ghdl-gcc: init at 4.1.0

Not truly a new package, but rather a new backend next to the existing
`mcode` and `llvm` ones. Adding the GCC backend too, as it is the only
one that supports code coverage report generation. For more info see:
https://devsaurus.github.io/ghdl_gcov/ghdl_gcov.html.

Co-authored-by: Rowan Goemans <goemansrowan@gmail.com>

pkgs/by-name/gh/ghdl/package.nix

@@ -5,10 +5,18 @@
 , zlib
 , llvm
 , lib
+, gcc-unwrapped
+, texinfo
+, gmp
+, mpfr
+, libmpc
+, gnutar
+, glibc
+, makeWrapper
 , backend ? "mcode"
 }:
 
-assert backend == "mcode" || backend == "llvm";
+assert backend == "mcode" || backend == "llvm" || backend == "gcc";
 
 stdenv.mkDerivation (finalAttrs: {
   pname = "ghdl-${backend}";
@@ -25,20 +33,29 @@ stdenv.mkDerivation (finalAttrs: {
 
   nativeBuildInputs = [
     gnat
+  ] ++ lib.optionals (backend == "gcc") [
+    texinfo
+    makeWrapper
   ];
   buildInputs = [
     zlib
   ] ++ lib.optionals (backend == "llvm") [
     llvm
+  ] ++ lib.optionals (backend == "gcc") [
+    gmp
+    mpfr
+    libmpc
   ];
   propagatedBuildInputs = [
-  ] ++ lib.optionals (backend == "llvm") [
+  ] ++ lib.optionals (backend == "llvm" || backend == "gcc") [
     zlib
   ];
 
   preConfigure = ''
     # If llvm 7.0 works, 7.x releases should work too.
     sed -i 's/check_version  7.0/check_version  7/g' configure
+  '' + lib.optionalString (backend == "gcc") ''
+    ${gnutar}/bin/tar -xf ${gcc-unwrapped.src}
   '';
 
   configureFlags = [
@@ -47,14 +64,51 @@ stdenv.mkDerivation (finalAttrs: {
     "--enable-synth"
   ] ++ lib.optionals (backend == "llvm") [
     "--with-llvm-config=${llvm.dev}/bin/llvm-config"
+  ] ++ lib.optionals (backend == "gcc") [
+    "--with-gcc=gcc-${gcc-unwrapped.version}"
+  ];
+
+  buildPhase = lib.optionalString (backend == "gcc") ''
+    make copy-sources
+    mkdir gcc-objs
+    cd gcc-objs
+    ../gcc-${gcc-unwrapped.version}/configure \
+      --with-native-system-header-dir=/include \
+      --with-build-sysroot=${lib.getDev glibc} \
+      --prefix=$out \
+      --enable-languages=c,vhdl \
+      --disable-bootstrap \
+      --disable-lto \
+      --disable-multilib \
+      --disable-libssp \
+      --disable-libgomp \
+      --disable-libquadmath
+    make -j $NIX_BUILD_CORES
+    make install
+    cd ../
+    make -j $NIX_BUILD_CORES ghdllib
+  '';
+
+  postFixup = lib.optionalString (backend == "gcc") ''
+    wrapProgram $out/bin/ghdl \
+      --set LIBRARY_PATH ${lib.makeLibraryPath [
+        glibc
+      ]}
+  '';
+
+  hardeningDisable = [
+  ] ++ lib.optionals (backend == "gcc") [
+    # GCC compilation fails with format errors
+    "format"
   ];
 
   enableParallelBuilding = true;
 
   passthru = {
-    # run with either of
+    # run with:
     # nix-build -A ghdl-mcode.passthru.tests
     # nix-build -A ghdl-llvm.passthru.tests
+    # nix-build -A ghdl-gcc.passthru.tests
     tests = {
       simple = callPackage ./test-simple.nix { inherit backend; };
     };

pkgs/by-name/gh/ghdl/test-simple.nix

@@ -1,7 +1,7 @@
-{ stdenv, ghdl-llvm, ghdl-mcode, backend }:
+{ stdenv, lib, ghdl-llvm, ghdl-mcode, ghdl-gcc, backend }:
 
 let
-  ghdl = if backend == "llvm" then ghdl-llvm else ghdl-mcode;
+  ghdl = if backend == "llvm" then ghdl-llvm else if backend == "gcc" then ghdl-gcc else ghdl-mcode;
 in
 stdenv.mkDerivation {
   name = "ghdl-test-simple";
@@ -13,7 +13,7 @@ stdenv.mkDerivation {
     mkdir -p ghdlwork
     ghdl -a --workdir=ghdlwork --ieee=synopsys simple.vhd simple-tb.vhd
     ghdl -e --workdir=ghdlwork --ieee=synopsys -o sim-simple tb
-  '' + (if backend == "llvm" then ''
+  '' + (if backend == "llvm" || backend == "gcc" then ''
     ./sim-simple --assert-level=warning > output.txt
   '' else ''
     ghdl -r --workdir=ghdlwork --ieee=synopsys tb > output.txt

pkgs/top-level/all-packages.nix

@@ -15676,6 +15676,8 @@ with pkgs;
 
   ghdl-mcode = callPackage ../by-name/gh/ghdl/package.nix { backend = "mcode"; };
 
+  ghdl-gcc = callPackage ../by-name/gh/ghdl/package.nix { backend = "gcc"; };
+
   ghdl-llvm = callPackage ../by-name/gh/ghdl/package.nix {
     backend = "llvm";
     inherit (llvmPackages_15) llvm;