Import LLVM 10.0.0 release including clang, lld and lldb.

ok hackroom
tested by plenty

1 files changed, 604 insertions, 0 deletions

diff --git a/gnu/llvm/lldb/packages/Python/lldbsuite/test/commands/settings/TestSettings.py b/gnu/llvm/lldb/packages/Python/lldbsuite/test/commands/settings/TestSettings.py
new file mode 100644
index 00000000000..1130821bac0
--- /dev/null
+++ b/gnu/llvm/lldb/packages/Python/lldbsuite/test/commands/settings/TestSettings.py
@@ -0,0 +1,604 @@
+"""
+Test lldb settings command.
+"""
+
+
+
+import os
+import re
+import lldb
+from lldbsuite.test.decorators import *
+from lldbsuite.test.lldbtest import *
+from lldbsuite.test import lldbutil
+
+
+class SettingsCommandTestCase(TestBase):
+
+    mydir = TestBase.compute_mydir(__file__)
+    NO_DEBUG_INFO_TESTCASE = True
+
+    def test_apropos_should_also_search_settings_description(self):
+        """Test that 'apropos' command should also search descriptions for the settings variables."""
+
+        self.expect("apropos 'environment variable'",
+                    substrs=["target.env-vars",
+                             "environment variables",
+                             "executable's environment"])
+
+    def test_append_target_env_vars(self):
+        """Test that 'append target.run-args' works."""
+        # Append the env-vars.
+        self.runCmd('settings append target.env-vars MY_ENV_VAR=YES')
+        # And add hooks to restore the settings during tearDown().
+        self.addTearDownHook(
+            lambda: self.runCmd("settings clear target.env-vars"))
+
+        # Check it immediately!
+        self.expect('settings show target.env-vars',
+                    substrs=['MY_ENV_VAR=YES'])
+
+    def test_insert_before_and_after_target_run_args(self):
+        """Test that 'insert-before/after target.run-args' works."""
+        # Set the run-args first.
+        self.runCmd('settings set target.run-args a b c')
+        # And add hooks to restore the settings during tearDown().
+        self.addTearDownHook(
+            lambda: self.runCmd("settings clear target.run-args"))
+
+        # Now insert-before the index-0 element with '__a__'.
+        self.runCmd('settings insert-before target.run-args 0 __a__')
+        # And insert-after the index-1 element with '__A__'.
+        self.runCmd('settings insert-after target.run-args 1 __A__')
+        # Check it immediately!
+        self.expect('settings show target.run-args',
+                    substrs=['target.run-args',
+                             '[0]: "__a__"',
+                             '[1]: "a"',
+                             '[2]: "__A__"',
+                             '[3]: "b"',
+                             '[4]: "c"'])
+
+    @expectedFailureAll(oslist=["windows"], bugnumber="llvm.org/pr44430")
+    def test_replace_target_run_args(self):
+        """Test that 'replace target.run-args' works."""
+        # Set the run-args and then replace the index-0 element.
+        self.runCmd('settings set target.run-args a b c')
+        # And add hooks to restore the settings during tearDown().
+        self.addTearDownHook(
+            lambda: self.runCmd("settings clear target.run-args"))
+
+        # Now replace the index-0 element with 'A', instead.
+        self.runCmd('settings replace target.run-args 0 A')
+        # Check it immediately!
+        self.expect('settings show target.run-args',
+                    substrs=['target.run-args (arguments) =',
+                             '[0]: "A"',
+                             '[1]: "b"',
+                             '[2]: "c"'])
+
+    def test_set_prompt(self):
+        """Test that 'set prompt' actually changes the prompt."""
+
+        # Set prompt to 'lldb2'.
+        self.runCmd("settings set prompt 'lldb2 '")
+
+        # Immediately test the setting.
+        self.expect("settings show prompt", SETTING_MSG("prompt"),
+                    startstr='prompt (string) = "lldb2 "')
+
+        # The overall display should also reflect the new setting.
