C语言 “错误：数字常量之前的预期标识符或'（'”-？
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原文地址: http://stackoverflow.com/questions/4160225/
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"error: expected identifier or ‘(’ before numeric constant" –?
提问by Ryan Lester
The error in the title occurs on the '#define' line for every single function-like macro in this header file (starting at line 45). Am I doing something wrong?
标题中的错误出现#define在此头文件中每个类似函数的宏的“ ”行（从第 45 行开始）。难道我做错了什么？
#ifndef ASSEMBLER_H
#define ASSEMBLER_H
/* Ports */
#define Input 0
#define Output 15
/* Registers */
#define Z 0
#define A 1
#define B 2
#define C 3
#define D 4
#define E 5
#define F 6
#define G 7
/* OP Codes */
/*-----Control--------*/
#define HLT_OP 0
#define JMP_OP 1
#define CJMP_OP 2
#define OJMP_OP 3
/*-----Load/Store-----*/
#define LOAD_OP 4
#define STORE_OP 5
#define LOADI_OP 6
#define NOP_OP 7
/*-----Math-----------*/
#define ADD_OP 8
#define SUB_OP 9
/*-----Device I/O-----*/
#define IN_OP 10
#define OUT_OP 11
/*-----Comparison-----*/
#define EQU_OP 12
#define LT_OP 13
#define LTE_OP 14
#define NOT_OP 15
/* Macros */
/*-----Control--------*/
#define HLT()
( HLT_OP << 28 )
#define JMP(address)
( (JMP_OP << 28) | (address) )
#define CJMP(address)
( (CJMP_OP << 28) | (address) )
#define OJMP(address)
( (OJMP_OP << 28) | (address) )
/*-----Load/Store-----*/
#define LOAD(dest, value)
( (LOAD_OP << 28) | ((dest) << 24) | (value) )
#define STORE(dest, value)
( (STORE_OP << 28) | ((dest) << 24) | (value) )
#define LOADI(dest, value)
( (LOADI_OP << 28) | ((dest) << 24) | (value) )
#define NOP()
( NOP_OP << 28 )
/*-----Math-----------*/
#define ADD(dest, op1, op2)
( (ADD_OP << 28) | ((dest) << 24) | ((op1) << 20) | ((op2) << 16) )
#define SUB(dest, op1, op2)
( (SUB_OP << 28) | ((dest) << 24) | ((op1) << 20) | ((op2) << 16) )
/*-----Device I/O-----*/
#define IN(reg)
( (IN_OP << 28) | ((reg) << 24) | (Input) )
#define OUT(reg)
( (OUT_OP << 28) | ((reg) << 24) | (Output) )
/*-----Comparison-----*/
#define EQU(reg1, reg2)
( (EQU_OP << 28) | ((reg1) << 24) | ((reg2) << 20) )
# define LT(reg1, reg2)
( (LT_OP << 28) | ((reg1) << 24) | ((reg2) << 20) )
#define LTE(reg1, reg2)
( (LTE_OP << 28) | ((reg1) << 24) | ((reg2) << 20) )
#define NOT()
( NOT_OP << 28 )
#endif
回答by James McNellis
A preprocessing directive (like #define) is terminated by a newline, so it can only be one line long. If you want a multi-line macro definition, you need to escape the newline:
预处理指令（如#define）由换行符终止，因此它只能是一行。如果你想要一个多行的宏定义，你需要转义换行符：
// v Make this the last character on the line
#define NOT() \
( NOT_OP << 28 )
回答by Patrick
Macro's should be written on 1 line, not 2.
宏应该写在 1 行，而不是 2 行。
This is wrong:
这是错误的：
#define NOT()
( NOT_OP << 28 )
This is right:
这是对的：
#define NOT() ( NOT_OP << 28 )
If you really want to write it on multiple lines, use a backslash to 'escape' the new line. like this:
如果您真的想将其写在多行上，请使用反斜杠来“转义”新行。像这样：
#define NOT() \
( NOT_OP << 28 )
回答by Diego Sevilla
Hmmm... I guess you're not putting the subsitution for the #definein a different line, right?
嗯...我猜你不会把 的替代品#define放在不同的行中，对吗？
#define JMP(address)
( (JMP_OP << 28) | (address) )
should be
应该
#define JMP(address) ( (JMP_OP << 28) | (address) )
instead, for example. #definedeclarations have to be in just one line, or use \at the end of a line to expand to the next.
相反，例如。#define声明必须只在一行中，或者\在一行的末尾使用以扩展到下一行。
