我有一个.c文件和两个标头。我不知道为什么会出现这些错误。我试图在网上找到解决方案，但无法将其应用到我的代码中。
Structs.h
#ifndef STRUCTS_H
#define STRUCTS_H
typedef struct stream
{
char* enc; //binary string
int pos;
}stream;
typedef struct tag
{
int tagClass;
char tagConstructed;
char tagNumber;
}tag;
#endif
Funcs.h错误：
Error 22 error C2143: syntax error : missing '{' before '&' c:\users\natasha\documents\visual studio 2012\projects\asn1\asn1\functions.c 15 1 asn1
Error 26 error C2143: syntax error : missing '{' before '&' c:\users\natasha\documents\visual studio 2012\projects\asn1\asn1\functions.c 36 1 asn1
Error 21 error C2143: syntax error : missing ')' before '&' c:\users\natasha\documents\visual studio 2012\projects\asn1\asn1\functions.c 15 1 asn1
Error 25 error C2143: syntax error : missing ')' before '&' c:\users\natasha\documents\visual studio 2012\projects\asn1\asn1\functions.c 36 1 asn1
Error 15 error C2061: syntax error : identifier 'isUniversal' c:\users\natasha\documents\visual studio 2012\projects\asn1\asn1\functions.c 3 1 asn1
Error 18 error C2061: syntax error : identifier 'isEOC' c:\users\natasha\documents\visual studio 2012\projects\asn1\asn1\functions.c 7 1 asn1
Error 17 error C2059: syntax error : 'type' c:\users\natasha\documents\visual studio 2012\projects\asn1\asn1\functions.c 3 1 asn1
Error 20 error C2059: syntax error : 'type' c:\users\natasha\documents\visual studio 2012\projects\asn1\asn1\functions.c 7 1 asn1
Error 16 error C2059: syntax error : ';' c:\users\natasha\documents\visual studio 2012\projects\asn1\asn1\functions.c 3 1 asn1
Error 19 error C2059: syntax error : ';' c:\users\natasha\documents\visual studio 2012\projects\asn1\asn1\functions.c 7 1 asn1
Error 24 error C2059: syntax error : ')' c:\users\natasha\documents\visual studio 2012\projects\asn1\asn1\functions.c 15 1 asn1
Error 28 error C2059: syntax error : ')' c:\users\natasha\documents\visual studio 2012\projects\asn1\asn1\functions.c 36 1 asn1
Error 23 error C2059: syntax error : '&' c:\users\natasha\documents\visual studio 2012\projects\asn1\asn1\functions.c 15 1 asn1
Error 27 error C2059: syntax error : '&' c:\users\natasha\documents\visual studio 2012\projects\asn1\asn1\functions.c 36 1 asn1
#ifndef FUNCS_H
#define FUNCS_H
#include "Structs.h"
bool isUniversal(tag curTag);
bool isEOC(tag curTag);
char getByte(stream curStream);
void parseTag(stream & str, tag & tag);
char parseLength(stream & str);
#endif
Functions.c错误：
Error 22 error C2143: syntax error : missing '{' before '&' c:\users\natasha\documents\visual studio 2012\projects\asn1\asn1\functions.c 15 1 asn1
Error 26 error C2143: syntax error : missing '{' before '&' c:\users\natasha\documents\visual studio 2012\projects\asn1\asn1\functions.c 36 1 asn1
Error 21 error C2143: syntax error : missing ')' before '&' c:\users\natasha\documents\visual studio 2012\projects\asn1\asn1\functions.c 15 1 asn1
Error 25 error C2143: syntax error : missing ')' before '&' c:\users\natasha\documents\visual studio 2012\projects\asn1\asn1\functions.c 36 1 asn1
