os.remove shouldn't fail, if file doesn't exist

[ismailp]

Summary

os.remove might throw an exception (of type OSError), if given file
doesn't exist. Catch the exception, and ignore it iff errno is
ENOENT. Rethrow the exception, if errno is not ENOENT.

[ismailp]

Moved to the correct list.

[emaste]

scripts/Python/buildSwigPython.py

686–687 ↗

(On Diff #16507)

Do we not have the same issue here?

[ismailp]

scripts/Python/buildSwigPython.py

686–687 ↗

(On Diff #16507)

Presumably, yes. I wasn't trying with LLDB_DISABLE_PYTHON, but with CMake generated Xcode project on Darwin, and region below failed. I didn't examine all instances of os.remove, I guess I should have.

How about:

def removeignoreenoent(filename):
  try:
    os.remove(filename)
  except OSError as e:
    import errno
    if e.errno != errno.ENOENT:
      raise
    pass

and call this function instead of os.remove. We might use a better/shorter name; any suggestions?

[ismailp]

Added a new function called removeignoreenoent.

[zturner]

scripts/Python/buildSwigPython.py

435 ↗

(On Diff #16515)

Please add underscores between the words, to be consistent with the naming convention used elsewhere in this function.

[ismailp]

Use underscores in function name to match with the existing style.

[emaste]

Looks fine with a couple of minor comments.

scripts/Python/buildSwigPython.py

431–433 ↗

(On Diff #16518)

This comment seems overly verbose -- it's clear from reading the function that this is what happens. What about something succinct like "Remove a file, ignoring error if it does not exist."

604 ↗

(On Diff #16518)

random whitespace change

[ismailp]

Added a succint comment, and removed whitespace change.

[ismailp]

Ping.

[emaste]

lgtm

[ki.stfu]

lgtm

[ki.stfu]

ismailp,

it was committed?

[ki.stfu]

Friendly ping

[ismailp]

Thanks, landed in r229334.

lldb/trunk/scripts/Python/buildSwigPython.py

def get_config_build_dir( vDictArgs, vstrFrameworkPythonDir ):
   bHaveConfigBldDir = vDictArgs.has_key( "--cfgBldDir" );
   if bHaveConfigBldDir:
     strConfigBldDir = vDictArgs[ "--cfgBldDir" ];
   if (bHaveConfigBldDir == False) or (strConfigBldDir.__len__() == 0):
     strConfigBldDir = vstrFrameworkPythonDir;
   
   return (bOk, strConfigBldDir, strErrMsg);
 
+"""
+Removes given file, ignoring error if it doesn't exist.
+"""
+def remove_ignore_enoent(filename):
+  try:
+    os.remove( strSwigOutputFile );
+  except OSError as e:
+    import errno
+    if e.errno != errno.ENOENT:
+      raise
+    pass
+
 #++---------------------------------------------------------------------------
 # Details:  Do a SWIG code rebuild. Any number returned by SWIG which is not
 #     zero is treated as an error. The generate dependencies flag decides
 #     how SWIG is rebuilt and if set false will cause the script to exit
 #     immediately with the exit status + 200 if status is not zero. 
 # Args:   vDictArgs     - (R) Program input parameters.
 #     vstrSwigDepFile   - (R) SWIG dependency file.
 #     vstrCfgBldDir   - (R) Configuration build directory.
def main( vDictArgs ):
 
   strEnvVarLLDBDisablePython = os.getenv( "LLDB_DISABLE_PYTHON", None );
   # We don't want Python for this build, but touch the output file so we 
   # don't have to conditionalize the build on this as well.
     # Note, at present iOS doesn't have Python, so if you're building for 
     # iOS be sure to set LLDB_DISABLE_PYTHON to 1.
   if (strEnvVarLLDBDisablePython != None) and \
      (strEnvVarLLDBDisablePython == "1"):
-    os.remove( strSwigOutputFile );
+    remove_ignore_enoent( strSwigOutputFile )
     open( strSwigOutputFile, 'w' ).close(); # Touch the file
     if bDebug:
       strMsg = strMsgLldbDisablePython;
     return (0, strMsg );
     
   # If this project is being built with LLDB_DISABLE_PYTHON defined,
   # don't bother generating Python swig bindings -- we don't have
   # Python available.
   strEnvVarGccPreprocessDefs = os.getenv( "GCC_PREPROCESSOR_DEFINITIONS", 
                       None );
   if (strEnvVarGccPreprocessDefs != None) or \
      (strEnvVarLLDBDisablePython != None):
-    os.remove( strSwigOutputFile );
+    remove_ignore_enoent( strSwigOutputFile )
     open( strSwigOutputFile, 'w' ).close(); # Touch the file
     if bDebug:
       strMsg = strMsgLldbDisableGccEnv;
     return (0, strMsg);
     
   bOk = bOk and get_header_files( vDictArgs );
   bOk = bOk and get_interface_files( vDictArgs );