Relax gcc tests taking into account the desired compilers

setup.py

@@ -9,44 +9,57 @@
 # Check our environment
 # - Need to be on linux
 # - Need kernel 2.6.18+
+#   - Skip check by setting the environment variable PRCTL_SKIP_KERNEL_CHECK to TRUE or 1
 # - Need python 2.4+
 # - Need gcc
+#   - Skip check by setting the environment variable PRCTL_SKIP_CC_CHECK to TRUE or 1
 # - Need C headers
+#   - Skip check by setting the environment variable PRCTL_SKIP_LIBC_CHECK to TRUE or 1
 # - Need libcap headers
+#   - Skip check by setting the environment variable PRCTL_SKIP_LIBCAP_CHECK to TRUE or 1
 if not sys.platform.startswith('linux'):
     sys.stderr.write("This module only works on linux\n")
     sys.exit(1)
 
+
+truthy_environment_variable = ("true", "yes", "1")
+
+disable_kernel_check = os.environ.get("PRCTL_SKIP_KERNEL_CHECK", "False").lower() in truthy_environment_variable
 kvers = os.uname()[2]
-if kvers < '2.6.18' and not os.environ.get("PRCTL_SKIP_KERNEL_CHECK",False):
+if kvers < '2.6.18' and not disable_kernel_check:
     sys.stderr.write("This module requires linux 2.6.18 or newer\n")
     sys.exit(1)
 
 if sys.version_info[:2] < (2,4):
     sys.stderr.write("This module requires python 2.4 or newer\n")
     sys.exit(1)
 
-exit = False
+GCC = os.environ.get('CC', 'gcc')
+disable_cc_check = os.environ.get("PRCTL_SKIP_CC_CHECK", "False").lower() in truthy_environment_variable
 try:
-    subprocess.call(['gcc','-v'], stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+    subprocess.call([GCC,'-v'], stdout=subprocess.PIPE, stderr=subprocess.PIPE)
 except:
     sys.stderr.write("You need to install gcc to build this module\n")
-    sys.exit(1)
+    if not disable_kernel_check:
+        sys.exit(1)
 
-sp = subprocess.Popen(['cpp'], stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE, env=os.environ)
+CPP = os.environ.get('CPP', 'cpp')
+CPPFLAGS = os.environ.get("CPPFLAGS", "").split(' ')
+disable_libc_check = os.environ.get("PRCTL_SKIP_LIBC_CHECK", "False").lower() in truthy_environment_variable
+sp = subprocess.Popen([CPP] + CPPFLAGS, stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE, env=os.environ)
 sp.communicate('#include <sys/prctl.h>\n'.encode())
 if sp.returncode:
     sys.stderr.write("You need to install libc development headers to build this module\n")
-    exit = True
+    if not disable_libc_check:
+        sys.exit(1)
 
-sp = subprocess.Popen(['cpp'], stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE, env=os.environ)
+sp = subprocess.Popen([CPP] + CPPFLAGS, stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE, env=os.environ)
 sp.communicate('#include <sys/capability.h>\n'.encode())
+disable_libcap_check = os.environ.get("PRCTL_SKIP_LIBCAP_CHECK", "False").lower() in truthy_environment_variable
 if sp.returncode:
     sys.stderr.write("You need to install libcap development headers to build this module\n")
-    exit = True
-
-if exit:
-    sys.exit(1)
+    if not disable_libcap_check:
+        sys.exit(1)
 
 _prctl = Extension("_prctl",
                    sources = ['_prctlmodule.c'],
@@ -60,6 +73,7 @@
       url = "http://github.com/seveas/python-prctl",
       description = "Python(ic) interface to the linux prctl syscall",
       py_modules = ["prctl"],
+      python_requires='>=2.4',
       ext_modules = [_prctl],
       classifiers = [
         'Development Status :: 5 - Production/Stable',