[lldb/Interpreter] Fix ambiguous partial command resolution

This patch is a follow-up to llvm#97263 that fix ambigous abbreviated
command resolution.

When multiple commands are resolved, instead of failing to pick a
command to run, this patch changes to resolution logic to check if there
is either a single user command match or a single alias match and if so,
it will run that command instead of the others.

This has as a side-effect that we don't need to make aliases for every
substring of aliases to support abbrivated alias resolution.

Signed-off-by: Med Ismail Bennani <[email protected]>

Author: medismailben

lldb/include/lldb/Interpreter/CommandInterpreter.h

@@ -295,6 +295,10 @@ class CommandInterpreter : public Broadcaster,
                                       StringList *matches = nullptr,
                                       StringList *descriptions = nullptr) const;
 
+  CommandObject *
+  GetAliasCommandObject(llvm::StringRef cmd, StringList *matches = nullptr,
+                        StringList *descriptions = nullptr) const;
+
   /// Determine whether a root level, built-in command with this name exists.
   bool CommandExists(llvm::StringRef cmd) const;
 

lldb/source/Interpreter/CommandInterpreter.cpp

@@ -520,10 +520,6 @@ void CommandInterpreter::Initialize() {
 
   cmd_obj_sp = GetCommandSPExact("scripting run");
   if (cmd_obj_sp) {
-    AddAlias("sc", cmd_obj_sp);
-    AddAlias("scr", cmd_obj_sp);
-    AddAlias("scri", cmd_obj_sp);
-    AddAlias("scrip", cmd_obj_sp);
     AddAlias("script", cmd_obj_sp);
   }
 
@@ -1302,6 +1298,36 @@ CommandObject *CommandInterpreter::GetUserCommandObject(
   return {};
 }
 
+CommandObject *CommandInterpreter::GetAliasCommandObject(
+    llvm::StringRef cmd, StringList *matches, StringList *descriptions) const {
+  std::string cmd_str(cmd);
+  auto find_exact = [&](const CommandObject::CommandMap &map) {
+    auto found_elem = map.find(std::string(cmd));
+    if (found_elem == map.end())
+      return (CommandObject *)nullptr;
+    CommandObject *exact_cmd = found_elem->second.get();
+    if (exact_cmd) {
+      if (matches)
+        matches->AppendString(exact_cmd->GetCommandName());
+      if (descriptions)
+        descriptions->AppendString(exact_cmd->GetHelp());
+      return exact_cmd;
+    }
+    return (CommandObject *)nullptr;
+  };
+
+  CommandObject *exact_cmd = find_exact(GetAliases());
+  if (exact_cmd)
+    return exact_cmd;
+
+  // We didn't have an exact command, so now look for partial matches.
+  StringList tmp_list;
+  StringList *matches_ptr = matches ? matches : &tmp_list;
+  AddNamesMatchingPartialString(GetAliases(), cmd_str, *matches_ptr);
+
+  return {};
+}
+
 bool CommandInterpreter::CommandExists(llvm::StringRef cmd) const {
   return m_command_dict.find(std::string(cmd)) != m_command_dict.end();
 }
@@ -3421,6 +3447,19 @@ CommandInterpreter::ResolveCommandImpl(std::string &command_line,
   std::string next_word;
   StringList matches;
   bool done = false;
+
+  auto build_alias_cmd = [&](std::string &full_name) {
+    revised_command_line.Clear();
+    matches.Clear();
+    std::string alias_result;
+    cmd_obj =
+        BuildAliasResult(full_name, scratch_command, alias_result, result);
+    revised_command_line.Printf("%s", alias_result.c_str());
+    if (cmd_obj) {
+      wants_raw_input = cmd_obj->WantsRawCommandString();
+    }
+  };
+
   while (!done) {
     char quote_char = '\0';
     std::string suffix;
@@ -3432,14 +3471,7 @@ CommandInterpreter::ResolveCommandImpl(std::string &command_line,
       bool is_real_command =
           (!is_alias) || (cmd_obj != nullptr && !cmd_obj->IsAlias());
       if (!is_real_command) {
-        matches.Clear();
-        std::string alias_result;
-        cmd_obj =
-            BuildAliasResult(full_name, scratch_command, alias_result, result);
-        revised_command_line.Printf("%s", alias_result.c_str());
-        if (cmd_obj) {
-          wants_raw_input = cmd_obj->WantsRawCommandString();
-        }
+        build_alias_cmd(full_name);
       } else {
         if (cmd_obj) {
           llvm::StringRef cmd_name = cmd_obj->GetCommandName();
@@ -3486,21 +3518,38 @@ CommandInterpreter::ResolveCommandImpl(std::string &command_line,
     if (cmd_obj == nullptr) {
       const size_t num_matches = matches.GetSize();
       if (matches.GetSize() > 1) {
-        StreamString error_msg;
-        error_msg.Printf("Ambiguous command '%s'. Possible matches:\n",
-                         next_word.c_str());
+        StringList user_cmd_matches;
+        GetUserCommandObject(next_word, &user_cmd_matches);
+
+        StringList alias_matches;
+        GetAliasCommandObject(next_word, &alias_matches);
+
+        if (user_cmd_matches.GetSize() == 1) {
+          cmd_obj = GetCommandObject(user_cmd_matches.GetStringAtIndex(0));
+          done = static_cast<bool>(cmd_obj);
+        } else if (alias_matches.GetSize() == 1) {
+          std::string full_name;
+          GetAliasFullName(alias_matches.GetStringAtIndex(0), full_name);
+          build_alias_cmd(full_name);
+          done = static_cast<bool>(cmd_obj);
+        } else {
+          StreamString error_msg;
+          error_msg.Printf("Ambiguous command '%s'. Possible matches:\n",
+                           next_word.c_str());
 
-        for (uint32_t i = 0; i < num_matches; ++i) {
-          error_msg.Printf("\t%s\n", matches.GetStringAtIndex(i));
+          for (uint32_t i = 0; i < num_matches; ++i) {
+            error_msg.Printf("\t%s\n", matches.GetStringAtIndex(i));
+          }
+          result.AppendRawError(error_msg.GetString());
         }
-        result.AppendRawError(error_msg.GetString());
       } else {
         // We didn't have only one match, otherwise we wouldn't get here.
         lldbassert(num_matches == 0);
         result.AppendErrorWithFormat("'%s' is not a valid command.\n",
                                      next_word.c_str());
       }
-      return nullptr;
+      if (!done)
+        return nullptr;
     }
 
     if (cmd_obj->IsMultiwordObject()) {