+        self.expect("settings show", SETTING_MSG("prompt"),
+                    substrs=['prompt (string) = "lldb2 "'])
+
+        # Use '-r' option to reset to the original default prompt.
+        self.runCmd("settings clear prompt")
+
+    def test_set_term_width(self):
+        """Test that 'set term-width' actually changes the term-width."""
+
+        self.runCmd("settings set term-width 70")
+
+        # Immediately test the setting.
+        self.expect("settings show term-width", SETTING_MSG("term-width"),
+                    startstr="term-width (int) = 70")
+
+        # The overall display should also reflect the new setting.
+        self.expect("settings show", SETTING_MSG("term-width"),
+                    substrs=["term-width (int) = 70"])
+
+    # rdar://problem/10712130
+    @skipIf(oslist=["windows"], bugnumber="llvm.org/pr44431")
+    def test_set_frame_format(self):
+        """Test that 'set frame-format' with a backtick char in the format string works as well as fullpath."""
+        self.build()
+
+        exe = self.getBuildArtifact("a.out")
+        self.runCmd("file " + exe, CURRENT_EXECUTABLE_SET)
+
+        def cleanup():
+            self.runCmd(
+                "settings set frame-format %s" %
+                self.format_string, check=False)
+
+        # Execute the cleanup function during test case tear down.
+        self.addTearDownHook(cleanup)
+
+        self.runCmd("settings show frame-format")
+        m = re.match(
+            '^frame-format \(format-string\) = "(.*)\"$',
+            self.res.GetOutput())
+        self.assertTrue(m, "Bad settings string")
+        self.format_string = m.group(1)
+
+        # Change the default format to print function.name rather than
+        # function.name-with-args
+        format_string = "frame #${frame.index}: ${frame.pc}{ ${module.file.basename}\`${function.name}{${function.pc-offset}}}{ at ${line.file.fullpath}:${line.number}}{, lang=${language}}\n"
+        self.runCmd("settings set frame-format %s" % format_string)
+
+        # Immediately test the setting.
+        self.expect("settings show frame-format", SETTING_MSG("frame-format"),
+                    substrs=[format_string])
+
+        self.runCmd("breakpoint set -n main")
+        self.runCmd("process launch --working-dir '{0}'".format(self.get_process_working_directory()),
+                RUN_SUCCEEDED)
+        self.expect("thread backtrace",
+                    substrs=["`main", self.getSourceDir()])
+
+    def test_set_auto_confirm(self):
+        """Test that after 'set auto-confirm true', manual confirmation should not kick in."""
+        self.build()
+
+        exe = self.getBuildArtifact("a.out")
+        self.runCmd("file " + exe, CURRENT_EXECUTABLE_SET)
+
+        self.runCmd("settings set auto-confirm true")
+
+        # Immediately test the setting.
+        self.expect("settings show auto-confirm", SETTING_MSG("auto-confirm"),
+                    startstr="auto-confirm (boolean) = true")
+
+        # Now 'breakpoint delete' should just work fine without confirmation
+        # prompt from the command interpreter.
+        self.runCmd("breakpoint set -n main")
+        self.expect("breakpoint delete",
+                    startstr="All breakpoints removed")
+
+        # Restore the original setting of auto-confirm.
+        self.runCmd("settings clear auto-confirm")
+        self.expect("settings show auto-confirm", SETTING_MSG("auto-confirm"),
+                    startstr="auto-confirm (boolean) = false")
+
+    @skipIf(archs=no_match(['x86_64', 'i386', 'i686']))
+    def test_disassembler_settings(self):
+        """Test that user options for the disassembler take effect."""
