{"id":136,"date":"2010-04-17T23:11:31","date_gmt":"2010-04-18T08:11:31","guid":{"rendered":"\/blog\/?p=136"},"modified":"2023-09-21T09:39:20","modified_gmt":"2023-09-21T00:39:20","slug":"vc-pragma-pack","status":"publish","type":"post","link":"https:\/\/hasu0707.duckdns.org\/blog\/?p=136","title":{"rendered":"[VC] #pragma pack"},"content":{"rendered":"\n

\uba54\ubaa8\ub9ac \ud328\ud0b9
<\/H3>
1.\uc694\uc57d

#pragma pack\uc744 \uc774\uc6a9\ud558\uc5ec \uba54\ubaa8\ub9ac\ub97c \ud2b9\uc815 align\uc73c\ub85c packing\ud560 \uc218 \uc788\ub2e4.


2.\ubcf8\ubb38

\ub370\ube0c\ud53c\uc544\uc5d0 \ub2e4\uc74c\uacfc \uac19\uc740 \ud301\uc774 \uc62c\ub77c\uc654\ub2e4.

-----------------------------------------------------------------

\uad6c\uc870\uccb4 \/ \uacf5\uc6a9\uccb4 \ub3c4\ub294 \ud074\ub798\uc2a4\ub97c \ubc14\uc774\ud2b8 \uc2a4\ud2b8\ub9bc\uc73c\ub85c \ubcc0\ud654\uc2dc\ucf1c\uc57c\ud55c\ub2e4\uba74 \uba54\ubaa8\ub9ac\ub97c \ud328\ud0b9\ud558\uc790.
- \uc0ac\uc6a9\ud558\ub294 \uad6c\uc870\uccb4 \ub610\ub294 \uacf5\uc6a9\uccb4 \/ \ud074\ub798\uc2a4\ub97c \ubc14\uc774\ud2b8 \uc2a4\ud2b8\ub9bc\uc73c\ub85c \ubcc0\ud654\uc2dc\ucf1c\uc57c\ud55c\ub2e4\uba74, \uba54\ubaa8\ub9ac\ub97c 1 \ubc14\uc774\ud2b8 \uc815\uc5f4\uc744 \uc2dc\ucf1c\uc57c \uc815\ud655\ud55c \ubc14\uc774\ud2b8 \ub2e8\uc704 \ud06c\uae30\ub97c \uac14\uc2b5\ub2c8\ub2e4. \uc8fc\ub85c \ud1b5\uc2e0 \ud504\ub85c\uadf8\ub7a8\uc744 \ub9cc\ub4dc\ub294 \uacbd\uc6b0\uc5d0 \ud574\ub2f9\ud558\uaca0\uad70\uc694

\uc608 ) 
   <\/PRE>----------------------------------------------------------------- 

\uadf8\ub7fc \uc65c \uc774\ub7f0 \ubc29\ubc95\uc744 \uc0ac\uc6a9\ud574\uc57c\ud558\ub294\uc9c0\uc640 \uc880\ub354 \uad6c\uccb4\uc801\uc778 \uc6a9\ubc95\uc744 \uc54c\uc544\ubcf4\uaca0\ub2e4. 

\uba3c\uc800 alignment\ub294 compiler\uc5d0\uc11c \uad6c\uc870\uccb4\/\uacf5\uc6a9\uccb4 \ub370\uc774\ud130\ub97c \ucc98\ub9ac\ud558\ub294 \ub2e8\uc704\uac00 \ub41c\ub2e4. \uc774\uac83\uc740 VC\uc758 [Project Settings]\uc758 C\/C++\ud0ed\uc758 Code Generation\ud56d\ubaa9\uc5d0\uc11c \uc870\uc808 \uac00\ub2a5\ud558\ub2e4. \ub610\ud55c \ucef4\ud30c\uc77c\ub7ec \uc635\uc158\uc758 \/Zp\uac00 \uc774\ub7ec\ud55c \uc5ed\ud65c\uc744 \ud55c\ub2e4. 

\ub514\ud3f4\ud2b8\uac12\uc740 8\uc774\ub2e4. \uc774\uac83\uc740 \uc6b0\ub9ac\uac00 \uad6c\uc870\uccb4\ub97c \ub9cc\ub4e4\uba74 8byte\ub2e8\uc704\ub85c alignment\uac00 \uc815\ud574\uc9c4\ub2e4\ub294 \uc758\ubbf8\uc774\ub2e4. 

