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1. 什么是Prefast
Prefast是一种代码分析工具，它能够帮助你找到编译器不能找到的错误或者缺陷。Prefast首次被微软集成到Visual Studio 2005 Team Suite中去，使用起来非常方便。
2.怎么使用Prefast
在vs2005 Team Suite中，使用Prefast非常简单。修改你的工程属性，设置Enable Code Analysis For C/C++为Yes.
效果:
注意到有可能错误的地方以浅灰色显示在编辑器中了。
3.Prefast能帮你找到哪些错误
1)没有初始化
// no initial
void defect1()
{
int a;
int b;
b = a;
}
会报: d:\test\testcode\testcode.cpp(18) : warning C6001: Using uninitialized memory 'a': Lines: 15, 16, 18
2)空指针取值
// one path dereference NULL
void defect4( int b, int c)
{
int * p = NULL;
int a = 1 ;
if (b == 1 ) {
if (c == 1 ) {
p = & a;
}
else {
}
}
else {
if (c == 1 ) {
}
else {
p = & a;
}
}
* p;
return ;
}
会报:d:\test\testcode\testcode.cpp(65) : warning C6011: Dereferencing NULL pointer 'p': Lines: 45, 46, 48, 57, 65
3)可能错误的运算符优先级
void defect5()
{
int a = 1 ;
int b = 1 ;
int c = 1 ;
if (a & b == c)
return ;
}
会报: d:\test\testcode\testcode.cpp(76) : warning C6281: Incorrect order of operations: relational operators have higher precedence than bitwise operators
4)可能的buffer overrun
void defect8()
{
char buf[ 100 ];
char buf2[ 200 ];
int i = 100 ;
sprintf(buf, " hello world %d " , i);
strcpy(buf, buf2);
}
会报: d:\test\testcode\testcode.cpp(133) : warning C6202: Buffer overrun for 'buf', which is possibly stack allocated, in call to 'strcpy': length '200' exceeds buffer size '100'
5)可能的无穷循环
// infinite loop
void defect14()
{
signed char i;
for (i = 100 ; i >= 0 ; i ++ ) {
;
}
}
会报: d:\test\testcode\testcode.cpp(198) : warning C6292: Ill-defined for-loop: counts up from maximum
6)格式字符串错误
// Format string mismatch
void defect21()
{
char buff[ 5 ];
sprintf(buff, " %s %s " , " a " );
}
会报: d:\test\testcode\testcode.cpp(277) : warning C6063: Missing string argument to 'sprintf' that corresponds to conversion specifier '2'
7)安全问题
void defect27()
{
CreateProcess(NULL,
" c:\\program files\\Project.exe arg1 " , // correct "\"c:\\program files\\Project.exe\" arg1",
NULL,
NULL,
false ,
0 ,
NULL,
NULL,
NULL,
NULL);
}
会报: d:\test\testcode\testcode.cpp(327) : warning C6277: NULL application name with an unquoted path in call to 'CreateProcessA': results in a security vulnerability if the path contains spaces
8)=和==误用
void defect32()
{
int a = 1 ;
if (a = 2 )
return ;
}
会报: d:\test\testcode\testcode.cpp(405) : warning C6282: Incorrect operator: assignment of constant in Boolean context. Consider using '==' instead
9)逻辑运算问题
// always false
void defect45()
{
int x;
if ( 0 && x ++ ) {
;
}
}
会报: d:\test\testcode\testcode.cpp(564) : warning C6237: ( && ) is always zero. is never evaluated and might have side effects
10)其他 | 