Allow markdown

Last files from oldmds removed. All the content is in the new structure now. COPYING replaced with the md version.

Update NEWS.md

13 files changed, 194 insertions, 290 deletions

diff --git a/doc/building/VendorPrimitives.rst b/doc/building/VendorPrimitives.md
index b608c0825..b608c0825 100644
--- a/doc/building/VendorPrimitives.rst
+++ b/doc/building/VendorPrimitives.md
diff --git a/doc/building/index.rst b/doc/building/index.rst
index ea35d19c0..9cdc812f9 100644
--- a/doc/building/index.rst
+++ b/doc/building/index.rst
@@ -3,35 +3,173 @@
 Building GHDL
 #############
 
+GHDL currently supports three supported different backends (code generators): mcode, GCC and LLVM. Here is a short comparison, so that you can choose the one you want to use:
+
+* mcode (an internal code generator)
++ very easy to build
+- but x86_64/i386 only
++ very quick analysis time
++ can analyze very big designs
+- simulation is slower
+- no executable created
+
+* GCC
++ generated code is faster (particularly with -O or -O2)
++ generated code can be debugged (with -g)
++ the output is an executable
++ ported to many platforms (x86, x86_64, powerpc, sparc)
+- analyze can takes time (particularly for big units)
+- build is more complex
+
+* LLVM
++ same advantages of gcc (good generated code, debuggable)
++ easier to build than gcc
+
+As GHDL is written in Ada, you need to use the GNU Ada compiler (GNAT). I recommend to use GNAT GPL from http://libre.adacore.com (free). GHDL was tested with GNAT GPL 2014.  Any later version should work.
+The only other dependency is zlib (On ubuntu/debian, install zlib1g-dev).
+
 .. TODO::
 
   - `./doc/oldmds/BUILD.txt <https://github.com/tgingold/ghdl/blob/master/doc/oldmds/BUILD.txt>`_
   - Directory structure of the main branch [1138: #279]
   - Coverage, `gcov`, is unique to gcc. That specific difference is not explained anywhere. Should be added.
   - @1138 Backtraces optional -patchable-
-
-GCC backend
+  - Very briefly, why is mode faster for analysis and GCC/LLVM for simulation?
+	   
+Mcode backend
 =================
 
-- `./doc/oldmds/gcc/INSTALL <https://github.com/tgingold/ghdl/blob/master/doc/oldmds/gcc/INSTALL>`_
-- `./doc/oldmds/gcc/README <https://github.com/tgingold/ghdl/blob/master/doc/oldmds/gcc/README>`_
 - Linux
 
+This is as simple as:
+
+$ ./configure --prefix=PREFIX
+
+  where PREFIX is the directory for installation
+
+$ make
+
+  This builds the ghdl_mcode executable, which can be used as is.
+
+$ make install
+
+  To install within PREFIX
+
+- Windows MinGW 32/64
+- Windows GNAT GPL (32 only)
+
+.. TODO::
+
+	Note: this was tested with Windows XP SP2 familly edition.
+
+	Note: If you want to create the installer, GHDL should be built on a FAT partition.  NSIS rounds files date to be FAT compliant (seconds are always even) and because GHDL stores dates, the files date must not be modified.
+
+	The Ada95 GNAT compiler (GNAT GPL 2005 is known to work), along with NSIS to create the installer. Then unzip, edit winbuild to use correct path for makensis, and run winbuild. The installer is in the windows directory.
+	   
 LLVM backend 
 =================
 
 - Linux
+
+You need to build and install llvm.  The supported versions are 3.5
+till 3.9, but only debugging is only supported with llvm 3.5
+(Usually llvm also depends on libedit).
+
+First configure ghdl with '--with-llvm-config'
+$ ./configure --with-llvm-config
+
+If llvm-config is not in your path, you can specify it:
+$ ./configure --with-llvm-config=LLVM_INSTALL/bin/llvm-config
+
+If you want to have stack backtraces on errors (like assert failure or
+index of out bounds), you need to configure and build libbacktrace from gcc
+(you don't need to configure gcc), and add to configure:
+  --with-backtrace-lib=/path-to-gcc-build/libbacktrace/.libs/libbacktrace.a
+
+Then build with 'make' and install with 'make install'.
+  
 - Mac OS?
 - Windows MinGW 32/64
-	  
-Mcode backend
+	   
+GCC backend
 =================
 
