[lldb] Omit --show-globals in help target var (#85855)

This option doesn't exist. It is currently displayed by `help target
var` due to a bug introduced by 41ae8e7 in 2018.

Some code for `target var` and `frame var` is shared, and some hard-code
constants are used in order to filter out options that belong only to
`frame var`. However, the aforementioned commit failed to update these
constants properly. This patch addresses the issue by having a _single_
place where the filtering of options needs to be done.

Author: felipepiovezan

lldb/source/Interpreter/OptionGroupVariable.cpp

@@ -50,6 +50,11 @@ static constexpr OptionDefinition g_variable_options[] = {
      "Specify a summary string to use to format the variable output."},
 };
 
+static constexpr auto g_num_frame_options = 4;
+static const auto g_variable_options_noframe =
+    llvm::ArrayRef<OptionDefinition>(g_variable_options)
+        .drop_front(g_num_frame_options);
+
 static Status ValidateNamedSummary(const char *str, void *) {
   if (!str || !str[0])
     return Status("must specify a valid named summary");
@@ -77,9 +82,9 @@ OptionGroupVariable::SetOptionValue(uint32_t option_idx,
                                     llvm::StringRef option_arg,
                                     ExecutionContext *execution_context) {
   Status error;
-  if (!include_frame_options)
-    option_idx += 3;
-  const int short_option = g_variable_options[option_idx].short_option;
+  llvm::ArrayRef<OptionDefinition> variable_options =
+      include_frame_options ? g_variable_options : g_variable_options_noframe;
+  const int short_option = variable_options[option_idx].short_option;
   switch (short_option) {
   case 'r':
     use_regex = true;
@@ -128,16 +133,9 @@ void OptionGroupVariable::OptionParsingStarting(
   summary_string.Clear();
 }
 
-#define NUM_FRAME_OPTS 3
-
 llvm::ArrayRef<OptionDefinition> OptionGroupVariable::GetDefinitions() {
-  auto result = llvm::ArrayRef(g_variable_options);
-  // Show the "--no-args", "--no-locals" and "--show-globals" options if we are
-  // showing frame specific options
-  if (include_frame_options)
-    return result;
-
-  // Skip the "--no-args", "--no-locals" and "--show-globals" options if we are
-  // not showing frame specific options (globals only)
-  return result.drop_front(NUM_FRAME_OPTS);
+  // Show the "--no-args", "--no-recognized-args", "--no-locals" and
+  // "--show-globals" options if we are showing frame specific options
+  return include_frame_options ? g_variable_options
+                               : g_variable_options_noframe;
 }

lldb/test/API/functionalities/target_var/TestTargetVar.py

@@ -15,6 +15,16 @@ class targetCommandTestCase(TestBase):
     def testTargetVarExpr(self):
         self.build()
         lldbutil.run_to_name_breakpoint(self, "main")
+        self.expect(
+            "help target variable",
+            substrs=[
+                "--no-args",
+                "--no-recognized-args",
+                "--no-locals",
+                "--show-globals",
+            ],
+            matching=False,
+        )
         self.expect("target variable i", substrs=["i", "42"])
         self.expect(
             "target variable var", patterns=["\(incomplete \*\) var = 0[xX](0)*dead"]