singular: add an option to install as libsingular

pkgs/applications/science/math/singular/default.nix

@@ -1,4 +1,6 @@
-{ stdenv, fetchurl, gmp, bison, perl, autoconf, ncurses, readline, coreutils }:
+{ stdenv, fetchurl, gmp, bison, perl, autoconf, ncurses, readline, coreutils, pkgconfig
+, asLibsingular ? false
+}:
 
 stdenv.mkDerivation rec {
   name = "singular-${version}";
@@ -9,23 +11,33 @@ stdenv.mkDerivation rec {
     sha256 = "1j4mcpnwzdp3h4qspk6ww0m67rmx4s11cy17pvzbpf70lm0jzzh2";
   };
 
-  buildInputs = [ gmp bison perl autoconf ncurses readline coreutils ];
+  buildInputs = [ gmp perl ncurses readline ];
+  nativeBuildInputs = [ autoconf bison pkgconfig ];
 
   preConfigure = ''
     find . -exec sed -e 's@/bin/rm@${coreutils}&@g' -i '{}' ';'
     find . -exec sed -e 's@/bin/uname@${coreutils}&@g' -i '{}' ';'
+    ${stdenv.lib.optionalString asLibsingular ''NIX_CFLAGS_COMPILE="$NIX_CFLAGS_COMPILE -DLIBSINGULAR"''}
   '';
 
   hardeningDisable = stdenv.lib.optional stdenv.isi686 "stackprotector";
 
-  postInstall = ''
-    rm -rf "$out/LIB"
-    cp -Tr Singular/LIB "$out/lib"
-    ln -s "$out"/*/include "$out"
+  # The Makefile actually defaults to `make install` anyway
+  buildPhase = "true;";
+
+  installPhase = ''
+    mkdir -p "$out"
+    cp -r Singular/LIB "$out/LIB"
+    make install${stdenv.lib.optionalString asLibsingular "-libsingular"}
+
+    binaries="$(find "$out"/* \( -type f -o -type l \) -perm -111 \! -name '*.so' -maxdepth 1)"
+    ln -s "$out"/*/{include,lib} "$out"
     mkdir -p "$out/bin"
-    ln -s "$out/"*/Singular "$out/bin"
+    ln -s $binaries "$out/bin"
   '';
 
+  enableParallelBuild = true;
+
   meta = with stdenv.lib; {
     description = "A CAS for polynomial computations";
     maintainers = with maintainers;

pkgs/top-level/all-packages.nix

@@ -16712,6 +16712,9 @@ in
   };
 
   singular = callPackage ../applications/science/math/singular {};
+  libsingular = callPackage ../applications/science/math/singular {
+    asLibsingular = true;
+  };
 
   scilab = callPackage ../applications/science/math/scilab {
     withXaw3d = false;