Compiler options listed by category

This article contains a categorical list of compiler options. For an alphabetical list, see Compiler options listed alphabetically.

Optimization

Option Purpose
/favor:<blend|AMD64|INTEL64|ATOM> Produces code that is optimized for a specified architecture, or for a range of architectures.
/O1 Creates small code.
/O2 Creates fast code.
/Ob<n> Controls inline expansion.
/Od Disables optimization.
/Og Deprecated. Uses global optimizations.
/Oi[-] Generates intrinsic functions.
/Os Favors small code.
/Ot Favors fast code.
/Ox A subset of /O2 that doesn't include /GF or /Gy.
/Oy Omits frame pointer. (x86 only)

Code generation

Option Purpose
/arch:<IA32|SSE|SSE2|AVX|AVX2|AVX512> Minimum CPU architecture requirements. IA32, SSE, and SSE2 are x86 only.
/clr Produces an output file to run on the common language runtime.
/clr:implicitKeepAlive- Turn off implicit emission of System::GC::KeepAlive(this).
/clr:initialAppDomain Enable initial AppDomain behavior of Visual C++ 2002.
/clr:netcore Produce assemblies targeting .NET Core runtime.
/clr:noAssembly Don't produce an assembly.
/clr:nostdimport Don't import any required assemblies implicitly.
/clr:nostdlib Ignore the system .NET framework directory when searching for assemblies.
/clr:pure Produce an IL-only output file (no native executable code).
/clr:safe Produce an IL-only verifiable output file.
/EHa Enable C++ exception handling (with SEH exceptions).
/EHc extern "C" defaults to nothrow.
/EHr Always generate noexcept runtime termination checks.
/EHs Enable C++ exception handling (no SEH exceptions).
/fp:contract Consider floating-point contractions when generating code.
/fp:except[-] Consider floating-point exceptions when generating code.
/fp:fast "fast" floating-point model; results are less predictable.
/fp:precise "precise" floating-point model; results are predictable.
/fp:strict "strict" floating-point model (implies /fp:except).
/fpcvt:BC Backward-compatible floating-point to unsigned integer conversions.
/fpcvt:IA Intel native floating-point to unsigned integer conversion behavior.
/fsanitize Enables compilation of sanitizer instrumentation such as AddressSanitizer.
/fsanitize-coverage Enables compilation of code coverage instrumentation for libraries such as LibFuzzer.
/GA Optimizes for Windows applications.
/Gd Uses the __cdecl calling convention. (x86 only)
/Ge Deprecated. Activates stack probes.
/GF Enables string pooling.
/Gh Calls hook function _penter.
/GH Calls hook function _pexit.
/GL[-] Enables whole program optimization.
/Gm[-] Deprecated. Enables minimal rebuild.
/Gr Uses the __fastcall calling convention. (x86 only)
/GR[-] Enables run-time type information (RTTI).
/GS[-] Checks buffer security.
/Gs[n] Controls stack probes.
/GT Supports fiber safety for data allocated by using static thread-local storage.
/Gu[-] Ensure distinct functions have distinct addresses.
/guard:cf[-] Adds control flow guard security checks.
/guard:ehcont[-] Enables EH continuation metadata.
/Gv Uses the __vectorcall calling convention. (x86 and x64 only)
/Gw[-] Enables whole-program global data optimization.
/GX[-] Deprecated. Enables synchronous exception handling. Use /EH instead.
/Gy[-] Enables function-level linking.
/Gz Uses the __stdcall calling convention. (x86 only)
/GZ Deprecated. Enables fast checks. (Same as /RTC1)
/homeparams Forces parameters passed in registers to be written to their locations on the stack upon function entry. This compiler option is only for the x64 compilers (native and cross compile).
/hotpatch Creates a hotpatchable image.
/Qfast_transcendentals Generates fast transcendentals.
/QIfist Deprecated. Suppresses the call of the helper function _ftol when a conversion from a floating-point type to an integral type is required. (x86 only)
/Qimprecise_fwaits Removes fwait commands inside try blocks.
/QIntel-jcc-erratum Mitigates the performance impact of the Intel JCC erratum microcode update.
/Qpar Enables automatic parallelization of loops.
/Qpar-report:n Enables reporting levels for automatic parallelization.
/Qsafe_fp_loads Uses integer move instructions for floating-point values and disables certain floating point load optimizations.
/Qspectre[-] Enable mitigations for CVE 2017-5753, for a class of Spectre attacks.
/Qspectre-load Generate serializing instructions for every load instruction.
/Qspectre-load-cf Generate serializing instructions for every control flow instruction that loads memory.
/Qvec-report:n Enables reporting levels for automatic vectorization.
/RTC1 Enable fast runtime checks (equivalent to /RTCsu).
/RTCc Convert to smaller type checks at run-time.
/RTCs Enable stack frame runtime checks.
/RTCu Enables uninitialized local usage checks.
/volatile:iso Acquire/release semantics not guaranteed on volatile accesses.
/volatile:ms Acquire/release semantics guaranteed on volatile accesses.

