[lldb] Correct style of error messages

The LLVM Style Guide says the following about error and warning
messages [1]:

> [T]o match error message styles commonly produced by other tools,
> start the first sentence with a lowercase letter, and finish the last
> sentence without a period, if it would end in one otherwise.

I often provide this feedback during code review, but we still have a
bunch of places where we have inconsistent error message, which bothers
me as a user. This PR identifies a handful of those places and updates
the messages to be consistent.

[1] https://llvm.org/docs/CodingStandards.html#error-and-warning-messages

Author: JDevlieghere

lldb/source/API/SBCommandInterpreter.cpp

@@ -208,7 +208,7 @@ void SBCommandInterpreter::HandleCommandsFromFile(
   LLDB_INSTRUMENT_VA(this, file, override_context, options, result);
 
   if (!IsValid()) {
-    result->AppendError("SBCommandInterpreter is not valid.");
+    result->AppendError("SBCommandInterpreter is not valid");
     return;
   }
 

lldb/source/Commands/CommandObjectBreakpoint.cpp

@@ -609,12 +609,12 @@ class CommandObjectBreakpointSet : public CommandObjectParsed {
       const size_t num_files = m_options.m_filenames.GetSize();
       if (num_files == 0) {
         if (!GetDefaultFile(target, file, result)) {
-          result.AppendError("No file supplied and no default file available.");
+          result.AppendError("no file supplied and no default file available");
           return;
         }
       } else if (num_files > 1) {
-        result.AppendError("Only one file at a time is allowed for file and "
-                           "line breakpoints.");
+        result.AppendError("only one file at a time is allowed for file and "
+                           "line breakpoints");
         return;
       } else
         file = m_options.m_filenames.GetFileSpecAtIndex(0);
@@ -784,7 +784,7 @@ class CommandObjectBreakpointSet : public CommandObjectParsed {
       }
       result.SetStatus(eReturnStatusSuccessFinishResult);
     } else if (!bp_sp) {
-      result.AppendError("Breakpoint creation failed: No breakpoint created.");
+      result.AppendError("breakpoint creation failed: no breakpoint created");
     }
   }
 
@@ -940,7 +940,7 @@ class CommandObjectBreakpointEnable : public CommandObjectParsed {
     size_t num_breakpoints = breakpoints.GetSize();
 
     if (num_breakpoints == 0) {
-      result.AppendError("No breakpoints exist to be enabled.");
+      result.AppendError("no breakpoints exist to be enabled");
       return;
     }
 
@@ -1048,7 +1048,7 @@ the second re-enables the first location.");
     size_t num_breakpoints = breakpoints.GetSize();
 
     if (num_breakpoints == 0) {
-      result.AppendError("No breakpoints exist to be disabled.");
+      result.AppendError("no breakpoints exist to be disabled");
       return;
     }
 
@@ -1224,7 +1224,7 @@ class CommandObjectBreakpointList : public CommandObjectParsed {
         }
         result.SetStatus(eReturnStatusSuccessFinishNoResult);
       } else {
-        result.AppendError("Invalid breakpoint ID.");
+        result.AppendError("invalid breakpoint ID");
       }
     }
   }
@@ -1318,7 +1318,7 @@ class CommandObjectBreakpointClear : public CommandObjectParsed {
 
     // Early return if there's no breakpoint at all.
     if (num_breakpoints == 0) {
-      result.AppendError("Breakpoint clear: No breakpoint cleared.");
+      result.AppendError("breakpoint clear: no breakpoint cleared");
       return;
     }
 
@@ -1364,7 +1364,7 @@ class CommandObjectBreakpointClear : public CommandObjectParsed {
       output_stream.EOL();
       result.SetStatus(eReturnStatusSuccessFinishNoResult);
     } else {
-      result.AppendError("Breakpoint clear: No breakpoint cleared.");
+      result.AppendError("breakpoint clear: no breakpoint cleared");
     }
   }
 
@@ -1459,7 +1459,7 @@ class CommandObjectBreakpointDelete : public CommandObjectParsed {
     size_t num_breakpoints = breakpoints.GetSize();
 
     if (num_breakpoints == 0) {
-      result.AppendError("No breakpoints exist to be deleted.");
+      result.AppendError("no breakpoints exist to be deleted");
       return;
     }
 