+        self.build()
+
+        exe = self.getBuildArtifact("a.out")
+        self.runCmd("file " + exe, CURRENT_EXECUTABLE_SET)
+
+        # AT&T syntax
+        self.runCmd("settings set target.x86-disassembly-flavor att")
+        self.runCmd("settings set target.use-hex-immediates false")
+        self.expect("disassemble -n numberfn",
+                    substrs=["$90"])
+        self.runCmd("settings set target.use-hex-immediates true")
+        self.runCmd("settings set target.hex-immediate-style c")
+        self.expect("disassemble -n numberfn",
+                    substrs=["$0x5a"])
+        self.runCmd("settings set target.hex-immediate-style asm")
+        self.expect("disassemble -n numberfn",
+                    substrs=["$5ah"])
+
+        # Intel syntax
+        self.runCmd("settings set target.x86-disassembly-flavor intel")
+        self.runCmd("settings set target.use-hex-immediates false")
+        self.expect("disassemble -n numberfn",
+                    substrs=["90"])
+        self.runCmd("settings set target.use-hex-immediates true")
+        self.runCmd("settings set target.hex-immediate-style c")
+        self.expect("disassemble -n numberfn",
+                    substrs=["0x5a"])
+        self.runCmd("settings set target.hex-immediate-style asm")
+        self.expect("disassemble -n numberfn",
+                    substrs=["5ah"])
+
+    @skipIfDarwinEmbedded   # <rdar://problem/34446098> debugserver on ios etc can't write files
+    def test_run_args_and_env_vars(self):
+        """Test that run-args and env-vars are passed to the launched process."""
+        self.build()
+        exe = self.getBuildArtifact("a.out")
+        self.runCmd("file " + exe, CURRENT_EXECUTABLE_SET)
+
+        # Set the run-args and the env-vars.
+        # And add hooks to restore the settings during tearDown().
+        self.runCmd('settings set target.run-args A B C')
+        self.addTearDownHook(
+            lambda: self.runCmd("settings clear target.run-args"))
+        self.runCmd('settings set target.env-vars ["MY_ENV_VAR"]=YES')
+        self.addTearDownHook(
+            lambda: self.runCmd("settings clear target.env-vars"))
+
+        self.runCmd("process launch --working-dir '{0}'".format(self.get_process_working_directory()),
+                RUN_SUCCEEDED)
+
+        # Read the output file produced by running the program.
+        output = lldbutil.read_file_from_process_wd(self, "output2.txt")
+
+        self.expect(
+            output,
+            exe=False,
+            substrs=[
+                "argv[1] matches",
+                "argv[2] matches",
+                "argv[3] matches",
+                "Environment variable 'MY_ENV_VAR' successfully passed."])
+
+    @skipIfRemote  # it doesn't make sense to send host env to remote target
+    def test_pass_host_env_vars(self):
+        """Test that the host env vars are passed to the launched process."""
+        self.build()
+
+        exe = self.getBuildArtifact("a.out")
+        self.runCmd("file " + exe, CURRENT_EXECUTABLE_SET)
+
+        # By default, inherit-env is 'true'.
+        self.expect(
+            'settings show target.inherit-env',
+            "Default inherit-env is 'true'",
+            startstr="target.inherit-env (boolean) = true")
+
+        # Set some host environment variables now.
+        os.environ["MY_HOST_ENV_VAR1"] = "VAR1"
+        os.environ["MY_HOST_ENV_VAR2"] = "VAR2"
+
+        # This is the function to unset the two env variables set above.
+        def unset_env_variables():
+            os.environ.pop("MY_HOST_ENV_VAR1")
+            os.environ.pop("MY_HOST_ENV_VAR2")
+
+        self.addTearDownHook(unset_env_variables)
+        self.runCmd("process launch --working-dir '{0}'".format(self.get_process_working_directory()),
+                RUN_SUCCEEDED)
+
+        # Read the output file produced by running the program.