Output files

Option Purpose
/doc Processes documentation comments to an XML file.
/FA Configures an assembly listing file.
/Fa Creates an assembly listing file.
/Fd Renames program database file.
/Fe Renames the executable file.
/Fi Specifies the preprocessed output file name.
/Fm Creates a mapfile.
/Fo Creates an object file.
/Fp Specifies a precompiled header file name.
/FR, /Fr Name generated .sbr browser files. /Fr is deprecated.
/Ft<dir> Location of the header files generated for #import.

Preprocessor

Option Purpose
/AI<dir> Specifies a directory to search to resolve file references passed to the #using directive.
/C Preserves comments during preprocessing.
/D<name>{=|#}<text> Defines constants and macros.
/E Copies preprocessor output to standard output.
/EP Copies preprocessor output to standard output.
/FI<file> Preprocesses the specified include file.
/FU<file> Forces the use of a file name, as if it had been passed to the #using directive.
/Fx Merges injected code with the source file.
/I<dir> Searches a directory for include files.
/P Writes preprocessor output to a file.
/PD Print all macro definitions.
/PH Generate #pragma file_hash when preprocessing.
/U<name> Removes a predefined macro.
/u Removes all predefined macros.
/X Ignores the standard include directory.

Header units/modules

Option Purpose
/exportHeader Create the header units files (.ifc) specified by the input arguments.
/headerUnit Specify where to find the header unit file (.ifc) for the specified header.
/headerName Build a header unit from the specified header.
/ifcOutput Specify output file or directory for .ifc files.
/interface Treat the input file as a module interface unit.
/internalPartition Treat the input file as an internal partition unit.
/reference Use named module IFC.
/scanDependencies List module and header unit dependencies in C++ Standard JSON form.
/sourceDependencies List all source-level dependencies.
/sourceDependencies:directives List module and header unit dependencies.
/translateInclude Treat #include as import.

