fix doc/building

3 files changed, 26 insertions, 37 deletions

diff --git a/doc/building/llvm/GNULinux-GNAT.rst b/doc/building/llvm/GNULinux-GNAT.rst
index 3733d763f..5f97c99b7 100644
--- a/doc/building/llvm/GNULinux-GNAT.rst
+++ b/doc/building/llvm/GNULinux-GNAT.rst
@@ -1,26 +1,23 @@
-.. _BUILD:mcode:GNULinux-GNAT:
+.. _BUILD:llvm:GNULinux-GNAT:
 
-GNU/Linux with GCC/GNAT
-#######################
+LLVM Backend on GNU/Linux with GCC/GNAT
+#######################################
 
-On Linux, GHDL is configured by ``configure`` and build by ``make``.
+.. HINT:: You need to install LLVM (usually depends on ``libedit``, see :ghdlsharp:`29`). The supported versions are 3.5 till 5.0, but debugging is only supported with LLVM 3.5.
 
-* First, GHDL needs to be configured. It is common to specify a PREFIX
-  (installation directory like ``/usr/local`` or ``/opt/ghdl``). Without any
-  other option, ``configure`` select `mcode` as backend.
+* First configure GHDL with the proper arg ``./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``.
 
-* Next, ``make`` starts the compilation process.
-
-* Finally, ``make install`` installs GHDL into the installation directory
-  specified by PREFIX. You may need super user privileges (``sudo ...``).
+* Then, build with ``make`` and install with ``make install``.
 
 .. rubric:: Example:
 
 .. code-block:: Bash
 
-   cd <ghdl>
-   mkdir build
-   cd build
-   ../configure --prefix=PREFIX
-   make
-   sudo make install
+   $ cd <ghdl>
+   $ mkdir build
+   $ cd build
+   $ ../configure --with-llvm-config --prefix=PREFIX
+   $ make
+   $ make install
+
+.. HINT:: 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). Then add the following arg to configure: ``--with-backtrace-lib=/path-to-gcc-build/libbacktrace/.libs/libbacktrace.a``
diff --git a/doc/building/llvm/Windows-MinGW-GNAT.rst b/doc/building/llvm/Windows-MinGW-GNAT.rst
index 1329b80a1..0fce8f068 100644
--- a/doc/building/llvm/Windows-MinGW-GNAT.rst
+++ b/doc/building/llvm/Windows-MinGW-GNAT.rst
@@ -1,7 +1,7 @@
 .. _BUILD:llvm:Windows-MinGW-GNAT:
 
-GHDL with LLVM backend build on Windows with GCC/GNAT (MinGW)
-#############################################################
+LLVM Backend on Windows with GCC/GNAT (MinGW)
+#############################################
 
 On Windows with MinGW, GHDL is configured by ``configure`` and build by ``make``.
 
@@ -17,10 +17,10 @@ On Windows with MinGW, GHDL is configured by ``configure`` and build by ``make``
 .. rubric:: Example:
 
 .. code-block:: Bash
-   
-   cd <ghdl>
-   mkdir build
-   cd build
-   ../configure --prefix=PREFIX
-   make
-   make install
+
+   $ cd <ghdl>
+   $ mkdir build
+   $ cd build
+   $ ../configure --prefix=PREFIX
+   $ make
+   $ make install
diff --git a/doc/building/llvm/index.rst b/doc/building/llvm/index.rst
index 9f0bcc98a..dd01a8043 100644
--- a/doc/building/llvm/index.rst
+++ b/doc/building/llvm/index.rst
@@ -7,15 +7,7 @@ LLVM Backend
 
 * GCC (Gnu Compiler Collection)
 * GNAT (Ada compiler for GCC)
-* LLVM (Low-Level-Virtual Machine)
-
-  * 3.5
-  * 3.8
-  * 3.9
-  * 4.0
-  * 5.0
-
-* CLANG (Compiler front-end for LLVM)
+* LLVM (Low-Level-Virtual Machine) and CLANG (Compiler front-end for LLVM)
 
   * 3.5
   * 3.8
@@ -25,9 +17,9 @@ LLVM Backend
 
 .. rubric:: Supported platforms
 
-* :ref:`GNU/Linux with GCC <BUILD:llvm:GNULinux-GNAT>`
+* :doc:`GNULinux-GNAT`
+* :doc:`Windows-MinGW-GNAT`
 * Mac OS
-* :ref:`Windows (x86_64) with MinGW32/MinGW64 <BUILD:llvm:Windows-WinGW-GNAT>`
 
 .. toctree::
    :hidden: