diff --git a/gcc/d/Make-lang.in b/gcc/d/Make-lang.in
new file mode 100644
index 00000000000..b0999b93d30
--- /dev/null
+++ b/gcc/d/Make-lang.in
@@ -0,0 +1,274 @@
+# Make-lang.in -- Top level -*- makefile -*- fragment for the D frontend.
+# Copyright (C) 2006-2017 Free Software Foundation, Inc.
+
+# GCC is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3, or (at your option)
+# any later version.
+
+# GCC is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+
+# You should have received a copy of the GNU General Public License
+# along with GCC; see the file COPYING3.  If not see
+# <http://www.gnu.org/licenses/>.
+
+# This file provides the language dependent support in the main Makefile.
+
+# Installation name.
+
+D_INSTALL_NAME = $(shell echo gdc|sed '$(program_transform_name)')
+D_TARGET_INSTALL_NAME = $(target_noncanonical)-$(shell echo gdc|sed '$(program_transform_name)')
+
+# Name of phobos library
+D_LIBPHOBOS = -DLIBPHOBOS=\"gphobos\"
+
+# The name for selecting d in LANGUAGES.
+d: cc1d$(exeext)
+
+# Tell GNU make to ignore these if they exist.
+.PHONY: d
+
+# Create the compiler driver for D.
+CFLAGS-d/d-spec.o += $(DRIVER_DEFINES) $(D_LIBPHOBOS)
+
+GDC_OBJS = $(GCC_OBJS) d/d-spec.o
+gdc$(exeext): $(GDC_OBJS) $(EXTRA_GCC_OBJS) libcommon-target.a $(LIBDEPS)
+	+$(LINKER) $(ALL_LINKERFLAGS) $(LDFLAGS) -o $@ \
+	  $(GDC_OBJS) $(EXTRA_GCC_OBJS) libcommon-target.a \
+	  $(EXTRA_GCC_LIBS) $(LIBS)
+
+# Create a version of the gdc driver which calls the cross-compiler.
+gdc-cross$(exeext): gdc$(exeext)
+	-rm -f gdc-cross$(exeext)
+	cp gdc$(exeext) gdc-cross$(exeext)
+
+# Filter out pedantic and virtual overload warnings.
+d-warn = $(filter-out -pedantic -Woverloaded-virtual, $(STRICT_WARN))
+
+# D Frontend has slightly relaxed warnings compared to rest of GDC.
+DMD_WARN_CXXFLAGS = -Wno-deprecated -Wstrict-aliasing -Wuninitialized
+DMD_COMPILE = $(subst $(WARN_CXXFLAGS), $(DMD_WARN_CXXFLAGS), $(COMPILE))
+DMDGEN_COMPILE = $(subst $(COMPILER), $(COMPILER_FOR_BUILD), $(DMD_COMPILE))
+
+# D Frontend object files.
+D_FRONTEND_OBJS = \
+	d/argtypes.o d/aav.o d/access.o d/aliasthis.o d/apply.o d/arrayop.o \
+	d/attrib.o d/canthrow.o d/checkedint.o d/clone.o d/cond.o \
+	d/constfold.o d/cppmangle.o d/ctfeexpr.o d/dcast.o d/dclass.o \
+	d/declaration.o d/delegatize.o d/denum.o d/dimport.o d/dinterpret.o \
+	d/dmacro.o d/dmangle.o d/dmodule.o d/doc.o d/dscope.o d/dstruct.o \
+	d/dsymbol.o d/dtemplate.o d/dversion.o d/entity.o d/escape.o \
+	d/expression.o d/file.o d/filename.o d/func.o d/hdrgen.o \
+	d/identifier.o d/imphint.o d/init.o d/inline.o d/intrange.o d/json.o \
+	d/lexer.o d/mtype.o d/nogc.o d/newdelete.o d/nspace.o d/objc.o \
+	d/opover.o d/optimize.o d/outbuffer.o d/parse.o d/rmem.o \
+	d/rootobject.o d/sapply.o d/sideeffect.o d/speller.o d/statement.o \
+	d/statementsem.o d/staticassert.o d/stringtable.o d/tokens.o d/traits.o \
+	d/unittests.o d/utf.o d/utils.o
+
+# D Frontend generated files.
+D_GENERATED_SRCS = d/id.c d/id.h d/impcnvtab.c
+D_GENERATED_OBJS = d/id.o d/impcnvtab.o
+
+# Language-specific object files for D.
+D_OBJS = \
+	d/d-attribs.o d/d-builtins.o d/d-codegen.o d/d-convert.o \
+	d/d-diagnostic.o d/d-frontend.o d/d-incpath.o d/d-lang.o \
+	d/d-longdouble.o d/d-target.o d/decl.o d/expr.o d/imports.o \
+	d/intrinsics.o d/modules.o d/runtime.o d/toir.o d/typeinfo.o d/types.o
+
+# All language-specific object files for D.
+D_ALL_OBJS = $(D_FRONTEND_OBJS) $(D_GENERATED_OBJS) $(D_OBJS) $(D_TARGET_OBJS)
+
+d_OBJS = $(D_ALL_OBJS) d/d-spec.o
+
+cc1d$(exeext): $(D_ALL_OBJS) attribs.o $(BACKEND) $(LIBDEPS)
+	+$(LLINKER) $(ALL_LINKERFLAGS) $(LDFLAGS) -o $@ \
+		$(D_ALL_OBJS) attribs.o $(BACKEND) $(LIBS) $(BACKENDLIBS)
+
+# Documentation.