Language

Option Purpose
/await Enable coroutines (resumable functions) extensions.
/await:strict Enable standard C++20 coroutine support with earlier language versions.
/constexpr:backtrace<N> Show N constexpr evaluations in diagnostics (default: 10).
/constexpr:depth<N> Recursion depth limit for constexpr evaluation (default: 512).
/constexpr:steps<N> Terminate constexpr evaluation after N steps (default: 100000)
/openmp Enables #pragma omp in source code.
/openmp:experimental Enable OpenMP 2.0 language extensions plus select OpenMP 3.0+ language extensions.
/openmp:llvm OpenMP language extensions using LLVM runtime.
/permissive[-] Set standard-conformance mode.
/std:c++14 C++14 standard ISO/IEC 14882:2014 (default).
/std:c++17 C++17 standard ISO/IEC 14882:2017.
/std:c++20 C++20 standard ISO/IEC 14882:2020.
/std:c++latest The latest draft C++ standard preview features.
/std:c11 C11 standard ISO/IEC 9899:2011.
/std:c17 C17 standard ISO/IEC 9899:2018.
/vd{0|1|2} Suppresses or enables hidden vtordisp class members.
/vmb Uses best base for pointers to members.
/vmg Uses full generality for pointers to members.
/vmm Declares multiple inheritance.
/vms Declares single inheritance.
/vmv Declares virtual inheritance.
/Z7 Generates C 7.0-compatible debugging information.
/Za Disables some C89 language extensions in C code.
/Zc:alignedNew[-] Enable C++17 over-aligned dynamic allocation (on by default in C++17).
/Zc:auto[-] Enforce the new Standard C++ meaning for auto (on by default).
/Zc:char8_t[-] Enable or disable C++20 native u8 literal support as const char8_t (off by default, except under /std:c++20).
/Zc:__cplusplus[-] Enable the __cplusplus macro to report the supported standard (off by default).
/Zc:externC[-] Enforce Standard C++ rules for extern "C" functions (implied by /permissive-).
/Zc:externConstexpr[-] Enable external linkage for constexpr variables (off by default).
/Zc:forScope[-] Enforce Standard C++ for scoping rules (on by default).
/Zc:hiddenFriend[-] Enforce Standard C++ hidden friend rules (implied by /permissive-)
/Zc:implicitNoexcept[-] Enable implicit noexcept on required functions (on by default).
/Zc:inline[-] Remove unreferenced functions or data if they're COMDAT or have internal linkage only (off by default).
/Zc:lambda[-] Enable new lambda processor for conformance-mode syntactic checks in generic lambdas.
/Zc:noexceptTypes[-] Enforce C++17 noexcept rules (on by default in C++17 or later).
/Zc:preprocessor[-] Use the new conforming preprocessor (off by default, except in C11/C17).
/Zc:referenceBinding[-] A UDT temporary won't bind to a non-const lvalue reference (off by default).
/Zc:rvalueCast[-] Enforce Standard C++ explicit type conversion rules (off by default).
/Zc:sizedDealloc[-] Enable C++14 global sized deallocation functions (on by default).
/Zc:strictStrings[-] Disable string-literal to char* or wchar_t* conversion (off by default).
/Zc:ternary[-] Enforce conditional operator rules on operand types (off by default).
/Zc:threadSafeInit[-] Enable thread-safe local static initialization (on by default).
/Zc:throwingNew[-] Assume operator new throws on failure (off by default).
/Zc:trigraphs Enable trigraphs (obsolete, off by default).
/Zc:tlsGuards[-] Generate runtime checks for TLS variable initialization (on by default).
/Zc:twoPhase[-] Use non-conforming template parsing behavior (conforming by default).
/Zc:wchar_t[-] wchar_t is a native type, not a typedef (on by default).
/Zc:zeroSizeArrayNew[-] Call member new/delete for 0-size arrays of objects (on by default).
/Ze Deprecated. Enables C89 language extensions.
/Zf Improves PDB generation time in parallel builds.
/ZH:[MD5|SHA1|SHA_256] Specifies MD5, SHA-1, or SHA-256 for checksums in debug info.
/ZI Includes debug information in a program database compatible with Edit and Continue. (x86 only)
/Zi Generates complete debugging information.
/Zl Removes the default library name from the .obj file.
/Zo[-] Generate richer debugging information for optimized code.
/Zp[n] n Packs structure members.
/Zs Checks syntax only.
/ZW Produces an output file to run on the Windows Runtime.

Linking

Option Purpose
/F Sets stack size.
/LD Creates a dynamic-link library.
/LDd Creates a debug dynamic-link library.
/link Passes the specified option to LINK.
/LN Creates an MSIL .netmodule.
/MD Compiles to create a multithreaded DLL, by using MSVCRT.lib.
/MDd Compiles to create a debug multithreaded DLL, by using MSVCRTD.lib.
/MT Compiles to create a multithreaded executable file, by using LIBCMT.lib.
/MTd Compiles to create a debug multithreaded executable file, by using LIBCMTD.lib.

