warning malformed '#pragma pack(push[, id], n)' - ignored

bmp.c:8: warning: malformed '#pragma pack(push[, id], <n>)' - ignored

bmp.c:33: warning: #pragma pack (pop) encountered without matching #pragma pack (push, <n>)

這個警告很重要不能忽略，我遇到的這個問題適用於編譯器比較老的，因為韋東山自帶的虛擬機Ubuntu9.10用的是/work/tools/gcc- 3.4.5 -glibc -2.3.6，而視頻里用的編譯器是4.3幾，編譯器比較高

，這個警告是說結構體對齊的問題。對於自帶的較低的編譯器解決此問題很簡單： 修改BMP文件里的兩個結構體

#include <config.h>

#include <pic_operation.h>

#include <picfmt_manager.h>

#include <file.h>

#include <stdlib.h>

#include <string.h>

//#pragma pack(push) /* 將當前pack設置壓棧保存 */

//#pragma pack(1) /* 必須在結構體定義之前使用,這是為了讓結構體中各成員按1位元組對齊 */

typedef struct tagBITMAPFILEHEADER { /* bmfh */

unsigned short bfType;

unsigned long bfSize;

unsigned short bfReserved1;

unsigned short bfReserved2;

unsigned long bfOffBits;

} __attribute__((packed)) BITMAPFILEHEADER;

typedef struct tagBITMAPINFOHEADER { /* bmih */

unsigned long biSize;

unsigned long biWidth;

unsigned long biHeight;

unsigned short biPlanes;

unsigned short biBitCount;

unsigned long biCompression;

unsigned long biSizeImage;

unsigned long biXPelsPerMeter;

unsigned long biYPelsPerMeter;

unsigned long biClrUsed;

unsigned long biClrImportant;

} __attribute__((packed)) BITMAPINFOHEADER;

//#pragma pack(pop) /* 恢復先前的pack設置 */