哪些情況要重新編譯

㈠ oracle資料庫開發人員說『需要重新編譯一下』是什麼意思 是說要重新跑某個過程嗎

重新編譯，就是某個過程或者函數哪裡做了修改 需要重新編譯成可以執行的文件，並不是說重新跑某個過程。編譯完成之後，把編譯好了的過程再重新運行。

㈡ c++代碼在什麼情況下，修改了代碼，可以不需要編譯

無論是使用集成開發環境，還是使用makefile，都會根據文件的變動時間來判斷是否需要進行編譯。
例如使用main.cpp編譯出來main.exe文件。再次進行編譯時，會判斷main.cpp是否比main.exe更新。如果更新，就會觸發重新編譯。
正常情況下，修改代碼就應當進行代碼的重新編譯。但是在某些情況下，由於冗餘的頭文件引用導致不必要的擴大了編譯文件范圍。建議在包含頭文件時，盡量採用最小原則。不需要使用的頭文件就不要包含。

㈢ Delphi的命令行編譯命令

Borland出品的Delphi，有著閃電般的編譯速度，但是在界面控制項使用較多、工程項目較大的時候，編譯一個工程仍需要一段時間，打開龐大的Delphi IDE，也需要時間。其實，在一個工程開發結束，調試完成之後的Release編譯，完全可以用命令行來執行，因為Delphi的編譯器參數不像C++編譯器那樣復雜。

筆者把Delphi聯機手冊中關於命令行編譯(command-line compiler)的幾篇主題作了翻譯，希望對Delphi開發人員有幫助。

目錄
1. Command-line compiler
命令行編譯器
2. Command-line compiler options
命令行編譯器選項
3. Compiler directive options
編譯器指令選項
4. Compiler mode options
編譯模式選項
5. DCC32.CFG file
編譯器配置文件DCC32.CFG
6. Debug options
調試選項
7. Directory options
目錄選項
8. IDE command-line options
IDE命令行選項
9. Generated files
幾個IDE自動生成的文件介紹

Command-line compiler
命令行編譯器
Delphi's command-line compiler (dcc32.EXE) lets you invoke all the functions of the IDE compiler (DELPHI32.EXE) from the DOS command line (see IDE command-line options. Run the command-line compiler from the DOS prompt using the syntax:
Delphi』s命令行編譯器(dcc32.exe)允許你從DOS命令行方式(參照：IDE命令行選項)實現IDE編譯器(delphi32.exe)的所有功能。用DOS命令運行命令行編譯器語法如下：
dcc32 [options] filename [options]
dcc32 [選項] [文件名] [選項]
where options are zero or more parameters that provide information to the compiler and filename is the name of the source file to compile. If you type dcc32 alone, it displays a help screen of command-line options and syntax.
零或多個參數給編譯器提供信息，文件名指定需要編譯的源文件名。如果你單獨輸入dcc32，它會顯示一個關於命令行編譯的選項和語法的屏幕。
If filename does not have an extension, the command-line compiler assumes .dpr, then .pas, if no .dpr is found. If the file you're compiling to doesn't have an extension, you must append a period (.) to the end of the filename.
如果文件名沒有擴展名，命令行編譯器會查找擴展名為.dpr的同名文件，如果找不到，則查找擴展名為.pas的同名文件。如果你的源文件確實沒有擴展名，你需要在文件名的末尾添加(.)。
If the source text contained in filename is a program, the compiler creates an executable file named filename.EXE. If filename contains a library, the compiler creates a file named filename.DLL. If filename contains a package, the compiler creates a file named filename.BPL. If filename contains a unit, the compiler creates a unit file named filename.dcu.
如果指定的源文件是一個工程文件，編譯器會創建一個擴展名為.EXE的同名可執行文件。如果指定的源文件是一個庫文件，編譯器創建一個擴展名為.DLL的同名動態鏈接庫文件。如果指定的源文件是一個包文件，編譯器會創建一個擴展名為.BPL的同名包。如果指定的源文件是一個單元文件，編譯器會創建一個擴展名為.dcu的目標代碼文件。
You can specify a number of options for the command-line compiler. An option consists of a slash (/) or immediately followed by an option letter. In some cases, the option letter is followed by additional information, such as a number, a symbol, or a directory name. Options can be given in any order and can come before or after the file name.
你可以為命令行編譯器指定多個參數。一個參數包含一個破折號「-」(或「/」)和緊跟著的一個選項字元構成。通常情況下，選項字元後面會跟一些附加的信息，如一個數字、一個符號、一個目錄等。選項可以是任意順序並且可以在源文件名前面或後面。

