DMD(1)

📦 version 2.112.1, in alpine 3.24

💅 DMD(1) — Digital Mars D2.x Compiler

okay bestie, gather round, because this is the manual page for dmd, the Digital Mars D2.x Compiler, and it's a whole moment. It lives over at The D Language Foundation, the manual name is dmd, and honestly it's giving "tiny file, enormous power." Let's get into it 💖

✨ SYNOPSIS ✨

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

🌸 DESCRIPTION 🌸

dmd compiles source code written in the D programming language. that's it, that's the vibe. she takes your D code and turns it into something a computer can actually run. iconic behavior, no cap 🫶

🎀 OPTIONS 🎀

this is the long part, so grab a snack. every single one of these is real, i promise 👑

🦋 Inputs (the things you feed her)

  • file, file.d, file.htm, file.html — D source files to compile. your actual code goes here.
  • 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 — and yes, it may contain # single-line comments. cute, right?

🌈 The full flag lineup (in order, bestie, i'm not skipping any)

  • -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 — do code coverage analysis.
  • -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=level — compile in debug code <= level.
  • -debug=ident — compile in debug code identified by ident.
  • -debuglib=name — set symbolic debug library to name.
  • -defaultlib=name — set default library to name.
  • -deps — print module dependencies (imports/file/version/debug/lib).
  • -deps=filename — write module dependencies to filename (only imports).
  • -dllimport=value — Windows only: select symbols to dllimport (none/defaultLibsOnly/externalOnly/all).
  • -edition[=NNNNG[<filename>]] — set language edition to edition year, 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= — 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.
  • -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[=[?|h|help|silent|verbose]] — write C++ 'header' equivalent to stdout.
  • -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=table — specify the non-ASCII tables for D identifiers.
  • -identifiers-importc=table — specify the non-ASCII tables for ImportC identifiers.
  • -ignore — deprecated flag, unsupported pragmas are always ignored now. she's retired, let her rest 💀
  • -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=id — generate instructions for architecture identified by id.
  • -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.
  • -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=level — compile in version code >= level.
  • -version=ident — compile in version code identified by ident.
  • -vgc — list all gc allocations including hidden ones.
  • -visibility=value — default visibility of symbols (default/hidden/public).
  • -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 🧚

these are the language changes you can pull up with -transition=id, and each one is a little side quest of its own:

  • 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. if you do not want dmd running the linker, use the -c switch. simple as that 🫶

the actual linking is done by running gcc. why? because it ensures compatibility with modules compiled with gcc. teamwork makes the dream work, periodt.

🌟 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. literal legend behavior, we stan 💅

⭐ ONLINE DOCUMENTATION ⭐

https://dlang.org/dmd.html

🌈 SEE ALSO 🌈

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

ok that's the whole page bestie, you're officially dmd-literate 🎓✨

💖 that's a wrap! brought to you by The D Language Foundation, dated 2026-05-01 — go compile something iconic 💖

📦 where this page comes from