pclint测试c或c++实例.doc

PC-lint测试C/C+实例实例1：test.cpp1 #include 2 class X3 4 int *p;5 public:6 X()7 p = new int20; 8 void init()9 memset( p, 20, a ); 10 X()11 delete p; 12 ;编译这个文件，VC6.0产生0 errors 0 warnings, 而lint程序产生了如下8条警告信息,有些还是很有用处的提示。PC-lint 告警信息：test.cpp(12): error 783: (Info - Line does not end with new-line)test.cpp(7): error 1732: (Info - new in constructor for class X which has no assignment operator)test.cpp(7): error 1733: (Info - new in constructor for class X which has no copy constructor) memset( p, 20, a ); test.cpp(9): error 669: (Warning - Possible data overrun for function memset(void *, int, unsigned int), argument 3 (size=97) exceeds argument 1 (size=80) Reference: test.cpp: lines 7, 9)test.cpp(7): error 831: (Info - Reference cited in prior message)test.cpp(9): error 831: (Info - Reference cited in prior message) delete p; test.cpp(11): error 424: (Warning - Inappropriate deallocation (delete) for new data) - Wrap-up for Module: test.cpptest.cpp(2): error 753: (Info - local class X (line 2, file test.cpp) not referenced)error 900: (Note - Successful completion,8 messages produced)根据错误提示修改后的程序如下：#include class X /*lint -e753 */ /只声明实现类X，没有写main()应用类x,故可以屏蔽。 int *p;public: X() /构造函数 p = NULL; X (const X &x) /拷贝构造函数 p = new int20; memcpy(p, x.p, 20*sizeof(int); X & operator= (const X &x) /赋值操作符 if (this = &x) /检查自赋值 return *this; int *temp = new int20; memcpy(temp, x.p, 20*sizeof(int); /复制指针指向内容 delete p; /删除原有指针(将删除操作符放在后面，避免X=X特殊情况下，内容的丢失) p=temp; /建立新指向 return *this; void init() if (NULL = p) return; / 判断指针是否为空 memset( p, a, 20*sizeof(int); X() delete p; ;/在;后面回车换行以消除告警test.cpp(12): error 783: (Info - Line does not end with new-line)注意： 为需要动态分配内存的类声明一个拷贝构造函数和一个赋值操作符（可参考effective_c+2e 条款11）再次运行pclintPC-lint for C/C+ (NT) Vers. 9.00a, Copyright Gimpel Software 1985-2008- Module: test.cpp (C+)- Global Wrap-up error 900: (Note - Successful completion, 0 messages produced)实例2：实现输入的两个复数的四则运算。/*File name:Complex.hFunction:A simple complex calculator demo*/#include using namespace std;class complex public: / public interface complex(double r, double i); / constructor void assign(void); / user input to define a complex / overload operators to friend functions friend complex operator + (complex &c1, complex &c2); friend complex operator - (complex &c1, complex &c2); friend complex operator * (complex &c1, complex &c2); friend complex operator / (complex &c1, complex &c2); friend ostream& operator (ostream &out, complex x); private: double real; double imag;/*File name:Complex.cppFunction:A simple complex calculator demo*/#include Complex.hcomplex:complex(double r = 0.0, double i = 0.0) real = r; imag = i; return;void complex:assign(void) cout Please input the real part : real; cout Please input the imaginary part: imag; return;ostream& operator (ostream &out, complex x) if (x.imag 0) return (out x.real + ( x.imag ) i endl); else return (out x.real + x.imag i endl); complex operator + (complex &c1, complex &c2) return complex(c1.real + c2.real, c1.imag + c2.imag); complex operator - (complex &c1, complex &c2) return complex(c1.real - c2.real, c1.imag - c2.imag); complex operator * (complex &c1, complex &c2) return complex(c1.real * c2.real - c1.imag * c2.imag) ,(c1.real * c2. imag + c2.real * c1.imag); complex operator / (complex &c1, complex &c2) double denominator = c2.real * c2.real + c2.imag * c2.imag; return complex(c1.real * c2.real + c1.imag * c2.imag) / denominator ,(c1.imag * c2.real - c1.real * c2.imag) / denominator); int main(void) complex c1(5, 4), c2(2, 10); cout c1 = c1; cout c2 = c2; cout c1 + c2 = c1 + c2; cout c1 - c2 = c1 - c2; cout c1 * c2 = c1 * c2; cout c1 / c2 = c1 / c2; c1.assign(); cout Current c1 = c1; c2.assign(); cout Current c2 = c2; cout c1 + c2 = c1 + c2; cout c1 - c2 = c1 - c2; cout c1 * c2 = c1 * c2; cout c1 / c2 = c1 / c2; return 0;编译这两个文件， VC6.0编译器产生0 errors 0 warnings, 而pclint程序产生了如下27条警告信息, PC-lint 告警信息如下：PC-lint for C/C+ (NT) Vers. 9.00a, Copyright Gimpel Software 1985-2008- Module: Bcomplex.cpp (C+);Bcomplex.h(19): error 783: (Info - Line does not end with new-line)Bcomplex.h(19): error 1712: (Info - default constructor not defined for class complex) Bcomplex.cpp(30): error 1746: (Info - parameter x in function operator(std:basic_ostreamchar,std:char_traits &, complex) could be made const reference)Bcomplex.cpp(35): error 1764: (Info - Reference parameter c1 (line 32) could be declared const ref)Bcomplex.cpp(32): error 830: (Info - Location cited in prior message)Bcomplex.cpp(35): error 1764: (Info - Reference parameter c2 (line 32) could be declared const ref)Bcomplex.cpp(32): error 830: (Info - Location cited in prior message)Bcomplex.cpp(40): error 1764: (Info - Reference parameter c1 (line 37) could be declared const ref)Bcomplex.cpp(37): error 830: (Info - Location cited in prior message)Bcomplex.cpp(40): error 1764: (Info - Reference parameter c2 (line 37) could be declared const ref)Bcomplex.cpp(37): error 830: (Info - Location cited in prior message)Bcomplex.cpp(45): error 1764: (Info - Reference parameter c1 (line 42) could be declared const ref)Bcomplex.cpp(42): error 830: (Info - Location cited in prior message)Bcomplex.cpp(45): error 1764: (Info - Reference parameter c2 (line 42) could be declared const ref)Bcomplex.cpp(42): error 830: (Info - Location cited in prior message)Bcomplex.cpp(51): error 1764: (Info - Reference parameter c1 (line 47) could be declared const ref)Bcomplex.cpp(47): error 830: (Info - Location cited in prior message)Bcomplex.cpp(51): error 1764: (Info - Reference parameter c2 (line 47) could be declared const ref)Bcomplex.cpp(47): error 830: (Info - Location cited in prior message) complex c1(5, 4), c2(2, 10);Bcomplex.cpp(55): error 747: (Info - Significant prototype coercion (arg. no. 1) int to double)Bcomplex.cpp(55): error 747: (Info - Significant prototype coercion (arg. no. 2) int to double)Bcomplex.cpp(55): error 747: (Info - Significant prototype coercion (arg. no. 1) int to double)Bcomplex.cpp(55): error 747: (Info - Significant prototype coercion (arg. no. 2) int to double)- Global Wrap-up error 1754: (Info - Expected symbol operator*= to be declared for class complex) error 1754: (Info - Expected symbol operator+= to be declared for class complex) error 1754: (Info - Expected symbol operator-= to be declared for class complex) error 1754: (Info - Expected symbol operator/= to be declared for class complex) error 900: (Note - Successful completion, 27 messages produced)根据提示修改代码如下：/*File name:Complex.hFunction:A simple complex calculator demo*/#include using namespace std;class complex public: / public interface complex(void); / void constructor complex(double r, double i); / constructor void assign(void); / user input to define a complex / overload operators to friend functions friend complex operator + (const complex &c1, const complex &c2); friend complex operator - (const complex &c1, const complex &c2); friend complex operator * (const complex &c1, const complex &c2); friend complex operator / (const complex &c1, const complex &c2); friend ostream& operator (ostream &out, const complex &x); private: double real; double imag;/*File name:Complex.cppFunction:A simple complex calculator demo*/#include Complex.hcomplex:complex(void) real = 0; imag = 0; return;complex:complex(double r = 0.0, double i = 0.0) real = r; imag = i; return;void complex:assign(void) cout Please input the real part : real; cout Please input the imaginary part: imag; return;ostream& operator (ostream &out, const complex &x) if (x.imag 0) return (out x.real + ( x.imag ) i endl); else return (out x.real + x.imag i endl); complex operator + (const complex &c1, const complex &c2) return complex(c1.real + c2.real, c1.imag + c2.imag); complex operator - (const complex &c1, const complex &c2) return complex(c1.real - c2.real, c1.imag - c2.imag); complex operator * (const complex &c1, const complex &c2) return complex(c1.real * c2.real - c1.imag * c2.imag),(c1.real * c2. imag + c2.real * c1.imag); complex operator / (const complex &c1, const complex &c2) double denominator = c2.real * c2.real + c2.imag * c2.imag; return complex(c1.real * c2.real + c1.imag * c2.imag) / denominator,(c1.imag * c2.real - c1.real * c2.imag) / denominator); int main(void) complex c1(5.0, 4.0), c2(2.0, 10.0); cout c1 = c1; cout c2 = c2; cout c1 + c2 = c1 + c2; cout c1 - c2 = c1 - c2; cout c1 * c2 = c1 * c2; cout c1 / c2 = c1 / c2; c1.assign(); cout Current c1 = c1; c2.assign(); cout Current c2 = c2; cout c1 + c2 = c1 + c2; cout c1 - c2 = c1 - c2; cout c1 * c2 = c1 * c2; cout c1 / c2 = c1 / c2; return 0;再次运行pclint，信息如下：PC-lint for C/C+ (NT) Vers. 9.00a, Copyright Gimpel Software 1985-2008- Module: Complex.cpp (C+)- Global Wrap-up error 1754: (Info - Expected symbol operator*= to be declared for class complex) error 1754: (Info - Expected symbol operator+= to be declared for class complex) error 1754: (Info - Expected symbol operator-= to be declared for class complex) error 1754: (Info - Expected symbol operator/= to be declared for class complex) error 900: (Note - Successful completion, 4 messages produced)编号1754信息：如果类中出现重载操作符时(operator op，op为+、-、*、/)，pclint建议声明相应的重载赋值操作符,这里不声明也没问题。可以用/*lint -e1754*/进行屏蔽。参看参看PC-Lint目录下的msg.txt文件，里面有详细的解释。实例3：PC-lint通过检查下面的代码可以发现比其他的C语言编译器发现更多的问题，包括其中的错误和潜在的问题。1：2：char *report( int m, int n, char *p ) 3： 4：int result; 5：char *temp; 6：long nm; 7：int i, k, kk; 8：char name11 = Joe Jakeson; /error 784 向name数组赋值时丢掉了结尾的nul字符9：10：nm = n * m; 11：temp = p = ? null : p; / error 779字符串常量不能用于”=”操作符12：for( i = 0; i 0 ) result = 1; 20：else if( kk 0 ) result = -1; 21：22：if( m = result ) return( temp ); / error 644 result也有可能没有被初始化23：else return( name ); / error 604 返回的是一个局部对象name的地址24： / error 783 没有以新一行结束PC-lint检查信息如下：PC-lint for C/C+ (NT) Vers. 9.00a, Copyright Gimpel Software 1985-2008- Module: test.cpp (C+) char name11 = Joe Jakeson; test.cpp(8): error 784: (Info - Nul character truncated from string) temp = p = ? null : p; test.cpp(10): error 779: (Info - String constant in comparison operator =)test.cpp(5): error 830: (Info - Location cited in prior message) for( i = 0; i 0 ) result = 1; test.cpp(18): error 771: (Info - Symbol kk (line 7) conceivably not initialized)test.cpp(7): error 830: (Info - Location cited in prior message) if( m = result ) test.cpp(21): error 644: (Warning - Variable result (line 4) may not have been