Error 15 error C2061: syntax error : identifier 'isUniversal' c:\users\natasha\documents\visual studio 2012\projects\asn1\asn1\functions.c 3 1 asn1
Error 18 error C2061: syntax error : identifier 'isEOC' c:\users\natasha\documents\visual studio 2012\projects\asn1\asn1\functions.c 7 1 asn1
Error 17 error C2059: syntax error : 'type' c:\users\natasha\documents\visual studio 2012\projects\asn1\asn1\functions.c 3 1 asn1
Error 20 error C2059: syntax error : 'type' c:\users\natasha\documents\visual studio 2012\projects\asn1\asn1\functions.c 7 1 asn1
Error 16 error C2059: syntax error : ';' c:\users\natasha\documents\visual studio 2012\projects\asn1\asn1\functions.c 3 1 asn1
Error 19 error C2059: syntax error : ';' c:\users\natasha\documents\visual studio 2012\projects\asn1\asn1\functions.c 7 1 asn1
Error 24 error C2059: syntax error : ')' c:\users\natasha\documents\visual studio 2012\projects\asn1\asn1\functions.c 15 1 asn1
Error 28 error C2059: syntax error : ')' c:\users\natasha\documents\visual studio 2012\projects\asn1\asn1\functions.c 36 1 asn1
Error 23 error C2059: syntax error : '&' c:\users\natasha\documents\visual studio 2012\projects\asn1\asn1\functions.c 15 1 asn1
Error 27 error C2059: syntax error : '&' c:\users\natasha\documents\visual studio 2012\projects\asn1\asn1\functions.c 36 1 asn1
#include "Funcs.h"
bool isUniversal(tag curTag) {
return curTag.tagClass == 0x00;
}
bool isEOC(tag curTag) {
return (curTag.tagClass == 0x00) && (curTag.tagNumber == 0x00);
}
char getByte(stream curStream) {
return curStream.enc[curStream.pos];
}
void parseTag(stream & str, tag & tag)
{
char buf, tempNumber;
buf = getByte(str);
tempNumber = 0x00;
tag.tagClass = buf >> 6;
tag.tagConstructed = ((buf & 0x20) != 0);
tag.tagNumber = buf & 0x1F;
if (tag.tagNumber == 0x1F)
{
do
{
str.pos++;
buf = getByte(str);
tempNumber = (tempNumber << 7) | (buf & 0x7F);
}while(buf & 0x80);
tag.tagNumber = tempNumber;
}
}
char parseLength(stream & str) {
char buf, len;
int numberOfOctets, i;
buf = getByte(str);
len = 0x00;
numberOfOctets = 0;
if (buf < 0x80) {
len = buf; //short form
} else { //long form
numberOfOctets = buf & 0x7F;
for (i = 0; i < numberOfOctets; ++i) {
len = (len * 256) + getByte(str);
str.pos++;
}
}
return len;
}
答案 0 :(得分：1)
C没有像C ++那样的引用。由于void parseLength(stream & str);，&的语法无效。不过，你可以改用指针。
例如，要将parseLength()函数转换为使用指针（并更改返回类型以匹配定义），原型将变为：
char parseLength(stream *str);
在函数体中，您需要根据需要取消引用指针，如下所示：
char parseLength(stream *str) {
char buf, len;
int numberOfOctets, i;
buf = getByte(*str); /* use "*" to get the object from the pointer */
len = 0x00;
numberOfOctets = 0;
if (buf < 0x80) {
len = buf; //short form
} else { //long form
numberOfOctets = buf & 0x7F;
for (i = 0; i < numberOfOctets; ++i) {
len = (len * 256) + getByte(*str);
str->pos++; /* Use "->" to access struct members from the pointer */
}
}
return len;
}
此外，您需要传递地址（指针）而不是实际对象，因此您还需要更改对函数的调用，例如。 parseLength(str)至parseLength(&str)。
您当然需要对parseTag()以及尝试使用引用的任何其他代码进行类似的更改。
可能像getByte()这样的其他一些函数也应该使用指针而不是实际的结构...例如，如果getByte()需要修改pos成员它被传递的stream参数使得它影响来自调用者的对象，而不仅仅是它的副本。
另外，parseLength()可能应该返回int或size_t而不是char - len看起来需要比{{1}更大的范围{1}}。