octave: add 4.2.0; fix Blas/Lapack; use AutotoolsPackage (#2858)

* octave: add 4.2.0; fix Blas/Lapack; use AutotoolsPackage

* fix a bug

var/spack/repos/builtin/packages/octave/package.py

@@ -26,7 +26,7 @@
 import sys
 
 
-class Octave(Package):
+class Octave(AutotoolsPackage):
     """GNU Octave is a high-level language, primarily intended for numerical
     computations. It provides a convenient command line interface for solving
     linear and nonlinear problems numerically, and for performing other
@@ -38,6 +38,7 @@ class Octave(Package):
 
     extendable = True
 
+    version('4.2.0', '443ba73782f3531c94bcf016f2f0362a58e186ddb8269af7dcce973562795567')
     version('4.0.2', 'c2a5cacc6e4c52f924739cdf22c2c687')
     version('4.0.0', 'a69f8320a4f20a8480c1b278b1adb799')
 
@@ -97,15 +98,18 @@ class Octave(Package):
     depends_on('suite-sparse', when='+suitesparse')
     depends_on('zlib',         when='+zlib')
 
-    def install(self, spec, prefix):
-        config_args = [
-            "--prefix=%s" % prefix
-        ]
+    def configure_args(self):
+        # See
+        # https://github.com/macports/macports-ports/blob/master/math/octave/
+        # https://github.com/Homebrew/homebrew-science/blob/master/octave.rb
+
+        spec = self.spec
+        config_args = []
 
         # Required dependencies
         config_args.extend([
-            "--with-blas=%s"   % spec['blas'].prefix.lib,
-            "--with-lapack=%s" % spec['lapack'].prefix.lib
+            "--with-blas=%s" % spec['blas'].blas_libs.ld_flags,
+            "--with-lapack=%s" % spec['lapack'].lapack_libs.ld_flags
         ])
 
         # Strongly recommended dependencies
@@ -210,10 +214,7 @@ def install(self, spec, prefix):
         else:
             config_args.append("--without-z")
 
-        configure(*config_args)
-
-        make()
-        make("install")
+        return config_args
 
     # ========================================================================
     # Set up environment to make install easy for Octave extensions.