+        output = lldbutil.read_file_from_process_wd(self, "output1.txt")
+
+        self.expect(
+            output,
+            exe=False,
+            substrs=[
+                "The host environment variable 'MY_HOST_ENV_VAR1' successfully passed.",
+                "The host environment variable 'MY_HOST_ENV_VAR2' successfully passed."])
+
+    @skipIfDarwinEmbedded   # <rdar://problem/34446098> debugserver on ios etc can't write files
+    def test_set_error_output_path(self):
+        """Test that setting target.error/output-path for the launched process works."""
+        self.build()
+
+        exe = self.getBuildArtifact("a.out")
+        self.runCmd("file " + exe, CURRENT_EXECUTABLE_SET)
+
+        # Set the error-path and output-path and verify both are set.
+        self.runCmd("settings set target.error-path '{0}'".format(
+            lldbutil.append_to_process_working_directory(self, "stderr.txt")))
+        self.runCmd("settings set target.output-path '{0}".format(
+            lldbutil.append_to_process_working_directory(self, "stdout.txt")))
+        # And add hooks to restore the original settings during tearDown().
+        self.addTearDownHook(
+            lambda: self.runCmd("settings clear target.output-path"))
+        self.addTearDownHook(
+            lambda: self.runCmd("settings clear target.error-path"))
+
+        self.expect("settings show target.error-path",
+                    SETTING_MSG("target.error-path"),
+                    substrs=['target.error-path (file)', 'stderr.txt"'])
+
+        self.expect("settings show target.output-path",
+                    SETTING_MSG("target.output-path"),
+                    substrs=['target.output-path (file)', 'stdout.txt"'])
+
+        self.runCmd("process launch --working-dir '{0}'".format(self.get_process_working_directory()),
+                RUN_SUCCEEDED)
+
+        output = lldbutil.read_file_from_process_wd(self, "stderr.txt")
+        message = "This message should go to standard error."
+        if lldbplatformutil.hasChattyStderr(self):
+            self.expect(output, exe=False, substrs=[message])
+        else:
+            self.expect(output, exe=False, startstr=message)
+
+        output = lldbutil.read_file_from_process_wd(self, "stdout.txt")
+        self.expect(output, exe=False,
+                    startstr="This message should go to standard out.")
+
+    def test_print_dictionary_setting(self):
+        self.runCmd("settings clear target.env-vars")
+        self.runCmd("settings set target.env-vars [\"MY_VAR\"]=some-value")
+        self.expect("settings show target.env-vars",
+                    substrs=["MY_VAR=some-value"])
+        self.runCmd("settings clear target.env-vars")
+
+    def test_print_array_setting(self):
+        self.runCmd("settings clear target.run-args")
+        self.runCmd("settings set target.run-args gobbledy-gook")
+        self.expect("settings show target.run-args",
+                    substrs=['[0]: "gobbledy-gook"'])
+        self.runCmd("settings clear target.run-args")
+
+    def test_settings_with_quotes(self):
+        self.runCmd("settings clear target.run-args")
+        self.runCmd("settings set target.run-args a b c")
+        self.expect("settings show target.run-args",
+                    substrs=['[0]: "a"',
+                             '[1]: "b"',
+                             '[2]: "c"'])
+        self.runCmd("settings set target.run-args 'a b c'")
+        self.expect("settings show target.run-args",
+                    substrs=['[0]: "a b c"'])
+        self.runCmd("settings clear target.run-args")
+        self.runCmd("settings clear target.env-vars")
+        self.runCmd(
+            'settings set target.env-vars ["MY_FILE"]="this is a file name with spaces.txt"')
+        self.expect("settings show target.env-vars",
+                    substrs=['MY_FILE=this is a file name with spaces.txt'])
+        self.runCmd("settings clear target.env-vars")
+        # Test and make sure that setting "format-string" settings obeys quotes
+        # if they are provided
+        self.runCmd("settings set thread-format    'abc def'   ")
+        self.expect("settings show thread-format",
+                    'thread-format (format-string) = "abc def"')
+        self.runCmd('settings set thread-format    "abc def"   ')
+        self.expect("settings show thread-format",
+                    'thread-format (format-string) = "abc def"')