+
+D_TEXI_FILES = \
+	d/gdc.texi \
+	$(gcc_docdir)/include/fdl.texi \
+	$(gcc_docdir)/include/gpl_v3.texi \
+	$(gcc_docdir)/include/gcc-common.texi \
+	gcc-vers.texi
+
+doc/gdc.info: $(D_TEXI_FILES)
+	if test "x$(BUILD_INFO)" = xinfo; then \
+	  rm -f doc/gdc.info*; \
+	  $(MAKEINFO) $(MAKEINFOFLAGS) -I $(gcc_docdir) \
+		-I $(gcc_docdir)/include -o $@ $<; \
+	else true; fi
+
+doc/gdc.dvi: $(D_TEXI_FILES)
+	$(TEXI2DVI) -I $(abs_docdir) -I $(abs_docdir)/include -o $@ $<
+
+doc/gdc.pdf: $(D_TEXI_FILES)
+	$(TEXI2PDF) -I $(abs_docdir) -I $(abs_docdir)/include -o $@ $<
+
+$(build_htmldir)/d/index.html: $(D_TEXI_FILES)
+	$(mkinstalldirs) $(@D)
+	rm -f $(@D)/*
+	$(TEXI2HTML) -I $(gcc_docdir) -I $(gcc_docdir)/include \
+		-I $(srcdir)/d -o $(@D) $<
+
+.INTERMEDIATE: gdc.pod
+
+gdc.pod: d/gdc.texi
+	-$(TEXI2POD) -D gdc < $< > $@
+
+# Build hooks.
+
+d.all.cross: gdc-cross$(exeext)
+d.start.encap: gdc$(exeext)
+d.rest.encap:
+d.info: doc/gdc.info
+d.dvi: doc/gdc.dvi
+d.pdf: doc/gdc.pdf
+d.html: $(build_htmldir)/d/index.html
+d.srcinfo: doc/gdc.info
+	-cp -p $^ $(srcdir)/doc
+d.srcextra:
+
+d.tags: force
+	cd $(srcdir)/d; \
+	etags -o TAGS.sub *.c *.cc *.h dfrontend/*.h dfrontend/*.c; \
+	etags --include TAGS.sub --include ../TAGS.sub
+
+d.man: doc/gdc.1
+d.srcman: doc/gdc.1
+	-cp -p $^ $(srcdir)/doc
+
+# 'make check' in gcc/ looks for check-d, as do all toplevel D-related
+# check targets.  However, our DejaGNU framework requires 'check-gdc' as its
+# entry point.  We feed the former to the latter here.
+check-d: check-gdc
+lang_checks += check-gdc
+lang_checks_parallelized += check-gdc
+check_gdc_parallelize = 10
+
+# Install hooks.
+
+d.install-common: installdirs
+	-rm -f $(DESTDIR)$(bindir)/$(D_INSTALL_NAME)$(exeext)
+	$(INSTALL_PROGRAM) gdc$(exeext) $(DESTDIR)$(bindir)/$(D_INSTALL_NAME)$(exeext)
+	-if test -f cc1d$(exeext); then \
+	  if test -f gdc-cross$(exeext); then \
+	    :; \
+	  else \
+	    rm -f $(DESTDIR)$(bindir)/$(D_TARGET_INSTALL_NAME)$(exeext); \
+	    ( cd $(DESTDIR)$(bindir) && \
+	      $(LN) $(D_INSTALL_NAME)$(exeext) $(D_TARGET_INSTALL_NAME)$(exeext) ); \
+	  fi; \
+	fi
+
+d.install-plugin:
+
+d.install-info: $(DESTDIR)$(infodir)/gdc.info
+
+d.install-pdf: doc/gdc.pdf
+	@$(NORMAL_INSTALL)
+	test -z "$(pdfdir)" || $(mkinstalldirs) "$(DESTDIR)$(pdfdir)/gcc"
+	@for p in doc/gdc.pdf; do \
+	  if test -f "$$p"; then d=; else d="$(srcdir)/"; fi; \
+	  f=$(pdf__strip_dir) \
+	  echo " $(INSTALL_DATA) '$$d$$p' '$(DESTDIR)$(pdfdir)/gcc/$$f'"; \
+	  $(INSTALL_DATA) "$$d$$p" "$(DESTDIR)$(pdfdir)/gcc/$$f"; \
+	done
+
+d.install-html: $(build_htmldir)/d
+	@$(NORMAL_INSTALL)
+	test -z "$(htmldir)" || $(mkinstalldirs) "$(DESTDIR)$(htmldir)"
+	@for p in $(build_htmldir)/d; do \
+	  if test -f "$$p" || test -d "$$p"; then d=""; else d="$(srcdir)/"; fi; \
+	  f=$(html__strip_dir) \
+	  if test -d "$$d$$p"; then \
+	    echo " $(mkinstalldirs) '$(DESTDIR)$(htmldir)/$$f'"; \
+	    $(mkinstalldirs) "$(DESTDIR)$(htmldir)/$$f" || exit 1; \
+	    echo " $(INSTALL_DATA) '$$d$$p'/* '$(DESTDIR)$(htmldir)/$$f'"; \
+	    $(INSTALL_DATA) "$$d$$p"/* "$(DESTDIR)$(htmldir)/$$f"; \
+	  else \
+	    echo " $(INSTALL_DATA) '$$d$$p' '$(DESTDIR)$(htmldir)/$$f'"; \
+	    $(INSTALL_DATA) "$$d$$p" "$(DESTDIR)$(htmldir)/$$f"; \
+	  fi; \
+	done
+
+d.install-man: $(DESTDIR)$(man1dir)/$(D_INSTALL_NAME)$(man1ext)
+
+$(DESTDIR)$(man1dir)/$(D_INSTALL_NAME)$(man1ext): doc/gdc.1 installdirs
+	-rm -f $@
+	-$(INSTALL_DATA) $< $@
+	-chmod a-x $@
+
+d.uninstall:
+	-rm -rf $(DESTDIR)$(bindir)/$(D_INSTALL_NAME)$(exeext)
+	-rm -rf $(DESTDIR)$(man1dir)/$(D_INSTALL_NAME)$(man1ext)
+	-rm -rf $(DESTDIR)$(bindir)/$(D_TARGET_INSTALL_NAME)$(exeext)
+	-rm -rf $(DESTDIR)$(infodir)/gdc.info*
+
+# Clean hooks.