-- `./doc/oldmds/mcode/README <https://github.com/tgingold/ghdl/blob/master/doc/oldmds/windows/mcode/README>`_
 - Linux
-- Windows GNAT GPL (32 only)
-- Windows MinGW 32/64
 
+You need to download and untar the sources of
+gcc version 4.9 [do not modify this line as this is read by scripts].
+
+First configure ghdl, specify gcc source dir and prefix.
+(replace /usr/local by your prefix directory):
+$ ./configure --with-gcc=/path/to/gcc/source/dir --prefix=/usr/local
+
+Then invoke make to copy ghdl sources in the source dir:
+$ make copy-sources
+
+There are some dependencies for building gcc (gmp, mpfr and mpc). If you have
+not them installed on your system, you can either build them manually or use
+the 'download_prerequisite' script provided in gcc source tree (recommended).
+
+$ cd /path/to/gcc/source/dir
+$ ./contrib/download_prerequisites
+
+Then configure gcc.  The list of --disable configure options could be
+adjusted for your needs.  GHDL don't require all these optional
+libraries and disabling them speed-up the build. Note the prefix
+directory must be the same as the one used to configure ghdl.
+If you have manually built gmp/mpfr/mpc (without using the script
+in contrib) and if you have installed them in a non-standard
+directory, you may need to add --with-gmp=GMP_INSTALL_DIR.
+
+$ mkdir gcc-objs; cd gcc-objs
+$ ../gcc-4.9.3/configure --prefix=/usr/local --enable-languages=c,vhdl \
+  --disable-bootstrap --disable-lto --disable-multilib \
+  --disable-libssp --disable-libgomp --disable-libquadmath
+$ make -j2
+
+Install gcc:
+$ make install
+or if you don't want to install makeinfo:
+$ make install MAKEINFO=true
+
+Build and install vhdl libraries:
+$ cd /path/to/ghdl/source/dir
+$ make ghdllib
+$ make install
+
+- Windows?
+
+.. TODO:
+
+    Since the content of BUILD.txt is moved to the docs, what shall we do with this line? +gcc version 6.3 [do not modify this line as this is read by scripts].
+
+	Note for ppc64 (and AIX ?) platform: the object file format contains an identifier for the source language. Because gcc doesn't know about the VHDL, gcc crashes very early. This could be fixed with a very simple change in gcc/config/rs6000/rs6000.c, function rs6000_output_function_epilogue (as of gcc 4.8):
+       else if (! strcmp (language_string, "GNU Objective-C"))
+        i = 14;
+       else
+-       gcc_unreachable ();
++       i = 0;
+       fprintf (file, "%d,", i);
+
+       /* 8 single bit fields: global linkage (not set for C extern linkage,
+
+	Install file for the binary distribution of GHDL. The binary are installed in /usr/local directory.  You cannot change this default location, unless you set links. You must be root to install this distribution. To install ghdl: `tar -C / -jxvf @TARFILE@.tar.bz2`. Note: you must also have a C compiler and zlib installed.
+
+- Notes for developpers
+
+Developping with the gcc backend:
+Once gcc (with ghdl) has been built once, it is possible to work on ghdl
+sources tree without copying them in gcc tree. Commands are:
+$ make ghdl1-gcc     	     # To build the compiler
+$ make ghdl_gcc		     # To build the driver
+$ make libs.vhdl.local_gcc   # To compile the vhdl libraries
+$ make grt-all		     # To build the ghdl runtime
+$ make grt.links	     # To locally install the ghdl runtime
+
+.. TODO::
+
+	gcc object dir
+	
 Test suites
 =================
 
diff --git a/doc/conf.py b/doc/conf.py
index 08a242310..2d431acfe 100644
--- a/doc/conf.py
+++ b/doc/conf.py
@@ -18,6 +18,10 @@ import shlex
 import re
 import subprocess
 
