Fix #254: libtool & distutils want certain compiler names.

This changes the compiler wrappers so that they are called by the same
name as the wrapped compiler.  Many builds make assumptions about
compiler names, and we need the spack compilers to be recognizable so
that build systems will get their flags right.

This adds per-compiler subdirectories to lib/spack/spack/env directory
that contain symlinks to cc for the C, C++, F77, and F90
compilers. The build now sets CC, CXX, F77, and F90 to point to these
links instead of to the generically named cc, c++, f77, and f90
wrappers.

lib/spack/env/cc

@@ -86,22 +86,22 @@ done
 #
 command=$(basename "$0")
 case "$command" in
-    cc|gcc|c89|c99|clang|xlc)
+    cc|c89|c99|gcc|clang|icc|pgcc|xlc)
         command="$SPACK_CC"
         language="C"
         ;;
-    c++|CC|g++|clang++|xlC)
+    c++|CC|g++|clang++|icpc|pgCC|xlc++)
         command="$SPACK_CXX"
         language="C++"
         ;;
-    f77|xlf)
-        command="$SPACK_F77"
-        language="Fortran 77"
-        ;;
-    fc|f90|f95|xlf90)
+    f90|fc|f95|gfortran|ifort|pgf90|xlf90)
         command="$SPACK_FC"
         language="Fortran 90"
         ;;
+    f77|gfortran|ifort|pgf77|xlf)
+        command="$SPACK_F77"
+        language="Fortran 77"
+        ;;
     cpp)
         mode=cpp
         ;;

lib/spack/env/clang/clang

@@ -0,0 +1 @@
+../cc

lib/spack/env/clang/clang++

@@ -0,0 +1 @@
+../cc

lib/spack/env/gcc/g++

@@ -0,0 +1 @@
+../cc

lib/spack/env/gcc/gcc

@@ -0,0 +1 @@
+../cc

lib/spack/env/gcc/gfortran

@@ -0,0 +1 @@
+../cc

lib/spack/env/intel/icc

@@ -0,0 +1 @@
+../cc

lib/spack/env/intel/icpc

@@ -0,0 +1 @@
+../cc

lib/spack/env/intel/ifort

@@ -0,0 +1 @@
+../cc

lib/spack/env/pgi/case-insensitive/pgCC

@@ -0,0 +1 @@
+../../cc

lib/spack/env/pgi/pgcc

@@ -0,0 +1 @@
+../cc

lib/spack/env/pgi/pgf77

@@ -0,0 +1 @@
+../cc

lib/spack/env/pgi/pgf90

@@ -0,0 +1 @@
+../cc

lib/spack/env/xl/xlc

@@ -0,0 +1 @@
+../cc

lib/spack/env/xl/xlc++

@@ -0,0 +1 @@
+../cc

lib/spack/env/xl/xlf

@@ -0,0 +1 @@
+../cc

lib/spack/env/xl/xlf90

@@ -0,0 +1 @@
+../cc

lib/spack/spack/build_environment.py

@@ -88,10 +88,14 @@ def set_compiler_environment_variables(pkg):
     compiler = pkg.compiler
 
     # Set compiler variables used by CMake and autotools
-    os.environ['CC']  = join_path(spack.build_env_path, 'cc')
-    os.environ['CXX'] = join_path(spack.build_env_path, 'c++')
-    os.environ['F77'] = join_path(spack.build_env_path, 'f77')
-    os.environ['FC']  = join_path(spack.build_env_path, 'f90')
+    assert all(key in pkg.compiler.link_paths
+               for key in ('cc', 'cxx', 'f77', 'fc'))
+
+    link_dir = spack.build_env_path
+    os.environ['CC']  = join_path(link_dir, pkg.compiler.link_paths['cc'])
+    os.environ['CXX'] = join_path(link_dir, pkg.compiler.link_paths['cxx'])
+    os.environ['F77'] = join_path(link_dir, pkg.compiler.link_paths['f77'])
+    os.environ['FC']  = join_path(link_dir, pkg.compiler.link_paths['fc'])
 