Miscellaneous

Option Purpose
/? Lists the compiler options.
@ Specifies a response file.
/analyze Enables code analysis.
/bigobj Increases the number of addressable sections in an .obj file.
/c Compiles without linking.
/cgthreads Specifies number of cl.exe threads to use for optimization and code generation.
/errorReport Deprecated. Error reporting is controlled by Windows Error Reporting (WER) settings.
/execution-charset Set execution character set.
/fastfail Enable fast-fail mode.
/FC Displays the full path of source code files passed to cl.exe in diagnostic text.
/FS Forces writes to the PDB file to be serialized through MSPDBSRV.EXE.
/H Deprecated. Restricts the length of external (public) names.
/HELP Lists the compiler options.
/J Changes the default char type.
/JMC Supports native C++ Just My Code debugging.
/kernel The compiler and linker will create a binary that can be executed in the Windows kernel.
/MP Builds multiple source files concurrently.
/nologo Suppresses display of sign-on banner.
/presetPadding Zero initialize padding for stack based class types.
/showIncludes Displays a list of all include files during compilation.
/source-charset Set source character set.
/Tc Specifies a C source file.
/TC Specifies all source files are C.
/Tp Specifies a C++ source file.
/TP Specifies all source files are C++.
/utf-8 Set source and execution character sets to UTF-8.
/V Deprecated. Sets the version string.
/validate-charset Validate UTF-8 files for only compatible characters.
/volatileMetadata Generate metadata on volatile memory accesses.
/Yc Create .PCH file.
/Yd Deprecated. Places complete debugging information in all object files. Use /Zi instead.
/Yl Injects a PCH reference when creating a debug library.
/Yu Uses a precompiled header file during build.
/Y- Ignores all other precompiled-header compiler options in the current build.
/Zm Specifies the precompiled header memory allocation limit.

Diagnostics

Option Purpose
/diagnostics:caret[-] Diagnostics format: prints column and the indicated line of source.
/diagnostics:classic Use legacy diagnostics format.
/diagnostics Diagnostics format: prints column information.
/external:anglebrackets Treat all headers included via <> as external.
/external:env:<var> Specify an environment variable with locations of external headers.
/external:I <path> Specify location of external headers.
/external:templates[-] Evaluate warning level across template instantiation chain.
/external:W<n> Set warning level for external headers.
/options:strict Unrecognized compiler options are errors.
/sdl Enable more security features and warnings.
/w Disable all warnings.
/W0, /W1, /W2, /W3, /W4 Set output warning level.
/w1<n>, /w2<n>, /w3<n>, /w4<n> Set warning level for the specified warning.
/Wall Enable all warnings, including warnings that are disabled by default.
/wd<n> Disable the specified warning.
/we<n> Treat the specified warning as an error.
/WL Enable one-line diagnostics for error and warning messages when compiling C++ source code from the command line.
/wo<n> Display the specified warning only once.
/Wv:xx[.yy[.zzzzz]] Disable warnings introduced after the specified version of the compiler.
/WX Treat warnings as errors.

Experimental options

Experimental options may only be supported by certain versions of the compiler. They may also behave differently in different compiler versions. Often the best, or only, documentation for experimental options is in the Microsoft C++ Team Blog.

Option Purpose
/experimental:module Enables experimental module support.

Deprecated and removed compiler options

Option Purpose
/clr:noAssembly Deprecated. Use /LN (Create MSIL Module) instead.
/errorReport Deprecated. Error reporting is controlled by Windows Error Reporting (WER) settings.
/experimental:preprocessor Deprecated. Enables experimental conforming preprocessor support. Use /Zc:preprocessor
/Fr Deprecated. Creates a browse information file without local variables.
/Ge Deprecated. Activates stack probes. On by default.
/Gm Deprecated. Enables minimal rebuild.
/GX Deprecated. Enables synchronous exception handling. Use /EH instead.
/GZ Deprecated. Enables fast checks. Use /RTC1 instead.
/H Deprecated. Restricts the length of external (public) names.
/Og Deprecated. Uses global optimizations.
/QIfist Deprecated. Once used to specify how to convert from a floating-point type to an integral type.
/V Deprecated. Sets the .obj file version string.
/Wp64 Obsolete. Detects 64-bit portability problems.
/Yd Deprecated. Places complete debugging information in all object files. Use /Zi instead.
/Zc:forScope- Deprecated. Disables conformance in for loop scope.
/Ze Deprecated. Enables language extensions.
/Zg Removed in Visual Studio 2015. Generates function prototypes.

See also

C/C++ building reference
MSVC compiler options
MSVC compiler command-line syntax