+        # Make sure when no quotes are provided that we maintain any trailing
+        # spaces
+        self.runCmd('settings set thread-format abc def   ')
+        self.expect("settings show thread-format",
+                    'thread-format (format-string) = "abc def   "')
+        self.runCmd('settings clear thread-format')
+
+    @expectedFailureAll(oslist=["windows"], bugnumber="llvm.org/pr44430")
+    def test_settings_with_trailing_whitespace(self):
+
+        # boolean
+        # Set to known value
+        self.runCmd("settings set target.skip-prologue true")
+        # Set to new value with trailing whitespace
+        self.runCmd("settings set target.skip-prologue false ")
+        # Make sure the setting was correctly set to "false"
+        self.expect(
+            "settings show target.skip-prologue",
+            SETTING_MSG("target.skip-prologue"),
+            startstr="target.skip-prologue (boolean) = false")
+        self.runCmd("settings clear target.skip-prologue", check=False)
+        # integer
+        self.runCmd("settings set term-width 70")      # Set to known value
+        # Set to new value with trailing whitespaces
+        self.runCmd("settings set term-width 60 \t")
+        self.expect("settings show term-width", SETTING_MSG("term-width"),
+                    startstr="term-width (int) = 60")
+        self.runCmd("settings clear term-width", check=False)
+        # string
+        self.runCmd("settings set target.arg0 abc")    # Set to known value
+        # Set to new value with trailing whitespaces
+        self.runCmd("settings set target.arg0 cde\t ")
+        self.expect("settings show target.arg0", SETTING_MSG("target.arg0"),
+                    startstr='target.arg0 (string) = "cde"')
+        self.runCmd("settings clear target.arg0", check=False)
+        # file
+        path1 = self.getBuildArtifact("path1.txt")
+        path2 = self.getBuildArtifact("path2.txt")
+        self.runCmd(
+            "settings set target.output-path %s" %
+            path1)   # Set to known value
+        self.expect(
+            "settings show target.output-path",
+            SETTING_MSG("target.output-path"),
+            startstr='target.output-path (file) = ',
+            substrs=[path1])
+        self.runCmd("settings set target.output-path %s " %
+                    path2)  # Set to new value with trailing whitespaces
+        self.expect(
+            "settings show target.output-path",
+            SETTING_MSG("target.output-path"),
+            startstr='target.output-path (file) = ',
+            substrs=[path2])
+        self.runCmd("settings clear target.output-path", check=False)
+        # enum
+        # Set to known value
+        self.runCmd("settings set stop-disassembly-display never")
+        # Set to new value with trailing whitespaces
+        self.runCmd("settings set stop-disassembly-display always ")
+        self.expect(
+            "settings show stop-disassembly-display",
+            SETTING_MSG("stop-disassembly-display"),
+            startstr='stop-disassembly-display (enum) = always')
+        self.runCmd("settings clear stop-disassembly-display", check=False)
+        # language
+        # Set to known value
+        self.runCmd("settings set target.language c89")
+        # Set to new value with trailing whitespace
+        self.runCmd("settings set target.language c11 ")
+        self.expect(
+            "settings show target.language",
+            SETTING_MSG("target.language"),
+            startstr="target.language (language) = c11")
+        self.runCmd("settings clear target.language", check=False)
+        # arguments
+        self.runCmd("settings set target.run-args 1 2 3")  # Set to known value
+        # Set to new value with trailing whitespaces
+        self.runCmd("settings set target.run-args 3 4 5 ")
+        self.expect(
+            "settings show target.run-args",
+            SETTING_MSG("target.run-args"),
+            substrs=[
+                'target.run-args (arguments) =',
+                '[0]: "3"',
+                '[1]: "4"',
+                '[2]: "5"'])
+        self.runCmd("settings set target.run-args 1 2 3")  # Set to known value
+        # Set to new value with trailing whitespaces
+        self.runCmd("settings set target.run-args 3 \  \ ")
+        self.expect(
+            "settings show target.run-args",
+            SETTING_MSG("target.run-args"),
+            substrs=[