     # Set SPACK compiler variables so that our wrapper knows what to call
     if compiler.cc:
@@ -110,11 +114,23 @@ def set_build_environment_variables(pkg):
     """This ensures a clean install environment when we build packages.
     """
     # Add spack build environment path with compiler wrappers first in
-    # the path.  We handle case sensitivity conflicts like "CC" and
-    # "cc" by putting one in the <build_env_path>/case-insensitive
+    # the path. We add both spack.env_path, which includes default
+    # wrappers (cc, c++, f77, f90), AND a subdirectory containing
+    # compiler-specific symlinks.  The latter ensures that builds that
+    # are sensitive to the *name* of the compiler see the right name
+    # when we're building wtih the wrappers.
+    #
+    # Conflicts on case-insensitive systems (like "CC" and "cc") are
+    # handled by putting one in the <build_env_path>/case-insensitive
     # directory.  Add that to the path too.
-    env_paths = [spack.build_env_path,
-                 join_path(spack.build_env_path, 'case-insensitive')]
+    env_paths = []
+    def add_env_path(path):
+        env_paths.append(path)
+        ci = join_path(path, 'case-insensitive')
+        if os.path.isdir(ci): env_paths.append(ci)
+    add_env_path(spack.build_env_path)
+    add_env_path(join_path(spack.build_env_path, pkg.compiler.name))
+
     path_put_first("PATH", env_paths)
     path_set(SPACK_ENV_PATH, env_paths)
 

lib/spack/spack/compilers/clang.py

@@ -37,6 +37,12 @@ class Clang(Compiler):
     # Subclasses use possible names of Fortran 90 compiler
     fc_names = []
 
+    # Named wrapper links within spack.build_env_path
+    link_paths = { 'cc'  : 'clang/clang',
+                   'cxx' : 'clang/clang++',
+                   # Use default wrappers for fortran, in case provided in compilers.yaml
+                   'f77' : 'f77',
+                   'fc'  : 'f90' }
 
     @classmethod
     def default_version(self, comp):

lib/spack/spack/compilers/gcc.py

@@ -42,6 +42,12 @@ class Gcc(Compiler):
     # MacPorts builds gcc versions with prefixes and -mp-X.Y suffixes.
     suffixes = [r'-mp-\d\.\d']
 
+    # Named wrapper links within spack.build_env_path
+    link_paths = {'cc'  : 'gcc/gcc',
+                  'cxx' : 'gcc/g++',
+                  'f77' : 'gcc/gfortran',
+                  'fc'  : 'gcc/gfortran' }
+
     @property
     def cxx11_flag(self):
         if self.version < ver('4.3'):

lib/spack/spack/compilers/intel.py

@@ -37,6 +37,12 @@ class Intel(Compiler):
     # Subclasses use possible names of Fortran 90 compiler
     fc_names = ['ifort']
 
+    # Named wrapper links within spack.build_env_path
+    link_paths = { 'cc'  : 'intel/icc',
+                   'cxx' : 'intel/icpc',
+                   'f77' : 'intel/ifort',
+                   'fc'  : 'intel/ifort' }
+
     @property
     def cxx11_flag(self):
         if self.version < ver('11.1'):

lib/spack/spack/compilers/pgi.py

@@ -37,6 +37,12 @@ class Pgi(Compiler):
     # Subclasses use possible names of Fortran 90 compiler
     fc_names = ['pgf95', 'pgf90']
 
+    # Named wrapper links within spack.build_env_path
+    link_paths = { 'cc'  : 'pgi/pgcc',
+                   'cxx' : 'pgi/case-insensitive/pgCC',
+                   'f77' : 'pgi/pgf77',
+                   'fc'  : 'pgi/pgf90' }
+
     @classmethod
     def default_version(cls, comp):
         """The '-V' option works for all the PGI compilers.

lib/spack/spack/compilers/xl.py

@@ -38,6 +38,12 @@ class Xl(Compiler):
     # Subclasses use possible names of Fortran 90 compiler
     fc_names = ['xlf90','xlf90_r','xlf95','xlf95_r','xlf2003','xlf2003_r','xlf2008','xlf2008_r']
 
+    # Named wrapper links within spack.build_env_path
+    link_paths = { 'cc'  : 'xl/xlc',
+                   'cxx' : 'xl/xlc++',
+                   'f77' : 'xl/xlf',
+                   'fc'  : 'xl/xlf90' }
+
     @property
     def cxx11_flag(self):
         if self.version < ver('13.1'):