+# http://docs.readthedocs.io/en/latest/getting_started.html#in-markdown
+from recommonmark.parser import CommonMarkParser
+source_parsers = { '.md': CommonMarkParser, }
+
 # If extensions (or modules to document with autodoc) are in another directory,
 # add these directories to sys.path here. If the directory is relative to the
 # documentation root, use os.path.abspath to make it absolute, like shown here.
@@ -55,7 +59,7 @@ templates_path = ['_templates', '_themes']
 # The suffix(es) of source filenames.
 # You can specify multiple suffix as a list of string:
 # source_suffix = ['.rst', '.md']
-source_suffix = '.rst'
+source_suffix = ['.rst', '.md']
 
 # The encoding of source files.
 #source_encoding = 'utf-8-sig'
diff --git a/doc/index.rst b/doc/index.rst
index ea328da82..55bc93101 100644
--- a/doc/index.rst
+++ b/doc/index.rst
@@ -16,20 +16,17 @@ LRM) is a plus.
    .. image:: https://badges.gitter.im/ghdl/ghdl1.svg
       :target: https://gitter.im/ghdl/ghdl1
       :alt: Join
+
+   .. raw:: html
+
+      <br />
+
    .. image:: https://travis-ci.org/tgingold/ghdl.svg?branch=master
       :target: https://travis-ci.org/tgingold/ghdl
       :alt: Build status by Travis-CI
    .. image:: https://ci.appveyor.com/api/projects/status/r5dtv6amsppigpsp/branch/release?svg=true
       :target: https://ci.appveyor.com/project/Paebbels/poc/branch/release
       :alt: Build status by AppVeyor
-   .. image:: https://badges.gitter.im/ghdl/ghdl1.svg
-      :target: https://gitter.im/ghdl/ghdl1
-      :alt: Join
-
-   .. raw:: html
-
-      <br />
-
    .. image:: https://img.shields.io/github/tag/tgingold/ghdl.svg?style=flat
       :alt: Latest tag
    .. image:: https://img.shields.io/github/release/tgingold/ghdl.svg?style=flat
@@ -64,7 +61,6 @@ labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam
 et justo duo dolores et ea rebum. Stet clita kasd gubergren, no sea takimata
 sanctus est Lorem ipsum dolor sit amet
 
-
 ------------------------------------
 
 .. |docdate| date:: %b %d, %Y - %H:%M
diff --git a/doc/intro/Contributing.rst b/doc/intro/Contributing.rst
index 3c9b50862..6919d4496 100644
--- a/doc/intro/Contributing.rst
+++ b/doc/intro/Contributing.rst
@@ -72,4 +72,9 @@ Again, rewriting part of it is a good way to improve it.
 	- Minimum-(non)-Working-Example (MWE)
   - Pull Requests (PRs)
 	- Check Building -> GHDL -> Directory Structure]
-	- Beware that some commit messages can `automatically close <https://help.github.com/articles/closing-issues-via-commit-messages/>`_ PRs]
\ No newline at end of file
+	- Beware that some commit messages can `automatically close <https://help.github.com/articles/closing-issues-via-commit-messages/>`_ PRs]
+	
+	There is a mailing list for any questions.  You can subscribe via: https://mail.gna.org/listinfo/ghdl-discuss/
+	Please report bugs on https://github.com/tgingold/ghdl/issues
+
+	If you cannot compile, please report the gcc version, GNAT version and gcc source version.
\ No newline at end of file
diff --git a/doc/intro/Copyrights.rst b/doc/intro/Copyrights.rst
index 3db6050c6..07c1780b3 100644
--- a/doc/intro/Copyrights.rst
+++ b/doc/intro/Copyrights.rst
@@ -48,4 +48,28 @@ points in distributing VHDL executable.  Please, send a comment
 
