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Visual Studio 2005
Visual Studio
Visual C++
Building a C/C++ Program
C/C++ Building Reference
Compiling a C/C++ Program
Compiler Options
Compiler Options Listed Alphabetically
@ (Specify a Compiler Response File)
/AI (Specify Metadata Directories)
/analyze (Enterprise Code Analysis)
/arch (Minimum CPU Architecture)
/bigobj (Increase Number of Sections in .obj file)
/C (Preserve Comments During Preprocessing)
/c (Compile Without Linking)
/clr (Common Language Runtime Compilation)
/D (Preprocessor Definitions)
/doc (Process Documentation Comments)
/E (Preprocess to stdout)
/EH (Exception Handling Model)
/EP (Preprocess to stdout Without #line Directives)
/errorReport (Report Internal Compiler Errors)
/F (Set Stack Size)
Output-File (/F) Options
/favor (Optimize for 64)
/FC (Full Path of Source Code File in Diagnostics)
/fp (Specify Floating-Point Behavior)
/G (Optimize for Processor) Options
/GA (Optimize for Windows Application)
/Gd, /Gr, /Gz (Calling Convention)
/Ge (Enable Stack Probes)
/GF (Eliminate Duplicate Strings)
/GH (Enable _pexit Hook Function)
/Gh (Enable _penter Hook Function)
/GL (Whole Program Optimization)
/Gm (Enable Minimal Rebuild)
/GR (Enable Run-Time Type Information)
/GS (Buffer Security Check)
/Gs (Control Stack Checking Calls)
/GT (Support Fiber-Safe Thread-Local Storage)
/GX (Enable Exception Handling)
/Gy (Enable Function-Level Linking)
/GZ (Enable Stack Frame Run-Time Error Checking)
/H (Restrict Length of External Names)
/HELP (Compiler Command-Line Help)
/homeparams (Copy Register Parameters to Stack)
/hotpatch (Create Hotpatchable Image)
/I (Additional Include Directories)
/J (Default char Type Is unsigned)
/link (Pass Options to Linker)
/LN (Create MSIL Module)
/MD, /MT, /LD (Use Run-Time Library)
/nologo (Suppress Startup Banner)
/O Options (Optimize Code)
/openmp (Enable OpenMP 2.0 Support)
/P (Preprocess to a File)
/Q Options (Low-Level Operations)
/RTC (Run-Time Error Checks)
/showIncludes (List Include Files)
/Tc, /Tp, /TC, /TP (Specify Source File Type)
/U, /u (Undefine Symbols)
/V (Version Number)
/vd (Disable Construction Displacements)
/vmb, /vmg (Representation Method)
/vmm, /vms, /vmv (General Purpose Representation)
/w, /Wn, /WX, /Wall, /wln, /wdn, /wen, /won (Warning Level)
/WL (Enable One-Line Diagnostics)
/Wp64 (Detect 64-Bit Portability Issues)
/X (Ignore Standard Include Paths)
/Y (Precompiled Headers)
/Z7, /Zi, /ZI (Debug Information Format)
/Za, /Ze (Disable Language Extensions)
/Zc (Conformance)
/Zg (Generate Function Prototypes)
/Zl (Omit Default Library Name)
/Zm (Specify Precompiled Header Memory Allocation Limit)
/Zp (Struct Member Alignment)
/Zs (Syntax Check Only)
/Zx (Debug Optimized Itanium Code)
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/U, /u (Undefine Symbols)

Visual Studio 2005

Undefine previously defined symbols. /U undefines the specified symbol. /u undefines all previously defined symbols.

Copy 

/U[ ]symbol
/u
symbol

The symbol you want undefined.

Neither option can undefine symbols created with the #define directive.

Both options undefine the following Microsoft-specific macros.

Symbol Function

_CHAR_UNSIGNED

Default char type is unsigned. Defined when /J is specified.

_CPPRTTI

Defined for code compiled with the /GR (Enable Run-Time Type Information) option.

_CPPUNWIND

Defined for code compiled with the /EHsc (Enable Exception Handling) option.

_DLL

Defined when /MD is specified.

_M_IX86

Defined to 600, by default, for x86 targets.

_MSC_VER

For more information, see Predefined Macros.

_WIN32

Defined for applications for WIN32. Always defined.

_MT

Defined when /MD or /MT is specified.

To set this compiler option in the Visual Studio development environment

  1. Open the project's Property Pages dialog box. For details, see How to: Open Project Property Pages.

  2. Click the C/C++ folder.

  3. Click the Advanced property page.

  4. Modify the Undefine Preprocessor Definitions or Undefine All Preprocessor Definitions properties.

To set this compiler option programmatically

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