CUR_PATH_NAMES = $(subst /,$(SPACE),$(subst $(SPACE),_,$(CURDIR)))   
  PROGRAM = $(word $(words $(CUR_PATH_NAMES)),$(CUR_PATH_NAMES))   
  ifeq ($(PROGRAM),)   
    PROGRAM = a.out   
  endif   
endif   
ifeq ($(SRCDIRS),)   
  SRCDIRS = .   
endif   
SOURCES = $(foreach d,$(SRCDIRS),$(wildcard $(addprefix $(d)/*,$(SRCEXTS))))   
HEADERS = $(foreach d,$(SRCDIRS),$(wildcard $(addprefix $(d)/*,$(HDREXTS))))   
SRC_CXX = $(filter-out %.c,$(SOURCES))   
OBJS    = $(addsuffix .o, $(basename $(SOURCES)))   
DEPS    = $(OBJS:.o=.d)   
  
## Define some useful variables.   
DEP_OPT = $(shell if `$(CC) --version | grep "GCC" >/dev/null`; then echo "-MM -MP"; else echo "-M"; fi )   
DEPEND      = $(CC)  $(DEP_OPT)  $(MY_CFLAGS) $(CFLAGS) $(CPPFLAGS)   
DEPEND.d    = $(subst -g ,,$(DEPEND))   
COMPILE.c   = $(CC)  $(MY_CFLAGS) $(CFLAGS)   $(CPPFLAGS) -c   
COMPILE.cxx = $(CXX) $(MY_CFLAGS) $(CXXFLAGS) $(CPPFLAGS) -c   
LINK.c      = $(CC)  $(MY_CFLAGS) $(CFLAGS)   $(CPPFLAGS) $(LDFLAGS)   
LINK.cxx    = $(CXX) $(MY_CFLAGS) $(CXXFLAGS) $(CPPFLAGS) $(LDFLAGS)   
  
.PHONY: all objs tags ctags clean distclean help show   
  
# Delete the default suffixes   
.SUFFIXES:   
	
all: $(PROGRAM)   
	  
# Rules for creating dependency files (.d).   
#------------------------------------------   
%.d:%.c 
	@echo -n $(dir $<) > $@   
	@$(DEPEND.d) $< >> $@   
  
%.d:%.C   
	@echo -n $(dir $<) > $@   
	@$(DEPEND.d) $< >> $@   
  
%.d:%.cc   
	@echo -n $(dir $<) > $@   
	@$(DEPEND.d) $< >> $@   
  
%.d:%.cpp   
	@echo -n $(dir $<) > $@   
	@$(DEPEND.d) $< >> $@   
  
%.d:%.CPP   
	@echo -n $(dir $<) > $@   
	@$(DEPEND.d) $< >> $@   
  
%.d:%.c++   
	@echo -n $(dir $<) > $@   
	@$(DEPEND.d) $< >> $@   
  
%.d:%.cp   
	@echo -n $(dir $<) > $@   
	@$(DEPEND.d) $< >> $@   
  
%.d:%.cxx   
	@echo -n $(dir $<) > $@   
	@$(DEPEND.d) $< >> $@   
  
# Rules for generating object files (.o).   
#----------------------------------------   
objs:$(OBJS)   
  
%.o:%.c   
	$(COMPILE.c) $< -o $@   
  
%.o:%.C   
	$(COMPILE.cxx) $< -o $@   
  
%.o:%.cc   
	$(COMPILE.cxx) $< -o $@   
  
%.o:%.cpp   
	$(COMPILE.cxx) $< -o $@   
  
%.o:%.CPP   
	$(COMPILE.cxx) $< -o $@   
  
%.o:%.c++   
	$(COMPILE.cxx) $< -o $@   
  
%.o:%.cp   
	$(COMPILE.cxx) $< -o $@   
  
%.o:%.cxx   
	$(COMPILE.cxx) $< -o $@   
  
# Rules for generating the tags.   
#-------------------------------------   
tags: $(HEADERS) $(SOURCES)   
	$(ETAGS) $(ETAGSFLAGS) $(HEADERS) $(SOURCES)   
  
ctags: $(HEADERS) $(SOURCES)   
	$(CTAGS) $(CTAGSFLAGS) $(HEADERS) $(SOURCES)   
  
# Rules for generating the executable.   
#-------------------------------------   
$(PROGRAM):$(OBJS)   
ifeq ($(SRC_CXX),)              # C program   
    $(LINK.c)   $(OBJS) $(MY_LIBS) -o $@   
    @echo Type ./$@ to execute the program.   
else                            # C++ program   
	$(LINK.cxx) $(OBJS) $(MY_LIBS) -o $@   
	@echo Type ./$@ to execute the program.   
endif   
  
ifndef NODEP   
ifneq ($(DEPS),)   
  sinclude $(DEPS)   
endif   
endif   
  
clean:   
	$(RM) $(OBJS) $(PROGRAM) $(PROGRAM).exe   
  
distclean: clean   
	$(RM) $(DEPS) TAGS   
  
# Show help.   
help:   
	@echo 'Generic Makefile for C/C++ Programs (gcmakefile) version 0.5'  
	@echo 'Copyright (C) 2007, 2008 whyglinux <[email protected]>'  
	@echo   
	@echo 'Usage: make [TARGET]'  
	@echo 'TARGETS:'  
	@echo '  all       (=make) compile and link.'  
	@echo '  NODEP=yes make without generating dependencies.'  
	@echo '  objs      compile only (no linking).'  
	@echo '  tags      create tags for Emacs editor.'  
	@echo '  ctags     create ctags for VI editor.'  
	@echo '  clean     clean objects and the executable file.'  
	@echo '  distclean clean objects, the executable and dependencies.'  
	@echo '  show      show variables (for debug use only).'  
	@echo '  help      print this message.'  
	@echo   
	@echo 'Report bugs to <whyglinux AT gmail DOT com>.'  
  
# Show variables (for debug use only.)   
show:   
	@echo 'PROGRAM     :' $(PROGRAM)   
	@echo 'SRCDIRS     :' $(SRCDIRS)   
	@echo 'HEADERS     :' $(HEADERS)   
    @echo 'SOURCES     :' $(SOURCES)   
    @echo 'SRC_CXX     :' $(SRC_CXX)   
    @echo 'OBJS        :' $(OBJS)   
	@echo 'DEPS        :' $(DEPS)   
	@echo 'DEPEND      :' $(DEPEND)   
	@echo 'COMPILE.c   :' $(COMPILE.c)   
	@echo 'COMPILE.cxx :' $(COMPILE.cxx)   
	@echo 'link.c      :' $(LINK.c)   
	@echo 'link.cxx    :' $(LINK.cxx)   
  
## End of the Makefile ##  Suggestions are welcome  ## All rights reserved ##   
##############################################################