   - https://www.gnu.org/licenses/old-licenses/gpl-2.0.html
   - Available in the following formats: plain text, Texinfo, LaTeX, standalone HTML, Docbook, Markdown, ODF, RT
-  - See `#280 <https://github.com/tgingold/ghdl/issues/280#issuecomment-279595802>`_
\ No newline at end of file
+  - See `#280 <https://github.com/tgingold/ghdl/issues/280#issuecomment-279595802>`_
+  
+	GHDL is copyright (c) 2002 - 2015 Tristan Gingold.
+
+	This program 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 2 of the License, or (at your option) any later version.
+
+	This program 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 this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+	
+  - Contributors to ghdl:
+	- Tristan Gingold    (sole author of ghdl as a whole)
+	- Brian Drummond     (gcc4.8.2 update, OSVVM port, some bugfixes)
+	- David Koontz       (Mac OSX builds, LRM compliance work, bugfix analyses)
+	- Joris van Rantwijk (Debian packaging)
+	- Brian Davis        (Windows Mcode builds)
+	- Adam Jensen        (FreeBSD builds)
+	- Felix Bertram      (VPI interface)
+
+with apologies to anyone who ought to be on this list but isn't.
+Thanks also to all those who have reported bugs and support issues,
+and often patches and testcases to either:
+https://gna.org/bugs/?group=ghdl
+or
+https://sourceforge.net/p/ghdl-updates/tickets/
\ No newline at end of file
diff --git a/doc/oldmds/BUILD.txt b/doc/oldmds/BUILD.txt
deleted file mode 100644
index 27029b757..000000000
--- a/doc/oldmds/BUILD.txt
+++ /dev/null
@@ -1,140 +0,0 @@
-Build GHDL (Long instructions)
-******************************
-
-GHDL supports many backend (code generator), so you first must choose
-the backend you want to use.  There are currently 3 supported backends:
-
-* gcc
-* mcode (this is an internal code generator for x86_64 and i386)
-* llvm (experimental)
-
-Here is a short comparaison:
-
-* gcc:
-+ generated code is faster (particularly with -O or -O2)
-+ generated code can be debugged (with -g)
-+ the output is an executable
-+ ported to many platforms (x86, x86_64, powerpc, sparc)
-- analyze can takes time (particularly for big units)
-- build is more complex
-
-* mcode
-+ very easy to build
-- but x86_64/i386 only
-+ very quick analysis time
-+ can analyze very big designs
-- simulation is slower
-- no executable created
-
-* llvm
-+ same advantages of gcc (good generated code, debuggable)
-+ easier to build than gcc
-
-As GHDL is written in Ada, you need to use the GNU Ada compiler (GNAT).
-I recommend to use GNAT GPL from http://libre.adacore.com (free).
-GHDL was tested with GNAT GPL 2014.  Any later version should work.
-The only other dependency is zlib (On ubuntu/debian, install zlib1g-dev).
-
-On UNIX and MinGW systems, you also need standard utilities like sh,
-cmp or make.  On MSYS2 packages msys/diffutils and msys/make must be
-installed.
-
-In these instructions, the configure script is executed in the source
-directory; but you can execute in a different directory too, like
-this:
-$ mkdir ghdl-objs
-$ cd ghdl-objs
-$ ../path/to/ghdl/configure ...
-
-Building with mcode backend
-***************************
-
-This is as simple as:
-$ ./configure --prefix=PREFIX
-  where PREFIX is the directory for installation
-$ make
-  This builds the ghdl_mcode executable, which can be used as is.
-$ make install
-  To install within PREFIX
-
-Building with the gcc backend
-*****************************
-
-You need to download and untar the sources of
-gcc version 4.9.x, 5.x, 6.x or 7.x
-
-First configure ghdl, specify gcc source dir and prefix.
-(replace /usr/local by your prefix directory):
-$ ./configure --with-gcc=/path/to/gcc/source/dir --prefix=/usr/local
-
-Then invoke make to copy ghdl sources in the source dir:
-$ make copy-sources
-
-There are some dependencies for building gcc (gmp, mpfr and mpc). If you have