\ub2e4\uc74c\uacfc \uac19\uc740 \uad6c\uc870\uccb4\uac00 \uc788\ub2e4. 

typedef<\/FONT><\/B> struct<\/FONT><\/B> GTcpPacket 

{ 

    char<\/FONT><\/B> mark1[8<\/FONT>]; 

    int<\/FONT><\/B> len; 

}GTCPPACKET, FAR * LPGTCPPACKET, *PGTCPPACKET; 

<\/PRE>\uc704 \uad6c\uc870\uccb4\uc758 \ud06c\uae30\ub97c \uacc4\uc0b0\ud574\ubcf4\uba74 

GTcpPacket packet; 

int<\/FONT><\/B> nAllSize = sizeof<\/FONT><\/B>(packet); 

int<\/FONT><\/B> nSize1 = sizeof<\/FONT><\/B>(packet.mark1); 

TRACE(\"size:%d, %d\\n\"<\/FONT>, nAllSize, nSize1); 

<\/PRE>size:12, 8 

\uad6c\uc870\uccb4 \uc804\uccb4\uc758 \ud06c\uae30\uac00 12(8+4)\uc774\uace0 mark1\uc758 \ud06c\uae30\uac00 8\uc784\uc744 \uc54c \uc218 \uc788\ub2e4. 

typedef<\/FONT><\/B> struct<\/FONT><\/B> GTcpPacket 

{ 

    char<\/FONT><\/B> mark1[9<\/FONT>]; 

    int<\/FONT><\/B> len; 

}GTCPPACKET, FAR * LPGTCPPACKET, *PGTCPPACKET; 

<\/PRE>\uc640 \uac19\uc774 mark1\uc758 \ud06c\uae30\ub97c 1byte \ub298\ub838\ub2e4. 

\uacb0\uacfc\ub97c \ucd9c\ub825\ud574\ubcf4\uba74 

size:16, 9 

\uc640 \uac19\uc774 \ub41c\ub2e4. \uc774\ub860\uc801\uc73c\ub85c\ub294 9+4 = 13\ub418\uc5b4\uc57c\ud558\uaca0\uc9c0\ub9cc compiler\uc758 alignmemnt\uc758 \uc601\ud5a5\uc73c\ub85c \uc774\ub7ec\ud55c \ud604\uc0c1\uc774 \uc77c\uc5b4\ub098\ub294 \uac83\uc774\ub2e4. 

\ub370\uc774\ud53c\uc544\uc5d0 \uc5b8\uae09\ub41c \ubc29\ubc95\uc73c\ub85c alignment\ub97c \uc870\uc808\ud574\ubcf4\uc790. 

#pragma<\/FONT><\/B> pack(push,enter_byte_packing) 

#pragma<\/FONT><\/B> pack(1<\/FONT>) 

typedef<\/FONT><\/B> struct<\/FONT><\/B> GTcpPacket 

{ 

    char<\/FONT><\/B> mark1[9<\/FONT>]; 

    int<\/FONT><\/B> len; 

}GTCPPACKET, FAR * LPGTCPPACKET, *PGTCPPACKET; 

#pragma<\/FONT><\/B> pack(push,enter_byte_packing) 

<\/PRE>size:13, 9 

\uc774\uacbd\uc6b0\ub294 \uacb0\uacfc\uac00 \uc815\uc0c1\uc801\uc73c\ub85c \ub098\uc654\ub2e4. 

#pragma pack\uc744 \uc4f0\uc9c0\uc54a\uace0\ub3c4 VC\uc758 \ud504\ub85c\uc81d\ud2b8 \uc138\ud305\uc5d0\uc11c \uc774\ub7ec\ud55c alignment\ub97c \uc870\uc808\ud560 \uc218 \uc788\ub2e4\uace0 \uc55e\uc11c \uc124\uba85\ud588\ub2e4. \uadf8\ub7ec\ub098 \uc774\ub7ec\ud55c \ubc29\ubc95\uc740 \ud504\ub85c\uc81d\ud2b8 \uc804\uccb4\uc5d0 \uac78\ucc98\uc11c \uc801\uc6a9\ub418\uae30\ub54c\ubb38\uc5d0 \ud2b9\uc815 \uad6c\ubb38\/\ud30c\uc77c\uc5d0\ub9cc \uc801\uc6a9\ud560\ub54c\ub294 \ub370\ube0c\ud53c\uc544\uc5d0\uc11c \uc5b8\uae09\ud55c #pragma pack\uc744 \uc0ac\uc6a9\ud55c\ub2e4. 

\uadf8\ub7f0 #pragma pack\uc758 \uc6a9\ubc95\uc744 \uc880\ub354 \uad6c\uccb4\uc801\uc73c\ub85c \uc54c\uc544\ubcf4\uc790. 