Command-line compiler options
命令行編譯選項
The IDE lets you set various options through the menus; the command-line compiler gives you access to these options using the slash (/) delimiter. You can also precede options with a hyphen (-) instead of a slash (/), but those options that start with a hyphen must be separated by blanks. For example, the following two command lines are equivalent and legal:
IDE允許你使用菜單來設置各種編譯選項，而命令行編譯器允許你使用字元「/」作為分隔符來設定這些編譯選項。你也可以使用連字元「-」來代替「/」，但是用「-」引出的參數之間必須用空格隔開。例如，下面兩個命令都是等同的也是合法的：
DCC -IC:\DELPHI -DDEBUG SORTNAME -$R- -$U+
DCC /IC:\DELPHI/DDEBUG SORTNAME /$R-/$U+
The first command line uses hyphens with at least one blank separating options. The second uses slashes and no separation is needed.
第一個編譯命令用「-」引出參數，且參數之間有多個空格分隔。第二個編譯命令用「/」引出參數，參數之間不必要分隔。
The following table lists the command-line options. In addition to the listed options, all single-letter compiler directives can be specified on the command line, as described in Compiler directive options.
下列表中列出所有的命令行參數。在附加的選項列表中，所有的單字元編譯器指令都可以在命令行編譯中使用，詳情請參照：編譯器指令。
Option Description
選項 描述
Aunit=alias 設置單元別名
B 編譯所有單元
CC 編譯控制台程序
CG 編譯圖形界面程序
Ddefines 編譯條件符號定義
Epath 可執行文件輸出路徑
Foffset 查找運行期間錯誤
GD 生成完整.Map文件
GP 生成.Map文件Public段
GS 生成.Map文件Segment段
H 輸出提示信息
Ipaths 文件包含路徑
J 生成.Obj目標文件
JP 生成C++類型.Obj目標文件
Kaddress Set image base address
LEpath 包.BPL文件輸出路徑
LNpath .dcp文件輸出路徑
LUpackage 使用運行期間包列表
M 編譯有改動的源文件
Npath dcu/dpu文件輸出目錄
Opaths .Obj文件(匯編目標代碼文件)路徑
P 按8.3格式文件名查找
Q 安靜模式
Rpaths 資源文件(.RES)路徑
TXext 目標文件擴展名
Upaths 單元文件路徑
V 為Turbo Debugger生成調試信息文件
VN 以.Giant格式生成包含命名空間的調試信息文件(將用於C++Builder)
VR 生成調試信息文件.rsm
W 輸出警告信息
Z Disable implicit compilation
$directive Compiler directives
--Help 顯示編譯選項的幫助。同樣的，如果你在命令行單獨輸入dcc32，也會顯示編譯選項的幫助。
--version 顯示產品名稱和版本

Compiler directive options
編譯器指令選項
Delphi supports the compiler directives described in Compiler directives. The $ and D command-line options allow you to change the default states of most compiler directives. Using $ and D on the command line is equivalent to inserting the corresponding compiler directive at the beginning of each source file compiled.
Delphi支持用編譯器指令關鍵字描述的編譯器指令。使用「$」和「D」命令行選項可以改變所有的默認編譯器狀態。用「$」和「D」命令行選項等同於在源文件的前面添加編譯器指令。
Switch directive option
編譯器指令選項開關
The $ option lets you change the default state of all of the switch directives. The syntax of a switch directive option is $ followed by the directive letter, followed by a plus (+) or a minus (-). For example:
「$」允許你改變每一種編譯器指令默認狀態。編譯器指令的語法是「$」後緊跟一個指令字元，再跟一個「-」或「+」。例如：
dcc32 MYSTUFF -$R-
compiles MYSTUFF.pas with range-checking turned off, while:
不使用邊界檢查編譯MYSTUFF.pas單元：
dcc32 MYSTUFF -$R+
compiles it with range checking turned on. Note that if a {$R+} or {$R-} compiler directive appears in the source text, it overrides the -$R command-line option.
使用界面檢查編譯MYSTUFF.pas單元。如果將編譯器指令{$R+}或{$R-}添加到源文件的開始，它將覆蓋從命令行傳入的參數。
You can repeat the -$ option in order to specify multiple compiler directives:
你可以用多個「$」來指定多個編譯器指令，如：
dcc32 MYSTUFF -$R--$I--$V--$U+
Alternately, the command-line compiler lets you write a list of directives (except for $M), separated by commas:
命令行編譯器允許作用逗號分隔的編譯器指定列表，如：
dcc32 MYSTUFF -$R-,I-,V-,U+
只需要用一個「$」符號。
Only one dollar sign ($) is needed.
注意，因為$M的格式不一樣，你不能在逗號分隔的指令列表中使用$M
Note that, because of its format, you cannot use the $M directive in a list of directives separated by commas.
Conditional defines option
條件編譯選項
The -D option lets you define conditional symbols, corresponding to the {$DEFINE symbol} compiler directive. The -D option must be followed by one or more conditional symbols separated by semicolons (;). For example, the following command line:
「-D」選項允許你定義一個編譯條件，符合你用{$DEFINE symbol}定義的編譯器指令。「-D」選項後必須跟隨一或多個用分號分隔的編譯條件符號，如下命令：
dcc32 MYSTUFF -DIOCHECK;DEBUG;LIST
defines three conditional symbols, iocheck, debug, and list, for the compilation of MYSTUFF.pas. This is equivalent to inserting:
定義了三個編譯條件符號：IOCHECK,DEBUG,LIST,用於MYSTUFF.pas單元中。這等同於在源文件中插入以下語句：
{$DEFINE IOCHECK}
{$DEFINE DEBUG}
{$DEFINE LIST}
at the beginning of MYSTUFF.pas. If you specify multiple -D directives, you can concatenate the symbol lists. Therefore:
如果你指定了多個「-D」選項，你可以聯接它們，如下：
dcc32 MYSTUFF -DIOCHECK-DDEBUG-DLIST