+                'target.run-args (arguments) =',
+                '[0]: "3"',
+                '[1]: " "',
+                '[2]: " "'])
+        self.runCmd("settings clear target.run-args", check=False)
+        # dictionaries
+        self.runCmd("settings clear target.env-vars")  # Set to known value
+        # Set to new value with trailing whitespaces
+        self.runCmd("settings set target.env-vars A=B C=D\t ")
+        self.expect(
+            "settings show target.env-vars",
+            SETTING_MSG("target.env-vars"),
+            substrs=[
+                'target.env-vars (dictionary of strings) =',
+                'A=B',
+                'C=D'])
+        self.runCmd("settings clear target.env-vars", check=False)
+        # regex
+        # Set to known value
+        self.runCmd("settings clear target.process.thread.step-avoid-regexp")
+        # Set to new value with trailing whitespaces
+        self.runCmd(
+            "settings set target.process.thread.step-avoid-regexp foo\\ ")
+        self.expect(
+            "settings show target.process.thread.step-avoid-regexp",
+            SETTING_MSG("target.process.thread.step-avoid-regexp"),
+            substrs=['target.process.thread.step-avoid-regexp (regex) = foo\\ '])
+        self.runCmd(
+            "settings clear target.process.thread.step-avoid-regexp",
+            check=False)
+        # format-string
+        self.runCmd("settings clear disassembly-format")  # Set to known value
+        # Set to new value with trailing whitespaces
+        self.runCmd("settings set disassembly-format foo ")
+        self.expect("settings show disassembly-format",
+                    SETTING_MSG("disassembly-format"),
+                    substrs=['disassembly-format (format-string) = "foo "'])
+        self.runCmd("settings clear disassembly-format", check=False)
+
+    def test_settings_list(self):
+        # List settings (and optionally test the filter to only show 'target' settings).
+        self.expect("settings list target", substrs=["language", "arg0", "detach-on-error"])
+        self.expect("settings list target", matching=False, substrs=["packet-timeout"])
+        self.expect("settings list", substrs=["language", "arg0", "detach-on-error", "packet-timeout"])
+
+    def test_settings_remove_single(self):
+        # Set some environment variables and use 'remove' to delete them.
+        self.runCmd("settings set target.env-vars a=b c=d")
+        self.expect("settings show target.env-vars", substrs=["a=b", "c=d"])
+        self.runCmd("settings remove target.env-vars a")
+        self.expect("settings show target.env-vars", matching=False, substrs=["a=b"])
+        self.expect("settings show target.env-vars", substrs=["c=d"])
+        self.runCmd("settings remove target.env-vars c")
+        self.expect("settings show target.env-vars", matching=False, substrs=["a=b", "c=d"])
+
+    def test_settings_remove_multiple(self):
+        self.runCmd("settings set target.env-vars a=b c=d e=f")
+        self.expect("settings show target.env-vars", substrs=["a=b", "c=d", "e=f"])
+        self.runCmd("settings remove target.env-vars a e")
+        self.expect("settings show target.env-vars", matching=False, substrs=["a=b", "e=f"])
+        self.expect("settings show target.env-vars", substrs=["c=d"])
+
+    def test_settings_remove_nonexistent_value(self):
+        self.expect("settings remove target.env-vars doesntexist", error=True,
+                    substrs=["no value found named 'doesntexist'"])
+
+    def test_settings_remove_nonexistent_settings(self):
+        self.expect("settings remove doesntexist alsodoesntexist", error=True,
+                    substrs=["error: invalid value path 'doesntexist'"])
+
+    def test_settings_remove_missing_arg(self):
+        self.expect("settings remove", error=True,
+                    substrs=["'settings remove' takes an array or dictionary item, or"])
+
+    def test_settings_remove_empty_arg(self):
+        self.expect("settings remove ''", error=True,
+                    substrs=["'settings remove' command requires a valid variable name"])
+
+    def test_all_settings_exist(self):
+        self.expect("settings show",
+                    substrs=["auto-confirm",
+                             "frame-format",
+                             "notify-void",
+                             "prompt",
+                             "script-lang",