@@ -1504,7 +1504,7 @@ class CommandObjectBreakpointDelete : public CommandObjectParsed {
         }
       }
       if (valid_bp_ids.GetSize() == 0) {
-        result.AppendError("No disabled breakpoints.");
+        result.AppendError("no disabled breakpoints");
         return;
       }
     } else {
@@ -1712,7 +1712,7 @@ class CommandObjectBreakpointNameConfigure : public CommandObjectParsed {
 
     const size_t argc = command.GetArgumentCount();
     if (argc == 0) {
-      result.AppendError("No names provided.");
+      result.AppendError("no names provided");
       return;
     }
 
@@ -1799,7 +1799,7 @@ class CommandObjectBreakpointNameAdd : public CommandObjectParsed {
 protected:
   void DoExecute(Args &command, CommandReturnObject &result) override {
     if (!m_name_options.m_name.OptionWasSet()) {
-      result.AppendError("No name option provided.");
+      result.AppendError("no name option provided");
       return;
     }
 
@@ -1813,7 +1813,7 @@ class CommandObjectBreakpointNameAdd : public CommandObjectParsed {
 
     size_t num_breakpoints = breakpoints.GetSize();
     if (num_breakpoints == 0) {
-      result.AppendError("No breakpoints, cannot add names.");
+      result.AppendError("no breakpoints, cannot add names");
       return;
     }
 
@@ -1825,7 +1825,7 @@ class CommandObjectBreakpointNameAdd : public CommandObjectParsed {
 
     if (result.Succeeded()) {
       if (valid_bp_ids.GetSize() == 0) {
-        result.AppendError("No breakpoints specified, cannot add names.");
+        result.AppendError("no breakpoints specified, cannot add names");
         return;
       }
       size_t num_valid_ids = valid_bp_ids.GetSize();
@@ -1873,7 +1873,7 @@ class CommandObjectBreakpointNameDelete : public CommandObjectParsed {
 protected:
   void DoExecute(Args &command, CommandReturnObject &result) override {
     if (!m_name_options.m_name.OptionWasSet()) {
-      result.AppendError("No name option provided.");
+      result.AppendError("no name option provided");
       return;
     }
 
@@ -1887,7 +1887,7 @@ class CommandObjectBreakpointNameDelete : public CommandObjectParsed {
 
     size_t num_breakpoints = breakpoints.GetSize();
     if (num_breakpoints == 0) {
-      result.AppendError("No breakpoints, cannot delete names.");
+      result.AppendError("no breakpoints, cannot delete names");
       return;
     }
 
@@ -1899,7 +1899,7 @@ class CommandObjectBreakpointNameDelete : public CommandObjectParsed {
 
     if (result.Succeeded()) {
       if (valid_bp_ids.GetSize() == 0) {
-        result.AppendError("No breakpoints specified, cannot delete names.");
+        result.AppendError("no breakpoints specified, cannot delete names");
         return;
       }
       ConstString bp_name(m_name_options.m_name.GetCurrentValue());

lldb/source/Commands/CommandObjectCommands.cpp

@@ -418,7 +418,7 @@ other command as far as there is only one alias command match.");
       if ((pos != std::string::npos) && (pos > 0))
         raw_command_string = raw_command_string.substr(pos);
     } else {
-      result.AppendError("Error parsing command string.  No alias created.");
+      result.AppendError("error parsing command string.  No alias created");
       return;
     }
 
@@ -2888,7 +2888,7 @@ class CommandObjectCommandsContainerDelete : public CommandObjectParsed {
     size_t num_args = command.GetArgumentCount();
 
     if (num_args == 0) {
-      result.AppendError("No command was specified.");
+      result.AppendError("no command was specified");
       return;
     }
 

lldb/source/Commands/CommandObjectFrame.cpp

@@ -140,15 +140,15 @@ class CommandObjectFrameDiagnose : public CommandObjectParsed {
     } else {
       StopInfoSP stop_info_sp = thread->GetStopInfo();
       if (!stop_info_sp) {
-        result.AppendError("No arguments provided, and no stop info.");
+        result.AppendError("no arguments provided, and no stop info");
         return;
       }
 
       valobj_sp = StopInfo::GetCrashingDereference(stop_info_sp);
     }
 
     if (!valobj_sp) {
-      result.AppendError("No diagnosis available.");
+      result.AppendError("no diagnosis available");
       return;
     }
 