is equivalent to the first example.
等同於第一個例子。

Compiler mode options
編譯模式選項
A few options affect how the compiler itself functions. As with the other options, you can use these with either the hyphen or the slash format. Remember to separate the options with at least one blank.
有幾個選項能影響編譯器自身的功能。像其它選項一個，你可以使用「/」或「-」的格式。別忘了用至少一個空格分隔這些選項。
Make (-M) option
選項(-M)
The command-line compiler has built-in MAKE logic to aid in project maintenance. The -M option instructs command-line compiler to check all units upon which the file being compiled depends. Using this option results in a much quicker compile time.
命令行編譯器使用構造邏輯的方式來維護工程。「-M」選項指示編譯器檢查所有與編譯文件相關聯的文件。用這個參數會導致編譯時間增大。
A unit is recompiled under the following conditions:
一個源文件在下列情況下會重新編譯：
The source file for that unit has been modified since the unit file was created.
源文件被創建以來被修改過；
用「$I」指令包含的任何文件，用「$L」包含的任何.Obj文件，或用「$R」關聯的任何資源文件.Res,比源文件中的要新；
Any file included with the $I directive, any .OBJ file linked in by the $L directive, or any .res file referenced by the $R directive, is newer than the unit file.
The interface section of a unit referenced in a uses statement has changed.
單元介面部分interface的uses段有改動。
Units compiled with the -Z option are excluded from the make logic.
在單元編譯時指令「-Z」在構造邏輯期不被接受。
If you were applying this option to the previous example, the command would be:
如果你在上一個例子中使用這個指令，編譯命令就應該是：
dcc32 MYSTUFF -M
Build all (-B) option
編譯所有 選項(-B)
Instead of relying on the -M option to determine what needs to be updated, you can tell command-line compiler to update all units upon which your program depends using the -B option. You can't use -M and -B at the same time. The -B option is slower than the -M option and is usually unnecessary.
用於取代要知道哪些單元需要更新-M的選項，你可以使用-B選項來更新所有你的程序中關聯的單元。你不能在程序中同時使用-M和-B。選項-B比-M速度更慢，而且它並不是必需的。
If you were using this option in the previous example, the command would be
如果你在前一個例子中使用這個參數，編譯命令就應該是：
dcc32 MYSTUFF -B
Find error (-F) option
查找錯誤 選項(-F)
When a program terminates e to a runtime error, it displays an error code and the address at which the error occurred. By specifying that address in a -Faddress option, you can locate the statement in the source text that caused the error, provided your program and units were compiled with debug information enabled (via the $D compiler directive).
當一個程序由於運行期間錯誤而終止時，它會顯示一個錯誤號和錯誤地址在錯誤發生時。用-Faddress選項來指定錯誤地址，你在源文件中能找到引發錯誤的位置，如果你的程序和單元編譯時附加了調試信息(使用$D編譯器指令)。
In order for the command-line compiler to find the runtime error with -F, you must compile the program with all the same command-line parameters you used the first time you compiled it.
為了命令行編譯器能用-F選項查找運行期間錯誤，你必須傳遞與第一次編譯時相同的指令列表。
As mentioned previously, you must compile your program and units with debug information enabled for the command-line compiler to be able to find runtime errors. By default, all programs and units are compiled with debug information enabled, but if you turn it off, using a {$D-} compiler directive or a -$D- option, the command-line compiler will not be able to locate runtime errors.
先前提到過，你的程序和單元必須啟用調試信息，命令行編譯器才能查找運行期間錯誤。默認情況下，所有的程序和單都是啟用調試信息的，除非你用{-D}或-$D-指令關閉它，這樣，命令行編譯器就不能查找運行期間錯誤了。
Use packages (-LU) option
使用包(-LU)選項
Use the -LU option to list additional runtime packages that you want to use in the application being compiled. Runtime packages already listed in the Project Options dialog box need not be repeated on the command line.
使用-LU選項來在編譯時添加你應用程序中要用到的運行期間包。運行期間包已經在「工程選項」對話框中列舉的，不必再在命令行中添加。
Disable implicit compilation (-Z) option
(此選項在delphi6.0/7.0中有不同描述，在此不作翻譯)
The -Z option prevents packages and units from being implicitly recompiled later. With packages, it is equivalent to placing {$ IMPLICITBUILD OFF} in the .dpk file. Use -Z when compiling packages that provide low-level functionality, that change infrequently between builds, or whose source code will not be distributed.
Target file extension (-TX) option
目標文件擴展名(-TX)選項
The -TX option lets you override the default extension for the output file. For example,
選項-TX允許你改寫默認的輸出文件擴展名。例如：
dcc32 MYSTUFF -TXSYS
generates compiled output in a file called MYSTUFF.SYS.
生成的將是一個叫做MYSTUFF.SYS的文件。
Quiet (-Q) option
安靜模式(-Q)選項
The quiet mode option suppresses the printing of file names and line numbers ring compilation. When the command-line compiler is invoked with the quiet mode option
安靜模式選項禁止在編譯時顯示文件名及代碼行數，如果命令行編譯器調用這個選項的話。
dcc32 MYSTUFF -Q its output is limited to the startup right message and the usual statistics at the end of compilation. If any errors occur, they will be reported.

它的輸出僅限於起始時行版權信息以及結尾的統計信息。當然，如果發生錯誤，它也會輸出。

DCC32.CFG file
DCC32.CFG配置文件
You can set up a list of options in a configuration file called DCC32.CFG, which will then be used in addition to the options entered on the command line. Each line in configuration file corresponds to an extra command-line argument inserted before the actual command-line arguments. Thus, by creating a configuration file, you can change the default setting of any command-line option.
你可以設置一個編譯選項列表到一個叫做DCC32.CFG的配置文件中，它將用於編譯時附加到命令行參數後。配置文件的每一行都相當於一個額外的命令行參數插入到實際的命令行參數前(注意，是實際參數前)。因而，你可以使用這個配置文件改變一些命令行參數的默認設置。
The command-line compiler lets you enter the same command-line option several times, ignoring all but the last occurrence. This way, even though you've changed some settings with a configuration file, you can still override them on the command line.
命令行編譯器允許你輸入相同的命令行參數，它將忽略所有除最後一個之外。這個的話，盡管通過配置文件你可以改變一些設置，你仍然可以覆蓋它使用命令行參數。
When dcc32 starts, it looks for DCC32.CFG in the current directory. If the file isn't found there, dcc32 looks in the directory where DCC32.EXE resides.
當dcc32啟動時，它查找DCC32.CFG文件在當前目錄。如果文件沒有找到，dcc32會查找它所在的目錄。
Here's an example DCC32.CFG file, defining some default directories for include, object, and unit files, and changing the default states of the $O and $R compiler directives:
以下是一個DCC32.CFG配置文件的例子，定義了關於文件包含、OBJ文件包含、單元文件搜索路徑信息，並改變了編譯器指令$O和$R的默認值。
-IC:\DELPHI\INC;C:\DELPHI\SRC
-OC:\DELPHI\ASM
-UC:\DELPHI\UNITS
-$R+
-$O-
Now, if you type:
現在，如果你輸入：
dcc32 MYSTUFF
the compiler performs as if you had typed the following:
編譯器把它當作你輸入如下命令：
dcc32 -IC:\DELPHI\INC;C:\DELPHI\SRC -OC:\DELPHI\ASM -UC:\DELPHI\UNITS -$R+ -$O- MYSTUFF