-not them installed on your system, you can either build them manually or use
-the 'download_prerequisite' script provided in gcc source tree (recommended).
-
-$ cd /path/to/gcc/source/dir
-$ ./contrib/download_prerequisites
-
-Then configure gcc.  The list of --disable configure options could be
-adjusted for your needs.  GHDL don't require all these optional
-libraries and disabling them speed-up the build. Note the prefix
-directory must be the same as the one used to configure ghdl.
-If you have manually built gmp/mpfr/mpc (without using the script
-in contrib) and if you have installed them in a non-standard
-directory, you may need to add --with-gmp=GMP_INSTALL_DIR.
-If your system gcc was configured with --enable-default-pie (check if
-that option appears in the output of gcc -v), you should also add it.
-
-$ mkdir gcc-objs; cd gcc-objs
-$ ../gcc-4.9.3/configure --prefix=/usr/local --enable-languages=c,vhdl \
-  --disable-bootstrap --disable-lto --disable-multilib \
-  --disable-libssp --disable-libgomp --disable-libquadmath
-$ make -j2
-
-Install gcc:
-$ make install
-or if you don't want to install makeinfo:
-$ make install MAKEINFO=true
-
-Build and install vhdl libraries:
-$ cd /path/to/ghdl/source/dir
-$ make ghdllib
-$ make install
-
-Building with the llvm backend
-******************************
-
-You need to build and install llvm.  The supported versions are 3.5
-till 5.x, but only debugging is only supported with llvm 3.5
-(Usually llvm also depends on libedit).
-
-First configure ghdl with '--with-llvm-config'
-$ ./configure --with-llvm-config
-
-If llvm-config is not in your path, you can specify it:
-$ ./configure --with-llvm-config=LLVM_INSTALL/bin/llvm-config
-
-If you want to have stack backtraces on errors (like assert failure or
-index of out bounds), you need to configure and build libbacktrace from gcc
-(you don't need to configure gcc), and add to configure:
-  --with-backtrace-lib=/path-to-gcc-build/libbacktrace/.libs/libbacktrace.a
-
-Then build with 'make' and install with 'make install'.
-
-Notes for developpers
-*********************
-
-Developping with the gcc backend:
-Once gcc (with ghdl) has been built once, it is possible to work on ghdl
-sources tree without copying them in gcc tree. Commands are:
-$ make ghdl1-gcc     	     # To build the compiler
-$ make ghdl_gcc		     # To build the driver
-$ make libs.vhdl.local_gcc   # To compile the vhdl libraries
-$ make grt-all		     # To build the ghdl runtime
-
-In src/ortho/gcc, create a Makefile.conf file that sets the following
-variables:
-AGCC_GCCSRC_DIR=/path/to/gcc/sources
-AGCC_GCCOBJ_DIR=/path/to/gcc/build
diff --git a/doc/oldmds/gcc/INSTALL b/doc/oldmds/gcc/INSTALL
deleted file mode 100644
index b341317b5..000000000
--- a/doc/oldmds/gcc/INSTALL
+++ /dev/null
@@ -1,21 +0,0 @@
-Install file for the binary distribution of GHDL.
-
-GHDL is Copyright 2002 - 2015 Tristan Gingold.
-GHDL 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 2 of the License, or
-(at your option) any later version.
-
-The binary are installed in /usr/local directory.  You cannot change this
-default location, unless you set links.
-
-You must be root to install this distribution.
-
-To install ghdl:
-$ su
-# tar -C / -jxvf @TARFILE@.tar.bz2
-
-Note: you must also have a C compiler and zlib installed.
-
-Tristan Gingold.
-
diff --git a/doc/oldmds/gcc/README b/doc/oldmds/gcc/README
deleted file mode 100644
index c58e0f923..000000000
--- a/doc/oldmds/gcc/README
+++ /dev/null
@@ -1,51 +0,0 @@
-This is the README from the source distribution of GHDL.
-
-To get the binary distribution or more information, go to:
- https://github.com/tgingold/ghdl
-
-Copyright:
-**********
-GHDL is copyright (c) 2002 - 2015 Tristan Gingold.
-See the GHDL manual for more details.
-
-This program 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 2 of the License, or
