Merge pull request #3760 from apple/🍒/austria/f75885977cef

Fix error reporting for "process load" and add a test for it.

Author: JDevlieghere

lldb/source/Plugins/Platform/POSIX/PlatformPOSIX.cpp

@@ -589,6 +589,8 @@ PlatformPOSIX::MakeLoadImageUtilityFunction(ExecutionContext &exe_ctx,
       result_ptr->image_ptr = dlopen(name, RTLD_LAZY);
       if (result_ptr->image_ptr)
         result_ptr->error_str = nullptr;
+      else
+        result_ptr->error_str = dlerror();
       return nullptr;
     }
     

lldb/test/API/functionalities/load_unload/TestLoadUnload.py

@@ -240,6 +240,15 @@ def run_lldb_process_load_and_unload_commands(self):
         else:
             remoteDylibPath = localDylibPath
 
+        # First make sure that we get some kind of error if process load fails.
+        # We print some error even if the load fails, which isn't formalized.
+        # The only plugin at present (Posix) that supports this says "unknown reasons".
+        # If another plugin shows up, let's require it uses "unknown error" as well.
+        non_existant_shlib = "/NoSuchDir/NoSuchSubdir/ReallyNo/NotAFile"
+        self.expect("process load %s"%(non_existant_shlib), error=True, matching=False,
+                    patterns=["unknown reasons"])
+        
+
         # Make sure that a_function does not exist at this point.
         self.expect(
             "image lookup -n a_function",

lldb/test/API/functionalities/load_using_paths/TestLoadUsingPaths.py

@@ -65,7 +65,12 @@ def test_load_using_paths(self):
         # First try with no correct directories on the path, and make sure that doesn't blow up:
         token = process.LoadImageUsingPaths(lib_spec, paths, out_spec, error)
         self.assertEqual(token, lldb.LLDB_INVALID_IMAGE_TOKEN, "Only looked on the provided path.")
-
+        # Make sure we got some error back in this case.  Since we don't actually know what
+        # the error will look like, let's look for the absence of "unknown reasons".
+        error_str = error.description
+        self.assertNotEqual(len(error_str), 0, "Got an empty error string")
+        self.assertNotIn("unknown reasons", error_str, "Error string had unknown reasons")
+        
         # Now add the correct dir to the paths list and try again:
         paths.AppendString(self.hidden_dir)
         token = process.LoadImageUsingPaths(lib_spec, paths, out_spec, error)
@@ -121,8 +126,6 @@ def test_load_using_paths(self):
 
         process.UnloadImage(token)
 
-
-
         # Finally, passing in an absolute path should work like the basename:
         # This should NOT work because we've taken hidden_dir off the paths:
         abs_spec = lldb.SBFileSpec(os.path.join(self.hidden_dir, self.lib_name))
@@ -137,5 +140,3 @@ def test_load_using_paths(self):
 
         self.assertNotEqual(token, lldb.LLDB_INVALID_IMAGE_TOKEN, "Got a valid token")
         self.assertEqual(out_spec, lldb.SBFileSpec(self.hidden_lib), "Found the expected library")
-
-