+
+d.mostlyclean:
+	-rm -f d/*$(objext)
+	-rm -f d/*$(coverageexts)
+	-rm -f $(D_GENERATED_SRCS) verstr.h
+	-rm -f d/gdc$(exeext) gdc-cross$(exeext) d/cc1d$(exeext)
+d.clean:
+d.distclean:
+d.maintainer-clean:
+	-rm -f $(docobjdir)/gdc.1
+
+# Stage hooks.
+
+d.stage1: stage1-start
+	-mv d/*$(objext) stage1/d
+d.stage2: stage2-start
+	-mv d/*$(objext) stage2/d
+d.stage3: stage3-start
+	-mv d/*$(objext) stage3/d
+d.stage4: stage4-start
+	-mv d/*$(objext) stage4/d
+d.stageprofile: stageprofile-start
+	-mv d/*$(objext) stageprofile/d
+d.stagefeedback: stagefeedback-start
+	-mv d/*$(objext) stagefeedback/d
+
+# Include the dfrontend and build directories for headers.
+D_INCLUDES = -I$(srcdir)/d -I$(srcdir)/d/dfrontend -Id
+
+CFLAGS-d/id.o += $(D_INCLUDES)
+CFLAGS-d/impcnvtab.o += $(D_INCLUDES)
+
+# Override build rules for D frontend.
+d/%.o: d/dfrontend/%.c $(D_GENERATED_SRCS) d/verstr.h
+	$(DMD_COMPILE) $(D_INCLUDES) $<
+	$(POSTCOMPILE)
+
+# Generated programs.
+d/idgen: d/idgen.dmdgen.o
+	+$(LINKER_FOR_BUILD) $(BUILD_LINKER_FLAGS) $(BUILD_LDFLAGS) -o $@ $^
+
+d/impcvgen: d/impcnvgen.dmdgen.o
+	+$(LINKER_FOR_BUILD) $(BUILD_LINKER_FLAGS) $(BUILD_LDFLAGS) -o $@ $^
+
+# Generated sources.
+d/id.c: d/idgen
+	cd d && ./idgen
+
+# idgen also generates id.h; just verify it exists.
+d/id.h: d/id.c
+
+d/impcnvtab.c: d/impcvgen
+	cd d && ./impcvgen
+
+d/verstr.h: d/VERSION
+	cat $^ > $@
+
+d/%.dmdgen.o: $(srcdir)/d/dfrontend/%.c
+	$(DMDGEN_COMPILE) $(D_INCLUDES) $<
+	$(POSTCOMPILE)
diff --git a/gcc/d/config-lang.in b/gcc/d/config-lang.in
new file mode 100644
index 00000000000..e3690850728
--- /dev/null
+++ b/gcc/d/config-lang.in
@@ -0,0 +1,33 @@
+# config-lang.in -- Top level configure fragment for gcc D frontend.
+# Copyright (C) 2006-2017 Free Software Foundation, Inc.
+
+# GCC is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3, or (at your option)
+# any later version.
+
+# GCC is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+
+# You should have received a copy of the GNU General Public License
+# along with GCC; see the file COPYING3.  If not see
+# <http://www.gnu.org/licenses/>.
+
+# Configure looks for the existence of this file to auto-config each language.
+# We define several parameters used by configure:
+#
+# language	- name of language as it would appear in $(LANGUAGES)
+# compilers	- value to add to $(COMPILERS)
+
+language="d"
+
+compilers="cc1d\$(exeext)"
+
+target_libs="target-libphobos target-zlib target-libbacktrace"
+
+gtfiles="\$(srcdir)/d/d-tree.h \$(srcdir)/d/d-builtins.cc \$(srcdir)/d/d-lang.cc \$(srcdir)/d/typeinfo.cc"
+
+# Do not build by default.
+build_by_default="no"
diff --git a/gcc/d/gdc.texi b/gcc/d/gdc.texi
new file mode 100644
index 00000000000..05737be3a33
--- /dev/null
+++ b/gcc/d/gdc.texi
@@ -0,0 +1,775 @@
+\input texinfo @c -*-texinfo-*-
+@setfilename gdc.info
+@settitle The GNU D Compiler
+
+@c Merge the standard indexes into a single one.
+@syncodeindex fn cp
+@syncodeindex vr cp
+@syncodeindex ky cp
+@syncodeindex pg cp
+@syncodeindex tp cp
+
+@include gcc-common.texi
+
+@c Copyright years for this manual.
+@set copyrights-d 2006-2017
+
+@copying
+@c man begin COPYRIGHT
+Copyright @copyright{} @value{copyrights-d} Free Software Foundation, Inc.
+
+Permission is granted to copy, distribute and/or modify this document
+under the terms of the GNU Free Documentation License, Version 1.3 or
+any later version published by the Free Software Foundation; with no
+Invariant Sections, the Front-Cover Texts being (a) (see below), and
+with the Back-Cover Texts being (b) (see below).
+A copy of the license is included in the
+@c man end
+section entitled ``GNU Free Documentation License''.
+@ignore
+@c man begin COPYRIGHT
+man page gfdl(7).
+@c man end
+@end ignore
+
+@c man begin COPYRIGHT
+
+(a) The FSF's Front-Cover Text is:
+
+     A GNU Manual
+
+(b) The FSF's Back-Cover Text is:
+
+     You have freedom to copy and modify this GNU Manual, like GNU
+     software.  Copies published by the Free Software Foundation raise
+     funds for GNU development.
+@c man end
+@end copying
+
+@ifinfo
+@format
+@dircategory Software development
+@direntry
+* gdc: (gdc).               A GCC-based compiler for the D language
+@end direntry
+@end format
+
+@insertcopying
+@end ifinfo
+
+@titlepage
+@title The GNU D Compiler
+@versionsubtitle
+@author David Friedman, Iain Buclaw
+
+@page
+@vskip 0pt plus 1filll
+Published by the Free Software Foundation @*
+51 Franklin Street, Fifth Floor@*
+Boston, MA 02110-1301, USA@*
+@sp 1
+@insertcopying
+@end titlepage
+@contents
+@page
+
+@node Top
+@top Introduction
+
+This manual describes how to use @command{gdc}, the GNU compiler for
+the D programming language.  This manual is specifically about
+@command{gdc}.  For more information about the D programming
+language in general, including language specifications and standard
+package documentation, see @uref{http://dlang.org/}.
+
+@menu
+* Copying::                     The GNU General Public License.
+* GNU Free Documentation License::
+                                How you can share and copy this manual.
+* Invoking gdc::                How to run gdc.
+* Index::                       Index.
+@end menu
+
+
+@include gpl_v3.texi
+
+@include fdl.texi
+
+
+@node Invoking gdc
+@chapter Invoking gdc
+
+@c man title gdc A GCC-based compiler for the D language
+
+@ignore
+@c man begin SYNOPSIS gdc
+gdc [@option{-c}|@option{-S}] [@option{-g}] [@option{-pg}]
+    [@option{-O}@var{level}] [@option{-W}@var{warn}@dots{}]
+    [@option{-I}@var{dir}@dots{}] [@option{-L}@var{dir}@dots{}]
+    [@option{-f}@var{option}@dots{}] [@option{-m}@var{machine-option}@dots{}]
+    [@option{-o} @var{outfile}] [@@@var{file}] @var{infile}@dots{}
+
+Only the most useful options are listed here; see below for the
+remainder.
+@c man end
+@c man begin SEEALSO
+gpl(7), gfdl(7), fsf-funding(7), gcc(1)
+and the Info entries for @file{gdc} and @file{gcc}.
+@c man end
+@end ignore
+
+@c man begin DESCRIPTION gdc
+
+The @command{gdc} command is a frontend to @command{gcc} and supports many
+of the same options.  @xref{Option Summary, , Option Summary, gcc,
+Using the GNU Compiler Collection (GCC)}.  This manual only documents
+the options specific to @command{gdc}.
+
+@c man end
+
+@menu
+* Input and Output files::  Controlling the kind of output:
+                            an executable, object files, assembler files,
+* Runtime Options::         Options controlling runtime behaviour
+* Directory Options::       Where to find module files
+* Code Generation::         Options controlling the output of gdc
+* Warnings::                Options controlling warnings specific to gdc
+* Linking::                 Options influceing the linking step
+* Developer Options::       Options you won't use
+* Environment Variables::   Environment variables that affect @command{gdc}.
+@end menu
+
+@c man begin OPTIONS
+
+@node Input and Output files
+@section Input and Output files
+@cindex suffixes for D source
+@cindex D source file suffixes
+
+For any given input file, the file name suffix determines what kind of
+compilation is done.  The following kinds of input file names are supported:
+
+@table @gcctabopt
+@item @var{file}.d
+D source files.
+@item @var{file}.dd
+Ddoc source files.
+@item @var{file}.di
+D interface files.
+@end table
+
+You can specify more than one input file on the @command{gdc} command line,
+in which case they will all be compiled.  If you specify a
+@code{-o @var{file}} option, all the input files will be compiled together,
+producing a single output file, named @var{file}.  This is allowed even
+when using @code{-S} or @code{-c}.
+
+@cindex D interface files.
+A D interface file contains only what an import of the module needs,
+rather than the whole implementation of that module.  They can be created
+by @command{gdc} from a D source file by using the @code{-fintfc} option.
+When the compiler resolves an import declaration, it searches for matching
+@file{.di} files first, then for @file{.d}.
