GCC backend¶
Todo
Instructions to build GHDL with GCC backend on Windows are not available yet.
Requirements
- GCC (Gnu Compiler Collection)
- GNAT (Ada compiler for GCC)
- GCC source files. Download and untar the sources of version 4.9.x, 5.x, 6.x, 7.x, 8.x, 9.x or 10.x.
Hint
There are some dependencies for building GCC (gmp
, mpfr
and mpc
). If you have not installed them on your system, you can either build them manually or use the download_prerequisites
script provided in the GCC source tree (recommended): cd /path/to/gcc/source/dir && ./contrib/download_prerequisites
.
- First configure GHDL, specify GCC source directory and installation prefix (like
/usr/local
or/opt/ghdl
). - Next, invoke
make copy-sources
to copy GHDL sources in the source directory. - Then, configure GCC. The list of
--disable
configure options can be adjusted to your needs. GHDL does not require all these optional libraries and disabling them will speed up the build. - Now, build and install GCC with
make
. - Last, build and install GHDL libraries.
Example:
$ cd <ghdl>
$ mkdir build
$ cd build
$ ../configure --with-gcc=/path/to/gcc/source/dir --prefix=/usr/local
$ make copy-sources
$ mkdir gcc-objs; cd gcc-objs
$ /path/to/gcc/source/dir/configure --prefix=/usr/local --enable-languages=c,vhdl \
--disable-bootstrap --disable-lto --disable-multilib --disable-libssp \
--disable-libgomp --disable-libquadmath
$ make -j2 && make install
$ cd /path/to/ghdl/source/dir/build
$ make ghdllib
$ make install
Hint
Note that the prefix directory to configure gcc
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
.
Hint
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.
Hint
If you don’t want to install makeinfo
, do make install MAKEINFO=true
instead.
Hint
Once GCC (with GHDL) has been built once, it is possible to work on the GHDL source tree without copying it in the GCC tree. Commands are:
$ make ghdl1-gcc # Build the compiler
$ make ghdl_gcc # Build the driver
$ make libs.vhdl.local_gcc # Compile the vhdl libraries
$ make grt-all # Build the GHDL runtime
$ make install.vpi.local # Locally install vpi files
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
If your system gcc was built with --enable-default-pie
, add
-no-pie
option for linking.
Hint
For ppc64/ppc64le platform, the object file format contains an identifier for the source language. Because gcc doesn’t know about VHDL, gcc crashes very early. This could be fixed with a very simple change in gcc/config/rs6000/rs6000.c
(gcc/config/rs6000/rs6000-logue.c
since gcc 10), function rs6000_output_function_epilogue
:
|| ! strcmp (language_string, "GNU GIMPLE")
|| ! strcmp (language_string, "GNU Go")
|| ! strcmp (language_string, "GNU D")
- || ! strcmp (language_string, "libgccjit"))
+ || ! strcmp (language_string, "libgccjit")
+ || ! strcmp (language_string, "vhdl"))
i = 0;