\ud504\ub85c\ud1a0\ud0c0\uc785 

#pragma<\/FONT><\/B> pack( [ [ { push | pop}, ] [  identifier, ] ] [ n ] ) <\/PRE>push, pop\uc774 \uc788\ub294\uac83\uc774 \ud2b9\uc774\ud560 \uac83\uc774\ub2e4. \uc774\uac83\uc740 \ucef4\ud30c\uc774\ub7ec \uc2a4\ud14d\uc744 \uc774\uc6a9\ud568\uc744 \uc758\ubbf8\ud55c\ub2e4. \uc989 \ub4a4\uc5d0 \ubd99\ub294 identifier \ub85c push\ud55c \uc774\ud6c4\uc758 \ucef4\ud30c\uc77c\ub7ec \uc635\uc158\uc740 n\uc73c\ub85c \uc9c0\uc815\ud55c \uac12\uc744 \uc801\uc6a9\ubc1b\uace0 pop\ud558\uba74 \uc9c0\uc815\ub41c \uc635\uc158\uc774 \ud480\ub9ac\uac8c\ub41c\ub2e4. 

MSDN\uc758 \uc608\uc81c\uc5d0 \ubcf4\uba74 \uc774\ub7ec\ud55c \ubc29\ubc95\uc73c\ub85c \ud5e4\ub354\ud30c\uc77c \uc804\uccb4\ub97c \ud2b9\uc815 alignment\ub85c \uc9c0\uc815\ud558\ub294\uac83\uc744 \ubcfc \uc218 \uc788\ub294\ub370 \ub2e4\uc74c\uacfc \uac19\ub2e4. 

#pragma<\/FONT><\/B> pack( push, before_include1 ) 

#include<\/FONT><\/B> \"include1.h\"<\/FONT> 

#pragma<\/FONT><\/B> pack( pop, before_include1 ) 

<\/PRE>\uc5ec\uae30\uc11c identifier\ub294 \uadf8\ub0e5 \uad6c\ubd84\uc790\uc774\ubbc0\ub85c push\ub54c\uc640 pop\ub54c\uc5d0 \uc77c\uce58\ub418\ub294\uac83\ub9cc \uc4f0\uba74 \uc5b4\ub5a4\uac83\uc774\ub4e0 \uc0c1\uad00\uc5c6\ub2e4. \ub2e8... \uc911\ubcf5\ud574\uc11c \uc0ac\uc6a9\ud558\uc9c0\ub294 \ub9d0\uae30\ub97c...

\ucd9c\ucc98 : http:\/\/blog.daum.net\/sandwind\/13423451
\n","protected":false},"excerpt":{"rendered":"
\uba54\ubaa8\ub9ac \ud328\ud0b91.\uc694\uc57d #pragma pack\uc744 \uc774\uc6a9\ud558\uc5ec \uba54\ubaa8\ub9ac\ub97c \ud2b9\uc815 align\uc73c\ub85c packing\ud560 \uc218 \uc788\ub2e4. 2.\ubcf8\ubb38 \ub370\ube0c\ud53c\uc544\uc5d0 \ub2e4\uc74c\uacfc \uac19\uc740 \ud301\uc774 \uc62c\ub77c\uc654\ub2e4. —————————————————————– \uad6c\uc870\uccb4 \/ \uacf5\uc6a9\uccb4 \ub3c4\ub294 \ud074\ub798\uc2a4\ub97c \ubc14\uc774\ud2b8 \uc2a4\ud2b8\ub9bc\uc73c\ub85c \ubcc0\ud654\uc2dc\ucf1c\uc57c\ud55c\ub2e4\uba74 \uba54\ubaa8\ub9ac\ub97c \ud328\ud0b9\ud558\uc790. – \uc0ac\uc6a9\ud558\ub294 \uad6c\uc870\uccb4 \ub610\ub294 \uacf5\uc6a9\uccb4 \/ \ud074\ub798\uc2a4\ub97c \ubc14\uc774\ud2b8 \uc2a4\ud2b8\ub9bc\uc73c\ub85c \ubcc0\ud654\uc2dc\ucf1c\uc57c\ud55c\ub2e4\uba74, \uba54\ubaa8\ub9ac\ub97c 1 \ubc14\uc774\ud2b8 \uc815\uc5f4\uc744 \uc2dc\ucf1c\uc57c \uc815\ud655\ud55c \ubc14\uc774\ud2b8 \ub2e8\uc704 \ud06c\uae30\ub97c \uac14\uc2b5\ub2c8\ub2e4. \uc8fc\ub85c \ud1b5\uc2e0 \ud504\ub85c\uadf8\ub7a8\uc744 \ub9cc\ub4dc\ub294 \uacbd\uc6b0\uc5d0 \ud574\ub2f9\ud558\uaca0\uad70\uc694 \uc608 […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_import_markdown_pro_load_document_selector":0,"_import_markdown_pro_submit_text_textarea":"","site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center 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