+
+@cindex Ddoc source files.
+A Ddoc source file contains code in the D macro processor language.  It is
+primarily designed for use in producing user documentation from embedded
+comments, with a slight affinity towards HTML generation.  If a @file{.d}
+source file starts with the string @code{Ddoc} then it is treated as general
+purpose documentation, not as a D source file.
+
+@node Runtime Options
+@section Runtime Options
+@cindex options, runtime
+
+These options affect the runtime behavior of programs compiled with
+@command{gdc}.
+
+@table @gcctabopt
+
+@item -fall-instantiations
+@cindex @option{-fall-instantiations}
+@cindex @option{-fno-all-instantiations}
+Generate code for all template instantiations.  The default template emission
+strategy is to not generate code for declarations that were either
+instantiated speculatively, such as from @code{__traits(compiles, ...)}, or
+that come from an imported module not being compiled.
+
+@item -fno-assert
+@cindex @option{-fassert}
+@cindex @option{-fno-assert}
+Turn off code generation for @code{assert} contracts.
+
+@item -fno-bounds-check
+@cindex @option{-fbounds-check}
+@cindex @option{-fno-bounds-check}
+Turns off array bounds checking for all functions, which can improve
+performance for code that uses array extensively.  Note that this
+can result in unpredictable behavior if the code in question actually
+does violate array bounds constraints.  It is safe to use this option
+if you are sure that your code will never throw a @code{RangeError}.
+
+@item -fbounds-check=@var{value}
+@cindex @option{-fbounds-check=}
+An alternative to @option{-fbounds-check} that allows more control
+as to where bounds checking is turned on or off.  The following values
+are supported:
+
+@table @samp
+@item on
+@cindex @option{-fbounds-check=on}
+Turns on array bounds checking for all functions.
+@item safeonly
+@cindex @option{-fbounds-check=safeonly}
+Turns on array bounds checking only for @code{@@safe} functions.
+@item off
+@cindex @option{-fbounds-check=off}
+Turns off array bounds checking completely.
+@end table
+
+@item -fno-builtin
+@cindex @option{-fbuiltin}
+@cindex @option{-fno-builtin}
+Don't recognize built-in functions that do not begin with
+@samp{__builtin_} as prefix.  By default, the compiler will recognize
+when a function in the @code{core.stdc} package is a built-in function.
+
+@item -fdebug
+@item -fdebug=@var{value}
+@cindex @option{-fdebug}
+@cindex @option{-fno-debug}
+Turn on compilation of conditional @code{debug} code into the program.
+The @option{-fdebug} option itself sets the debug level to @code{1},
+while @option{-fdebug=} enables @code{debug} code that are identified
+by any of the following values:
+
+@table @samp
+@item level
+@cindex @option{-fdebug=level}
+Sets the debug level to @var{level}, any @code{debug} code <= @var{level}
+is compiled into the program.
+@item ident
+@cindex @option{-fdebug=ident}
+Turns on compilation of any @code{debug} code identified by @var{ident}.
+@end table
+
+@item -fno-invariants
+@cindex @option{-finvariants}
+@cindex @option{-fno-invariants}
+Turns off code generation for class @code{invariant} contracts.
+
+@item -fno-moduleinfo
+@cindex @option{-fmoduleinfo}
+@cindex @option{-fno-moduleinfo}
+Turns off generation of the @code{ModuleInfo} and related functions
+that would become unreferenced without it, which may allow linking
+to programs not written in D.  Functions that will not be generated
+include module constructor and destructors (@code{static this} and
+@code{static ~this}), @code{unittest} code, and @code{DSO} registry
+functions for dynamically linked code.
+
+@item -fonly=@var{filename}
+@cindex @option{-fonly}
+Tells the compiler to parse and run semantic analysis on all modules
+on the command line, but only generate code for the module specified
+by @var{filename}.
+
+@item -fno-postconditions
+@cindex @option{-fpostconditions}
+@cindex @option{-fno-postconditions}
+Turns off code generation for postcondition @code{out} contracts.
+
+@item -fno-preconditions
+@cindex @option{-fpreconditions}
+@cindex @option{-fno-preconditions}
+Turns off code generation for precondition @code{in} contracts.
+
+@item -frelease
+@cindex @option{-frelease}
+@cindex @option{-fno-release}
+Turns on compiling in release mode, which means not emitting runtime
+checks for contracts and asserts.  Array bounds checking is not done
+for @code{@@system} and @code{@@trusted} functions, and assertion
+failures are undefined behaviour.
+
+This is equivalent to compiling with the following options:
+
+@example
+gdc -fno-assert -fbounds-check=safe -fno-invariants \
+    -fno-postconditions -fno-preconditions -fno-switch-errors
+@end example
+
+@item -fno-switch-errors
+@cindex @option{-fswitch-errors}
+@cindex @option{-fno-switch-errors}
+This option controls what code should be generated when no case is
+matched in a @code{final switch} statement.  The default run time
+behavior is that a @code{SwitchError} will be thrown.  Turning off
+@option{-fswitch-errors} means that instead the execution of the
+program is immediately halted.
+
+@item -funittest
+@cindex @option{-funittest}
+@cindex @option{-fno-unittest}
+Turns on compilation of @code{unittest} code, and turns on the
+@code{version(unittest)} identifier.  This implies @option{-fassert}.
