[lldb] Make cursor index in CompletionRequest unsigned

The fact that index==-1 means "no arguments" is not obvious and only
used in one place from what I can tell. Also fixes several warnings
about using the cursor index as if it was a size_t when comparing.

Not fully NFC as we now also correctly update the partial argument list
when injecting the fake empty argument in the CompletionRequest
constructor.

llvm-svn: 372566

lldb/include/lldb/Utility/CompletionRequest.h

@@ -126,8 +126,8 @@ public:
     m_partial_parsed_line.Shift();
   }
 
-  void SetCursorIndex(int i) { m_cursor_index = i; }
-  int GetCursorIndex() const { return m_cursor_index; }
+  void SetCursorIndex(size_t i) { m_cursor_index = i; }
+  size_t GetCursorIndex() const { return m_cursor_index; }
 
   void SetCursorCharPosition(int pos) { m_cursor_char_position = pos; }
   int GetCursorCharPosition() const { return m_cursor_char_position; }
@@ -208,7 +208,7 @@ private:
   /// The command line until the cursor position parsed as arguments.
   Args m_partial_parsed_line;
   /// The index of the argument in which the completion cursor is.
-  int m_cursor_index;
+  size_t m_cursor_index;
   /// The cursor position in the argument indexed by m_cursor_index.
   int m_cursor_char_position;
 

lldb/source/Commands/CommandObjectSettings.cpp

@@ -130,9 +130,8 @@ insert-before or insert-after.");
 
     const size_t argc = request.GetParsedLine().GetArgumentCount();
     const char *arg = nullptr;
-    int setting_var_idx;
-    for (setting_var_idx = 0; setting_var_idx < static_cast<int>(argc);
-         ++setting_var_idx) {
+    size_t setting_var_idx;
+    for (setting_var_idx = 0; setting_var_idx < argc; ++setting_var_idx) {
       arg = request.GetParsedLine().GetArgumentAtIndex(setting_var_idx);
       if (arg && arg[0] != '-')
         break; // We found our setting variable name index

lldb/source/Interpreter/CommandInterpreter.cpp

@@ -1756,7 +1756,7 @@ void CommandInterpreter::HandleCompletionMatches(CompletionRequest &request) {
 
   // For any of the command completions a unique match will be a complete word.
 
-  if (request.GetCursorIndex() == -1) {
+  if (request.GetPartialParsedLine().GetArgumentCount() == 0) {
     // We got nothing on the command line, so return the list of commands
     bool include_aliases = true;
     StringList new_matches, descriptions;
@@ -1780,7 +1780,7 @@ void CommandInterpreter::HandleCompletionMatches(CompletionRequest &request) {
         new_matches.DeleteStringAtIndex(0);
         new_descriptions.DeleteStringAtIndex(0);
         request.GetParsedLine().AppendArgument(llvm::StringRef());
-        request.SetCursorIndex(request.GetCursorIndex() + 1);
+        request.SetCursorIndex(request.GetCursorIndex() + 1U);
         request.SetCursorCharPosition(0);
       }
     }

lldb/source/Interpreter/Options.cpp

@@ -655,8 +655,8 @@ bool Options::HandleOptionCompletion(CompletionRequest &request,
   llvm::StringRef cur_opt_str = request.GetCursorArgumentPrefix();
 
   for (size_t i = 0; i < opt_element_vector.size(); i++) {
-    int opt_pos = opt_element_vector[i].opt_pos;
-    int opt_arg_pos = opt_element_vector[i].opt_arg_pos;
+    size_t opt_pos = static_cast<size_t>(opt_element_vector[i].opt_pos);
+    size_t opt_arg_pos = static_cast<size_t>(opt_element_vector[i].opt_arg_pos);
     int opt_defs_index = opt_element_vector[i].opt_defs_index;
     if (opt_pos == request.GetCursorIndex()) {
       // We're completing the option itself.

lldb/source/Utility/CompletionRequest.cpp

@@ -22,34 +22,28 @@ CompletionRequest::CompletionRequest(llvm::StringRef command_line,
   // parsed_line is the one containing the cursor, and the cursor is after the
   // last character.
   m_parsed_line = Args(command_line);
-  m_partial_parsed_line = Args(command_line.substr(0, raw_cursor_pos));
+  llvm::StringRef partial_command(command_line.substr(0, raw_cursor_pos));
+  m_partial_parsed_line = Args(partial_command);
 