-(at your option) any later version.
-
-This program 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 this program; if not, write to the Free Software
-Foundation, Inc., 59 Temple Place - Suite 330,
-Boston, MA 02111-1307, USA.
-
-
-Building GHDL from sources:
-***************************
-
-See BUILD.txt
-
-Please report bugs and issues on https://github.com/tgingold/ghdl/issues
-
-If you cannot compile, please report the gcc version, GNAT version and gcc
-source version.
-
-* Note for ppc64 (and AIX ?) platform:
-The object file format contains an identifier for the source language. Because
-gcc doesn't know about the VHDL, gcc crashes very early. This could be fixed
-with a very simple change in gcc/config/rs6000/rs6000.c,
-function rs6000_output_function_epilogue (as of gcc 4.8):
-       else if (! strcmp (language_string, "GNU Objective-C"))
-        i = 14;
-       else
--       gcc_unreachable ();
-+       i = 0;
-       fprintf (file, "%d,", i);
-
-       /* 8 single bit fields: global linkage (not set for C extern linkage,
-
-Tristan Gingold.
diff --git a/doc/oldmds/mcode-README b/doc/oldmds/mcode-README
deleted file mode 100644
index 1e591b0b5..000000000
--- a/doc/oldmds/mcode-README
+++ /dev/null
@@ -1,47 +0,0 @@
-This is the README from the source distribution of GHDL.
-
-To get the binary distribution or more information, go to http://ghdl.free.fr
-
-Copyright:
-**********
-GHDL is copyright (c) 2002, 2003, 2004, 2005 Tristan Gingold.
-See the GHDL manual for more details.
-
-This program 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 2 of the License, or
-(at your option) any later version.
-
-This program 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 this program; if not, write to the Free Software
-Foundation, Inc., 59 Temple Place - Suite 330,
-Boston, MA 02111-1307, USA.
-
-
-Building GHDL from sources for Windows:
-***************************************
-
-Note: this was tested with Windows XP SP2 familly edition.
-
-Note: If you want to create the installer, GHDL should be built on a
-FAT partition.  NSIS rounds files date to be FAT compliant (seconds are always
-even) and because GHDL stores dates, the files date must not be modified.
-
-Required:
-* the Ada95 GNAT compiler (GNAT GPL 2005 is known to work).
-* NSIS to create the installer.
-
-Unzip,
-edit winbuild to use correct path for makensis,
-run winbuild.
-
-The installer is in the windows directory.
-
-Send bugs and comments on https://github.com/tgingold/ghdl
-
-Tristan Gingold.
diff --git a/doc/oldmds/STYLE b/doc/references/CodingStyle.rst
index c7acb2756..76d33b5ca 100644
--- a/doc/oldmds/STYLE
+++ b/doc/references/CodingStyle.rst
@@ -1,5 +1,7 @@
-GHDL coding style
-*****************
+.. _REF:Style:
+
+Coding style
+#################
 
 Ada subset: use only a simple (VHDL like) subset of Ada: no tasking, no
 controlled types...  VHDL users should easily understand that subset.
@@ -86,5 +88,4 @@ Do not initialize variables, constants must be declared before variables:
       Sub    : Iir;
    begin
 If the initialization expression has a side effect (such as allocation), do
-not use a constant.
-
+not use a constant.
\ No newline at end of file
diff --git a/doc/references/CondigStyle.rst b/doc/references/CondigStyle.rst
deleted file mode 100644
index 51e236ee8..000000000
--- a/doc/references/CondigStyle.rst
+++ /dev/null
@@ -1,6 +0,0 @@
-.. _REF:Style:
-
-Coding style
-#################
-
-- `./doc/oldmds/gcc/STYLE <https://github.com/tgingold/ghdl/blob/master/doc/oldmds/STYLE>`_
\ No newline at end of file
diff --git a/doc/using/InvokingGHDL.rst b/doc/using/InvokingGHDL.rst
index d4bcda438..bf901bccc 100644
--- a/doc/using/InvokingGHDL.rst
+++ b/doc/using/InvokingGHDL.rst
@@ -1,4 +1,5 @@
 .. _USING:Invoking:
+.. program:: ghdl
 
 *************
 Invoking GHDL