+
+@item -fversion=@var{value}
+@cindex @option{-fversion}
+Turns on compilation of conditional @code{version} code into the program
+identified by any of the following values:
+
+@table @samp
+@item level
+@cindex @option{-fversion=level}
+Sets the version level to @var{level}, any @code{version} code >= @var{level}
+is compiled into the program.
+@item ident
+@cindex @option{-fversion=ident}
+Turns on compilation of @code{version} code identified by @var{ident}.
+@end table
+
+@end table
+
+@node Directory Options
+@section Options for Directory Search
+@cindex directory options
+@cindex options, directory search
+@cindex search path
+
+These options specify directories to search for files, libraries, and
+other parts of the compiler:
+
+@table @gcctabopt
+
+@item -I@var{dir}
+@cindex @option{-I}
+Specify a directory to use when searching for imported modules at
+compile time.  Multiple @option{-I} options can be used, and the
+paths are searched in the same order.
+
+@item -J@var{dir}
+@cindex @option{-J}
+Specify a directory to use when searching for files in string imports
+at compile time.  This switch is required in order to use
+@code{import(file)} expressions.  Multiple @option{-J} options can be
+used, and the paths are searched in the same order.
+
+@item -L@var{dir}
+@cindex @option{-L}
+When linking, specify a library search directory, as with @command{gcc}.
+
+@item -B@var{dir}
+@cindex @option{-B}
+This option specifies where to find the executables, libraries,
+source files, and data files of the compiler itself, as with @command{gcc}.
+
+@item -fmodule-filepath=@var{module}=@var{spec}
+@cindex @option{-fmodule-filepath}
+This option manipulates file paths of imported modules, such that if an
+imported module matches all or the leftmost part of @var{module}, the file
+path in @var{spec} is used as the location to search for D sources.
+This is used when the source file path and names are not the same as the
+package and module hierachy.  Consider the following examples:
+
+@example
+gdc test.d -fmodule-filepath=A.B=foo.d -fmodule-filepath=C=bar
+@end example
+
+This will tell the compiler to search in all import paths for the source
+file @var{foo.d} when importing @var{A.B}, and the directory @var{bar/}
+when importing @var{C}, as annotated in the following D code:
+
+@example
+module test;
+import A.B;     // Matches A.B, searches for foo.d
+import C.D.E;   // Matches C, searches for bar/D/E.d
+import A.B.C;   // No match, searches for A/B/C.d
+@end example
+
+@item -imultilib @var{dir}
+@cindex @option{-imultilib}
+Use @var{dir} as a subdirectory of the gcc directory containing
+target-specific D sources and interfaces.
+
+@item -iprefix @var{prefix}
+@cindex @option{-iprefix}
+Specify @var{prefix} as the prefix for the gcc directory containing
+target-specific D sources and interfaces.  If the @var{prefix} represents
+a directory, you should include the final @code{'/'}.
+
+@item -nostdinc
+@cindex @option{-nostdinc}
+Do not search the standard system directories for D source and interface
+files.  Only the directories that have been specified with @option{-I} options
+(and the directory of the current file, if appropriate) are searched.
+
+@end table
+
+@node Code Generation
+@section Code Generation
+@cindex options, code generation
+
+In addition to the many @command{gcc} options controlling code generation,
+@command{gdc} has several options specific to itself.
+
+@table @gcctabopt
+
+@item -M
+@cindex @option{-M}
+Output the module dependencies of all source files being compiled in a
+format suitable for @command{make}.  The compiler outputs one
+@command{make} rule containing the object file name for that source file,
+a colon, and the names of all imported files.
+
+@item -MM
+@cindex @option{-MM}
+Like @option{-M} but does not mention imported modules from the D standard
+library package directories.
+
+@item -MF @var{file}
+@cindex @option{-MF}
+When used with @option{-M} or @option{-MM}, specifies a @var{file} to write
+the dependencies to.  When used with the driver options @option{-MD} or
+@option{-MMD}, @option{-MF} overrides the default dependency output file.
+
+@item -MG
+@cindex @option{-MG}
+This option is for compatibility with @command{gcc}, and is ignored by the
+compiler.
+
+@item -MP
+@cindex @option{-MP}
+Outputs a phony target for each dependency other than the modules being
+compiled, causing each to depend on nothing.
+
+@item -MT @var{target}
+@cindex @option{-MT}
+Change the @var{target} of the rule emitted by dependency generation
+to be exactly the string you specify.  If you want multiple targets,
+you can specify them as a single argument to @option{-MT}, or use
+multiple @option{-MT} options.
+
+@item -MQ @var{target}
+@cindex @option{-MQ}
+Same as @option{-MT}, but it quotes any characters which are special to
+@command{make}.
+
+@item -MD
+@cindex @option{-MD}
+This option is equivalent to @option{-M -MF @var{file}}.  The driver
+determines @var{file} based on the name of the input file, removes any
+directory components and suffix, and applies a @file{.deps} suffix.
+
+@item -MMD
+@cindex @option{-MMD}
+Like @option{-MD} but does not mention imported modules from the D standard
+library package directories.
+
+@item -X
+@cindex @option{-X}
+Output information describing the contents of all source files being
+compiled in JSON format to a file.  The driver determines @var{file} based
+on the name of the input file, removes any directory components and suffix,
+and applies a @file{.json} suffix.
