Adding pic_flag property to compilers (#2375)

Different compilers have different flags for PIC (position-independent
code). This patch provides a common ground to accessing it inside specs.

See discussions in #508 and #2373. This patch does not address the issue
of mixed compilers as mentioned in #508.

6 files changed, 24 insertions, 0 deletions

diff --git a/lib/spack/spack/compilers/clang.py b/lib/spack/spack/compilers/clang.py
index da18adcecd..b2095defe5 100644
--- a/lib/spack/spack/compilers/clang.py
+++ b/lib/spack/spack/compilers/clang.py
@@ -78,6 +78,10 @@ class Clang(Compiler):
             else:
                 return "-std=c++11"
 
+    @property
+    def pic_flag(self):
+        return "-fPIC"
+
     @classmethod
     def default_version(cls, comp):
         """The '--version' option works for clang compilers.
diff --git a/lib/spack/spack/compilers/gcc.py b/lib/spack/spack/compilers/gcc.py
index 557b1c13a9..80d24910c3 100644
--- a/lib/spack/spack/compilers/gcc.py
+++ b/lib/spack/spack/compilers/gcc.py
@@ -74,6 +74,10 @@ class Gcc(Compiler):
         else:
             return "-std=c++14"
 
+    @property
+    def pic_flag(self):
+        return "-fPIC"
+
     @classmethod
     def fc_version(cls, fc):
         return get_compiler_version(
diff --git a/lib/spack/spack/compilers/intel.py b/lib/spack/spack/compilers/intel.py
index 14f4d2dc91..4ff7185c84 100644
--- a/lib/spack/spack/compilers/intel.py
+++ b/lib/spack/spack/compilers/intel.py
@@ -65,6 +65,10 @@ class Intel(Compiler):
         else:
             return "-std=c++11"
 
+    @property
+    def pic_flag(self):
+        return "-fPIC"
+
     @classmethod
     def default_version(cls, comp):
         """The '--version' option seems to be the most consistent one
diff --git a/lib/spack/spack/compilers/nag.py b/lib/spack/spack/compilers/nag.py
index 5ba235adbb..c1da95a6c3 100644
--- a/lib/spack/spack/compilers/nag.py
+++ b/lib/spack/spack/compilers/nag.py
@@ -56,6 +56,10 @@ class Nag(Compiler):
         # However, it can be mixed with a compiler that does support it
         return "-std=c++11"
 
+    @property
+    def pic_flag(self):
+        return "-PIC"
+
     # Unlike other compilers, the NAG compiler passes options to GCC, which
     # then passes them to the linker. Therefore, we need to doubly wrap the
     # options with '-Wl,-Wl,,'
diff --git a/lib/spack/spack/compilers/pgi.py b/lib/spack/spack/compilers/pgi.py
index 37ffe44028..146c153041 100644
--- a/lib/spack/spack/compilers/pgi.py
+++ b/lib/spack/spack/compilers/pgi.py
@@ -55,6 +55,10 @@ class Pgi(Compiler):
     def cxx11_flag(self):
         return "-std=c++11"
 
+    @property
+    def pic_flag(self):
+        return "-fpic"
+
     @classmethod
     def default_version(cls, comp):
         """The '-V' option works for all the PGI compilers.
diff --git a/lib/spack/spack/compilers/xl.py b/lib/spack/spack/compilers/xl.py
index 5c83209781..f4b7c4237d 100644
--- a/lib/spack/spack/compilers/xl.py
+++ b/lib/spack/spack/compilers/xl.py
@@ -58,6 +58,10 @@ class Xl(Compiler):
         else:
             return "-qlanglvl=extended0x"
 
+    @property
+    def pic_flag(self):
+        return "-qpic"
+
     @classmethod
     def default_version(cls, comp):
         """The '-qversion' is the standard option fo XL compilers.