docstr: Test for existence of a function within a tuple of libraries.
  
  This is used as a smoke test to check whether a certain library is available.
  As a test, this creates a simple C program that calls the specified function,
  and then distutils is used to compile that program and link it with the specified libraries.
  Returns True if both the compile and link are successful, False otherwise.
docstr_tok: ["Test","for","existence","of","a","function","within","a","tuple","of","libraries",".","This","is","used","as","a","smoke","test","to","check","whether","a","certain","library","is","available",".","As","a","test",",","this","creates","a","simple","C","program","that","calls","the","specified","function",",","and","then","distutils","is","used","to","compile","that","program","and","link","it","with","the","specified","libraries",".","Returns","True","if","both","the","compile","and","link","are","successful",",","False","otherwise","."]
code: def has_function(self, funcname, libraries, verbose=False):
      """
      Test for existence of a function within a tuple of libraries.
  
      This is used as a smoke test to check whether a certain library is available.
      As a test, this creates a simple C program that calls the specified function,
      and then distutils is used to compile that program and link it with the specified libraries.
      Returns True if both the compile and link are successful, False otherwise.
      """
      tempdir = (
          None  # we create a temporary directory to hold various files
      )
      filestderr = (
          None  # handle to open file to which we redirect stderr
      )
      oldstderr = None  # file descriptor for stderr
      try:
          # Echo compile and link commands that are used.
          if verbose:
              distutils.log.set_verbosity(1)
  
          # Create a compiler object.
          compiler = distutils.ccompiler.new_compiler(verbose=verbose)
  
          # Configure compiler and linker to build according to Python install.
          distutils.sysconfig.customize_compiler(compiler)
  
          # Create a temporary directory to hold test files.
          tempdir = tempfile.mkdtemp()
  
          # Define a simple C program that calls the function in question
          prog = (
              "void %s(void); int main(int argc, char** argv) { %s(); return 0; }"
              % (funcname, funcname)
          )
  
          # Write the test program to a file.
          filename = os.path.join(tempdir, "test.c")
          with open(filename, "w") as f:
              f.write(prog)
  
          # Redirect stderr file descriptor to a file to silence compile/link warnings.
          if not verbose:
              filestderr = open(
                  os.path.join(tempdir, "stderr.txt"), "w"
              )
              oldstderr = os.dup(sys.stderr.fileno())
              os.dup2(filestderr.fileno(), sys.stderr.fileno())
  
          # Workaround for behavior in distutils.ccompiler.CCompiler.object_filenames()
          # Otherwise, a local directory will be used instead of tempdir
          drive, driveless_filename = os.path.splitdrive(filename)
          root_dir = (
              driveless_filename[0]
              if os.path.isabs(driveless_filename)
              else ""
          )
          output_dir = os.path.join(drive, root_dir)
  
          # Attempt to compile the C program into an object file.
          cflags = shlex.split(os.environ.get("CFLAGS", ""))
          objs = compiler.compile(
              [filename],
              output_dir=output_dir,
              extra_preargs=self.strip_empty_entries(cflags),
          )
  
          # Attempt to link the object file into an executable.
          # Be sure to tack on any libraries that have been specified.
          ldflags = shlex.split(os.environ.get("LDFLAGS", ""))
          compiler.link_executable(
              objs,
              os.path.join(tempdir, "a.out"),
              extra_preargs=self.strip_empty_entries(ldflags),
              libraries=libraries,
          )
  
          # Compile and link succeeded
          return True
  
      except CompileError:
          return False
  
      except LinkError:
          return False
  
      except:
          return False
  
      finally:
          # Restore stderr file descriptor and close the stderr redirect file.
          if oldstderr is not None:
              os.dup2(oldstderr, sys.stderr.fileno())
          if filestderr is not None:
              filestderr.close()
  
          # Delete the temporary directory holding the test program and stderr files.
          if tempdir is not None:
              shutil.rmtree(tempdir)
  
imports: import os
  import sys
  import time
  import importlib
  from pathlib import Path
  import subprocess
  import shlex
  import shutil
  import tempfile
  import distutils.ccompiler
  import distutils.log
  import distutils.sysconfig
  from distutils.errors import CompileError, LinkError
  from abc import ABC, abstractmethod
  from typing import List
label_desc: Use image node_id 16 for calling the OpBuilder obj's underlying member method code with example usage: obj.has_function(funcname, libraries, verbose) and returns: True, False, False, False