+
+@item -Xf @var{file}
+@cindex @option{-Xf}
+Same as @option{-X}, but writes all JSON contents to the specified
+@var{file}.
+
+@item -fdeps
+@cindex @option{-fdeps}
+Dump module dependencies of all source files being compiled in a machine
+readable format.  Suitable for any build tool that needs to track source
+file dependencies for incremental builds.
+
+@item -fdeps=@var{file}
+@cindex @option{-fdeps=}
+Same as @option{-fdeps}, but writes dependencies to the specified
+@var{file}.
+
+@item -fdoc
+@cindex @option{-fdoc}
+Generates @code{Ddoc} documentation and writes to a file.  The compiler
+determines @var{file} based on the name of the input file, removes any
+directory components and suffix, and applies a @file{.html} suffix.
+
+@item -fdoc-dir=@var{dir}
+@cindex @option{-fdoc-dir}
+Same as @option{-fdoc}, but writes documentation to @var{dir} directory.
+This option can be used with @option{-fdoc-file=@var{file}} to
+independently set the output file and directory path.
+
+@item -fdoc-file=@var{file}
+@cindex @option{-fdoc-file}
+Same as @option{-fdoc}, but writes documentation to @var{file}.  This
+option can be used with @option{-fdoc-dir=@var{dir}} to independently
+set the output file and directory path.
+
+@item -fdoc-inc=@var{file}
+@cindex @option{-fdoc-inc}
+Specify @var{file} as a @var{Ddoc} macro file to be read.  Multiple
+@option{-fdoc-inc} options can be used, and files are read and processed
+in the same order.
+
+@item -fintfc
+@cindex @option{-fintfc}
+Generates D interface files for all modules being compiled.  The compiler
+determines the output @var{file} based on the name of the input file,
+removes any directory components and suffix, and applies the @file{.di}
+suffix.
+
+@item -fintfc-dir=@var{dir}
+@cindex @option{-fintfc-dir}
+Same as @option{-fintfc}, but writes interface files to @var{dir}
+directory.  This option can be used with @option{-fintfc-file=@var{file}}
+to independently set the output file and directory path.
+
+@item -fintfc-file=@var{filename}
+@cindex @option{-fintfc-file}
+Same as @option{-fintfc} but writes interface files to @var{file}.  This
+option can be used with @option{-fintfc-dir=@var{dir}} to independently
+set the output file and directory path.
+
+@end table
+
+@node Warnings
+@section Warnings
+@cindex options to control warnings
+@cindex warning messages
+@cindex messages, warning
+@cindex suppressing warnings
+
+Warnings are diagnostic messages that report constructions that
+are not inherently erroneous but that are risky or suggest there
+is likely to be a bug in the program.  Unless @option{-Werror} is
+specified, they do not prevent compilation of the program.
+
+@table @gcctabopt
+
+@item -Wall
+@cindex @option{-Wall}
+@cindex @option{-Wno-all}
+Turns on all warnings messages.  Warnings are not a defined part of
+the D language, and all constructs for which this may generate a
+warning message are legal code.
+
+@item -Wcast-result
+@cindex @option{-Wcast-result}
+@cindex @option{-Wno-cast-result}
+Warn about casts that will produce a null or zero result.  Currently
+this is only done for casting between an imaginary and non-imaginary
+data type, or casting between a D and C++ class.
+
+@item -Wno-deprecated
+@cindex @option{-Wdeprecated}
+@cindex @option{-Wno-deprecated}
+Do not warn about usage of deprecated features and symbols with
+@code{deprecated} attributes.
+
+@item -Werror
+@cindex @option{-Werror}
+@cindex @option{-Wno-error}
+Turns all warnings into errors.
+
+@item -Wspeculative
+@cindex @option{-Wspeculative}
+@cindex @option{-Wno-speculative}
+Report on all error messages from speculative compiles, such as
+@code{__traits(compiles, ...)}.  This option does not report
+messages as warnings, and these messages therefore never become
+errors when the @option{-Werror} option is also used.
+
+@item -Wtemplates
+@cindex @option{-Wtemplates}
+@cindex @option{-Wno-templates}
+Warn when a template instantiation is encountered.  Some coding
+rules disallow templates, and this may be used to enforce that rule.
+
+@item -Wunknown-pragmas
+@cindex @option{-Wunknown-pragmas}
+@cindex @option{-Wno-unknown-pragmas}
+Warn when a @code{pragma()} is encountered that is not understood by
+@command{gdc}.  This differs from @option{-fignore-unknown-pragmas}
+where a pragma that is part of the D language, but not implemented by
+the compiler, will not get reported.
+
+@item -fignore-unknown-pragmas
+@cindex @option{-fignore-unknown-pragmas}
+@cindex @option{-fno-ignore-unknown-pragmas}
+Turns off errors for unsupported pragmas.
+
+@item -fmax-errors=@var{n}
+@cindex @option{-fmax-errors}
+Limits the maximum number of error messages to @var{n}, at which point
+@command{gdc} bails out rather than attempting to continue processing the
+source code.  If @var{n} is 0 (the default), there is no limit on the
+number of error messages produced.
+
+@item -fproperty
+@cindex @option{-fproperty}
+@cindex @option{-fno-property}
+Enforces the @code{@@property} syntax in D.
+
+@item -fsyntax-only
+@cindex @option{-fsyntax-only}
+@cindex @option{-fno-syntax-only}
+Check the code for syntax errors, but do not actually compile it.  This
+only suppresses the generation of the object code, and can be used in
+conjunction with @option{-fdoc} or @option{-fintfc} options.
