C2143: 在某類型前缺分號--VC裏面的各種問題，應該首先查閱msdn

今天將P_Demo.cpp=>P_Demo.c。

 

裏面某函數體定義如下：

void main_PR_Init() { g_nImageWidth = IMAGE_FIELD_WIDTH; //初始化全局變量NY@20070815 g_nImageHeight = IMAGE_FIELD_HEIGHT; TSint32 nImageWidth = g_nImageWidth;//初始化局部變量NY@20070815 TSint32 nImageHeight = g_nImageHeight; ... }

就報如下錯誤

p_demo.c(68) : error C2275: 'TSint32' : illegal use of this type as an expression
        讓我去../NY_ipp.h(60) : see declaration of 'TSint32'
p_demo.c(68) : error C2146: syntax error : missing ';' before identifier 'nImageWidth'
p_demo.c(68) : error C2065: 'nImageWidth' : undeclared identifier

而NY_ipp.h中定義TSint32如下：

    typedef signed int TSint32;

這顯然是沒有任何問題的。去查錯誤類型C2275，找不到任何信息。

 

以爲是程序識別不了我定義的TSint32。沒辦法，只好將TSint32替換成signed int

 

結果它仍然報錯

p_demo.c(68) : error C2143: syntax error : missing ';' before 'type'

 

再去msdn中去查該錯誤，這下就有戲了。MSDN解釋如下：

PRB: Executable Code Between Declarations Causes C2143 or C2144
ID: Q58559

 

SYMPTOMS
In Microsoft C, compiler errors C2143 and C2144 are defined as follows:

C2143: syntax error : missing 'token1' before 'token2'

C2144: syntax error : missing 'token' before type 'type'

CAUSE
You may receive this error message if your program places executable code before a data declaration, an acceptable practice in Kernighan-and-Ritchie C. This practice has been outlawed in later versions of the ANSI drafts.

This error message will normally occur if a required closing curly brace (}), right parenthesis [)], or semicolon (;) is missing. 聲明語句放在執行語句後面了，雖然K&R C允許，但是ANSI C不允許！

 

RESOLUTION
Placing all data declarations before all executable code corrects the programming error.

void main( )
{
   int i;
   printf( "Hello world!/n" );
   {
      int j;
   }
}
NOTE: In the C++ language, it is legal to declare data within a block of executable code.

注意：C++中允許在執行語句模塊（即一對大括號）中聲明數據；

 

MORE INFORMATION
The following code demonstrates this error message:

Sample Code

/* Compile options needed: none */ #include <stdio.h> void main(void) { int i; printf("Hello World/n"); int j; }
Compiling this code with a version of Microsoft C prior to C/C++ 7.0 will return the

following error message:
C2144: syntax error : missing ';' before type 'int'

C/C++ version 7.0 and Visual C/C++ issue the following error:
C2143: syntax error : missing ';' before 'type'