Debug options
調試選項
The compiler has two sets of command-line options that enable you to generate external debugging information: the map file options and the debug info options.
編譯器有兩個命令行參數可以生成外部調試信息:MAP文件選項和調試信息選項。
Map file (-G) options
Map文件(-G)選項
The -G option instructs the command-line compiler to generate a .map file that shows the layout of the executable file. Unlike the binary format of executable and .dcu files, a .map file is a legible text file that can be output on a printer or loaded into the editor. The -G option must be followed by the letter S, P, or D to indicate the desired level of information in the .map file. A .MAP file is divided into three sections:
選項-G指示命令行編譯器生成一個.map文件來查看一個可執行文件的布局。不同於可二進制的可執行文件和.dcu文件，.map文件是一個可讀的文本文件，可以被列印或是其它文本編輯器編輯。選項-G後必須跟字元S、P或D，去決定你想要在.map文件列出的信息。一個.MAP文件被分成三個節：
Segment
Publics
Line Numbers
-GS outputs only the Segment section, -GP outputs the Segment and Publics section, and -GD outputs all three sections. -GD also generates a .DRC file that contains tables of all string constants declared using the resourcestring keyword.
-GS選項只輸出Segment Section,-GS選項輸出Segment和Publics,-GD輸出所有的三個Sections.-GD選項也生成一個擴展名為.DRC的文件包含所有的用resourcestring關鍵字聲明的字元串常量。
For moles (program and units) compiled in the {$D+,L+} state (the default), the Publics section shows all global variables, proceres, and functions, and the Line Numbers section shows line numbers for all proceres and functions in the mole. In the {$D+,L-} state, only symbols defined in a unit's interface part are listed in the Publics section. For moles compiled in the {$D-} state, there are no entries in the Line Numbers section.
用默認的編譯選項{$D+,L+}編譯模塊(程序或單元)，Publics Section列舉所有的全局變數、過程和函數，Line Numbers Section列舉模塊中所有的過程和函數的行號。如果用{$D+,L-}編譯選項編譯模塊，Publics Section中僅列舉在單元的interface部分定義的符號。如果用{$D-}選項編譯模塊，在Line Numbers Section沒有任何入口。
Debug info (-V) options
調度選項(-V)
The -V options (-V, -VN. and -VR), which cause the compiler to generate debug information, can be combined on the command line.
選項-V、-VN、-VR會指示編譯器生成調試信息，它們能在命令行中組合使用。
Generate Turbo Debugger debug info (-V) option
生成Turbo Debugger使用的調試信息的選項(-V)
When you specify the -V option on the command line, the compiler appends Turbo Debugger 5.0-compatible external debug information at the end of the executable file. Turbo Debugger includes both source- and machine-level debugging and powerful breakpoints.
當你在命令行中使用-V選項時，編譯器會在可執行文件的末尾附加與Turbo Debugger5.0一致的外部調試信息。Turbo Debugger包含代碼和硬體級別的強大的斷點。
Even though the debug information generated by -V makes the resulting executable file larger, it does not affect the actual code in the executable, and does not require additional memory to run the program.
雖然附加調試信息到查執行文件中會使可執行文件增大，但是它並不影響實際可執行文件中的可執行代碼，也不需要額外的內存來啟動程序。
The extent of debug information appended to the executable file depends on the setting of the $D and $L compiler directives in each of the moles (program and units) that make up the application. For moles compiled in the {$D+,L+} state, which is the default, all constant, variable, type, procere, and function symbols are known to the debugger. In the {$D+,L-} state, only symbols defined in a unit's interface section are known to the debugger. In the {$D-} state, no line-number records are generated, so the debugger cannot display source lines whe