DMD(1)                     The D Language Foundation                    DMD(1)

NAME
       dmd - Digital Mars D2.x Compiler

SYNOPSIS
       dmd files ... [ -switch ... ]

DESCRIPTION
       dmd Compiles source code written in the D programming language.

OPTIONS
       file, file.d, file.htm, file.html
              D source files to compile

       file.di
              D interface files

       file.o Object files to link in

       file.a Library files to link in

       @cmdfile
              A file to read more command-line arguments from, which may
              contain # single-line comments

       -allinst
              Generate code for all template instantiations

       -betterC
              Omit generating some runtime information and helper functions

       -boundscheck=[on|safeonly|off]
              Bounds checks on, in @safe only, or off

       -c     Compile only, do not link

       -check=[assert|bounds|in|invariant|out|switch][=[on|off]]
              Enable or disable specific checks

       -check=[h|help|?]
              List information on all available checks

       -checkaction=[D|C|halt|context]
              Behavior on assert/boundscheck/finalswitch failure

       -checkaction=[h|help|?]
              List information on all available check actions

       -color Turn colored console output on

       -color=[on|off|auto]
              Force colored console output on or off, or only when not
              redirected (default)

       -conf=filename
              Use config file at filename

       -cov   Perform code coverage and generate `.lst` file

       -cov=ctfe
              Include code executed during CTFE in coverage report

       -cov=nnn
              Require at least nnn% code coverage

       -cpp=filename
              Use filename as the name of the C preprocessor to use for
              ImportC files

       -D     Generate documentation

       -Dddirectory
              Write documentation file to directory

       -Dffilename
              Write documentation file to filename

       -d     Silently allow deprecated features and symbols

       -de    Issue an error when deprecated features or symbols are used
              (halt compilation)

       -dw    Issue a message when deprecated features or symbols are used
              (default)

       -debug Compile in debug code

       -debug=ident
              Compile in debug code identified by ident

       -debuglib=libname
              Set symbolic debug library to libname

       -defaultlib=libname
              Set default library to libname

       -deps  Print module dependencies (imports/file/version/debug/lib)

       -deps=filename
              Write module dependencies to filename (only imports)

       -dllimport=[none|defaultLibsOnly|externalOnly|all]
              Windows only: select symbols to dllimport

       -edition[=NNNN[filename]]
              Set language edition to year NNNN, apply to filename

       -extern-std=standard
              Set C++ name mangling compatibility with standard

       -extern-std=[h|help|?]
              List all supported standards

       -fIBT  Generate Indirect Branch Tracking code

       -fPIC  Generate position independent code

       -fPIE  Generate position independent executables

       -ftime-trace
              Turn on compile time profiler, generate JSON file with results

       -ftime-trace-granularity=<mu>secs
              Minimum time granularity (in microseconds) traced by time
              profiler (default: 500)

       -ftime-trace-file=filename
              Specify output file for `-ftime-trace`

       -g     Add symbolic debug info

       -gdwarf=version
              Add DWARF symbolic debug info (default: 3)

       -gf    Emit debug info for all referenced types

       -gs    Always emit stack frame

       -gx    Add stack stomp code

       -H     Generate 'header' file

       -Hd=directory
              Write 'header' file to directory

       -Hf=filename
              Write 'header' file to filename

       -HC=[silent|verbose]
              Write C++ 'header' equivalent to stdout

       -HC=[?|h|help]
              List available options for C++ 'header' file generation

       -HCd=directory
              Write C++ 'header' file to directory

       -HCf=filename
              Write C++ 'header' file to filename instead of stdout

       --help Print help and exit

       -I=directory
              Look for imports also in directory

       -extI=directory
              Look for imports that are out of the currently compiling binary,
              used to set the module as DllImport

       -i[=pattern]
              Include imported modules in the compilation

       -identifiers=[UAX31|c99|c11|all]
              Specify the non-ASCII tables for D identifiers

       -identifiers-importc=[UAX31|c99|c11|all]
              Specify the non-ASCII tables for ImportC identifiers

       -ignore
              Deprecated flag, unsupported pragmas are always ignored now

       -inline
              Do function inlining

       -J=directory
              Look for string imports also in directory

       -L=linkerflag
              Pass linkerflag to link

       -lib   Generate library rather than object files

       -lowmem
              Enable garbage collection for the compiler

       -m32   Generate 32 bit code

       -m64   Generate 64 bit code

       -main  Add default main() if not present already (e.g. for unittesting)

       -makedeps[=filename]
              Print dependencies in Makefile compatible format to filename or
              stdout.