+
+@item -ftransition=@var{id}
+@cindex @option{-ftransition}
+Report additional information about D language changes identified by
+@var{id}.  The following values are supported:
+
+@table @samp
+@item all
+@cindex @option{-ftransition=all}
+List information on all language changes.
+@item checkimports
+@cindex @option{-ftransition=checkimports}
+Give deprecation messages about @option{-ftransition=import} anomalies.
+@item complex
+@cindex @option{-ftransition=complex}
+List all usages of complex or imaginary types.
+@item dip1000
+@cindex @option{-ftransition=dip1000}
+Implements @uref{http://wiki.dlang.org/DIP1000} (experimental).
+@item dip25
+@cindex @option{-ftransition=dip25}
+Implements @uref{http://wiki.dlang.org/DIP25} (experimental).
+@item field
+@cindex @option{-ftransition=field}
+List all non-mutable fields which occupy an object instance.
+@item import
+@cindex @option{-ftransition=import}
+Tells the compiler to revert to using an old lookup behavior for resolving
+unqualified symbol names, where this was done in a single pass, ignoring any
+protection attributes.  The default name lookup strategy is to use two passes,
+the first ignoring imported declarations, and the second only looking at imports.
+The protection (@code{private}, @code{package}, @code{protected}) of symbols is
+also enforced to resolve any conflicts between private and public symbols.
+@item nogc
+@cindex @option{-ftransition=nogc}
+List all hidden GC allocations.
+@item tls
+@cindex @option{-ftransition=tls}
+List all variables going into thread local storage.
+@end table
+
+@end table
+
+@node Linking
+@section Options for Linking
+@cindex options, linking
+@cindex linking, static
+
+These options come into play when the compiler links object files into an
+executable output file. They are meaningless if the compiler is not doing
+a link step.
+
+@table @gcctabopt
+
+@item -defaultlib @var{libname}
+@cindex @option{-defaultlib}
+Specify the library to use instead of libphobos when linking.  Options
+specifying the linkage of libphobos, such as @option{-static-libphobos}
+or @option{-shared-libphobos}, are ignored.
+
+@item -debuglib
+@cindex @option{-debuglib}
+Specify the debug library to use instead of libphobos when linking.
+This option has no effect unless the @option{-g} option was also given
+on the command line.  Options specifying the linkage of libphobos, such
+as @option{-static-libphobos} or @option{-shared-libphobos}, are ignored.
+
+@item -nophoboslib
+@cindex @option{-nophoboslib}
+Do not use the Phobos or D runtime library when linking.  Options specifying
+the linkage of libphobos, such as @option{-static-libphobos} or
+@option{-shared-libphobos}, are ignored.  The standard system libraries are
+used normally, unless @option{-nostdlib} or @option{-nodefaultlibs} is used.
+
+@item -shared-libphobos
+@cindex @option{-shared-libphobos}
+On systems that provide @file{libgphobos} and @file{libgdruntime} as a
+shared and a static library, this option forces the use of the shared
+version. If no shared version was built when the compiler was configured,
+this option has no effect.
+
+@item -static-libphobos
+@cindex @option{-static-libphobos}
+On systems that provide @file{libgphobos} and @file{libgdruntime} as a
+shared and a static library, this option forces the use of the static
+version. If no static version was built when the compiler was configured,
+this option has no effect.
+
+@end table
+
+@node Developer Options
+@section Developer Options
+@cindex developer options
+@cindex debug dump options
+@cindex dump options
+
+This section describes command-line options that are primarily of
+interest to developers or language tooling.
+
+@table @gcctabopt
+
+@item -fdump-d-original
+@cindex @option{-fdump-d-original}
+Dump the front-end AST after after parsing and running semantic on
+the source program.  Only really useful for debugging the compiler
+itself.
+
+@item -v
+@cindex @option{-v}
+Dump information about the compiler language processing stages as the source
+program is being compiled.  This includes listing all modules that are
+processed through the @code{parse}, @code{semantic}, @code{semantic2}, and
+@code{semantic3} stages; all @code{import} modules and their file paths;
+and all @code{function} bodies that are being compiled.
+
+@end table
+
+@c man end
+
+@node Environment Variables
+@section Environment variables affecting @command{gdc}
+@cindex environment variable
+
+@c man begin ENVIRONMENT
+
+In addition to the many @command{gcc} environment variables that control
+its operation, @command{gdc} has a few environment variables specific to
+itself.
+
+@vtable @env
+
+@item D_IMPORT_PATH
+@findex D_IMPORT_PATH
+The value of @env{D_IMPORT_PATH} is a list of directories separated by a
+special character, much like @env{PATH}, in which to look for imports.
+The special character, @code{PATH_SEPARATOR}, is target-dependent and
+determined at GCC build time.  For Microsoft Windows-based targets it is a
+semicolon, and for almost all other targets it is a colon.
+
+@item DDOCFILE
+@findex DDOCFILE
+If @env{DDOCFILE} is set, it specifies a text file of macro definitions
+to be read and used by the Ddoc generator.  This overrides any macros
+defined in other @file{.ddoc} files.
+
+@end vtable
+
+@c man end
+
+@node Index
+@unnumbered Index
+
+@printindex cp
+
+@bye