-  m_cursor_index = m_partial_parsed_line.GetArgumentCount() - 1;
-
-  if (m_cursor_index == -1)
+  if (m_partial_parsed_line.GetArgumentCount() == 0) {
+    m_cursor_index = 0;
     m_cursor_char_position = 0;
-  else
+  } else {
+    m_cursor_index = m_partial_parsed_line.GetArgumentCount() - 1U;
     m_cursor_char_position =
         strlen(m_partial_parsed_line.GetArgumentAtIndex(m_cursor_index));
+  }
 
-  const char *cursor = command_line.data() + raw_cursor_pos;
-  if (raw_cursor_pos > 0 && cursor[-1] == ' ') {
-    // We are just after a space.  If we are in an argument, then we will
-    // continue parsing, but if we are between arguments, then we have to
-    // complete whatever the next element would be. We can distinguish the two
-    // cases because if we are in an argument (e.g. because the space is
-    // protected by a quote) then the space will also be in the parsed
-    // argument...
-
-    const char *current_elem =
-        m_partial_parsed_line.GetArgumentAtIndex(m_cursor_index);
-    if (m_cursor_char_position == 0 ||
-        current_elem[m_cursor_char_position - 1] != ' ') {
-      m_parsed_line.InsertArgumentAtIndex(m_cursor_index + 1, llvm::StringRef(),
-                                          '\0');
-      m_cursor_index++;
-      m_cursor_char_position = 0;
-    }
+  // The cursor is after a space but the space is not part of the argument.
+  // Let's add an empty fake argument to the end to make sure the completion
+  // code Note: The space could be part of the last argument when it's quoted.
+  if (partial_command.endswith(" ") &&
+      !GetCursorArgumentPrefix().endswith(" ")) {
+    m_parsed_line.AppendArgument(llvm::StringRef());
+    m_partial_parsed_line.AppendArgument(llvm::StringRef());
+    // Set the cursor to the start of the fake argument.
+    m_cursor_index++;
+    m_cursor_char_position = 0;
   }
 }
 

lldb/unittests/Utility/CompletionRequestTest.cpp

@@ -14,7 +14,7 @@ using namespace lldb_private;
 TEST(CompletionRequest, Constructor) {
   std::string command = "a bad c";
   const unsigned cursor_pos = 3;
-  const int arg_index = 1;
+  const size_t arg_index = 1;
   const int arg_cursor_pos = 1;
   StringList matches;
   CompletionResult result;
@@ -31,6 +31,24 @@ TEST(CompletionRequest, Constructor) {
   EXPECT_STREQ(request.GetPartialParsedLine().GetArgumentAtIndex(1), "b");
 }
 
+TEST(CompletionRequest, FakeLastArg) {
+  // We insert an empty fake argument into the argument list when the
+  // cursor is after a space.
+  std::string command = "a bad c ";
+  const unsigned cursor_pos = command.size();
+  CompletionResult result;
+
+  CompletionRequest request(command, cursor_pos, result);
+
+  EXPECT_STREQ(request.GetRawLine().str().c_str(), command.c_str());
+  EXPECT_EQ(request.GetRawCursorPos(), cursor_pos);
+  EXPECT_EQ(request.GetCursorIndex(), 3U);
+  EXPECT_EQ(request.GetCursorCharPosition(), 0);
+
+  EXPECT_EQ(request.GetPartialParsedLine().GetArgumentCount(), 4U);
+  EXPECT_STREQ(request.GetPartialParsedLine().GetArgumentAtIndex(3), "");
+}
+
 TEST(CompletionRequest, TryCompleteCurrentArgGood) {
   std::string command = "a bad c";
   StringList matches, descriptions;
@@ -71,7 +89,7 @@ TEST(CompletionRequest, TryCompleteCurrentArgMode) {
 TEST(CompletionRequest, ShiftArguments) {
   std::string command = "a bad c";
   const unsigned cursor_pos = 3;
-  const int arg_index = 1;
+  const size_t arg_index = 1;
   const int arg_cursor_pos = 1;
   StringList matches;
   CompletionResult result;