+                             "stop-disassembly-count",
+                             "stop-disassembly-display",
+                             "stop-line-count-after",
+                             "stop-line-count-before",
+                             "stop-show-column",
+                             "term-width",
+                             "thread-format",
+                             "use-external-editor",
+                             "target.default-arch",
+                             "target.move-to-nearest-code",
+                             "target.expr-prefix",
+                             "target.language",
+                             "target.prefer-dynamic-value",
+                             "target.enable-synthetic-value",
+                             "target.skip-prologue",
+                             "target.source-map",
+                             "target.exec-search-paths",
+                             "target.max-children-count",
+                             "target.max-string-summary-length",
+                             "target.breakpoints-use-platform-avoid-list",
+                             "target.run-args",
+                             "target.env-vars",
+                             "target.inherit-env",
+                             "target.input-path",
+                             "target.output-path",
+                             "target.error-path",
+                             "target.disable-aslr",
+                             "target.disable-stdio",
+                             "target.x86-disassembly-flavor",
+                             "target.use-hex-immediates",
+                             "target.hex-immediate-style",
+                             "target.process.disable-memory-cache",
+                             "target.process.extra-startup-command",
+                             "target.process.thread.step-avoid-regexp",
+                             "target.process.thread.trace-thread"])
+
+    # settings under an ".experimental" domain should have two properties:
+    #   1. If the name does not exist with "experimental" in the name path,
+    #      the name lookup should try to find it without "experimental".  So
+    #      a previously-experimental setting that has been promoted to a
+    #      "real" setting will still be set by the original name.
+    #   2. Changing a setting with .experimental., name, where the setting
+    #      does not exist either with ".experimental." or without, should
+    #      not generate an error.  So if an experimental setting is removed,
+    #      people who may have that in their ~/.lldbinit files should not see
+    #      any errors.
+    def test_experimental_settings(self):
+        cmdinterp = self.dbg.GetCommandInterpreter()
+        result = lldb.SBCommandReturnObject()
+
+        # Set target.arg0 to a known value, check that we can retrieve it via
+        # the actual name and via .experimental.
+        self.expect('settings set target.arg0 first-value')
+        self.expect('settings show target.arg0', substrs=['first-value'])
+        self.expect('settings show target.experimental.arg0', substrs=['first-value'], error=False)
+
+        # Set target.arg0 to a new value via a target.experimental.arg0 name,
+        # verify that we can read it back via both .experimental., and not.
+        self.expect('settings set target.experimental.arg0 second-value', error=False)
+        self.expect('settings show target.arg0', substrs=['second-value'])
+        self.expect('settings show target.experimental.arg0', substrs=['second-value'], error=False)
+
+        # showing & setting an undefined .experimental. setting should generate no errors.
+        self.expect('settings show target.experimental.setting-which-does-not-exist', patterns=['^\s$'], error=False)
+        self.expect('settings set target.experimental.setting-which-does-not-exist true', error=False)
+
+        # A domain component before .experimental. which does not exist should give an error
+        # But the code does not yet do that.
+        # self.expect('settings set target.setting-which-does-not-exist.experimental.arg0 true', error=True)
+
+        # finally, confirm that trying to set a setting that does not exist still fails.
+        # (SHOWING a setting that does not exist does not currently yield an error.)
+        self.expect('settings set target.setting-which-does-not-exist true', error=True)