initialized)test.cpp(4): error 830: (Info - Location cited in prior message) return( name ); test.cpp(24): error 604: (Warning - Returning address of auto variable name) test.cpp(25): error 783: (Info - Line does not end with new-line)- Global Wrap-up error 900: (Note - Successful completion, 14 messages produced)实例4：#include void find(char arg)switch(arg)case a:printf(an); /没有break,可以用注释/lint fallthrough消除告警825case b:printf(bn); /同上case c: printf(cn); /case控制流一直没被break中断直接进入最后一个case或 /defult,可以用/* fall through */消除告警616 /没有default语句int main(int argc, char* argv) /参数argc和argv没有被引用char buff3 = a, b, c;int i = 0;while(1) /while(1)的问题，请使用for(;)替代find(buffi); printf(n);+i ; /+i使数组越界printf(OK!n); /程序不会被执行到的地方return 0;编译这个文件， VC6.0编译器产生0 errors 0 warnings, 而pclint程序产生了如下14条警告信息, PC-lint 告警信息如下：可见，在这里数组越界pclint同样没有检查出来。PC-lint for C/C+ (NT) Vers. 9.00a, Copyright Gimpel Software 1985-2008- Module: test.cpp (C+) case b:test.cpp(8): error 616: (Warning - control flows into case/default)test.cpp(8): error 825: (Info - control flows into case/default without -fallthrough comment) case c:test.cpp(10): error 616: (Warning - control flows into case/default)test.cpp(10): error 825: (Info - control flows into case/default without -fallthrough comment)test.cpp(12): error 744: (Info - switch statement has no default) while(1)test.cpp(18): error 716: (Info - while(1) . ) printf(OK!n);test.cpp(23): error 527: (Warning - Unreachable code at token printf)test.cpp(25): error 783: (Info - Line does not end with new-line)test.cpp(25): error 715: (Info - Symbol argv (line 14) not referenced)test.cpp(14): error 830: (Info - Location cited in prior message)test.cpp(25): error 818: (Info - Pointer parameter argv (line 14) could be declared as pointing to const)test.cpp(14): error 830: (Info - Location cited in prior message)test.cpp(25): error 715: (Info - Symbol argc (line 14) not referenced)test.cpp(14): error 830: (Info - Location cited in prior message)- Global Wrap-up error 900: (Note - Successful completion, 14 messages produced)根据提示修改代码如下： #include void find(char arg)switch(arg)case a:printf(an);/lint fallthroughcase b:printf(bn);/lint fallthroughcase c:printf(cn);break;default:printf(OKn);int main(int argc, char* argv) (void)argc; / pclint (void)argv; / pclintchar buff3 = a, b, c;int i = 0;for(;)find(buffi);printf(n);if(+i 2) break ;printf(OK!n);return 0;再次运行PClint就没有告警。实例5：#include #include using namespace std;/定义公共基类Personclass Person public: Person(char *nam,char s,int a) /构造函数 strcpy(name,nam);sex=s;age=a; protected: /保护成员 char name20; char sex; int age;/定义类Teacherclass Teacher:virtual public Person /声明Person为公用继承的虚基类 public: Teacher(char *nam,char s,int a,char *t):Person(nam,s,a) /构造函数 strcpy(title,t); protected: /保护成员 char title10; /职称;/定义类Studentclass Student:virtual public Person /声明Person为公用继承的虚基类 public: Student(char *nam,char s,int a,float sco): /构造函数 Person(nam,s,a),score(sco) /初始化表 protected: /保护成员 float score; /成绩 ;/定义多重继承的派生类Graduateclass Graduate:public Teacher,public Student /声明Teacher和Student类为公用继承的直接基类 public: Graduate(char *nam,char s,int a,char *t,float sco,float w): /构造函数 Person(nam,s,a),Teacher(nam,s,a,t),Student(nam,s,a,sco),wage(w) /初始化表 void show( ) /输出研究生的有关数据 coutname:nameendl; coutage:ageendl; coutsex:sexendl; coutscore:scoreendl; couttitle:titleendl; coutwages:wageendl; private: float wage; /工资 ;int main( ) Graduate grad1(Wang-li,f,24,assistant,89.5,1234.5); grad1.show( ); return 0;编译这个文件， VC6.0编译器产生