@@ -310,7 +310,7 @@ class CommandObjectFrameSelect : public CommandObjectParsed {
           if (frame_idx == 0) {
             // If you are already at the bottom of the stack, then just warn
             // and don't reset the frame.
-            result.AppendError("Already at the bottom of the stack.");
+            result.AppendError("already at the bottom of the stack");
             return;
           } else
             frame_idx = 0;
@@ -335,7 +335,7 @@ class CommandObjectFrameSelect : public CommandObjectParsed {
             if (frame_idx == num_frames - 1) {
               // If we are already at the top of the stack, just warn and don't
               // reset the frame.
-              result.AppendError("Already at the top of the stack.");
+              result.AppendError("already at the top of the stack");
               return;
             } else
               frame_idx = num_frames - 1;

lldb/source/Commands/CommandObjectLog.cpp

@@ -547,7 +547,7 @@ class CommandObjectLogTimerIncrement : public CommandObjectParsed {
         Timer::SetQuiet(!increment);
         result.SetStatus(eReturnStatusSuccessFinishNoResult);
       } else
-        result.AppendError("Could not convert increment value to boolean.");
+        result.AppendError("could not convert increment value to boolean");
     }
 
     if (!result.Succeeded()) {

lldb/source/Commands/CommandObjectMultiword.cpp

@@ -159,7 +159,7 @@ void CommandObjectMultiword::Execute(const char *args_string,
 
   auto sub_command = args[0].ref();
   if (sub_command.empty()) {
-    result.AppendError("Need to specify a non-empty subcommand.");
+    result.AppendError("need to specify a non-empty subcommand");
     return;
   }
 

lldb/source/Commands/CommandObjectProcess.cpp

@@ -259,7 +259,7 @@ class CommandObjectProcessLaunch : public CommandObjectProcessLaunchOrAttach {
         if (!exe_module_sp)
           exe_module_sp = target->GetExecutableModule();
         if (!exe_module_sp) {
-          result.AppendWarning("Could not get executable module after launch.");
+          result.AppendWarning("could not get executable module after launch");
         } else {
 
           const char *archname =

lldb/source/Commands/CommandObjectSource.cpp

@@ -513,7 +513,7 @@ class CommandObjectSourceInfo : public CommandObjectParsed {
           "No selected frame to use to find the default source.");
       return false;
     } else if (!cur_frame->HasDebugInformation()) {
-      result.AppendError("No debug info for the selected frame.");
+      result.AppendError("no debug info for the selected frame");
       return false;
     } else {
       const SymbolContext &sc =
@@ -553,11 +553,11 @@ class CommandObjectSourceInfo : public CommandObjectParsed {
         }
       }
       if (!m_module_list.GetSize()) {
-        result.AppendError("No modules match the input.");
+        result.AppendError("no modules match the input");
         return;
       }
     } else if (target.GetImages().GetSize() == 0) {
-      result.AppendError("The target has no associated executable images.");
+      result.AppendError("the target has no associated executable images");
       return;
     }
 

lldb/source/Commands/CommandObjectTarget.cpp

@@ -2420,7 +2420,7 @@ class CommandObjectTargetModulesDumpLineTable
     result.GetErrorStream().SetAddressByteSize(addr_byte_size);
 
     if (command.GetArgumentCount() == 0) {
-      result.AppendError("file option must be specified.");
+      result.AppendError("file option must be specified");
       return;
     } else {
       // Dump specified images (by basename or fullpath)
@@ -3565,13 +3565,13 @@ class CommandObjectTargetModulesShowUnwind : public CommandObjectParsed {
 
     ThreadList threads(process->GetThreadList());
     if (threads.GetSize() == 0) {
-      result.AppendError("The process must be paused to use this command.");
+      result.AppendError("the process must be paused to use this command");
       return;
     }
 
     ThreadSP thread(threads.GetThreadAtIndex(0));
     if (!thread) {
-      result.AppendError("The process must be paused to use this command.");
+      result.AppendError("the process must be paused to use this command");
       return;
     }
 

lldb/source/Commands/CommandObjectThread.cpp

@@ -1570,7 +1570,7 @@ class CommandObjectThreadReturn : public CommandObjectRaw {
     uint32_t frame_idx = frame_sp->GetFrameIndex();
 
     if (frame_sp->IsInlined()) {
-      result.AppendError("Don't know how to return from inlined frames.");
+      result.AppendError("don't know how to return from inlined frames");
       return;
     }