       -man   Open web browser on manual page

       -map   Generate linker .map file

       -mcpu=[baseline|avx|native]
              Set the target architecture for code generation

       -mcpu=[h|help|?]
              List all architecture options

       -mixin=filename
              Expand and save mixins to file specified by filename

       -mv=package.module=filespec
              Use filespec as source file for package.module

       -noboundscheck
              No array bounds checking (deprecated, use `-boundscheck=off`)

       -nothrow
              Assume no Exceptions will be thrown

       -nothrow-optimizations
              Allow skipping destructors when an Error unwinds through a
              nothrow function

       -O     Optimize

       -o-    Do not write object file

       -od=directory
              Write object & library files to directory

       -of=filename
              Name output file to filename

       -op    Preserve source path for output files

       -oq    Write object files with fully qualified file names

       -os=os Sets target operating system to os

       -P=preprocessorflag
              Pass preprocessorflag to C preprocessor

       -preview=name
              Enable an upcoming language change identified by name

       -preview=[h|help|?]
              List all upcoming language changes

       -profile
              Profile runtime performance of generated code

       -profile=gc
              Profile runtime allocations

       -release
              Contracts and asserts are not emitted, and bounds checking is
              performed only in @safe functions

       -revert=name
              Revert language change identified by name

       -revert=[h|help|?]
              List all revertable language changes

       -run   Compile, link, and run the program srcfile

       -shared
              Generate shared library (DLL)

       -target=triple
              Use triple as arch-[vendor-]os[-cenv[-<cppenv]]

       -transition=name
              Help with language change identified by name

       -transition=[h|help|?]
              List all language changes

       -unittest
              Compile in unit tests

       -v     Verbose

       -vasm  List generated assembler for each function

       -vcolumns
              Print character (column) numbers in diagnostics

       -verror-style=[digitalmars|gnu|sarif]
              Set the style for file/line number annotations on compiler
              messages

       -verror-supplements=num
              Limit the number of supplemental messages for each error (0
              means unlimited)

       -verrors=num
              Limit the number of error/deprecation messages (0 means
              unlimited)

       -verrors=[context|simple]
              Set the verbosity of error messages

       -verrors=spec
              Show errors from speculative compiles such as
              `__traits(compiles, ...)`

       --version
              Print compiler version and exit

       -version=ident
              Compile in version code identified by ident

       -vgc   List all GC allocations including hidden ones

       -visibility=[default|hidden|public]
              Default visibility of symbols

       -vtls  List all variables going into thread local storage

       -vtemplates[=list-instances]
              List statistics on template instantiations

       -w     Warnings as errors (compilation will halt)

       -wi    Warnings as messages (compilation will continue)

       -wo    Warnings about use of obsolete features (compilation will
              continue)

       -X     Generate JSON file

       -Xf=filename
              Write JSON file to filename

       -Xcc=driverflag
              Pass driverflag to linker driver (cc)

TRANSITIONS
       Language changes listed by -transition=id:

       field  List all non-mutable fields which occupy an object instance

       complex
              Give deprecation messages about all usages of complex or
              imaginary types

       tls    List all variables going into thread local storage

       in     List all usages of 'in' on parameter

LINKING
       Linking is done directly by the dmd compiler after a successful
       compile. To prevent dmd from running the linker, use the -c switch.

       The actual linking is done by running gcc.  This ensures compatibility
       with modules compiled with gcc.

FILES
       /etc/dmd.conf
              System wide dmd config file. See dmd.conf(5) for details.

ENVIRONMENT
       The D compiler dmd uses the following environment variables:

       DFLAGS    The value of DFLAGS is treated as if it were appended on the
                 command line to dmd.

AUTHOR
       Copyright (c) 1999-2026 by The D Language Foundation written by Walter
       Bright

ONLINE DOCUMENTATION
       https://dlang.org/dmd.html <https://dlang.org/dmd.html>

SEE ALSO
       dmd.conf(5) rdmd(1) dumpobj(1) obj2asm(1) gcc(1)

The D Language Foundation         2026-08-30                            DMD(1)